* [PATCH v16 00/10] arm64/riscv: Add support for crashkernel CMA reservation
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The crash memory allocation, and the exclude of crashk_res, crashk_low_res
and crashk_cma memory are almost identical across different architectures,
This patch set handle them in crash core in a general way, which eliminate
a lot of duplication code.
And add support for crashkernel CMA reservation for arm64 and riscv.
This patch set is rebased on v7.1-rc1.
Basic second kernel boot test were performed on QEMU platforms for x86,
ARM64 and RISC-V architectures with the following parameters:
"cma=256M crashkernel=4G crashkernel=64M,cma"
For first kernel, there will be such log:
# dmesg | grep crash
[ 0.000000] crashkernel low memory reserved: 0xe8000000 - 0xf0000000 (128 MB)
[ 0.000000] crashkernel reserved: 0x000000023e600000 - 0x000000033e600000 (4096 MB)
[ 0.000000] crashkernel CMA reserved: 64 MB in 1 ranges
# dmesg | grep cma
[ 0.000000] cma: Reserved 256 MiB at 0x00000000f0000000
[ 0.000000] cma: Reserved 64 MiB at 0x0000000100000000
For second kernel, there will be such log:
[ 0.000000] OF: fdt: Looking for usable-memory-range property...
[ 0.000000] OF: fdt: cap_mem_regions[0]: base=0x000000023e600000, size=0x0000000100000000
[ 0.000000] OF: fdt: cap_mem_regions[1]: base=0x00000000e8000000, size=0x0000000008000000
[ 0.000000] OF: fdt: cap_mem_regions[2]: base=0x0000000100000000, size=0x0000000004000000
Changes in v16:
- Split out the unrelated bugfixes as Baoquan suggested, which will
be a separate patch set later.
- Link to v15: https://lore.kernel.org/all/20260601094805.2928614-1-ruanjinjie@huawei.com/
Changes in v15:
- Unify the subject prefix formats as Huacai suggested.
- Fix powerpc pre-existing NULL pointer dereference [Sashiko [1]]
- Fix powerpc pre-existing __merge_memory_ranges() memory range
truncation [Sashiko [1]].
- Fix pre-existing arm64 CMA page leaks [Sashiko[2]].
- Fix pre-existing crash_load_dm_crypt_keys() Use-After-Free and
Double Free issue [Sashiko[3]].
- Fix vfree(headers) and uninitialized variables issue
and simplify the fix [Sashiko[2]].
- As walk_system_ram_res() and for_each_mem_range() use different
lock, unify and simplify the fix of TOCTOU buffer overflow via memory
region padding [Sashiko[4]].
- Fix the arm64 crash dump issues in Sashiko[5].
- Link to v14: https://lore.kernel.org/all/20260525084932.934910-1-ruanjinjie@huawei.com/
[1]: https://lore.kernel.org/all/20260525092207.96B9D1F000E9@smtp.kernel.org/
[2]: https://lore.kernel.org/all/20260525091149.1A1E01F00A3D@smtp.kernel.org/
[3]: https://lore.kernel.org/all/20260525105227.3C2421F000E9@smtp.kernel.org/
[4]: https://lore.kernel.org/all/20260525095447.944E11F000E9@smtp.kernel.org/
[5]: https://lore.kernel.org/all/20260525101746.9959D1F000E9@smtp.kernel.org/
Changes in v14:
- Fix image->elf_headers memory leak during retry loop for arm64 as Sashiko
AI code review pointed out.
- Solve the hotplug notifier arch_crash_handle_hotplug_event() AA
self-deadlock problem as Sashiko AI code review pointed out.
- Fix the TOCTOU issue in prepare_elf_headers() by get_online_mems().
- -ENOMEM -> -EAGAIN as Breno suggested.
- Add support for arm64 crash hotplug.
- Link to v13: https://lore.kernel.org/all/20260511030454.1730881-1-ruanjinjie@huawei.com/
Changes in v13:
- Rebased on v7.1-rc1.
- Update the commit message.
- Add Reviewed-by.
- Link to v12: https://lore.kernel.org/all/20260402072701.628293-1-ruanjinjie@huawei.com/
Changes in v12:
- Remove the unused "nr_mem_ranges" for x86.
- Add "Fix crashk_low_res not exclude bug" test log.
- Provide a separate patch for each architecture for using
crash_prepare_headers(), which will make the review more convenient.
- Add Reviewed-by and Tested-by.
- Link to v11: https://lore.kernel.org/all/20260328074013.3589544-1-ruanjinjie@huawei.com/
Changes in v11:
- Avoid silently drop crash memory if the crash kernel is built without
CONFIG_CMA.
- Remove unnecessary "cmem->nr_ranges = 0" for arch_crash_populate_cmem()
as we use kvzalloc().
- Provide a separate patch for each architecture to fix the existing
buffer overflow issue.
- Add Acked-bys for arm64.
Changes in v10:
- Fix crashk_low_res not excluded bug in the existing
RISC-V code.
- Fix an existing memory leak issue in the existing PowerPC code.
- Fix the ordering issue of adding CMA ranges to
"linux,usable-memory-range".
- Fix an existing concurrency issue. A Concurrent memory hotplug may occur
between reading memblock and attempting to fill cmem during kexec_load()
for almost all existing architectures.
- Link to v9: https://lore.kernel.org/all/20260323072745.2481719-1-ruanjinjie@huawei.com/
Changes in v9:
- Collect Reviewed-by and Acked-by, and prepare for Sashiko AI review.
- Link to v8: https://lore.kernel.org/all/20260302035315.3892241-1-ruanjinjie@huawei.com/
Changes in v8:
- Fix the build issues reported by kernel test robot and Sourabh.
- Link to v7: https://lore.kernel.org/all/20260226130437.1867658-1-ruanjinjie@huawei.com/
Changes in v7:
- Correct the inclusion of CMA-reserved ranges for kdump kernel in of/kexec
for arm64 and riscv.
- Add Acked-by.
- Link to v6: https://lore.kernel.org/all/20260224085342.387996-1-ruanjinjie@huawei.com/
Changes in v6:
- Update the crash core exclude code as Mike suggested.
- Rebased on v7.0-rc1.
- Add acked-by.
- Link to v5: https://lore.kernel.org/all/20260212101001.343158-1-ruanjinjie@huawei.com/
Jinjie Ruan (9):
riscv: kexec_file: Fix crashk_low_res not exclude bug
crash: Add crash_prepare_headers() to exclude crash kernel memory
arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
x86: kexec_file: Use crash_prepare_headers() helper to simplify code
riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify
code
powerpc/kexec_file: Use crash_exclude_core_ranges() helper
arm64: kexec_file: Add support for crashkernel CMA reservation
riscv: kexec_file: Add support for crashkernel CMA reservation
Sourabh Jain (1):
powerpc/crash: sort crash memory ranges before preparing elfcorehdr
.../admin-guide/kernel-parameters.txt | 16 +--
arch/arm64/kernel/machine_kexec_file.c | 40 +++----
arch/arm64/mm/init.c | 5 +-
arch/loongarch/kernel/machine_kexec_file.c | 40 +++----
arch/powerpc/include/asm/kexec_ranges.h | 1 -
arch/powerpc/kexec/crash.c | 5 +-
arch/powerpc/kexec/ranges.c | 101 +-----------------
arch/riscv/kernel/machine_kexec_file.c | 39 +++----
arch/riscv/mm/init.c | 5 +-
arch/x86/kernel/crash.c | 89 ++-------------
drivers/of/fdt.c | 9 +-
drivers/of/kexec.c | 9 ++
include/linux/crash_core.h | 9 ++
include/linux/crash_reserve.h | 4 +-
kernel/crash_core.c | 89 ++++++++++++++-
15 files changed, 180 insertions(+), 281 deletions(-)
--
2.34.1
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v16 00/10] arm64/riscv: Add support for crashkernel CMA reservation
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The crash memory allocation, and the exclude of crashk_res, crashk_low_res
and crashk_cma memory are almost identical across different architectures,
This patch set handle them in crash core in a general way, which eliminate
a lot of duplication code.
And add support for crashkernel CMA reservation for arm64 and riscv.
This patch set is rebased on v7.1-rc1.
Basic second kernel boot test were performed on QEMU platforms for x86,
ARM64 and RISC-V architectures with the following parameters:
"cma=256M crashkernel=4G crashkernel=64M,cma"
For first kernel, there will be such log:
# dmesg | grep crash
[ 0.000000] crashkernel low memory reserved: 0xe8000000 - 0xf0000000 (128 MB)
[ 0.000000] crashkernel reserved: 0x000000023e600000 - 0x000000033e600000 (4096 MB)
[ 0.000000] crashkernel CMA reserved: 64 MB in 1 ranges
# dmesg | grep cma
[ 0.000000] cma: Reserved 256 MiB at 0x00000000f0000000
[ 0.000000] cma: Reserved 64 MiB at 0x0000000100000000
For second kernel, there will be such log:
[ 0.000000] OF: fdt: Looking for usable-memory-range property...
[ 0.000000] OF: fdt: cap_mem_regions[0]: base=0x000000023e600000, size=0x0000000100000000
[ 0.000000] OF: fdt: cap_mem_regions[1]: base=0x00000000e8000000, size=0x0000000008000000
[ 0.000000] OF: fdt: cap_mem_regions[2]: base=0x0000000100000000, size=0x0000000004000000
Changes in v16:
- Split out the unrelated bugfixes as Baoquan suggested, which will
be a separate patch set later.
- Link to v15: https://lore.kernel.org/all/20260601094805.2928614-1-ruanjinjie@huawei.com/
Changes in v15:
- Unify the subject prefix formats as Huacai suggested.
- Fix powerpc pre-existing NULL pointer dereference [Sashiko [1]]
- Fix powerpc pre-existing __merge_memory_ranges() memory range
truncation [Sashiko [1]].
- Fix pre-existing arm64 CMA page leaks [Sashiko[2]].
- Fix pre-existing crash_load_dm_crypt_keys() Use-After-Free and
Double Free issue [Sashiko[3]].
- Fix vfree(headers) and uninitialized variables issue
and simplify the fix [Sashiko[2]].
- As walk_system_ram_res() and for_each_mem_range() use different
lock, unify and simplify the fix of TOCTOU buffer overflow via memory
region padding [Sashiko[4]].
- Fix the arm64 crash dump issues in Sashiko[5].
- Link to v14: https://lore.kernel.org/all/20260525084932.934910-1-ruanjinjie@huawei.com/
[1]: https://lore.kernel.org/all/20260525092207.96B9D1F000E9@smtp.kernel.org/
[2]: https://lore.kernel.org/all/20260525091149.1A1E01F00A3D@smtp.kernel.org/
[3]: https://lore.kernel.org/all/20260525105227.3C2421F000E9@smtp.kernel.org/
[4]: https://lore.kernel.org/all/20260525095447.944E11F000E9@smtp.kernel.org/
[5]: https://lore.kernel.org/all/20260525101746.9959D1F000E9@smtp.kernel.org/
Changes in v14:
- Fix image->elf_headers memory leak during retry loop for arm64 as Sashiko
AI code review pointed out.
- Solve the hotplug notifier arch_crash_handle_hotplug_event() AA
self-deadlock problem as Sashiko AI code review pointed out.
- Fix the TOCTOU issue in prepare_elf_headers() by get_online_mems().
- -ENOMEM -> -EAGAIN as Breno suggested.
- Add support for arm64 crash hotplug.
- Link to v13: https://lore.kernel.org/all/20260511030454.1730881-1-ruanjinjie@huawei.com/
Changes in v13:
- Rebased on v7.1-rc1.
- Update the commit message.
- Add Reviewed-by.
- Link to v12: https://lore.kernel.org/all/20260402072701.628293-1-ruanjinjie@huawei.com/
Changes in v12:
- Remove the unused "nr_mem_ranges" for x86.
- Add "Fix crashk_low_res not exclude bug" test log.
- Provide a separate patch for each architecture for using
crash_prepare_headers(), which will make the review more convenient.
- Add Reviewed-by and Tested-by.
- Link to v11: https://lore.kernel.org/all/20260328074013.3589544-1-ruanjinjie@huawei.com/
Changes in v11:
- Avoid silently drop crash memory if the crash kernel is built without
CONFIG_CMA.
- Remove unnecessary "cmem->nr_ranges = 0" for arch_crash_populate_cmem()
as we use kvzalloc().
- Provide a separate patch for each architecture to fix the existing
buffer overflow issue.
- Add Acked-bys for arm64.
Changes in v10:
- Fix crashk_low_res not excluded bug in the existing
RISC-V code.
- Fix an existing memory leak issue in the existing PowerPC code.
- Fix the ordering issue of adding CMA ranges to
"linux,usable-memory-range".
- Fix an existing concurrency issue. A Concurrent memory hotplug may occur
between reading memblock and attempting to fill cmem during kexec_load()
for almost all existing architectures.
- Link to v9: https://lore.kernel.org/all/20260323072745.2481719-1-ruanjinjie@huawei.com/
Changes in v9:
- Collect Reviewed-by and Acked-by, and prepare for Sashiko AI review.
- Link to v8: https://lore.kernel.org/all/20260302035315.3892241-1-ruanjinjie@huawei.com/
Changes in v8:
- Fix the build issues reported by kernel test robot and Sourabh.
- Link to v7: https://lore.kernel.org/all/20260226130437.1867658-1-ruanjinjie@huawei.com/
Changes in v7:
- Correct the inclusion of CMA-reserved ranges for kdump kernel in of/kexec
for arm64 and riscv.
- Add Acked-by.
- Link to v6: https://lore.kernel.org/all/20260224085342.387996-1-ruanjinjie@huawei.com/
Changes in v6:
- Update the crash core exclude code as Mike suggested.
- Rebased on v7.0-rc1.
- Add acked-by.
- Link to v5: https://lore.kernel.org/all/20260212101001.343158-1-ruanjinjie@huawei.com/
Jinjie Ruan (9):
riscv: kexec_file: Fix crashk_low_res not exclude bug
crash: Add crash_prepare_headers() to exclude crash kernel memory
arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
x86: kexec_file: Use crash_prepare_headers() helper to simplify code
riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify
code
powerpc/kexec_file: Use crash_exclude_core_ranges() helper
arm64: kexec_file: Add support for crashkernel CMA reservation
riscv: kexec_file: Add support for crashkernel CMA reservation
Sourabh Jain (1):
powerpc/crash: sort crash memory ranges before preparing elfcorehdr
.../admin-guide/kernel-parameters.txt | 16 +--
arch/arm64/kernel/machine_kexec_file.c | 40 +++----
arch/arm64/mm/init.c | 5 +-
arch/loongarch/kernel/machine_kexec_file.c | 40 +++----
arch/powerpc/include/asm/kexec_ranges.h | 1 -
arch/powerpc/kexec/crash.c | 5 +-
arch/powerpc/kexec/ranges.c | 101 +-----------------
arch/riscv/kernel/machine_kexec_file.c | 39 +++----
arch/riscv/mm/init.c | 5 +-
arch/x86/kernel/crash.c | 89 ++-------------
drivers/of/fdt.c | 9 +-
drivers/of/kexec.c | 9 ++
include/linux/crash_core.h | 9 ++
include/linux/crash_reserve.h | 4 +-
kernel/crash_core.c | 89 ++++++++++++++-
15 files changed, 180 insertions(+), 281 deletions(-)
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
* [PATCH v16 01/10] riscv: kexec_file: Fix crashk_low_res not exclude bug
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
As done in commit 944a45abfabc ("arm64: kdump: Reimplement crashkernel=X")
and commit 4831be702b95 ("arm64/kexec: Fix missing extra range for
crashkres_low.") for arm64, while implementing crashkernel=X,[high,low],
riscv should have excluded the "crashk_low_res" reserved ranges from
the crash kernel memory to prevent them from being exported through
/proc/vmcore, and the exclusion would need an extra crash_mem range.
Just simply tested on qemu with crashkernel=4G with kexec in [1] mentioned
in [2]. And the second kernel can be started normally.
# dmesg | grep crash
[ 0.000000] crashkernel low memory reserved: 0xf8000000 - 0x100000000 (128 MB)
[ 0.000000] crashkernel reserved: 0x000000017fe00000 - 0x000000027fe00000 (4096 MB)
Cc: Guo Ren <guoren@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
[1]: https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2
[2]: https://lore.kernel.org/all/20230726175000.2536220-1-chenjiahao16@huawei.com/
Fixes: 5882e5acf18d ("riscv: kdump: Implement crashkernel=X,[high,low]")
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/riscv/kernel/machine_kexec_file.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 54e2d9552e93..3f7766057cac 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -61,7 +61,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
unsigned int nr_ranges;
int ret;
- nr_ranges = 1; /* For exclusion of crashkernel region */
+ nr_ranges = 2; /* For exclusion of crashkernel region */
walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
@@ -76,8 +76,16 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
/* Exclude crashkernel region */
ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (!ret)
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
+ if (ret)
+ goto out;
+
+ if (crashk_low_res.end) {
+ ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+ if (ret)
+ goto out;
+ }
+
+ ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
out:
kfree(cmem);
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 01/10] riscv: kexec_file: Fix crashk_low_res not exclude bug
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
As done in commit 944a45abfabc ("arm64: kdump: Reimplement crashkernel=X")
and commit 4831be702b95 ("arm64/kexec: Fix missing extra range for
crashkres_low.") for arm64, while implementing crashkernel=X,[high,low],
riscv should have excluded the "crashk_low_res" reserved ranges from
the crash kernel memory to prevent them from being exported through
/proc/vmcore, and the exclusion would need an extra crash_mem range.
