* [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot
@ 2026-07-06 16:37 Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 1/5] x86/setup: remove unreachable memblock_reserve() return value check Sang-Heon Jeon
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: Sang-Heon Jeon @ 2026-07-06 16:37 UTC (permalink / raw)
To: rppt, Ard Biesheuvel, Borislav Petkov, Chris Zankel, Dave Hansen,
Ingo Molnar, John Paul Adrian Glaubitz, Madhavan Srinivasan,
Max Filippov, Michael Ellerman, Rich Felker, Thomas Gleixner,
Yoshinori Sato
Cc: linux-mm, Sang-Heon Jeon, Christophe Leroy (CS GROUP),
H. Peter Anvin, Ilias Apalodimas, linux-efi, linux-kernel,
linuxppc-dev, linux-sh, Nicholas Piggin, x86
memblock_reserve() can only return an error after memblock_allow_resize()
has been called. Before that it either succeeds or panics, never returning
an error.
Before memblock_allow_resize() is called, the return value checks of
memblock_reserve() are unreachable and can be removed.
All the call sites are in different trees, so I split the change into one
patch per arch/subsystem. The patches are independent and can be applied
separately.
---
Changes from v1 [1]
- add reviewed-by tag
- rebased onto latest memblock for-next
[1] https://lore.kernel.org/all/20260616182959.2429774-1-ekffu200098@gmail.com/
---
Hello Mike,
Like the previous memblock cleanup series, could you review and take this patch series to the memblock tree?
Thank you for taking valuable time.
Best Regards,
Sang-Heon Jeon
---
Sang-Heon Jeon (5):
x86/setup: remove unreachable memblock_reserve() return value check
sh: remove unreachable memblock_reserve() return value check
powerpc/fadump: remove unreachable memblock_reserve() return value
checks
xtensa: remove unreachable memblock_reserve() return value checks
Revert "tpm: do not ignore memblock_reserve return value"
arch/powerpc/kernel/fadump.c | 14 +++-----------
arch/sh/kernel/machine_kexec.c | 7 +------
arch/x86/kernel/setup.c | 7 ++-----
arch/xtensa/kernel/setup.c | 13 +++++++------
drivers/firmware/efi/tpm.c | 7 +------
5 files changed, 14 insertions(+), 34 deletions(-)
--
2.43.0
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 1/5] x86/setup: remove unreachable memblock_reserve() return value check
2026-07-06 16:37 [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot Sang-Heon Jeon
@ 2026-07-06 16:37 ` Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 2/5] sh: " Sang-Heon Jeon
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Sang-Heon Jeon @ 2026-07-06 16:37 UTC (permalink / raw)
To: rppt, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Cc: linux-mm, Sang-Heon Jeon, Ard Biesheuvel, Chris Zankel,
H. Peter Anvin, John Paul Adrian Glaubitz, linux-kernel,
Madhavan Srinivasan, Max Filippov, Michael Ellerman, Rich Felker,
x86, Yoshinori Sato
trim_snb_memory() runs from early_reserve_memory() in setup_arch(), before
e820__memblock_setup() calls memblock_allow_resize(). At that point
memblock_reserve() either succeeds or panics, never returning an error.
Therefore the return value check is unreachable, so remove it and the
related logic.
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
arch/x86/kernel/setup.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 46882ce79c3a..f9395bc632ca 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -742,11 +742,8 @@ static void __init trim_snb_memory(void)
* setup_arch(), so there is no need to reserve it here.
*/
- for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
- if (memblock_reserve(bad_pages[i], PAGE_SIZE))
- printk(KERN_WARNING "failed to reserve 0x%08lx\n",
- bad_pages[i]);
- }
+ for (i = 0; i < ARRAY_SIZE(bad_pages); i++)
+ memblock_reserve(bad_pages[i], PAGE_SIZE);
}
static void __init trim_bios_range(void)
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/5] sh: remove unreachable memblock_reserve() return value check
2026-07-06 16:37 [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 1/5] x86/setup: remove unreachable memblock_reserve() return value check Sang-Heon Jeon
@ 2026-07-06 16:37 ` Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 3/5] powerpc/fadump: remove unreachable memblock_reserve() return value checks Sang-Heon Jeon
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Sang-Heon Jeon @ 2026-07-06 16:37 UTC (permalink / raw)
To: rppt, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz
Cc: linux-mm, Sang-Heon Jeon, Ard Biesheuvel, Borislav Petkov,
Chris Zankel, Dave Hansen, Ingo Molnar, linux-kernel, linux-sh,
Madhavan Srinivasan, Max Filippov, Michael Ellerman,
Thomas Gleixner
reserve_crashkernel() runs from early_reserve_mem() in paging_init(),
before the same function calls memblock_allow_resize(). At that point
memblock_reserve() either succeeds or panics, never returning an error.
Therefore the return value check is unreachable, so remove it and the
related logic.