Just simply tested on qemu with crashkernel=4G with kexec in [1] mentioned
in [2]. And the second kernel can be started normally.
# dmesg | grep crash
[ 0.000000] crashkernel low memory reserved: 0xf8000000 - 0x100000000 (128 MB)
[ 0.000000] crashkernel reserved: 0x000000017fe00000 - 0x000000027fe00000 (4096 MB)
Cc: Guo Ren <guoren@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
[1]: https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2
[2]: https://lore.kernel.org/all/20230726175000.2536220-1-chenjiahao16@huawei.com/
Fixes: 5882e5acf18d ("riscv: kdump: Implement crashkernel=X,[high,low]")
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/riscv/kernel/machine_kexec_file.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 54e2d9552e93..3f7766057cac 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -61,7 +61,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
unsigned int nr_ranges;
int ret;
- nr_ranges = 1; /* For exclusion of crashkernel region */
+ nr_ranges = 2; /* For exclusion of crashkernel region */
walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
@@ -76,8 +76,16 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
/* Exclude crashkernel region */
ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (!ret)
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
+ if (ret)
+ goto out;
+
+ if (crashk_low_res.end) {
+ ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+ if (ret)
+ goto out;
+ }
+
+ ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
out:
kfree(cmem);
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 02/10] powerpc/crash: sort crash memory ranges before preparing elfcorehdr
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
From: Sourabh Jain <sourabhjain@linux.ibm.com>
During a memory hot-remove event, the elfcorehdr is rebuilt to exclude
the removed memory. While updating the crash memory ranges for this
operation, the crash memory ranges array can become unsorted. This
happens because remove_mem_range() may split a memory range into two
parts and append the higher-address part as a separate range at the end
of the array.
So far, no issues have been observed due to the unsorted crash memory
ranges. However, this could lead to problems once crash memory range
removal is handled by generic code, as introduced in the upcoming
patches in this series.
Currently, powerpc uses a platform-specific function,
remove_mem_range(), to exclude hot-removed memory from the crash memory
ranges. This function performs the same task as the generic
crash_exclude_mem_range() in crash_core.c. The generic helper also
ensures that the crash memory ranges remain sorted. So remove the
redundant powerpc-specific implementation and instead call
crash_exclude_mem_range_guarded() (which internally calls
crash_exclude_mem_range()) to exclude the hot-removed memory ranges.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baoquan he <bhe@redhat.com>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/powerpc/include/asm/kexec_ranges.h | 4 +-
arch/powerpc/kexec/crash.c | 5 +-
arch/powerpc/kexec/ranges.c | 87 +------------------------
3 files changed, 7 insertions(+), 89 deletions(-)
diff --git a/arch/powerpc/include/asm/kexec_ranges.h b/arch/powerpc/include/asm/kexec_ranges.h
index 14055896cbcb..ad95e3792d10 100644
--- a/arch/powerpc/include/asm/kexec_ranges.h
+++ b/arch/powerpc/include/asm/kexec_ranges.h
@@ -7,7 +7,9 @@
void sort_memory_ranges(struct crash_mem *mrngs, bool merge);
struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges);
int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
-int remove_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
+int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
+ unsigned long long mstart,
+ unsigned long long mend);
int get_exclude_memory_ranges(struct crash_mem **mem_ranges);
int get_reserved_memory_ranges(struct crash_mem **mem_ranges);
int get_crash_memory_ranges(struct crash_mem **mem_ranges);
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index e6539f213b3d..2e88ec5c4356 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -493,7 +493,7 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
struct crash_mem *cmem = NULL;
struct kexec_segment *ksegment;
void *ptr, *mem, *elfbuf = NULL;
- unsigned long elfsz, memsz, base_addr, size;
+ unsigned long elfsz, memsz, base_addr, size, end;
ksegment = &image->segment[image->elfcorehdr_index];
mem = (void *) ksegment->mem;
@@ -512,7 +512,8 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
if (image->hp_action == KEXEC_CRASH_HP_REMOVE_MEMORY) {
base_addr = PFN_PHYS(mn->start_pfn);
size = mn->nr_pages * PAGE_SIZE;
- ret = remove_mem_range(&cmem, base_addr, size);
+ end = base_addr + size - 1;
+ ret = crash_exclude_mem_range_guarded(&cmem, base_addr, end);
if (ret) {
pr_err("Failed to remove hot-unplugged memory from crash memory ranges\n");
goto out;
diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
index 867135560e5c..6c58bcc3e130 100644
--- a/arch/powerpc/kexec/ranges.c
+++ b/arch/powerpc/kexec/ranges.c
@@ -553,7 +553,7 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges)
#endif /* CONFIG_KEXEC_FILE */
#ifdef CONFIG_CRASH_DUMP
-static int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
+int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
unsigned long long mstart,
unsigned long long mend)
{
@@ -641,89 +641,4 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges)
pr_err("Failed to setup crash memory ranges\n");
return ret;
}
-
-/**
- * remove_mem_range - Removes the given memory range from the range list.
- * @mem_ranges: Range list to remove the memory range to.
- * @base: Base address of the range to remove.
- * @size: Size of the memory range to remove.
- *
- * (Re)allocates memory, if needed.
- *
- * Returns 0 on success, negative errno on error.
- */
-int remove_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
-{
- u64 end;
- int ret = 0;
- unsigned int i;
- u64 mstart, mend;
- struct crash_mem *mem_rngs = *mem_ranges;
-
- if (!size)
- return 0;
-
- /*
- * Memory range are stored as start and end address, use
- * the same format to do remove operation.
- */
- end = base + size - 1;
-
- for (i = 0; i < mem_rngs->nr_ranges; i++) {
- mstart = mem_rngs->ranges[i].start;
- mend = mem_rngs->ranges[i].end;
-
- /*
- * Memory range to remove is not part of this range entry
- * in the memory range list
- */
- if (!(base >= mstart && end <= mend))
- continue;
-
- /*
- * Memory range to remove is equivalent to this entry in the
- * memory range list. Remove the range entry from the list.
- */
- if (base == mstart && end == mend) {
- for (; i < mem_rngs->nr_ranges - 1; i++) {
- mem_rngs->ranges[i].start = mem_rngs->ranges[i+1].start;
- mem_rngs->ranges[i].end = mem_rngs->ranges[i+1].end;
- }
- mem_rngs->nr_ranges--;
- goto out;
- }
- /*
- * Start address of the memory range to remove and the
- * current memory range entry in the list is same. Just
- * move the start address of the current memory range
- * entry in the list to end + 1.
- */
- else if (base == mstart) {
- mem_rngs->ranges[i].start = end + 1;
- goto out;
- }
- /*
- * End address of the memory range to remove and the
- * current memory range entry in the list is same.
- * Just move the end address of the current memory
- * range entry in the list to base - 1.
- */
- else if (end == mend) {
- mem_rngs->ranges[i].end = base - 1;
- goto out;
- }
- /*
- * Memory range to remove is not at the edge of current
- * memory range entry. Split the current memory entry into
- * two half.
- */
- else {
- size = mem_rngs->ranges[i].end - end + 1;
- mem_rngs->ranges[i].end = base - 1;
- ret = add_mem_range(mem_ranges, end + 1, size);
- }
- }
-out:
- return ret;
-}
#endif /* CONFIG_CRASH_DUMP */
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 02/10] powerpc/crash: sort crash memory ranges before preparing elfcorehdr
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
From: Sourabh Jain <sourabhjain@linux.ibm.com>
During a memory hot-remove event, the elfcorehdr is rebuilt to exclude
the removed memory. While updating the crash memory ranges for this
operation, the crash memory ranges array can become unsorted. This
happens because remove_mem_range() may split a memory range into two
parts and append the higher-address part as a separate range at the end
of the array.
So far, no issues have been observed due to the unsorted crash memory
ranges. However, this could lead to problems once crash memory range
removal is handled by generic code, as introduced in the upcoming
patches in this series.
Currently, powerpc uses a platform-specific function,
remove_mem_range(), to exclude hot-removed memory from the crash memory
ranges. This function performs the same task as the generic
crash_exclude_mem_range() in crash_core.c. The generic helper also
ensures that the crash memory ranges remain sorted. So remove the
redundant powerpc-specific implementation and instead call
crash_exclude_mem_range_guarded() (which internally calls
crash_exclude_mem_range()) to exclude the hot-removed memory ranges.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baoquan he <bhe@redhat.com>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Cc: linux-kernel@vger.kernel.org
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/powerpc/include/asm/kexec_ranges.h | 4 +-
arch/powerpc/kexec/crash.c | 5 +-
arch/powerpc/kexec/ranges.c | 87 +------------------------
3 files changed, 7 insertions(+), 89 deletions(-)
diff --git a/arch/powerpc/include/asm/kexec_ranges.h b/arch/powerpc/include/asm/kexec_ranges.h
index 14055896cbcb..ad95e3792d10 100644
--- a/arch/powerpc/include/asm/kexec_ranges.h
+++ b/arch/powerpc/include/asm/kexec_ranges.h
@@ -7,7 +7,9 @@
void sort_memory_ranges(struct crash_mem *mrngs, bool merge);
struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges);
int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
-int remove_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
+int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
+ unsigned long long mstart,
+ unsigned long long mend);
int get_exclude_memory_ranges(struct crash_mem **mem_ranges);
int get_reserved_memory_ranges(struct crash_mem **mem_ranges);
int get_crash_memory_ranges(struct crash_mem **mem_ranges);
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index e6539f213b3d..2e88ec5c4356 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -493,7 +493,7 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
struct crash_mem *cmem = NULL;
struct kexec_segment *ksegment;
void *ptr, *mem, *elfbuf = NULL;
- unsigned long elfsz, memsz, base_addr, size;
+ unsigned long elfsz, memsz, base_addr, size, end;
ksegment = &image->segment[image->elfcorehdr_index];
mem = (void *) ksegment->mem;
@@ -512,7 +512,8 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
if (image->hp_action == KEXEC_CRASH_HP_REMOVE_MEMORY) {
base_addr = PFN_PHYS(mn->start_pfn);
size = mn->nr_pages * PAGE_SIZE;
- ret = remove_mem_range(&cmem, base_addr, size);
+ end = base_addr + size - 1;
+ ret = crash_exclude_mem_range_guarded(&cmem, base_addr, end);
if (ret) {
pr_err("Failed to remove hot-unplugged memory from crash memory ranges\n");
goto out;
diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
index 867135560e5c..6c58bcc3e130 100644
--- a/arch/powerpc/kexec/ranges.c
+++ b/arch/powerpc/kexec/ranges.c
@@ -553,7 +553,7 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges)
#endif /* CONFIG_KEXEC_FILE */
#ifdef CONFIG_CRASH_DUMP
-static int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
+int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
unsigned long long mstart,
unsigned long long mend)
{
@@ -641,89 +641,4 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges)
pr_err("Failed to setup crash memory ranges\n");
return ret;
}
-
-/**
- * remove_mem_range - Removes the given memory range from the range list.
- * @mem_ranges: Range list to remove the memory range to.
- * @base: Base address of the range to remove.
- * @size: Size of the memory range to remove.
- *
- * (Re)allocates memory, if needed.
- *
- * Returns 0 on success, negative errno on error.
- */
-int remove_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size)
-{
- u64 end;
- int ret = 0;
- unsigned int i;
- u64 mstart, mend;
- struct crash_mem *mem_rngs = *mem_ranges;
-
- if (!size)
- return 0;
-
- /*
- * Memory range are stored as start and end address, use
- * the same format to do remove operation.
- */
- end = base + size - 1;
-
- for (i = 0; i < mem_rngs->nr_ranges; i++) {
- mstart = mem_rngs->ranges[i].start;
- mend = mem_rngs->ranges[i].end;
-
- /*
- * Memory range to remove is not part of this range entry
- * in the memory range list
- */
- if (!(base >= mstart && end <= mend))
- continue;
-
- /*
- * Memory range to remove is equivalent to this entry in the
- * memory range list. Remove the range entry from the list.
- */
- if (base == mstart && end == mend) {
- for (; i < mem_rngs->nr_ranges - 1; i++) {
- mem_rngs->ranges[i].start = mem_rngs->ranges[i+1].start;
- mem_rngs->ranges[i].end = mem_rngs->ranges[i+1].end;
- }
- mem_rngs->nr_ranges--;
- goto out;
- }
- /*
- * Start address of the memory range to remove and the
- * current memory range entry in the list is same. Just
- * move the start address of the current memory range
- * entry in the list to end + 1.
- */
- else if (base == mstart) {
- mem_rngs->ranges[i].start = end + 1;
- goto out;
- }
- /*
- * End address of the memory range to remove and the
- * current memory range entry in the list is same.
- * Just move the end address of the current memory
- * range entry in the list to base - 1.
- */
- else if (end == mend) {
- mem_rngs->ranges[i].end = base - 1;
- goto out;
- }
- /*
- * Memory range to remove is not at the edge of current
- * memory range entry. Split the current memory entry into
- * two half.
- */
- else {
- size = mem_rngs->ranges[i].end - end + 1;
- mem_rngs->ranges[i].end = base - 1;
- ret = add_mem_range(mem_ranges, end + 1, size);
- }
- }
-out:
- return ret;
-}
#endif /* CONFIG_CRASH_DUMP */
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 03/10] crash: Add crash_prepare_headers() to exclude crash kernel memory
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The crash memory alloc, and the exclude of crashk_res, crashk_low_res
and crashk_cma memory are almost identical across different architectures,
handling them in the crash core would eliminate a lot of duplication, so
add crash_prepare_headers() helper to handle them in the common code.
To achieve the above goal, three architecture-specific functions are
introduced:
- arch_get_system_nr_ranges(). Pre-counts the max number of memory ranges.
- arch_crash_populate_cmem(). Collects the memory ranges and fills them
into cmem.
- arch_crash_exclude_ranges(). Architecture's additional crash memory
ranges exclusion, defaulting to empty.
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
include/linux/crash_core.h | 5 +++
kernel/crash_core.c | 82 ++++++++++++++++++++++++++++++++++++--
2 files changed, 84 insertions(+), 3 deletions(-)
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index c1dee3f971a9..583ffcc703d4 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -59,6 +59,8 @@ extern int crash_exclude_mem_range(struct crash_mem *mem,
unsigned long long mend);
extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
void **addr, unsigned long *sz);
+extern int crash_prepare_headers(int need_kernel_map, void **addr,
+ unsigned long *sz, unsigned long *nr_mem_ranges);
struct kimage;
struct kexec_segment;
@@ -76,6 +78,9 @@ int kexec_should_crash(struct task_struct *p);
int kexec_crash_loaded(void);
void crash_save_cpu(struct pt_regs *regs, int cpu);
extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
+extern unsigned int arch_get_system_nr_ranges(void);
+extern int arch_crash_populate_cmem(struct crash_mem *cmem);
+extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
#else /* !CONFIG_CRASH_DUMP*/
struct pt_regs;
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 4f21fc3b108b..481babc29131 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -168,9 +168,6 @@ static inline resource_size_t crash_resource_size(const struct resource *res)
return !res->end ? 0 : resource_size(res);
}
-
-
-
int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
void **addr, unsigned long *sz)
{
@@ -272,6 +269,85 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
return 0;
}
+static struct crash_mem *alloc_cmem(unsigned int nr_ranges)
+{
+ struct crash_mem *cmem;
+
+ cmem = kvzalloc_flex(*cmem, ranges, nr_ranges);
+ if (!cmem)
+ return NULL;
+
+ cmem->max_nr_ranges = nr_ranges;
+ return cmem;
+}
+
+unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
+int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
+int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
+
+static int crash_exclude_core_ranges(struct crash_mem *cmem)
+{
+ int ret, i;
+
+ /* Exclude crashkernel region */
+ ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+ if (ret)
+ return ret;
+
+ if (crashk_low_res.end) {
+ ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < crashk_cma_cnt; ++i) {
+ ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,
+ unsigned long *nr_mem_ranges)
+{
+ unsigned int max_nr_ranges;
+ struct crash_mem *cmem;
+ int ret;
+
+ max_nr_ranges = arch_get_system_nr_ranges();
+ if (!max_nr_ranges)
+ return -ENOMEM;
+
+ cmem = alloc_cmem(max_nr_ranges);
+ if (!cmem)
+ return -ENOMEM;
+
+ ret = arch_crash_populate_cmem(cmem);
+ if (ret)
+ goto out;
+
+ ret = crash_exclude_core_ranges(cmem);
+ if (ret)
+ goto out;
+
+ ret = arch_crash_exclude_ranges(cmem);
+ if (ret)
+ goto out;
+
+ /* Return the computed number of memory ranges, for hotplug usage */
+ if (nr_mem_ranges)
+ *nr_mem_ranges = cmem->nr_ranges;
+
+ ret = crash_prepare_elf64_headers(cmem, need_kernel_map, addr, sz);
+
+out:
+ kvfree(cmem);
+ return ret;
+}
+
/**
* crash_exclude_mem_range - exclude a mem range for existing ranges
* @mem: mem->range contains an array of ranges sorted in ascending order
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 03/10] crash: Add crash_prepare_headers() to exclude crash kernel memory
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The crash memory alloc, and the exclude of crashk_res, crashk_low_res
and crashk_cma memory are almost identical across different architectures,
handling them in the crash core would eliminate a lot of duplication, so
add crash_prepare_headers() helper to handle them in the common code.
To achieve the above goal, three architecture-specific functions are
introduced:
- arch_get_system_nr_ranges(). Pre-counts the max number of memory ranges.
- arch_crash_populate_cmem(). Collects the memory ranges and fills them
into cmem.
- arch_crash_exclude_ranges(). Architecture's additional crash memory
ranges exclusion, defaulting to empty.
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
include/linux/crash_core.h | 5 +++
kernel/crash_core.c | 82 ++++++++++++++++++++++++++++++++++++--
2 files changed, 84 insertions(+), 3 deletions(-)
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index c1dee3f971a9..583ffcc703d4 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -59,6 +59,8 @@ extern int crash_exclude_mem_range(struct crash_mem *mem,
unsigned long long mend);
extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
void **addr, unsigned long *sz);
+extern int crash_prepare_headers(int need_kernel_map, void **addr,
+ unsigned long *sz, unsigned long *nr_mem_ranges);
struct kimage;
struct kexec_segment;
@@ -76,6 +78,9 @@ int kexec_should_crash(struct task_struct *p);
int kexec_crash_loaded(void);
void crash_save_cpu(struct pt_regs *regs, int cpu);
extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
+extern unsigned int arch_get_system_nr_ranges(void);
+extern int arch_crash_populate_cmem(struct crash_mem *cmem);
+extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
#else /* !CONFIG_CRASH_DUMP*/
struct pt_regs;
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 4f21fc3b108b..481babc29131 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -168,9 +168,6 @@ static inline resource_size_t crash_resource_size(const struct resource *res)
return !res->end ? 0 : resource_size(res);
}
-
-
-
int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
void **addr, unsigned long *sz)
{
@@ -272,6 +269,85 @@ int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
return 0;
}
+static struct crash_mem *alloc_cmem(unsigned int nr_ranges)
+{
+ struct crash_mem *cmem;
+
+ cmem = kvzalloc_flex(*cmem, ranges, nr_ranges);
+ if (!cmem)
+ return NULL;
+
+ cmem->max_nr_ranges = nr_ranges;
+ return cmem;
+}
+
+unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
+int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
+int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
+
+static int crash_exclude_core_ranges(struct crash_mem *cmem)
+{
+ int ret, i;
+
+ /* Exclude crashkernel region */
+ ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+ if (ret)
+ return ret;
+
+ if (crashk_low_res.end) {
+ ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+ if (ret)
+ return ret;
+ }
+
+ for (i = 0; i < crashk_cma_cnt; ++i) {
+ ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,
+ unsigned long *nr_mem_ranges)
+{
+ unsigned int max_nr_ranges;
+ struct crash_mem *cmem;
+ int ret;
+
+ max_nr_ranges = arch_get_system_nr_ranges();
+ if (!max_nr_ranges)
+ return -ENOMEM;
+
+ cmem = alloc_cmem(max_nr_ranges);
+ if (!cmem)
+ return -ENOMEM;
+
+ ret = arch_crash_populate_cmem(cmem);
+ if (ret)
+ goto out;
+
+ ret = crash_exclude_core_ranges(cmem);
+ if (ret)
+ goto out;
+
+ ret = arch_crash_exclude_ranges(cmem);
+ if (ret)
+ goto out;
+
+ /* Return the computed number of memory ranges, for hotplug usage */
+ if (nr_mem_ranges)
+ *nr_mem_ranges = cmem->nr_ranges;
+
+ ret = crash_prepare_elf64_headers(cmem, need_kernel_map, addr, sz);
+
+out:
+ kvfree(cmem);
+ return ret;
+}
+
/**
* crash_exclude_mem_range - exclude a mem range for existing ranges
* @mem: mem->range contains an array of ranges sorted in ascending order
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 04/10] arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash
kernel memory in the crash core, which reduce code duplication.
Only the following two architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Use for_each_mem_range() to traverse
and pre-count the max number of memory ranges.
- arch_crash_populate_cmem(). Use for_each_mem_range to traverse
and collect the memory ranges and fills them into cmem.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/arm64/kernel/machine_kexec_file.c | 40 ++++++++------------------
1 file changed, 12 insertions(+), 28 deletions(-)
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index e31fabed378a..b019b31df48c 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -40,46 +40,30 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
}
#ifdef CONFIG_CRASH_DUMP
-static int prepare_elf_headers(void **addr, unsigned long *sz)
+unsigned int arch_get_system_nr_ranges(void)
{
- struct crash_mem *cmem;
- unsigned int nr_ranges;
- int ret;
- u64 i;
+ unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
phys_addr_t start, end;
+ u64 i;
- nr_ranges = 2; /* for exclusion of crashkernel region */
for_each_mem_range(i, &start, &end)
nr_ranges++;
- cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
- if (!cmem)
- return -ENOMEM;
+ return nr_ranges;
+}
+
+int arch_crash_populate_cmem(struct crash_mem *cmem)
+{
+ phys_addr_t start, end;
+ u64 i;
- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
for_each_mem_range(i, &start, &end) {
cmem->ranges[cmem->nr_ranges].start = start;
cmem->ranges[cmem->nr_ranges].end = end - 1;
cmem->nr_ranges++;
}
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret)
- goto out;
-
- if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
- if (ret)
- goto out;
- }
-
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
+ return 0;
}
#endif
@@ -109,7 +93,7 @@ int load_other_segments(struct kimage *image,
void *headers;
unsigned long headers_sz;
if (image->type == KEXEC_TYPE_CRASH) {
- ret = prepare_elf_headers(&headers, &headers_sz);
+ ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
if (ret) {
pr_err("Preparing elf core header failed\n");
goto out_err;
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 04/10] arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash
kernel memory in the crash core, which reduce code duplication.
Only the following two architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Use for_each_mem_range() to traverse
and pre-count the max number of memory ranges.
- arch_crash_populate_cmem(). Use for_each_mem_range to traverse
and collect the memory ranges and fills them into cmem.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/arm64/kernel/machine_kexec_file.c | 40 ++++++++------------------
1 file changed, 12 insertions(+), 28 deletions(-)
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index e31fabed378a..b019b31df48c 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -40,46 +40,30 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
}
#ifdef CONFIG_CRASH_DUMP
-static int prepare_elf_headers(void **addr, unsigned long *sz)
+unsigned int arch_get_system_nr_ranges(void)
{
- struct crash_mem *cmem;
- unsigned int nr_ranges;
- int ret;
- u64 i;
+ unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
phys_addr_t start, end;
+ u64 i;
- nr_ranges = 2; /* for exclusion of crashkernel region */
for_each_mem_range(i, &start, &end)
nr_ranges++;
- cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
- if (!cmem)
- return -ENOMEM;
+ return nr_ranges;
+}
+
+int arch_crash_populate_cmem(struct crash_mem *cmem)
+{
+ phys_addr_t start, end;
+ u64 i;
- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
for_each_mem_range(i, &start, &end) {
cmem->ranges[cmem->nr_ranges].start = start;
cmem->ranges[cmem->nr_ranges].end = end - 1;
cmem->nr_ranges++;
}
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret)
- goto out;
-
- if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
- if (ret)
- goto out;
- }
-
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
+ return 0;
}
#endif
@@ -109,7 +93,7 @@ int load_other_segments(struct kimage *image,
void *headers;
unsigned long headers_sz;
if (image->type == KEXEC_TYPE_CRASH) {
- ret = prepare_elf_headers(&headers, &headers_sz);
+ ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
if (ret) {
pr_err("Preparing elf core header failed\n");
goto out_err;
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 05/10] x86: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
memory in the crash core, which reduce code duplication.
Only the following three architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
to pre-count the max number of memory ranges.
- arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
to collect the memory ranges and fills them into cmem.
- arch_crash_exclude_ranges(). Exclude the low 1M for x86.
By the way, remove the unused "nr_mem_ranges" in
arch_crash_handle_hotplug_event().
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/x86/kernel/crash.c | 89 +++++------------------------------------
1 file changed, 11 insertions(+), 78 deletions(-)
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index cd796818d94d..cb2ce7acfec4 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -153,16 +153,8 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
return 0;
}
-/* Gather all the required information to prepare elf headers for ram regions */
-static struct crash_mem *fill_up_crash_elf_data(void)
+unsigned int arch_get_system_nr_ranges(void)
{
- unsigned int nr_ranges = 0;
- struct crash_mem *cmem;
-
- walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
- if (!nr_ranges)
- return NULL;
-
/*
* Exclusion of crash region, crashk_low_res and/or crashk_cma_ranges
* may cause range splits. So add extra slots here.
@@ -177,49 +169,16 @@ static struct crash_mem *fill_up_crash_elf_data(void)
* But in order to lest the low 1M could be changed in the future,
* (e.g. [start, 1M]), add a extra slot.
*/
- nr_ranges += 3 + crashk_cma_cnt;
- cmem = vzalloc(struct_size(cmem, ranges, nr_ranges));
- if (!cmem)
- return NULL;
-
- cmem->max_nr_ranges = nr_ranges;
+ unsigned int nr_ranges = 3 + crashk_cma_cnt;
- return cmem;
+ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
+ return nr_ranges;
}
-/*
- * Look for any unwanted ranges between mstart, mend and remove them. This
- * might lead to split and split ranges are put in cmem->ranges[] array
- */
-static int elf_header_exclude_ranges(struct crash_mem *cmem)
+int arch_crash_exclude_ranges(struct crash_mem *cmem)
{
- int ret = 0;
- int i;
-
/* Exclude the low 1M because it is always reserved */
- ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
- if (ret)
- return ret;
-
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret)
- return ret;
-
- if (crashk_low_res.end)
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
- crashk_low_res.end);
- if (ret)
- return ret;
-
- for (i = 0; i < crashk_cma_cnt; ++i) {
- ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
- crashk_cma_ranges[i].end);
- if (ret)
- return ret;
- }
-
- return 0;
+ return crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
}
static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
@@ -233,35 +192,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
return 0;
}
-/* Prepare elf headers. Return addr and size */
-static int prepare_elf_headers(void **addr, unsigned long *sz,
- unsigned long *nr_mem_ranges)
+int arch_crash_populate_cmem(struct crash_mem *cmem)
{
- struct crash_mem *cmem;
- int ret;
-
- cmem = fill_up_crash_elf_data();
- if (!cmem)
- return -ENOMEM;
-
- ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
- if (ret)
- goto out;
-
- /* Exclude unwanted mem ranges */
- ret = elf_header_exclude_ranges(cmem);
- if (ret)
- goto out;
-
- /* Return the computed number of memory ranges, for hotplug usage */
- *nr_mem_ranges = cmem->nr_ranges;
-
- /* By default prepare 64bit headers */
- ret = crash_prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz);
-
-out:
- vfree(cmem);
- return ret;
+ return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
}
#endif
@@ -419,7 +352,8 @@ int crash_load_segments(struct kimage *image)
.buf_max = ULONG_MAX, .top_down = false };
/* Prepare elf headers and add a segment */
- ret = prepare_elf_headers(&kbuf.buffer, &kbuf.bufsz, &pnum);
+ ret = crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &kbuf.buffer,
+ &kbuf.bufsz, &pnum);
if (ret)
return ret;
@@ -512,7 +446,6 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
{
void *elfbuf = NULL, *old_elfcorehdr;
- unsigned long nr_mem_ranges;
unsigned long mem, memsz;
unsigned long elfsz = 0;
@@ -530,7 +463,7 @@ void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
* Create the new elfcorehdr reflecting the changes to CPU and/or
* memory resources.
*/
- if (prepare_elf_headers(&elfbuf, &elfsz, &nr_mem_ranges)) {
+ if (crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &elfbuf, &elfsz, NULL)) {
pr_err("unable to create new elfcorehdr");
goto out;
}
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 05/10] x86: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
memory in the crash core, which reduce code duplication.
Only the following three architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
to pre-count the max number of memory ranges.
- arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
to collect the memory ranges and fills them into cmem.
- arch_crash_exclude_ranges(). Exclude the low 1M for x86.
By the way, remove the unused "nr_mem_ranges" in
arch_crash_handle_hotplug_event().
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/x86/kernel/crash.c | 89 +++++------------------------------------
1 file changed, 11 insertions(+), 78 deletions(-)
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index cd796818d94d..cb2ce7acfec4 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -153,16 +153,8 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
return 0;
}
-/* Gather all the required information to prepare elf headers for ram regions */
-static struct crash_mem *fill_up_crash_elf_data(void)
+unsigned int arch_get_system_nr_ranges(void)
{
- unsigned int nr_ranges = 0;
- struct crash_mem *cmem;
-
- walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
- if (!nr_ranges)
- return NULL;
-
/*
* Exclusion of crash region, crashk_low_res and/or crashk_cma_ranges
* may cause range splits. So add extra slots here.
@@ -177,49 +169,16 @@ static struct crash_mem *fill_up_crash_elf_data(void)
* But in order to lest the low 1M could be changed in the future,
* (e.g. [start, 1M]), add a extra slot.
*/
- nr_ranges += 3 + crashk_cma_cnt;
- cmem = vzalloc(struct_size(cmem, ranges, nr_ranges));
- if (!cmem)
- return NULL;
-
- cmem->max_nr_ranges = nr_ranges;
+ unsigned int nr_ranges = 3 + crashk_cma_cnt;
- return cmem;
+ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
+ return nr_ranges;
}
-/*
- * Look for any unwanted ranges between mstart, mend and remove them. This
- * might lead to split and split ranges are put in cmem->ranges[] array
- */
-static int elf_header_exclude_ranges(struct crash_mem *cmem)
+int arch_crash_exclude_ranges(struct crash_mem *cmem)
{
- int ret = 0;
- int i;
-
/* Exclude the low 1M because it is always reserved */
- ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
- if (ret)
- return ret;
-
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret)
- return ret;
-
- if (crashk_low_res.end)
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
- crashk_low_res.end);
- if (ret)
- return ret;
-
- for (i = 0; i < crashk_cma_cnt; ++i) {
- ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
- crashk_cma_ranges[i].end);
- if (ret)
- return ret;
- }
-
- return 0;
+ return crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
}
static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
@@ -233,35 +192,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
return 0;
}
-/* Prepare elf headers. Return addr and size */
-static int prepare_elf_headers(void **addr, unsigned long *sz,
- unsigned long *nr_mem_ranges)
+int arch_crash_populate_cmem(struct crash_mem *cmem)
{
- struct crash_mem *cmem;
- int ret;
-
- cmem = fill_up_crash_elf_data();
- if (!cmem)
- return -ENOMEM;
-
- ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
- if (ret)
- goto out;
-
- /* Exclude unwanted mem ranges */
- ret = elf_header_exclude_ranges(cmem);
- if (ret)
- goto out;
-
- /* Return the computed number of memory ranges, for hotplug usage */
- *nr_mem_ranges = cmem->nr_ranges;
-
- /* By default prepare 64bit headers */
- ret = crash_prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz);
-
-out:
- vfree(cmem);
- return ret;
+ return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
}
#endif
@@ -419,7 +352,8 @@ int crash_load_segments(struct kimage *image)
.buf_max = ULONG_MAX, .top_down = false };
/* Prepare elf headers and add a segment */
- ret = prepare_elf_headers(&kbuf.buffer, &kbuf.bufsz, &pnum);
+ ret = crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &kbuf.buffer,
+ &kbuf.bufsz, &pnum);
if (ret)
return ret;
@@ -512,7 +446,6 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
{
void *elfbuf = NULL, *old_elfcorehdr;
- unsigned long nr_mem_ranges;
unsigned long mem, memsz;
unsigned long elfsz = 0;
@@ -530,7 +463,7 @@ void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
* Create the new elfcorehdr reflecting the changes to CPU and/or
* memory resources.
*/
- if (prepare_elf_headers(&elfbuf, &elfsz, &nr_mem_ranges)) {
+ if (crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &elfbuf, &elfsz, NULL)) {
pr_err("unable to create new elfcorehdr");
goto out;
}
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 06/10] riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
memory in the crash core, which reduce code duplication.
Only the following two architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
to pre-counts the max number of memory ranges.
- arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
to collects the memory ranges and fills them into cmem.
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/riscv/kernel/machine_kexec_file.c | 47 +++++++-------------------
1 file changed, 12 insertions(+), 35 deletions(-)
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 3f7766057cac..439cbc50dfa6 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -44,6 +44,15 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
return 0;
}
+unsigned int arch_get_system_nr_ranges(void)
+{
+ unsigned int nr_ranges = 2; /* For exclusion of crashkernel region */
+
+ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
+
+ return nr_ranges;
+}
+
static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
{
struct crash_mem *cmem = arg;
@@ -55,41 +64,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
return 0;
}
-static int prepare_elf_headers(void **addr, unsigned long *sz)
+int arch_crash_populate_cmem(struct crash_mem *cmem)
{
- struct crash_mem *cmem;
- unsigned int nr_ranges;
- int ret;
-
- nr_ranges = 2; /* For exclusion of crashkernel region */
- walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
-
- cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
- if (!cmem)
- return -ENOMEM;
-
- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
- ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
- if (ret)
- goto out;
-
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret)
- goto out;
-
- if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
- if (ret)
- goto out;
- }
-
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
+ return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
}
static char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
@@ -281,7 +258,7 @@ int load_extra_segments(struct kimage *image, unsigned long kernel_start,
if (image->type == KEXEC_TYPE_CRASH) {
void *headers;
unsigned long headers_sz;
- ret = prepare_elf_headers(&headers, &headers_sz);
+ ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
if (ret) {
pr_err("Preparing elf core header failed\n");
goto out;
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 06/10] riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
memory in the crash core, which reduce code duplication.
Only the following two architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
to pre-counts the max number of memory ranges.
- arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
to collects the memory ranges and fills them into cmem.
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/riscv/kernel/machine_kexec_file.c | 47 +++++++-------------------
1 file changed, 12 insertions(+), 35 deletions(-)
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 3f7766057cac..439cbc50dfa6 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -44,6 +44,15 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
return 0;
}
+unsigned int arch_get_system_nr_ranges(void)
+{
+ unsigned int nr_ranges = 2; /* For exclusion of crashkernel region */
+
+ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
+
+ return nr_ranges;
+}
+
static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
{
struct crash_mem *cmem = arg;
@@ -55,41 +64,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
return 0;
}
-static int prepare_elf_headers(void **addr, unsigned long *sz)
+int arch_crash_populate_cmem(struct crash_mem *cmem)
{
- struct crash_mem *cmem;
- unsigned int nr_ranges;
- int ret;
-
- nr_ranges = 2; /* For exclusion of crashkernel region */
- walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
-
- cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
- if (!cmem)
- return -ENOMEM;
-
- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
- ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
- if (ret)
- goto out;
-
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret)
- goto out;
-
- if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
- if (ret)
- goto out;
- }
-
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
+ return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
}
static char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
@@ -281,7 +258,7 @@ int load_extra_segments(struct kimage *image, unsigned long kernel_start,
if (image->type == KEXEC_TYPE_CRASH) {
void *headers;
unsigned long headers_sz;
- ret = prepare_elf_headers(&headers, &headers_sz);
+ ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
if (ret) {
pr_err("Preparing elf core header failed\n");
goto out;
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 07/10] LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
memory in the crash core, which reduce code duplication.
Only the following two architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Use for_each_mem_range to traverse
and pre-count the max number of memory ranges.
- arch_crash_populate_cmem(). Use for_each_mem_range to traverse
and collect the memory ranges and fills them into cmem.
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Youling Tang <tangyouling@kylinos.cn>
Cc: Baoquan He <bhe@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/loongarch/kernel/machine_kexec_file.c | 40 +++++++---------------
1 file changed, 12 insertions(+), 28 deletions(-)
diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c
index 5584b798ba46..5412aa9f3568 100644
--- a/arch/loongarch/kernel/machine_kexec_file.c
+++ b/arch/loongarch/kernel/machine_kexec_file.c
@@ -56,46 +56,30 @@ static void cmdline_add_initrd(struct kimage *image, unsigned long *cmdline_tmpl
}
#ifdef CONFIG_CRASH_DUMP
-
-static int prepare_elf_headers(void **addr, unsigned long *sz)
+unsigned int arch_get_system_nr_ranges(void)
{
- int ret, nr_ranges;
- uint64_t i;
+ int nr_ranges = 2; /* for exclusion of crashkernel region */
phys_addr_t start, end;
- struct crash_mem *cmem;
+ uint64_t i;
- nr_ranges = 2; /* for exclusion of crashkernel region */
for_each_mem_range(i, &start, &end)
nr_ranges++;
- cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
- if (!cmem)
- return -ENOMEM;
+ return nr_ranges;
+}
+
+int arch_crash_populate_cmem(struct crash_mem *cmem)
+{
+ phys_addr_t start, end;
+ uint64_t i;
- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
for_each_mem_range(i, &start, &end) {
cmem->ranges[cmem->nr_ranges].start = start;
cmem->ranges[cmem->nr_ranges].end = end - 1;
cmem->nr_ranges++;
}
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret < 0)
- goto out;
-
- if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
- if (ret < 0)
- goto out;
- }
-
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
+ return 0;
}
/*
@@ -163,7 +147,7 @@ int load_other_segments(struct kimage *image,
void *headers;
unsigned long headers_sz;
- ret = prepare_elf_headers(&headers, &headers_sz);
+ ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
if (ret < 0) {
pr_err("Preparing elf core header failed\n");
goto out_err;
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 07/10] LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Use the newly introduced crash_prepare_headers() function to replace
the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
memory in the crash core, which reduce code duplication.
Only the following two architecture functions need to be implemented:
- arch_get_system_nr_ranges(). Use for_each_mem_range to traverse
and pre-count the max number of memory ranges.
- arch_crash_populate_cmem(). Use for_each_mem_range to traverse
and collect the memory ranges and fills them into cmem.
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Youling Tang <tangyouling@kylinos.cn>
Cc: Baoquan He <bhe@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/loongarch/kernel/machine_kexec_file.c | 40 +++++++---------------
1 file changed, 12 insertions(+), 28 deletions(-)
diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c
index 5584b798ba46..5412aa9f3568 100644
--- a/arch/loongarch/kernel/machine_kexec_file.c
+++ b/arch/loongarch/kernel/machine_kexec_file.c
@@ -56,46 +56,30 @@ static void cmdline_add_initrd(struct kimage *image, unsigned long *cmdline_tmpl
}
#ifdef CONFIG_CRASH_DUMP
-
-static int prepare_elf_headers(void **addr, unsigned long *sz)
+unsigned int arch_get_system_nr_ranges(void)
{
- int ret, nr_ranges;
- uint64_t i;
+ int nr_ranges = 2; /* for exclusion of crashkernel region */
phys_addr_t start, end;
- struct crash_mem *cmem;
+ uint64_t i;
- nr_ranges = 2; /* for exclusion of crashkernel region */
for_each_mem_range(i, &start, &end)
nr_ranges++;
- cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
- if (!cmem)
- return -ENOMEM;
+ return nr_ranges;
+}
+
+int arch_crash_populate_cmem(struct crash_mem *cmem)
+{
+ phys_addr_t start, end;
+ uint64_t i;
- cmem->max_nr_ranges = nr_ranges;
- cmem->nr_ranges = 0;
for_each_mem_range(i, &start, &end) {
cmem->ranges[cmem->nr_ranges].start = start;
cmem->ranges[cmem->nr_ranges].end = end - 1;
cmem->nr_ranges++;
}
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
- if (ret < 0)
- goto out;
-
- if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
- if (ret < 0)
- goto out;
- }
-
- ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
-
-out:
- kfree(cmem);
- return ret;
+ return 0;
}
/*
@@ -163,7 +147,7 @@ int load_other_segments(struct kimage *image,
void *headers;
unsigned long headers_sz;
- ret = prepare_elf_headers(&headers, &headers_sz);
+ ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
if (ret < 0) {
pr_err("Preparing elf core header failed\n");
goto out_err;
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 08/10] powerpc/kexec_file: Use crash_exclude_core_ranges() helper
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The crash memory exclude of crashk_res and crashk_cma memory on powerpc
are almost identical to the generic crash_exclude_core_ranges().
By introducing the architecture-specific arch_crash_exclude_mem_range()
function with a default implementation of crash_exclude_mem_range(),
and using crash_exclude_mem_range_guarded as powerpc's separate
implementation, the generic crash_exclude_core_ranges() helper function
can be reused.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/powerpc/include/asm/kexec_ranges.h | 3 ---
arch/powerpc/kexec/crash.c | 2 +-
arch/powerpc/kexec/ranges.c | 16 ++++------------
include/linux/crash_core.h | 4 ++++
kernel/crash_core.c | 19 +++++++++++++------
5 files changed, 22 insertions(+), 22 deletions(-)
diff --git a/arch/powerpc/include/asm/kexec_ranges.h b/arch/powerpc/include/asm/kexec_ranges.h
index ad95e3792d10..8489e844b447 100644
--- a/arch/powerpc/include/asm/kexec_ranges.h
+++ b/arch/powerpc/include/asm/kexec_ranges.h
@@ -7,9 +7,6 @@
void sort_memory_ranges(struct crash_mem *mrngs, bool merge);
struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges);
int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
-int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
- unsigned long long mstart,
- unsigned long long mend);
int get_exclude_memory_ranges(struct crash_mem **mem_ranges);
int get_reserved_memory_ranges(struct crash_mem **mem_ranges);
int get_crash_memory_ranges(struct crash_mem **mem_ranges);
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index 2e88ec5c4356..60a917a6beaa 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -513,7 +513,7 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
base_addr = PFN_PHYS(mn->start_pfn);
size = mn->nr_pages * PAGE_SIZE;
end = base_addr + size - 1;
- ret = crash_exclude_mem_range_guarded(&cmem, base_addr, end);
+ ret = arch_crash_exclude_mem_range(&cmem, base_addr, end);
if (ret) {
pr_err("Failed to remove hot-unplugged memory from crash memory ranges\n");
goto out;
diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
index 6c58bcc3e130..e5fea23b191b 100644
--- a/arch/powerpc/kexec/ranges.c
+++ b/arch/powerpc/kexec/ranges.c
@@ -553,9 +553,9 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges)
#endif /* CONFIG_KEXEC_FILE */
#ifdef CONFIG_CRASH_DUMP
-int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
- unsigned long long mstart,
- unsigned long long mend)
+int arch_crash_exclude_mem_range(struct crash_mem **mem_ranges,
+ unsigned long long mstart,
+ unsigned long long mend)
{
struct crash_mem *tmem = *mem_ranges;
@@ -604,18 +604,10 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges)
sort_memory_ranges(*mem_ranges, true);
}
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end);
+ ret = crash_exclude_core_ranges(mem_ranges);
if (ret)
goto out;
- for (i = 0; i < crashk_cma_cnt; ++i) {
- ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start,
- crashk_cma_ranges[i].end);
- if (ret)
- goto out;
- }
-
/*
* FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
* regions are exported to save their context at the time of
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index 583ffcc703d4..bc087124cd78 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -61,6 +61,7 @@ extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_ma
void **addr, unsigned long *sz);
extern int crash_prepare_headers(int need_kernel_map, void **addr,
unsigned long *sz, unsigned long *nr_mem_ranges);
+extern int crash_exclude_core_ranges(struct crash_mem **cmem);
struct kimage;
struct kexec_segment;
@@ -81,6 +82,9 @@ extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
extern unsigned int arch_get_system_nr_ranges(void);
extern int arch_crash_populate_cmem(struct crash_mem *cmem);
extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
+extern int arch_crash_exclude_mem_range(struct crash_mem **mem,
+ unsigned long long mstart,
+ unsigned long long mend);
#else /* !CONFIG_CRASH_DUMP*/
struct pt_regs;
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 481babc29131..2b36aa9fade0 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -285,24 +285,31 @@ unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
-static int crash_exclude_core_ranges(struct crash_mem *cmem)
+int __weak arch_crash_exclude_mem_range(struct crash_mem **mem,
+ unsigned long long mstart,
+ unsigned long long mend)
+{
+ return crash_exclude_mem_range(*mem, mstart, mend);
+}
+
+int crash_exclude_core_ranges(struct crash_mem **cmem)
{
int ret, i;
/* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+ ret = arch_crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
if (ret)
return ret;
if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+ ret = arch_crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
if (ret)
return ret;
}
for (i = 0; i < crashk_cma_cnt; ++i) {
- ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
- crashk_cma_ranges[i].end);
+ ret = arch_crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end);
if (ret)
return ret;
}
@@ -329,7 +336,7 @@ int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,
if (ret)
goto out;
- ret = crash_exclude_core_ranges(cmem);
+ ret = crash_exclude_core_ranges(&cmem);
if (ret)
goto out;
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 08/10] powerpc/kexec_file: Use crash_exclude_core_ranges() helper
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The crash memory exclude of crashk_res and crashk_cma memory on powerpc
are almost identical to the generic crash_exclude_core_ranges().
By introducing the architecture-specific arch_crash_exclude_mem_range()
function with a default implementation of crash_exclude_mem_range(),
and using crash_exclude_mem_range_guarded as powerpc's separate
implementation, the generic crash_exclude_core_ranges() helper function
can be reused.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
arch/powerpc/include/asm/kexec_ranges.h | 3 ---
arch/powerpc/kexec/crash.c | 2 +-
arch/powerpc/kexec/ranges.c | 16 ++++------------
include/linux/crash_core.h | 4 ++++
kernel/crash_core.c | 19 +++++++++++++------
5 files changed, 22 insertions(+), 22 deletions(-)
diff --git a/arch/powerpc/include/asm/kexec_ranges.h b/arch/powerpc/include/asm/kexec_ranges.h
index ad95e3792d10..8489e844b447 100644
--- a/arch/powerpc/include/asm/kexec_ranges.h
+++ b/arch/powerpc/include/asm/kexec_ranges.h
@@ -7,9 +7,6 @@
void sort_memory_ranges(struct crash_mem *mrngs, bool merge);
struct crash_mem *realloc_mem_ranges(struct crash_mem **mem_ranges);
int add_mem_range(struct crash_mem **mem_ranges, u64 base, u64 size);
-int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
- unsigned long long mstart,
- unsigned long long mend);
int get_exclude_memory_ranges(struct crash_mem **mem_ranges);
int get_reserved_memory_ranges(struct crash_mem **mem_ranges);
int get_crash_memory_ranges(struct crash_mem **mem_ranges);
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index 2e88ec5c4356..60a917a6beaa 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -513,7 +513,7 @@ static void update_crash_elfcorehdr(struct kimage *image, struct memory_notify *
base_addr = PFN_PHYS(mn->start_pfn);
size = mn->nr_pages * PAGE_SIZE;
end = base_addr + size - 1;
- ret = crash_exclude_mem_range_guarded(&cmem, base_addr, end);
+ ret = arch_crash_exclude_mem_range(&cmem, base_addr, end);
if (ret) {
pr_err("Failed to remove hot-unplugged memory from crash memory ranges\n");
goto out;
diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c
index 6c58bcc3e130..e5fea23b191b 100644
--- a/arch/powerpc/kexec/ranges.c
+++ b/arch/powerpc/kexec/ranges.c
@@ -553,9 +553,9 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges)
#endif /* CONFIG_KEXEC_FILE */
#ifdef CONFIG_CRASH_DUMP
-int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges,
- unsigned long long mstart,
- unsigned long long mend)
+int arch_crash_exclude_mem_range(struct crash_mem **mem_ranges,
+ unsigned long long mstart,
+ unsigned long long mend)
{
struct crash_mem *tmem = *mem_ranges;
@@ -604,18 +604,10 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges)
sort_memory_ranges(*mem_ranges, true);
}
- /* Exclude crashkernel region */
- ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end);
+ ret = crash_exclude_core_ranges(mem_ranges);
if (ret)
goto out;
- for (i = 0; i < crashk_cma_cnt; ++i) {
- ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start,
- crashk_cma_ranges[i].end);
- if (ret)
- goto out;
- }
-
/*
* FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL
* regions are exported to save their context at the time of
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index 583ffcc703d4..bc087124cd78 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -61,6 +61,7 @@ extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_ma
void **addr, unsigned long *sz);
extern int crash_prepare_headers(int need_kernel_map, void **addr,
unsigned long *sz, unsigned long *nr_mem_ranges);
+extern int crash_exclude_core_ranges(struct crash_mem **cmem);
struct kimage;
struct kexec_segment;
@@ -81,6 +82,9 @@ extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
extern unsigned int arch_get_system_nr_ranges(void);
extern int arch_crash_populate_cmem(struct crash_mem *cmem);
extern int arch_crash_exclude_ranges(struct crash_mem *cmem);
+extern int arch_crash_exclude_mem_range(struct crash_mem **mem,
+ unsigned long long mstart,
+ unsigned long long mend);
#else /* !CONFIG_CRASH_DUMP*/
struct pt_regs;
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 481babc29131..2b36aa9fade0 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -285,24 +285,31 @@ unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
-static int crash_exclude_core_ranges(struct crash_mem *cmem)
+int __weak arch_crash_exclude_mem_range(struct crash_mem **mem,
+ unsigned long long mstart,
+ unsigned long long mend)
+{
+ return crash_exclude_mem_range(*mem, mstart, mend);
+}
+
+int crash_exclude_core_ranges(struct crash_mem **cmem)
{
int ret, i;
/* Exclude crashkernel region */
- ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
+ ret = arch_crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
if (ret)
return ret;
if (crashk_low_res.end) {
- ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
+ ret = arch_crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
if (ret)
return ret;
}
for (i = 0; i < crashk_cma_cnt; ++i) {
- ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
- crashk_cma_ranges[i].end);
+ ret = arch_crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end);
if (ret)
return ret;
}
@@ -329,7 +336,7 @@ int crash_prepare_headers(int need_kernel_map, void **addr, unsigned long *sz,
if (ret)
goto out;
- ret = crash_exclude_core_ranges(cmem);
+ ret = crash_exclude_core_ranges(&cmem);
if (ret)
goto out;
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 09/10] arm64: kexec_file: Add support for crashkernel CMA reservation
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the
crashkernel= command line option") and commit ab475510e042 ("kdump:
implement reserve_crashkernel_cma") added CMA support for kdump
crashkernel reservation.
Crash kernel memory reservation wastes production resources if too
large, risks kdump failure if too small, and faces allocation difficulties
on fragmented systems due to contiguous block constraints. The new
CMA-based crashkernel reservation scheme splits the "large fixed
reservation" into a "small fixed region + large CMA dynamic region": the
CMA memory is available to userspace during normal operation to avoid
waste, and is reclaimed for kdump upon crash—saving memory while
improving reliability.
So extend crashkernel CMA reservation support to arm64. The following
changes are made to enable CMA reservation:
- Parse and obtain the CMA reservation size along with other crashkernel
parameters.
- Call reserve_crashkernel_cma() to allocate the CMA region for kdump.
- Include the CMA-reserved ranges for kdump kernel to use.
- Exclude the CMA-reserved ranges from the crash kernel memory to
prevent them from being exported through /proc/vmcore, which is already
done in the crash core.
Update kernel-parameters.txt to document CMA support for crashkernel on
arm64 architecture.
Tested-by: Breno Leitao <leitao@debian.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
v7:
- Correct the inclusion of CMA-reserved ranges for kdump
kernel in of/kexec.
v3:
- Add Acked-by.
v2:
- Free cmem in prepare_elf_headers()
- Add the mtivation.
---
Documentation/admin-guide/kernel-parameters.txt | 2 +-
arch/arm64/kernel/machine_kexec_file.c | 2 +-
arch/arm64/mm/init.c | 5 +++--
drivers/of/fdt.c | 9 +++++----
drivers/of/kexec.c | 9 +++++++++
include/linux/crash_reserve.h | 4 +++-
6 files changed, 22 insertions(+), 9 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 4d0f545fb3ec..52742fab49a9 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1119,7 +1119,7 @@ Kernel parameters
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
crashkernel=size[KMG],cma
- [KNL, X86, ppc] Reserve additional crash kernel memory from
+ [KNL, X86, ARM64, PPC] Reserve additional crash kernel memory from
CMA. This reservation is usable by the first system's
userspace memory and kernel movable allocations (memory
balloon, zswap). Pages allocated from this memory range
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index b019b31df48c..854d872dfd0f 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -42,7 +42,7 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
#ifdef CONFIG_CRASH_DUMP
unsigned int arch_get_system_nr_ranges(void)
{
- unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
+ unsigned int nr_ranges = 2 + crashk_cma_cnt; /* for exclusion of crashkernel region */
phys_addr_t start, end;
u64 i;
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 97987f850a33..227f58522dad 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -96,8 +96,8 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit;
static void __init arch_reserve_crashkernel(void)
{
+ unsigned long long crash_base, crash_size, cma_size = 0;
unsigned long long low_size = 0;
- unsigned long long crash_base, crash_size;
bool high = false;
int ret;
@@ -106,11 +106,12 @@ static void __init arch_reserve_crashkernel(void)
ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
&crash_size, &crash_base,
- &low_size, NULL, &high);
+ &low_size, &cma_size, &high);
if (ret)
return;
reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
+ reserve_crashkernel_cma(cma_size);
}
static phys_addr_t __init max_zone_phys(phys_addr_t zone_limit)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 82f7327c59ea..0470acbd1fcf 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -880,11 +880,12 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
/*
* The main usage of linux,usable-memory-range is for crash dump kernel.
* Originally, the number of usable-memory regions is one. Now there may
- * be two regions, low region and high region.
- * To make compatibility with existing user-space and older kdump, the low
- * region is always the last range of linux,usable-memory-range if exist.
+ * be 2 + CRASHK_CMA_RANGES_MAX regions, low region, high region and cma
+ * regions. To make compatibility with existing user-space and older kdump,
+ * the high and low region are always the first two ranges of
+ * linux,usable-memory-range if exist.
*/
-#define MAX_USABLE_RANGES 2
+#define MAX_USABLE_RANGES (2 + CRASHK_CMA_RANGES_MAX)
/**
* early_init_dt_check_for_usable_mem_range - Decode usable memory range
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index b6837e299e7f..029903b986cb 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -458,6 +458,15 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
if (ret)
goto out;
}
+
+ for (int i = 0; i < crashk_cma_cnt; i++) {
+ ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+ "linux,usable-memory-range",
+ crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end - crashk_cma_ranges[i].start + 1);
+ if (ret)
+ goto out;
+ }
#endif
}
diff --git a/include/linux/crash_reserve.h b/include/linux/crash_reserve.h
index f0dc03d94ca2..30864d90d7f5 100644
--- a/include/linux/crash_reserve.h
+++ b/include/linux/crash_reserve.h
@@ -14,9 +14,11 @@
extern struct resource crashk_res;
extern struct resource crashk_low_res;
extern struct range crashk_cma_ranges[];
+
+#define CRASHK_CMA_RANGES_MAX 4
#if defined(CONFIG_CMA) && defined(CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION)
#define CRASHKERNEL_CMA
-#define CRASHKERNEL_CMA_RANGES_MAX 4
+#define CRASHKERNEL_CMA_RANGES_MAX (CRASHK_CMA_RANGES_MAX)
extern int crashk_cma_cnt;
#else
#define crashk_cma_cnt 0
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 09/10] arm64: kexec_file: Add support for crashkernel CMA reservation
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the
crashkernel= command line option") and commit ab475510e042 ("kdump:
implement reserve_crashkernel_cma") added CMA support for kdump
crashkernel reservation.
Crash kernel memory reservation wastes production resources if too
large, risks kdump failure if too small, and faces allocation difficulties
on fragmented systems due to contiguous block constraints. The new
CMA-based crashkernel reservation scheme splits the "large fixed
reservation" into a "small fixed region + large CMA dynamic region": the
CMA memory is available to userspace during normal operation to avoid
waste, and is reclaimed for kdump upon crash—saving memory while
improving reliability.
So extend crashkernel CMA reservation support to arm64. The following
changes are made to enable CMA reservation:
- Parse and obtain the CMA reservation size along with other crashkernel
parameters.
- Call reserve_crashkernel_cma() to allocate the CMA region for kdump.
- Include the CMA-reserved ranges for kdump kernel to use.
- Exclude the CMA-reserved ranges from the crash kernel memory to
prevent them from being exported through /proc/vmcore, which is already
done in the crash core.
Update kernel-parameters.txt to document CMA support for crashkernel on
arm64 architecture.
Tested-by: Breno Leitao <leitao@debian.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
v7:
- Correct the inclusion of CMA-reserved ranges for kdump
kernel in of/kexec.
v3:
- Add Acked-by.
v2:
- Free cmem in prepare_elf_headers()
- Add the mtivation.
---
Documentation/admin-guide/kernel-parameters.txt | 2 +-
arch/arm64/kernel/machine_kexec_file.c | 2 +-
arch/arm64/mm/init.c | 5 +++--
drivers/of/fdt.c | 9 +++++----
drivers/of/kexec.c | 9 +++++++++
include/linux/crash_reserve.h | 4 +++-
6 files changed, 22 insertions(+), 9 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 4d0f545fb3ec..52742fab49a9 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1119,7 +1119,7 @@ Kernel parameters
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
crashkernel=size[KMG],cma
- [KNL, X86, ppc] Reserve additional crash kernel memory from
+ [KNL, X86, ARM64, PPC] Reserve additional crash kernel memory from
CMA. This reservation is usable by the first system's
userspace memory and kernel movable allocations (memory
balloon, zswap). Pages allocated from this memory range
diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index b019b31df48c..854d872dfd0f 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -42,7 +42,7 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
#ifdef CONFIG_CRASH_DUMP
unsigned int arch_get_system_nr_ranges(void)
{
- unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
+ unsigned int nr_ranges = 2 + crashk_cma_cnt; /* for exclusion of crashkernel region */
phys_addr_t start, end;
u64 i;
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 97987f850a33..227f58522dad 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -96,8 +96,8 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit;
static void __init arch_reserve_crashkernel(void)
{
+ unsigned long long crash_base, crash_size, cma_size = 0;
unsigned long long low_size = 0;
- unsigned long long crash_base, crash_size;
bool high = false;
int ret;
@@ -106,11 +106,12 @@ static void __init arch_reserve_crashkernel(void)
ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
&crash_size, &crash_base,
- &low_size, NULL, &high);
+ &low_size, &cma_size, &high);
if (ret)
return;
reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
+ reserve_crashkernel_cma(cma_size);
}
static phys_addr_t __init max_zone_phys(phys_addr_t zone_limit)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 82f7327c59ea..0470acbd1fcf 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -880,11 +880,12 @@ static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
/*
* The main usage of linux,usable-memory-range is for crash dump kernel.
* Originally, the number of usable-memory regions is one. Now there may
- * be two regions, low region and high region.
- * To make compatibility with existing user-space and older kdump, the low
- * region is always the last range of linux,usable-memory-range if exist.
+ * be 2 + CRASHK_CMA_RANGES_MAX regions, low region, high region and cma
+ * regions. To make compatibility with existing user-space and older kdump,
+ * the high and low region are always the first two ranges of
+ * linux,usable-memory-range if exist.
*/
-#define MAX_USABLE_RANGES 2
+#define MAX_USABLE_RANGES (2 + CRASHK_CMA_RANGES_MAX)
/**
* early_init_dt_check_for_usable_mem_range - Decode usable memory range
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index b6837e299e7f..029903b986cb 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -458,6 +458,15 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
if (ret)
goto out;
}
+
+ for (int i = 0; i < crashk_cma_cnt; i++) {
+ ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+ "linux,usable-memory-range",
+ crashk_cma_ranges[i].start,
+ crashk_cma_ranges[i].end - crashk_cma_ranges[i].start + 1);
+ if (ret)
+ goto out;
+ }
#endif
}
diff --git a/include/linux/crash_reserve.h b/include/linux/crash_reserve.h
index f0dc03d94ca2..30864d90d7f5 100644
--- a/include/linux/crash_reserve.h
+++ b/include/linux/crash_reserve.h
@@ -14,9 +14,11 @@
extern struct resource crashk_res;
extern struct resource crashk_low_res;
extern struct range crashk_cma_ranges[];
+
+#define CRASHK_CMA_RANGES_MAX 4
#if defined(CONFIG_CMA) && defined(CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION)
#define CRASHKERNEL_CMA
-#define CRASHKERNEL_CMA_RANGES_MAX 4
+#define CRASHKERNEL_CMA_RANGES_MAX (CRASHK_CMA_RANGES_MAX)
extern int crashk_cma_cnt;
#else
#define crashk_cma_cnt 0
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 10/10] riscv: kexec_file: Add support for crashkernel CMA reservation
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 7:34 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the
crashkernel= command line option") and commit ab475510e042 ("kdump:
implement reserve_crashkernel_cma") added CMA support for kdump
crashkernel reservation. This allows the kernel to dynamically allocate
contiguous memory for crash dumping when needed, rather than permanently
reserving a fixed region at boot time.
So extend crashkernel CMA reservation support to riscv. The following
changes are made to enable CMA reservation:
- Parse and obtain the CMA reservation size along with other crashkernel
parameters.
- Call reserve_crashkernel_cma() to allocate the CMA region for kdump.
- Include the CMA-reserved ranges for kdump kernel to use, which was
already done in of_kexec_alloc_and_setup_fdt().
- Exclude the CMA-reserved ranges from the crash kernel memory to
prevent them from being exported through /proc/vmcore, which was
already done in the crash core.
Update kernel-parameters.txt to document CMA support for crashkernel on
riscv architecture.
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Paul Walmsley <pjw@kernel.org> # arch/riscv
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++--------
arch/riscv/kernel/machine_kexec_file.c | 2 +-
arch/riscv/mm/init.c | 5 +++--
3 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 52742fab49a9..3ff3ddd516cf 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1119,14 +1119,14 @@ Kernel parameters
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
crashkernel=size[KMG],cma
- [KNL, X86, ARM64, PPC] Reserve additional crash kernel memory from
- CMA. This reservation is usable by the first system's
- userspace memory and kernel movable allocations (memory
- balloon, zswap). Pages allocated from this memory range
- will not be included in the vmcore so this should not
- be used if dumping of userspace memory is intended and
- it has to be expected that some movable kernel pages
- may be missing from the dump.
+ [KNL, X86, ARM64, RISCV, PPC] Reserve additional crash
+ kernel memory from CMA. This reservation is usable by
+ the first system's userspace memory and kernel movable
+ allocations (memory balloon, zswap). Pages allocated
+ from this memory range will not be included in the vmcore
+ so this should not be used if dumping of userspace memory
+ is intended and it has to be expected that some movable
+ kernel pages may be missing from the dump.
A standard crashkernel reservation, as described above,
is still needed to hold the crash kernel and initrd.
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 439cbc50dfa6..85f14abceb50 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -46,7 +46,7 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
unsigned int arch_get_system_nr_ranges(void)
{
- unsigned int nr_ranges = 2; /* For exclusion of crashkernel region */
+ unsigned int nr_ranges = 2 + crashk_cma_cnt; /* For exclusion of crashkernel region */
walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index decd7df40fa4..c848454b8349 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1295,7 +1295,7 @@ static inline void setup_vm_final(void)
*/
static void __init arch_reserve_crashkernel(void)
{
- unsigned long long low_size = 0;
+ unsigned long long low_size = 0, cma_size = 0;
unsigned long long crash_base, crash_size;
bool high = false;
int ret;
@@ -1305,11 +1305,12 @@ static void __init arch_reserve_crashkernel(void)
ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
&crash_size, &crash_base,
- &low_size, NULL, &high);
+ &low_size, &cma_size, &high);
if (ret)
return;
reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
+ reserve_crashkernel_cma(cma_size);
}
void __init paging_init(void)
--
2.34.1
^ permalink raw reply related [flat|nested] 41+ messages in thread
* [PATCH v16 10/10] riscv: kexec_file: Add support for crashkernel CMA reservation
@ 2026-06-08 7:34 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 7:34 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
ruanjinjie, leitao, coxu, Liam.Howlett, ryan.roberts, osandov,
jbohac, cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the
crashkernel= command line option") and commit ab475510e042 ("kdump:
implement reserve_crashkernel_cma") added CMA support for kdump
crashkernel reservation. This allows the kernel to dynamically allocate
contiguous memory for crash dumping when needed, rather than permanently
reserving a fixed region at boot time.
So extend crashkernel CMA reservation support to riscv. The following
changes are made to enable CMA reservation:
- Parse and obtain the CMA reservation size along with other crashkernel
parameters.
- Call reserve_crashkernel_cma() to allocate the CMA region for kdump.
- Include the CMA-reserved ranges for kdump kernel to use, which was
already done in of_kexec_alloc_and_setup_fdt().
- Exclude the CMA-reserved ranges from the crash kernel memory to
prevent them from being exported through /proc/vmcore, which was
already done in the crash core.
Update kernel-parameters.txt to document CMA support for crashkernel on
riscv architecture.
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Paul Walmsley <pjw@kernel.org> # arch/riscv
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++--------
arch/riscv/kernel/machine_kexec_file.c | 2 +-
arch/riscv/mm/init.c | 5 +++--
3 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 52742fab49a9..3ff3ddd516cf 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1119,14 +1119,14 @@ Kernel parameters
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.
crashkernel=size[KMG],cma
- [KNL, X86, ARM64, PPC] Reserve additional crash kernel memory from
- CMA. This reservation is usable by the first system's
- userspace memory and kernel movable allocations (memory
- balloon, zswap). Pages allocated from this memory range
- will not be included in the vmcore so this should not
- be used if dumping of userspace memory is intended and
- it has to be expected that some movable kernel pages
- may be missing from the dump.
+ [KNL, X86, ARM64, RISCV, PPC] Reserve additional crash
+ kernel memory from CMA. This reservation is usable by
+ the first system's userspace memory and kernel movable
+ allocations (memory balloon, zswap). Pages allocated
+ from this memory range will not be included in the vmcore
+ so this should not be used if dumping of userspace memory
+ is intended and it has to be expected that some movable
+ kernel pages may be missing from the dump.
A standard crashkernel reservation, as described above,
is still needed to hold the crash kernel and initrd.
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index 439cbc50dfa6..85f14abceb50 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -46,7 +46,7 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
unsigned int arch_get_system_nr_ranges(void)
{
- unsigned int nr_ranges = 2; /* For exclusion of crashkernel region */
+ unsigned int nr_ranges = 2 + crashk_cma_cnt; /* For exclusion of crashkernel region */
walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index decd7df40fa4..c848454b8349 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1295,7 +1295,7 @@ static inline void setup_vm_final(void)
*/
static void __init arch_reserve_crashkernel(void)
{
- unsigned long long low_size = 0;
+ unsigned long long low_size = 0, cma_size = 0;
unsigned long long crash_base, crash_size;
bool high = false;
int ret;
@@ -1305,11 +1305,12 @@ static void __init arch_reserve_crashkernel(void)
ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
&crash_size, &crash_base,
- &low_size, NULL, &high);
+ &low_size, &cma_size, &high);
if (ret)
return;
reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
+ reserve_crashkernel_cma(cma_size);
}
void __init paging_init(void)
--
2.34.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 41+ messages in thread
* Re: [PATCH v16 05/10] x86: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
(?)
@ 2026-06-08 7:47 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-06-08 7:47 UTC (permalink / raw)
To: Jinjie Ruan; +Cc: devicetree, conor+dt, robh
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [High] A Time-of-Check to Time-of-Use (TOCTOU) race condition with concurrent memory hotplug can cause an out-of-bounds array write in `prepare_elf64_ram_headers_callback()` due to a missing bounds check.
--
commit 4e1090b66ab88651797483f0d06242b9bd18b6b3
Author: Jinjie Ruan <ruanjinjie@huawei.com>
x86: kexec_file: Use crash_prepare_headers() helper to simplify code
This commit replaces x86's custom prepare_elf_headers() with the generic
crash_prepare_headers() helper. It implements the required architecture
callbacks arch_get_system_nr_ranges(), arch_crash_populate_cmem(), and
arch_crash_exclude_ranges() to manage crash memory regions.
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index cd796818d94d9..cb2ce7acfec45 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
[ ... ]
> -/* Prepare elf headers. Return addr and size */
> -static int prepare_elf_headers(void **addr, unsigned long *sz,
> - unsigned long *nr_mem_ranges)
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> {
> - struct crash_mem *cmem;
> - int ret;
> -
> - cmem = fill_up_crash_elf_data();
> - if (!cmem)
> - return -ENOMEM;
> -
> - ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> - if (ret)
> - goto out;
> -
> - /* Exclude unwanted mem ranges */
> - ret = elf_header_exclude_ranges(cmem);
> - if (ret)
> - goto out;
> -
> - /* Return the computed number of memory ranges, for hotplug usage */
> - *nr_mem_ranges = cmem->nr_ranges;
> -
> - /* By default prepare 64bit headers */
> - ret = crash_prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz);
> -
> -out:
> - vfree(cmem);
> - return ret;
> + return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> }
[Severity: High]
This is a pre-existing issue, but can this sequence lead to an out-of-bounds
write during concurrent memory hotplug?
The generic crash_prepare_headers() performs two lockless passes over system
RAM resources:
1. arch_get_system_nr_ranges() counts the regions to allocate cmem.
2. arch_crash_populate_cmem() populates them using walk_system_ram_res()
and prepare_elf64_ram_headers_callback().
Since sys_kexec_file_load() does not hold mem_hotplug_lock, and
walk_system_ram_res() temporarily drops resource_lock between iterations,
concurrent memory hot-add operations can insert new memory regions between or
during these passes.
If the number of dynamically added RAM regions exceeds the reserved padding,
the second pass will encounter more regions than cmem->max_nr_ranges.
prepare_elf64_ram_headers_callback() currently does not verify bounds before
appending new regions:
cmem->ranges[cmem->nr_ranges].start = res->start;
cmem->ranges[cmem->nr_ranges].end = res->end;
cmem->nr_ranges++;
Could this allow an out-of-bounds array write on the vmalloc heap if enough
memory ranges are hotplugged concurrently? Would it make sense to add a bounds
check to prepare_elf64_ram_headers_callback() to prevent exceeding
cmem->max_nr_ranges, or perhaps hold the memory hotplug lock across the passes?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260608073459.3119290-1-ruanjinjie@huawei.com?part=5
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 01/10] riscv: kexec_file: Fix crashk_low_res not exclude bug
2026-06-08 7:34 ` Jinjie Ruan
(?)
@ 2026-06-08 7:48 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-06-08 7:48 UTC (permalink / raw)
To: Jinjie Ruan; +Cc: robh, devicetree, conor+dt
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [High] A Time-of-Check to Time-of-Use (TOCTOU) race condition in `crash_prepare_headers()` and `arch_crash_populate_cmem()` can lead to an out-of-bounds array write (Heap Buffer Overflow) if system RAM resources are hotplugged concurrently.
--
commit d18db7747e63171595f6e6caa523eb4a8bcc5bc5
Author: Jinjie Ruan <ruanjinjie@huawei.com>
Subject: riscv: kexec_file: Fix crashk_low_res not exclude bug
This commit ensures the "crashk_low_res" reserved ranges are excluded
from the crash kernel memory in RISC-V kexec_file to prevent them from
being exported through /proc/vmcore. It adds the necessary exclusion
logic and an extra crash_mem range.
Link: https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2
Link: https://lore.kernel.org/all/20230726175000.2536220-1-chenjiahao16@huawei.com/
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index 54e2d9552e930..3f7766057cac3 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -61,7 +61,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
> unsigned int nr_ranges;
> int ret;
>
> - nr_ranges = 1; /* For exclusion of crashkernel region */
> + nr_ranges = 2; /* For exclusion of crashkernel region */
> walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
>
> cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
[Severity: High]
This is a pre-existing issue, but could this multi-pass allocation pattern
lead to an out-of-bounds array write if system RAM resources are hotplugged
concurrently?
Looking at the refactored logic in kernel/crash_core.c and the callbacks in
arch/riscv/kernel/machine_kexec_file.c, there appears to be a Time-of-Check
to Time-of-Use (TOCTOU) gap:
crash_prepare_headers()
arch_get_system_nr_ranges()
/* First walk: calculates max_nr_ranges */
cmem = alloc_cmem(max_nr_ranges)
arch_crash_populate_cmem(cmem)
/* Second walk: populates cmem */
Since neither the global resource_lock nor device_hotplug_lock is held across
both passes, a concurrent memory hotplug event (e.g., add_memory()) could
insert new RAM ranges into iomem_resource between the two passes.
If the second pass encounters more ranges than originally allocated,
prepare_elf64_ram_headers_callback() writes directly to the array and
increments the counter:
cmem->ranges[cmem->nr_ranges].start = res->start;
cmem->ranges[cmem->nr_ranges].end = res->end;
cmem->nr_ranges++;
Does this code need a bounds check against cmem->max_nr_ranges in the
callback to prevent a heap buffer overflow in the cmem->ranges array?
[ ... ]
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260608073459.3119290-1-ruanjinjie@huawei.com?part=1
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 07/10] LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
(?)
@ 2026-06-08 7:52 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-06-08 7:52 UTC (permalink / raw)
To: Jinjie Ruan; +Cc: conor+dt, robh, devicetree
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [High] A time-of-check to time-of-use (TOCTOU) race condition exists between arch_get_system_nr_ranges() and arch_crash_populate_cmem() against concurrent memory hotplug, potentially causing a buffer overflow or Use-After-Free.
--
commit e15fd7173b2be430036c153dea51e26db1b14d57
Author: Jinjie Ruan <ruanjinjie@huawei.com>
LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
This commit replaces prepare_elf_headers() with the generic
crash_prepare_headers() helper to simplify crash memory handling. It implements
arch_get_system_nr_ranges() to count memory ranges and
arch_crash_populate_cmem() to fill them.
> diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c
> index 5584b798ba464..5412aa9f35687 100644
> --- a/arch/loongarch/kernel/machine_kexec_file.c
> +++ b/arch/loongarch/kernel/machine_kexec_file.c
[ ... ]
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> +{
> + phys_addr_t start, end;
> + uint64_t i;
>
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> for_each_mem_range(i, &start, &end) {
> cmem->ranges[cmem->nr_ranges].start = start;
> cmem->ranges[cmem->nr_ranges].end = end - 1;
> cmem->nr_ranges++;
> }
[Severity: High]
This is a pre-existing issue, but is there a risk of a time-of-check to
time-of-use (TOCTOU) race condition here against concurrent memory hotplug?
Because sys_kexec_file_load() acquires kexec_mutex but does not hold memory
hotplug locks (e.g., mem_hotplug_begin()) or cpus_read_lock(), concurrent
memory hotplug events like add_memory_resource() could occur.
The generic crash_prepare_headers() separates counting and population:
kernel/crash_core.c:crash_prepare_headers() {
...
max_nr_ranges = arch_get_system_nr_ranges();
if (!max_nr_ranges)
return -ENOMEM;
cmem = alloc_cmem(max_nr_ranges);
...
ret = arch_crash_populate_cmem(cmem);
...
}
If memblock regions are added dynamically between the time max_nr_ranges is
calculated and the cmem->ranges array is populated in
arch_crash_populate_cmem(), won't the loop above iterate more times than
max_nr_ranges and blindly write out-of-bounds to the flexible ranges array?
Additionally, could a concurrent memblock_add_node() trigger a
memblock_double_array(), which reallocates the regions array and frees the
old one, resulting in a use-after-free while for_each_mem_range() is
traversing it?
> + return 0;
> }
>
> /*
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260608073459.3119290-1-ruanjinjie@huawei.com?part=7
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 06/10] riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
(?)
@ 2026-06-08 7:54 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-06-08 7:54 UTC (permalink / raw)
To: Jinjie Ruan; +Cc: robh, conor+dt, devicetree
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [High] A Time-of-Check to Time-of-Use (TOCTOU) race condition in kexec segment preparation can cause a heap buffer overflow if memory hotplug occurs.
--
commit b23452d9853c692b4f51771e551dbfc49512243d
Author: Jinjie Ruan <ruanjinjie@huawei.com>
riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
This patch simplifies the kexec_file code for RISC-V by using the newly
introduced crash_prepare_headers() helper. It replaces the architecture
specific prepare_elf_headers() with arch_get_system_nr_ranges() and
arch_crash_populate_cmem() to reduce code duplication.
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index 3f7766057cac3..439cbc50dfa69 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
[ ... ]
> @@ -55,41 +64,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> return 0;
> }
>
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> {
> - struct crash_mem *cmem;
> - unsigned int nr_ranges;
> - int ret;
> -
> - nr_ranges = 2; /* For exclusion of crashkernel region */
> - walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> -
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> -
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> - ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> - if (ret)
> - goto out;
> -
[ ... ]
> + return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> }
[Severity: High]
This is a pre-existing issue, but can this code suffer from a Time-of-Check
to Time-of-Use race condition during memory hotplug?
The crash_prepare_headers() helper in kernel/crash_core.c uses a lockless
two-pass sequence:
kernel/crash_core.c:crash_prepare_headers() {
...
max_nr_ranges = arch_get_system_nr_ranges();
...
cmem = alloc_cmem(max_nr_ranges);
...
ret = arch_crash_populate_cmem(cmem);
...
}
Since the kexec syscall does not hold mem_hotplug_lock or use
get_online_mems(), could a concurrent memory hotplug event call add_memory()
and insert a new resource into the system RAM resource tree between the two
passes?
If that happens, the second walk_system_ram_res() pass in
arch_crash_populate_cmem() would encounter the newly inserted memory range.
This would cause it to execute prepare_elf64_ram_headers_callback() more
times than initially counted.
Because prepare_elf64_ram_headers_callback() unconditionally writes to
cmem->ranges[cmem->nr_ranges] without verifying that
cmem->nr_ranges < cmem->max_nr_ranges, would this result in an out-of-bounds
write that corrupts adjacent heap memory?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260608073459.3119290-1-ruanjinjie@huawei.com?part=6
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 04/10] arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
(?)
@ 2026-06-08 7:56 ` sashiko-bot
-1 siblings, 0 replies; 41+ messages in thread
From: sashiko-bot @ 2026-06-08 7:56 UTC (permalink / raw)
To: Jinjie Ruan; +Cc: devicetree, robh, conor+dt
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [High] Lockless memblock iteration in `arch_get_system_nr_ranges()` and `arch_crash_populate_cmem()` can lead to TOCTOU buffer overflow and Use-After-Free due to concurrent memory hotplug.
--
commit 3445143d0dcc2150e57d4b72a58250e2bbaf7ea7
Author: Jinjie Ruan <ruanjinjie@huawei.com>
arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
This commit replaces the existing prepare_elf_headers() with the newly
introduced crash_prepare_headers() function. It implements the two required
architecture functions, arch_get_system_nr_ranges() and
arch_crash_populate_cmem(), to traverse and populate memory ranges.
> diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
> index e31fabed378a5..b019b31df48cb 100644
> --- a/arch/arm64/kernel/machine_kexec_file.c
> +++ b/arch/arm64/kernel/machine_kexec_file.c
[ ... ]
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +unsigned int arch_get_system_nr_ranges(void)
> {
> - struct crash_mem *cmem;
> - unsigned int nr_ranges;
> - int ret;
> - u64 i;
> + unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
> phys_addr_t start, end;
> + u64 i;
>
> - nr_ranges = 2; /* for exclusion of crashkernel region */
> for_each_mem_range(i, &start, &end)
> nr_ranges++;
>
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> + return nr_ranges;
> +}
> +
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> +{
> + phys_addr_t start, end;
> + u64 i;
>
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> for_each_mem_range(i, &start, &end) {
> cmem->ranges[cmem->nr_ranges].start = start;
> cmem->ranges[cmem->nr_ranges].end = end - 1;
> cmem->nr_ranges++;
> }
[Severity: High]
This isn't a bug introduced by this patch, but could this lockless memblock
iteration lead to a TOCTOU buffer overflow or use-after-free during
concurrent memory hotplug?
arch_get_system_nr_ranges() locklessly calculates the max_nr_ranges used to
allocate cmem. If memory is hot-plugged between this calculation and the
array population here in arch_crash_populate_cmem(), could the second loop
encounter more regions than initially allocated?
Because there is no bounds check against cmem->max_nr_ranges, could this
result in an out-of-bounds write past the flexible cmem->ranges array?
Additionally, memory hotplug calls memblock_add_node(), which can invoke
memblock_double_array(). This function reallocates memblock.memory.regions
and frees the old array. If this reallocation occurs while
for_each_mem_range() is iterating in either function, could the lockless
iteration dereference a freed regions array?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260608073459.3119290-1-ruanjinjie@huawei.com?part=4
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 01/10] riscv: kexec_file: Fix crashk_low_res not exclude bug
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 8:05 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:05 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> As done in commit 944a45abfabc ("arm64: kdump: Reimplement crashkernel=X")
> and commit 4831be702b95 ("arm64/kexec: Fix missing extra range for
> crashkres_low.") for arm64, while implementing crashkernel=X,[high,low],
> riscv should have excluded the "crashk_low_res" reserved ranges from
> the crash kernel memory to prevent them from being exported through
> /proc/vmcore, and the exclusion would need an extra crash_mem range.
>
> Just simply tested on qemu with crashkernel=4G with kexec in [1] mentioned
> in [2]. And the second kernel can be started normally.
>
> # dmesg | grep crash
> [ 0.000000] crashkernel low memory reserved: 0xf8000000 - 0x100000000 (128 MB)
> [ 0.000000] crashkernel reserved: 0x000000017fe00000 - 0x000000027fe00000 (4096 MB)
>
> Cc: Guo Ren <guoren@kernel.org>
> Cc: Baoquan He <bhe@redhat.com>
> [1]: https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2
> [2]: https://lore.kernel.org/all/20230726175000.2536220-1-chenjiahao16@huawei.com/
> Fixes: 5882e5acf18d ("riscv: kdump: Implement crashkernel=X,[high,low]")
> Reviewed-by: Guo Ren <guoren@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to this fix here. Therefore, we will skip fixing it in this
series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608074809.EE4201F00893@smtp.kernel.org/
> ---
> arch/riscv/kernel/machine_kexec_file.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index 54e2d9552e93..3f7766057cac 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -61,7 +61,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
> unsigned int nr_ranges;
> int ret;
>
> - nr_ranges = 1; /* For exclusion of crashkernel region */
> + nr_ranges = 2; /* For exclusion of crashkernel region */
> walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
>
> cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> @@ -76,8 +76,16 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
>
> /* Exclude crashkernel region */
> ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (!ret)
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> + if (ret)
> + goto out;
> +
> + if (crashk_low_res.end) {
> + ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> + if (ret)
> + goto out;
> + }
> +
> + ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
>
> out:
> kfree(cmem);
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 01/10] riscv: kexec_file: Fix crashk_low_res not exclude bug
@ 2026-06-08 8:05 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:05 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> As done in commit 944a45abfabc ("arm64: kdump: Reimplement crashkernel=X")
> and commit 4831be702b95 ("arm64/kexec: Fix missing extra range for
> crashkres_low.") for arm64, while implementing crashkernel=X,[high,low],
> riscv should have excluded the "crashk_low_res" reserved ranges from
> the crash kernel memory to prevent them from being exported through
> /proc/vmcore, and the exclusion would need an extra crash_mem range.
>
> Just simply tested on qemu with crashkernel=4G with kexec in [1] mentioned
> in [2]. And the second kernel can be started normally.
>
> # dmesg | grep crash
> [ 0.000000] crashkernel low memory reserved: 0xf8000000 - 0x100000000 (128 MB)
> [ 0.000000] crashkernel reserved: 0x000000017fe00000 - 0x000000027fe00000 (4096 MB)
>
> Cc: Guo Ren <guoren@kernel.org>
> Cc: Baoquan He <bhe@redhat.com>
> [1]: https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2
> [2]: https://lore.kernel.org/all/20230726175000.2536220-1-chenjiahao16@huawei.com/
> Fixes: 5882e5acf18d ("riscv: kdump: Implement crashkernel=X,[high,low]")
> Reviewed-by: Guo Ren <guoren@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to this fix here. Therefore, we will skip fixing it in this
series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608074809.EE4201F00893@smtp.kernel.org/
> ---
> arch/riscv/kernel/machine_kexec_file.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index 54e2d9552e93..3f7766057cac 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -61,7 +61,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
> unsigned int nr_ranges;
> int ret;
>
> - nr_ranges = 1; /* For exclusion of crashkernel region */
> + nr_ranges = 2; /* For exclusion of crashkernel region */
> walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
>
> cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> @@ -76,8 +76,16 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
>
> /* Exclude crashkernel region */
> ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (!ret)
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> + if (ret)
> + goto out;
> +
> + if (crashk_low_res.end) {
> + ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> + if (ret)
> + goto out;
> + }
> +
> + ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
>
> out:
> kfree(cmem);
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 04/10] arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 8:07 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:07 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the core CMA implementation introduced here. Therefore, we
will skip fixing it in this series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608075628.039FC1F00893@smtp.kernel.org/
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash
> kernel memory in the crash core, which reduce code duplication.
>
> Only the following two architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Use for_each_mem_range() to traverse
> and pre-count the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use for_each_mem_range to traverse
> and collect the memory ranges and fills them into cmem.
>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/arm64/kernel/machine_kexec_file.c | 40 ++++++++------------------
> 1 file changed, 12 insertions(+), 28 deletions(-)
>
> diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
> index e31fabed378a..b019b31df48c 100644
> --- a/arch/arm64/kernel/machine_kexec_file.c
> +++ b/arch/arm64/kernel/machine_kexec_file.c
> @@ -40,46 +40,30 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
> }
>
> #ifdef CONFIG_CRASH_DUMP
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +unsigned int arch_get_system_nr_ranges(void)
> {
> - struct crash_mem *cmem;
> - unsigned int nr_ranges;
> - int ret;
> - u64 i;
> + unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
> phys_addr_t start, end;
> + u64 i;
>
> - nr_ranges = 2; /* for exclusion of crashkernel region */
> for_each_mem_range(i, &start, &end)
> nr_ranges++;
>
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> + return nr_ranges;
> +}
> +
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> +{
> + phys_addr_t start, end;
> + u64 i;
>
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> for_each_mem_range(i, &start, &end) {
> cmem->ranges[cmem->nr_ranges].start = start;
> cmem->ranges[cmem->nr_ranges].end = end - 1;
> cmem->nr_ranges++;
> }
>
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret)
> - goto out;
> -
> - if (crashk_low_res.end) {
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> - if (ret)
> - goto out;
> - }
> -
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> -
> -out:
> - kfree(cmem);
> - return ret;
> + return 0;
> }
> #endif
>
> @@ -109,7 +93,7 @@ int load_other_segments(struct kimage *image,
> void *headers;
> unsigned long headers_sz;
> if (image->type == KEXEC_TYPE_CRASH) {
> - ret = prepare_elf_headers(&headers, &headers_sz);
> + ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
> if (ret) {
> pr_err("Preparing elf core header failed\n");
> goto out_err;
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 04/10] arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 8:07 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:07 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the core CMA implementation introduced here. Therefore, we
will skip fixing it in this series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608075628.039FC1F00893@smtp.kernel.org/
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash
> kernel memory in the crash core, which reduce code duplication.
>
> Only the following two architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Use for_each_mem_range() to traverse
> and pre-count the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use for_each_mem_range to traverse
> and collect the memory ranges and fills them into cmem.
>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/arm64/kernel/machine_kexec_file.c | 40 ++++++++------------------
> 1 file changed, 12 insertions(+), 28 deletions(-)
>
> diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
> index e31fabed378a..b019b31df48c 100644
> --- a/arch/arm64/kernel/machine_kexec_file.c
> +++ b/arch/arm64/kernel/machine_kexec_file.c
> @@ -40,46 +40,30 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
> }
>
> #ifdef CONFIG_CRASH_DUMP
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +unsigned int arch_get_system_nr_ranges(void)
> {
> - struct crash_mem *cmem;
> - unsigned int nr_ranges;
> - int ret;
> - u64 i;
> + unsigned int nr_ranges = 2; /* for exclusion of crashkernel region */
> phys_addr_t start, end;
> + u64 i;
>
> - nr_ranges = 2; /* for exclusion of crashkernel region */
> for_each_mem_range(i, &start, &end)
> nr_ranges++;
>
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> + return nr_ranges;
> +}
> +
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> +{
> + phys_addr_t start, end;
> + u64 i;
>
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> for_each_mem_range(i, &start, &end) {
> cmem->ranges[cmem->nr_ranges].start = start;
> cmem->ranges[cmem->nr_ranges].end = end - 1;
> cmem->nr_ranges++;
> }
>
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret)
> - goto out;
> -
> - if (crashk_low_res.end) {
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> - if (ret)
> - goto out;
> - }
> -
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> -
> -out:
> - kfree(cmem);
> - return ret;
> + return 0;
> }
> #endif
>
> @@ -109,7 +93,7 @@ int load_other_segments(struct kimage *image,
> void *headers;
> unsigned long headers_sz;
> if (image->type == KEXEC_TYPE_CRASH) {
> - ret = prepare_elf_headers(&headers, &headers_sz);
> + ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
> if (ret) {
> pr_err("Preparing elf core header failed\n");
> goto out_err;
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 06/10] riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 8:08 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:08 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
> memory in the crash core, which reduce code duplication.
>
> Only the following two architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
> to pre-counts the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
> to collects the memory ranges and fills them into cmem.
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the core CMA implementation introduced here. Therefore, we
will skip fixing it in this series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608075420.8C5871F00893@smtp.kernel.org/
>
> Cc: Paul Walmsley <pjw@kernel.org>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: Alexandre Ghiti <alex@ghiti.fr>
> Cc: Guo Ren <guoren@kernel.org>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/riscv/kernel/machine_kexec_file.c | 47 +++++++-------------------
> 1 file changed, 12 insertions(+), 35 deletions(-)
>
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index 3f7766057cac..439cbc50dfa6 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -44,6 +44,15 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
> return 0;
> }
>
> +unsigned int arch_get_system_nr_ranges(void)
> +{
> + unsigned int nr_ranges = 2; /* For exclusion of crashkernel region */
> +
> + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> +
> + return nr_ranges;
> +}
> +
> static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> {
> struct crash_mem *cmem = arg;
> @@ -55,41 +64,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> return 0;
> }
>
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> {
> - struct crash_mem *cmem;
> - unsigned int nr_ranges;
> - int ret;
> -
> - nr_ranges = 2; /* For exclusion of crashkernel region */
> - walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> -
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> -
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> - ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> - if (ret)
> - goto out;
> -
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret)
> - goto out;
> -
> - if (crashk_low_res.end) {
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> - if (ret)
> - goto out;
> - }
> -
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> -
> -out:
> - kfree(cmem);
> - return ret;
> + return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> }
>
> static char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
> @@ -281,7 +258,7 @@ int load_extra_segments(struct kimage *image, unsigned long kernel_start,
> if (image->type == KEXEC_TYPE_CRASH) {
> void *headers;
> unsigned long headers_sz;
> - ret = prepare_elf_headers(&headers, &headers_sz);
> + ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
> if (ret) {
> pr_err("Preparing elf core header failed\n");
> goto out;
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 06/10] riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 8:08 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:08 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
> memory in the crash core, which reduce code duplication.
>
> Only the following two architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
> to pre-counts the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
> to collects the memory ranges and fills them into cmem.
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the core CMA implementation introduced here. Therefore, we
will skip fixing it in this series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608075420.8C5871F00893@smtp.kernel.org/
>
> Cc: Paul Walmsley <pjw@kernel.org>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: Alexandre Ghiti <alex@ghiti.fr>
> Cc: Guo Ren <guoren@kernel.org>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/riscv/kernel/machine_kexec_file.c | 47 +++++++-------------------
> 1 file changed, 12 insertions(+), 35 deletions(-)
>
> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> index 3f7766057cac..439cbc50dfa6 100644
> --- a/arch/riscv/kernel/machine_kexec_file.c
> +++ b/arch/riscv/kernel/machine_kexec_file.c
> @@ -44,6 +44,15 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
> return 0;
> }
>
> +unsigned int arch_get_system_nr_ranges(void)
> +{
> + unsigned int nr_ranges = 2; /* For exclusion of crashkernel region */
> +
> + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> +
> + return nr_ranges;
> +}
> +
> static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> {
> struct crash_mem *cmem = arg;
> @@ -55,41 +64,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> return 0;
> }
>
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> {
> - struct crash_mem *cmem;
> - unsigned int nr_ranges;
> - int ret;
> -
> - nr_ranges = 2; /* For exclusion of crashkernel region */
> - walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> -
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> -
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> - ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> - if (ret)
> - goto out;
> -
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret)
> - goto out;
> -
> - if (crashk_low_res.end) {
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> - if (ret)
> - goto out;
> - }
> -
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> -
> -out:
> - kfree(cmem);
> - return ret;
> + return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> }
>
> static char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
> @@ -281,7 +258,7 @@ int load_extra_segments(struct kimage *image, unsigned long kernel_start,
> if (image->type == KEXEC_TYPE_CRASH) {
> void *headers;
> unsigned long headers_sz;
> - ret = prepare_elf_headers(&headers, &headers_sz);
> + ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
> if (ret) {
> pr_err("Preparing elf core header failed\n");
> goto out;
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 05/10] x86: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 8:21 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:21 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
> memory in the crash core, which reduce code duplication.
>
> Only the following three architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
> to pre-count the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
> to collect the memory ranges and fills them into cmem.
>
> - arch_crash_exclude_ranges(). Exclude the low 1M for x86.
>
> By the way, remove the unused "nr_mem_ranges" in
> arch_crash_handle_hotplug_event().
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the reowork here. Therefore, we will skip fixing it in this
series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608074748.58E8E1F00893@smtp.kernel.org/
>
> Cc: Thomas Gleixner <tglx@kernel.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Vivek Goyal <vgoyal@redhat.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/x86/kernel/crash.c | 89 +++++------------------------------------
> 1 file changed, 11 insertions(+), 78 deletions(-)
>
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index cd796818d94d..cb2ce7acfec4 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -153,16 +153,8 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
> return 0;
> }
>
> -/* Gather all the required information to prepare elf headers for ram regions */
> -static struct crash_mem *fill_up_crash_elf_data(void)
> +unsigned int arch_get_system_nr_ranges(void)
> {
> - unsigned int nr_ranges = 0;
> - struct crash_mem *cmem;
> -
> - walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> - if (!nr_ranges)
> - return NULL;
> -
> /*
> * Exclusion of crash region, crashk_low_res and/or crashk_cma_ranges
> * may cause range splits. So add extra slots here.
> @@ -177,49 +169,16 @@ static struct crash_mem *fill_up_crash_elf_data(void)
> * But in order to lest the low 1M could be changed in the future,
> * (e.g. [start, 1M]), add a extra slot.
> */
> - nr_ranges += 3 + crashk_cma_cnt;
> - cmem = vzalloc(struct_size(cmem, ranges, nr_ranges));
> - if (!cmem)
> - return NULL;
> -
> - cmem->max_nr_ranges = nr_ranges;
> + unsigned int nr_ranges = 3 + crashk_cma_cnt;
>
> - return cmem;
> + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> + return nr_ranges;
> }
>
> -/*
> - * Look for any unwanted ranges between mstart, mend and remove them. This
> - * might lead to split and split ranges are put in cmem->ranges[] array
> - */
> -static int elf_header_exclude_ranges(struct crash_mem *cmem)
> +int arch_crash_exclude_ranges(struct crash_mem *cmem)
> {
> - int ret = 0;
> - int i;
> -
> /* Exclude the low 1M because it is always reserved */
> - ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
> - if (ret)
> - return ret;
> -
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret)
> - return ret;
> -
> - if (crashk_low_res.end)
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
> - crashk_low_res.end);
> - if (ret)
> - return ret;
> -
> - for (i = 0; i < crashk_cma_cnt; ++i) {
> - ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
> - crashk_cma_ranges[i].end);
> - if (ret)
> - return ret;
> - }
> -
> - return 0;
> + return crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
> }
>
> static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> @@ -233,35 +192,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> return 0;
> }
>
> -/* Prepare elf headers. Return addr and size */
> -static int prepare_elf_headers(void **addr, unsigned long *sz,
> - unsigned long *nr_mem_ranges)
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> {
> - struct crash_mem *cmem;
> - int ret;
> -
> - cmem = fill_up_crash_elf_data();
> - if (!cmem)
> - return -ENOMEM;
> -
> - ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> - if (ret)
> - goto out;
> -
> - /* Exclude unwanted mem ranges */
> - ret = elf_header_exclude_ranges(cmem);
> - if (ret)
> - goto out;
> -
> - /* Return the computed number of memory ranges, for hotplug usage */
> - *nr_mem_ranges = cmem->nr_ranges;
> -
> - /* By default prepare 64bit headers */
> - ret = crash_prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz);
> -
> -out:
> - vfree(cmem);
> - return ret;
> + return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> }
> #endif
>
> @@ -419,7 +352,8 @@ int crash_load_segments(struct kimage *image)
> .buf_max = ULONG_MAX, .top_down = false };
>
> /* Prepare elf headers and add a segment */
> - ret = prepare_elf_headers(&kbuf.buffer, &kbuf.bufsz, &pnum);
> + ret = crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &kbuf.buffer,
> + &kbuf.bufsz, &pnum);
> if (ret)
> return ret;
>
> @@ -512,7 +446,6 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
> void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
> {
> void *elfbuf = NULL, *old_elfcorehdr;
> - unsigned long nr_mem_ranges;
> unsigned long mem, memsz;
> unsigned long elfsz = 0;
>
> @@ -530,7 +463,7 @@ void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
> * Create the new elfcorehdr reflecting the changes to CPU and/or
> * memory resources.
> */
> - if (prepare_elf_headers(&elfbuf, &elfsz, &nr_mem_ranges)) {
> + if (crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &elfbuf, &elfsz, NULL)) {
> pr_err("unable to create new elfcorehdr");
> goto out;
> }
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 05/10] x86: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 8:21 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:21 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
> memory in the crash core, which reduce code duplication.
>
> Only the following three architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Call get_nr_ram_ranges_callback()
> to pre-count the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use prepare_elf64_ram_headers_callback()
> to collect the memory ranges and fills them into cmem.
>
> - arch_crash_exclude_ranges(). Exclude the low 1M for x86.
>
> By the way, remove the unused "nr_mem_ranges" in
> arch_crash_handle_hotplug_event().
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the reowork here. Therefore, we will skip fixing it in this
series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608074748.58E8E1F00893@smtp.kernel.org/
>
> Cc: Thomas Gleixner <tglx@kernel.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Vivek Goyal <vgoyal@redhat.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/x86/kernel/crash.c | 89 +++++------------------------------------
> 1 file changed, 11 insertions(+), 78 deletions(-)
>
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index cd796818d94d..cb2ce7acfec4 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -153,16 +153,8 @@ static int get_nr_ram_ranges_callback(struct resource *res, void *arg)
> return 0;
> }
>
> -/* Gather all the required information to prepare elf headers for ram regions */
> -static struct crash_mem *fill_up_crash_elf_data(void)
> +unsigned int arch_get_system_nr_ranges(void)
> {
> - unsigned int nr_ranges = 0;
> - struct crash_mem *cmem;
> -
> - walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> - if (!nr_ranges)
> - return NULL;
> -
> /*
> * Exclusion of crash region, crashk_low_res and/or crashk_cma_ranges
> * may cause range splits. So add extra slots here.
> @@ -177,49 +169,16 @@ static struct crash_mem *fill_up_crash_elf_data(void)
> * But in order to lest the low 1M could be changed in the future,
> * (e.g. [start, 1M]), add a extra slot.
> */
> - nr_ranges += 3 + crashk_cma_cnt;
> - cmem = vzalloc(struct_size(cmem, ranges, nr_ranges));
> - if (!cmem)
> - return NULL;
> -
> - cmem->max_nr_ranges = nr_ranges;
> + unsigned int nr_ranges = 3 + crashk_cma_cnt;
>
> - return cmem;
> + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback);
> + return nr_ranges;
> }
>
> -/*
> - * Look for any unwanted ranges between mstart, mend and remove them. This
> - * might lead to split and split ranges are put in cmem->ranges[] array
> - */
> -static int elf_header_exclude_ranges(struct crash_mem *cmem)
> +int arch_crash_exclude_ranges(struct crash_mem *cmem)
> {
> - int ret = 0;
> - int i;
> -
> /* Exclude the low 1M because it is always reserved */
> - ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
> - if (ret)
> - return ret;
> -
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret)
> - return ret;
> -
> - if (crashk_low_res.end)
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
> - crashk_low_res.end);
> - if (ret)
> - return ret;
> -
> - for (i = 0; i < crashk_cma_cnt; ++i) {
> - ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
> - crashk_cma_ranges[i].end);
> - if (ret)
> - return ret;
> - }
> -
> - return 0;
> + return crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
> }
>
> static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> @@ -233,35 +192,9 @@ static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
> return 0;
> }
>
> -/* Prepare elf headers. Return addr and size */
> -static int prepare_elf_headers(void **addr, unsigned long *sz,
> - unsigned long *nr_mem_ranges)
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> {
> - struct crash_mem *cmem;
> - int ret;
> -
> - cmem = fill_up_crash_elf_data();
> - if (!cmem)
> - return -ENOMEM;
> -
> - ret = walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> - if (ret)
> - goto out;
> -
> - /* Exclude unwanted mem ranges */
> - ret = elf_header_exclude_ranges(cmem);
> - if (ret)
> - goto out;
> -
> - /* Return the computed number of memory ranges, for hotplug usage */
> - *nr_mem_ranges = cmem->nr_ranges;
> -
> - /* By default prepare 64bit headers */
> - ret = crash_prepare_elf64_headers(cmem, IS_ENABLED(CONFIG_X86_64), addr, sz);
> -
> -out:
> - vfree(cmem);
> - return ret;
> + return walk_system_ram_res(0, -1, cmem, prepare_elf64_ram_headers_callback);
> }
> #endif
>
> @@ -419,7 +352,8 @@ int crash_load_segments(struct kimage *image)
> .buf_max = ULONG_MAX, .top_down = false };
>
> /* Prepare elf headers and add a segment */
> - ret = prepare_elf_headers(&kbuf.buffer, &kbuf.bufsz, &pnum);
> + ret = crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &kbuf.buffer,
> + &kbuf.bufsz, &pnum);
> if (ret)
> return ret;
>
> @@ -512,7 +446,6 @@ unsigned int arch_crash_get_elfcorehdr_size(void)
> void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
> {
> void *elfbuf = NULL, *old_elfcorehdr;
> - unsigned long nr_mem_ranges;
> unsigned long mem, memsz;
> unsigned long elfsz = 0;
>
> @@ -530,7 +463,7 @@ void arch_crash_handle_hotplug_event(struct kimage *image, void *arg)
> * Create the new elfcorehdr reflecting the changes to CPU and/or
> * memory resources.
> */
> - if (prepare_elf_headers(&elfbuf, &elfsz, &nr_mem_ranges)) {
> + if (crash_prepare_headers(IS_ENABLED(CONFIG_X86_64), &elfbuf, &elfsz, NULL)) {
> pr_err("unable to create new elfcorehdr");
> goto out;
> }
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 07/10] LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 8:23 ` Jinjie Ruan
-1 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:23 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
> memory in the crash core, which reduce code duplication.
>
> Only the following two architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Use for_each_mem_range to traverse
> and pre-count the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use for_each_mem_range to traverse
> and collect the memory ranges and fills them into cmem.
>
> Cc: Huacai Chen <chenhuacai@kernel.org>
> Cc: WANG Xuerui <kernel@xen0n.name>
> Cc: Youling Tang <tangyouling@kylinos.cn>
> Cc: Baoquan He <bhe@redhat.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/loongarch/kernel/machine_kexec_file.c | 40 +++++++---------------
> 1 file changed, 12 insertions(+), 28 deletions(-)
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the rework here. Therefore, we will skip fixing it in this
series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608075258.0F6D91F00893@smtp.kernel.org/
>
> diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c
> index 5584b798ba46..5412aa9f3568 100644
> --- a/arch/loongarch/kernel/machine_kexec_file.c
> +++ b/arch/loongarch/kernel/machine_kexec_file.c
> @@ -56,46 +56,30 @@ static void cmdline_add_initrd(struct kimage *image, unsigned long *cmdline_tmpl
> }
>
> #ifdef CONFIG_CRASH_DUMP
> -
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +unsigned int arch_get_system_nr_ranges(void)
> {
> - int ret, nr_ranges;
> - uint64_t i;
> + int nr_ranges = 2; /* for exclusion of crashkernel region */
> phys_addr_t start, end;
> - struct crash_mem *cmem;
> + uint64_t i;
>
> - nr_ranges = 2; /* for exclusion of crashkernel region */
> for_each_mem_range(i, &start, &end)
> nr_ranges++;
>
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> + return nr_ranges;
> +}
> +
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> +{
> + phys_addr_t start, end;
> + uint64_t i;
>
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> for_each_mem_range(i, &start, &end) {
> cmem->ranges[cmem->nr_ranges].start = start;
> cmem->ranges[cmem->nr_ranges].end = end - 1;
> cmem->nr_ranges++;
> }
>
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret < 0)
> - goto out;
> -
> - if (crashk_low_res.end) {
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> - if (ret < 0)
> - goto out;
> - }
> -
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> -
> -out:
> - kfree(cmem);
> - return ret;
> + return 0;
> }
>
> /*
> @@ -163,7 +147,7 @@ int load_other_segments(struct kimage *image,
> void *headers;
> unsigned long headers_sz;
>
> - ret = prepare_elf_headers(&headers, &headers_sz);
> + ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
> if (ret < 0) {
> pr_err("Preparing elf core header failed\n");
> goto out_err;
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 07/10] LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
@ 2026-06-08 8:23 ` Jinjie Ruan
0 siblings, 0 replies; 41+ messages in thread
From: Jinjie Ruan @ 2026-06-08 8:23 UTC (permalink / raw)
To: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
leitao, coxu, Liam.Howlett, ryan.roberts, osandov, jbohac,
cfsworks, tangyouling, sourabhjain, ritesh.list, adityag,
liaoyuanhong, seanjc, fuqiang.wang, ardb, chenjiahao16, guoren,
x86, linux-doc, linux-kernel, linux-arm-kernel, loongarch,
linuxppc-dev, linux-riscv, devicetree, kexec
On 6/8/2026 3:34 PM, Jinjie Ruan wrote:
> Use the newly introduced crash_prepare_headers() function to replace
> the existing prepare_elf_headers(), allocate cmem and exclude crash kernel
> memory in the crash core, which reduce code duplication.
>
> Only the following two architecture functions need to be implemented:
> - arch_get_system_nr_ranges(). Use for_each_mem_range to traverse
> and pre-count the max number of memory ranges.
>
> - arch_crash_populate_cmem(). Use for_each_mem_range to traverse
> and collect the memory ranges and fills them into cmem.
>
> Cc: Huacai Chen <chenhuacai@kernel.org>
> Cc: WANG Xuerui <kernel@xen0n.name>
> Cc: Youling Tang <tangyouling@kylinos.cn>
> Cc: Baoquan He <bhe@redhat.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
> arch/loongarch/kernel/machine_kexec_file.c | 40 +++++++---------------
> 1 file changed, 12 insertions(+), 28 deletions(-)
The below AI reported TOCTOU bug is an existing artifact and completely
unrelated to the rework here. Therefore, we will skip fixing it in this
series to avoid unnecessary noise.
Link:
https://lore.kernel.org/all/20260608075258.0F6D91F00893@smtp.kernel.org/
>
> diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c
> index 5584b798ba46..5412aa9f3568 100644
> --- a/arch/loongarch/kernel/machine_kexec_file.c
> +++ b/arch/loongarch/kernel/machine_kexec_file.c
> @@ -56,46 +56,30 @@ static void cmdline_add_initrd(struct kimage *image, unsigned long *cmdline_tmpl
> }
>
> #ifdef CONFIG_CRASH_DUMP
> -
> -static int prepare_elf_headers(void **addr, unsigned long *sz)
> +unsigned int arch_get_system_nr_ranges(void)
> {
> - int ret, nr_ranges;
> - uint64_t i;
> + int nr_ranges = 2; /* for exclusion of crashkernel region */
> phys_addr_t start, end;
> - struct crash_mem *cmem;
> + uint64_t i;
>
> - nr_ranges = 2; /* for exclusion of crashkernel region */
> for_each_mem_range(i, &start, &end)
> nr_ranges++;
>
> - cmem = kmalloc_flex(*cmem, ranges, nr_ranges);
> - if (!cmem)
> - return -ENOMEM;
> + return nr_ranges;
> +}
> +
> +int arch_crash_populate_cmem(struct crash_mem *cmem)
> +{
> + phys_addr_t start, end;
> + uint64_t i;
>
> - cmem->max_nr_ranges = nr_ranges;
> - cmem->nr_ranges = 0;
> for_each_mem_range(i, &start, &end) {
> cmem->ranges[cmem->nr_ranges].start = start;
> cmem->ranges[cmem->nr_ranges].end = end - 1;
> cmem->nr_ranges++;
> }
>
> - /* Exclude crashkernel region */
> - ret = crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end);
> - if (ret < 0)
> - goto out;
> -
> - if (crashk_low_res.end) {
> - ret = crash_exclude_mem_range(cmem, crashk_low_res.start, crashk_low_res.end);
> - if (ret < 0)
> - goto out;
> - }
> -
> - ret = crash_prepare_elf64_headers(cmem, true, addr, sz);
> -
> -out:
> - kfree(cmem);
> - return ret;
> + return 0;
> }
>
> /*
> @@ -163,7 +147,7 @@ int load_other_segments(struct kimage *image,
> void *headers;
> unsigned long headers_sz;
>
> - ret = prepare_elf_headers(&headers, &headers_sz);
> + ret = crash_prepare_headers(true, &headers, &headers_sz, NULL);
> if (ret < 0) {
> pr_err("Preparing elf core header failed\n");
> goto out_err;
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 08/10] powerpc/kexec_file: Use crash_exclude_core_ranges() helper
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 8:48 ` Breno Leitao
-1 siblings, 0 replies; 41+ messages in thread
From: Breno Leitao @ 2026-06-08 8:48 UTC (permalink / raw)
To: Jinjie Ruan
Cc: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
coxu, Liam.Howlett, ryan.roberts, osandov, jbohac, cfsworks,
tangyouling, sourabhjain, ritesh.list, adityag, liaoyuanhong,
seanjc, fuqiang.wang, ardb, chenjiahao16, guoren, x86, linux-doc,
linux-kernel, linux-arm-kernel, loongarch, linuxppc-dev,
linux-riscv, devicetree, kexec
On Mon, Jun 08, 2026 at 03:34:57PM +0800, Jinjie Ruan wrote:
> The crash memory exclude of crashk_res and crashk_cma memory on powerpc
> are almost identical to the generic crash_exclude_core_ranges().
>
> By introducing the architecture-specific arch_crash_exclude_mem_range()
> function with a default implementation of crash_exclude_mem_range(),
> and using crash_exclude_mem_range_guarded as powerpc's separate
> implementation, the generic crash_exclude_core_ranges() helper function
> can be reused.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Hari Bathini <hbathini@linux.ibm.com>
> Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
> Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Breno leitao <leitao@debian.org>
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 08/10] powerpc/kexec_file: Use crash_exclude_core_ranges() helper
@ 2026-06-08 8:48 ` Breno Leitao
0 siblings, 0 replies; 41+ messages in thread
From: Breno Leitao @ 2026-06-08 8:48 UTC (permalink / raw)
To: Jinjie Ruan
Cc: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, akpm, bhe, rppt,
pasha.tatashin, pratyush, ruirui.yang, rdunlap, peterz, feng.tang,
dapeng1.mi, kees, elver, kuba, lirongqing, ebiggers, paulmck,
coxu, Liam.Howlett, ryan.roberts, osandov, jbohac, cfsworks,
tangyouling, sourabhjain, ritesh.list, adityag, liaoyuanhong,
seanjc, fuqiang.wang, ardb, chenjiahao16, guoren, x86, linux-doc,
linux-kernel, linux-arm-kernel, loongarch, linuxppc-dev,
linux-riscv, devicetree, kexec
On Mon, Jun 08, 2026 at 03:34:57PM +0800, Jinjie Ruan wrote:
> The crash memory exclude of crashk_res and crashk_cma memory on powerpc
> are almost identical to the generic crash_exclude_core_ranges().
>
> By introducing the architecture-specific arch_crash_exclude_mem_range()
> function with a default implementation of crash_exclude_mem_range(),
> and using crash_exclude_mem_range_guarded as powerpc's separate
> implementation, the generic crash_exclude_core_ranges() helper function
> can be reused.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Hari Bathini <hbathini@linux.ibm.com>
> Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
> Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> Cc: Shivang Upadhyay <shivangu@linux.ibm.com>
> Acked-by: Baoquan He <bhe@redhat.com>
> Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Breno leitao <leitao@debian.org>
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 00/10] arm64/riscv: Add support for crashkernel CMA reservation
2026-06-08 7:34 ` Jinjie Ruan
@ 2026-06-08 16:10 ` Andrew Morton
-1 siblings, 0 replies; 41+ messages in thread
From: Andrew Morton @ 2026-06-08 16:10 UTC (permalink / raw)
To: Jinjie Ruan
Cc: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, bhe, rppt, pasha.tatashin,
pratyush, ruirui.yang, rdunlap, peterz, feng.tang, dapeng1.mi,
kees, elver, kuba, lirongqing, ebiggers, paulmck, leitao, coxu,
Liam.Howlett, ryan.roberts, osandov, jbohac, cfsworks,
tangyouling, sourabhjain, ritesh.list, adityag, liaoyuanhong,
seanjc, fuqiang.wang, ardb, chenjiahao16, guoren, x86, linux-doc,
linux-kernel, linux-arm-kernel, loongarch, linuxppc-dev,
linux-riscv, devicetree, kexec
On Mon, 8 Jun 2026 15:34:49 +0800 Jinjie Ruan <ruanjinjie@huawei.com> wrote:
> The crash memory allocation, and the exclude of crashk_res, crashk_low_res
> and crashk_cma memory are almost identical across different architectures,
> This patch set handle them in crash core in a general way, which eliminate
> a lot of duplication code.
>
> And add support for crashkernel CMA reservation for arm64 and riscv.
fyi, AI review might have found a bunch of issues in arch-specific
code, all of them pre-existing.
https://sashiko.dev/#/patchset/20260608073459.3119290-1-ruanjinjie@huawei.com
^ permalink raw reply [flat|nested] 41+ messages in thread
* Re: [PATCH v16 00/10] arm64/riscv: Add support for crashkernel CMA reservation
@ 2026-06-08 16:10 ` Andrew Morton
0 siblings, 0 replies; 41+ messages in thread
From: Andrew Morton @ 2026-06-08 16:10 UTC (permalink / raw)
To: Jinjie Ruan
Cc: corbet, skhan, catalin.marinas, will, chenhuacai, kernel, maddy,
mpe, npiggin, chleroy, pjw, palmer, aou, alex, tglx, mingo, bp,
dave.hansen, hpa, robh, saravanak, bhe, rppt, pasha.tatashin,
pratyush, ruirui.yang, rdunlap, peterz, feng.tang, dapeng1.mi,
kees, elver, kuba, lirongqing, ebiggers, paulmck, leitao, coxu,
Liam.Howlett, ryan.roberts, osandov, jbohac, cfsworks,
tangyouling, sourabhjain, ritesh.list, adityag, liaoyuanhong,
seanjc, fuqiang.wang, ardb, chenjiahao16, guoren, x86, linux-doc,
linux-kernel, linux-arm-kernel, loongarch, linuxppc-dev,
linux-riscv, devicetree, kexec
On Mon, 8 Jun 2026 15:34:49 +0800 Jinjie Ruan <ruanjinjie@huawei.com> wrote:
> The crash memory allocation, and the exclude of crashk_res, crashk_low_res
> and crashk_cma memory are almost identical across different architectures,
> This patch set handle them in crash core in a general way, which eliminate
> a lot of duplication code.
>
> And add support for crashkernel CMA reservation for arm64 and riscv.
fyi, AI review might have found a bunch of issues in arch-specific
code, all of them pre-existing.
https://sashiko.dev/#/patchset/20260608073459.3119290-1-ruanjinjie@huawei.com
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 41+ messages in thread
end of thread, other threads:[~2026-06-08 16:10 UTC | newest]
Thread overview: 41+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-06-08 7:34 [PATCH v16 00/10] arm64/riscv: Add support for crashkernel CMA reservation Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 01/10] riscv: kexec_file: Fix crashk_low_res not exclude bug Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:48 ` sashiko-bot
2026-06-08 8:05 ` Jinjie Ruan
2026-06-08 8:05 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 02/10] powerpc/crash: sort crash memory ranges before preparing elfcorehdr Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 03/10] crash: Add crash_prepare_headers() to exclude crash kernel memory Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 04/10] arm64: kexec_file: Use crash_prepare_headers() helper to simplify code Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:56 ` sashiko-bot
2026-06-08 8:07 ` Jinjie Ruan
2026-06-08 8:07 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 05/10] x86: " Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:47 ` sashiko-bot
2026-06-08 8:21 ` Jinjie Ruan
2026-06-08 8:21 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 06/10] riscv: " Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:54 ` sashiko-bot
2026-06-08 8:08 ` Jinjie Ruan
2026-06-08 8:08 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 07/10] LoongArch: " Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:52 ` sashiko-bot
2026-06-08 8:23 ` Jinjie Ruan
2026-06-08 8:23 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 08/10] powerpc/kexec_file: Use crash_exclude_core_ranges() helper Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 8:48 ` Breno Leitao
2026-06-08 8:48 ` Breno Leitao
2026-06-08 7:34 ` [PATCH v16 09/10] arm64: kexec_file: Add support for crashkernel CMA reservation Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 7:34 ` [PATCH v16 10/10] riscv: " Jinjie Ruan
2026-06-08 7:34 ` Jinjie Ruan
2026-06-08 16:10 ` [PATCH v16 00/10] arm64/riscv: " Andrew Morton
2026-06-08 16:10 ` Andrew Morton
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