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
arch/sh/kernel/machine_kexec.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/arch/sh/kernel/machine_kexec.c b/arch/sh/kernel/machine_kexec.c
index 37073ca1e0ad..ba9c412f14d9 100644
--- a/arch/sh/kernel/machine_kexec.c
+++ b/arch/sh/kernel/machine_kexec.c
@@ -165,12 +165,7 @@ void __init reserve_crashkernel(void)
goto disable;
}
} else {
- ret = memblock_reserve(crashk_res.start, crash_size);
- if (unlikely(ret < 0)) {
- pr_err("crashkernel reservation failed - "
- "memory is in use\n");
- goto disable;
- }
+ memblock_reserve(crashk_res.start, crash_size);
}
crashk_res.end = crashk_res.start + crash_size - 1;
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 3/5] powerpc/fadump: remove unreachable memblock_reserve() return value checks
2026-07-06 16:37 [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 1/5] x86/setup: remove unreachable memblock_reserve() return value check Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 2/5] sh: " Sang-Heon Jeon
@ 2026-07-06 16:37 ` Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 4/5] xtensa: " Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 5/5] Revert "tpm: do not ignore memblock_reserve return value" Sang-Heon Jeon
4 siblings, 0 replies; 6+ messages in thread
From: Sang-Heon Jeon @ 2026-07-06 16:37 UTC (permalink / raw)
To: rppt, Madhavan Srinivasan, Michael Ellerman
Cc: linux-mm, Sang-Heon Jeon, Ard Biesheuvel, Borislav Petkov,
Christophe Leroy (CS GROUP), Chris Zankel, Dave Hansen,
Ingo Molnar, John Paul Adrian Glaubitz, linux-kernel,
linuxppc-dev, Max Filippov, Nicholas Piggin, Rich Felker,
Thomas Gleixner, Yoshinori Sato, Mukesh Kumar Chaurasiya
fadump_append_bootargs() and fadump_reserve_mem() both run from
early_init_devtree(), before it calls memblock_allow_resize(). At that
point memblock_reserve() either succeeds or panics, never returning an
error.
Therefore the return value checks are unreachable, so remove them and the
related logic.
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras@gmail.com>
---
arch/powerpc/kernel/fadump.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 7f79c9aea4a9..1629a82b9528 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -154,13 +154,8 @@ void __init fadump_append_bootargs(void)
if (!fw_dump.dump_active || !fw_dump.param_area_supported || !fw_dump.param_area)
return;
- if (fw_dump.param_area < fw_dump.boot_mem_top) {
- if (memblock_reserve(fw_dump.param_area, COMMAND_LINE_SIZE)) {
- pr_warn("WARNING: Can't use additional parameters area!\n");
- fw_dump.param_area = 0;
- return;
- }
- }
+ if (fw_dump.param_area < fw_dump.boot_mem_top)
+ memblock_reserve(fw_dump.param_area, COMMAND_LINE_SIZE);
append_args = (char *)fw_dump.param_area;
len = strlen(boot_command_line);
@@ -632,10 +627,7 @@ int __init fadump_reserve_mem(void)
(fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0))
goto error_out;
- if (memblock_reserve(base, size)) {
- pr_err("Failed to reserve memory!\n");
- goto error_out;
- }
+ memblock_reserve(base, size);
pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n",
(size >> 20), base, (memblock_phys_mem_size() >> 20));
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 4/5] xtensa: remove unreachable memblock_reserve() return value checks
2026-07-06 16:37 [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot Sang-Heon Jeon
` (2 preceding siblings ...)
2026-07-06 16:37 ` [PATCH v2 3/5] powerpc/fadump: remove unreachable memblock_reserve() return value checks Sang-Heon Jeon
@ 2026-07-06 16:37 ` Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 5/5] Revert "tpm: do not ignore memblock_reserve return value" Sang-Heon Jeon
4 siblings, 0 replies; 6+ messages in thread
From: Sang-Heon Jeon @ 2026-07-06 16:37 UTC (permalink / raw)
To: rppt, Chris Zankel, Max Filippov
Cc: linux-mm, Sang-Heon Jeon, Ard Biesheuvel, Borislav Petkov,
Dave Hansen, Ingo Molnar, John Paul Adrian Glaubitz, linux-kernel,
Madhavan Srinivasan, Michael Ellerman, Rich Felker,
Thomas Gleixner, Yoshinori Sato
mem_reserve() wraps memblock_reserve(), and its callers check the return
value. xtensa never calls memblock_allow_resize(), so memblock_reserve()
either succeeds or panics, never returning an error.
Therefore the return value checks are unreachable, so remove them and make
mem_reserve() return void.
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
arch/xtensa/kernel/setup.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index f72e280363be..c7367b81cc36 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -268,10 +268,10 @@ void __init init_arch(bp_tag_t *bp_start)
* Initialize system. Setup memory and reserve regions.
*/
-static inline int __init_memblock mem_reserve(unsigned long start,
- unsigned long end)
+static inline void __init_memblock mem_reserve(unsigned long start,
+ unsigned long end)
{
- return memblock_reserve(start, end - start);
+ memblock_reserve(start, end - start);
}
void __init setup_arch(char **cmdline_p)
@@ -290,11 +290,12 @@ void __init setup_arch(char **cmdline_p)
/* Reserve some memory regions */
#ifdef CONFIG_BLK_DEV_INITRD
- if (initrd_start < initrd_end &&
- !mem_reserve(__pa(initrd_start), __pa(initrd_end)))
+ if (initrd_start < initrd_end) {
+ mem_reserve(__pa(initrd_start), __pa(initrd_end));
initrd_below_start_ok = 1;
- else
+ } else {
initrd_start = 0;
+ }
#endif
mem_reserve(__pa(_stext), __pa(_end));
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 5/5] Revert "tpm: do not ignore memblock_reserve return value"
2026-07-06 16:37 [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot Sang-Heon Jeon
` (3 preceding siblings ...)
2026-07-06 16:37 ` [PATCH v2 4/5] xtensa: " Sang-Heon Jeon
@ 2026-07-06 16:37 ` Sang-Heon Jeon
4 siblings, 0 replies; 6+ messages in thread
From: Sang-Heon Jeon @ 2026-07-06 16:37 UTC (permalink / raw)
To: rppt, Ard Biesheuvel
Cc: linux-mm, Sang-Heon Jeon, Borislav Petkov, Chris Zankel,
Dave Hansen, Ilias Apalodimas, Ingo Molnar,
John Paul Adrian Glaubitz, linux-efi, linux-kernel,
Madhavan Srinivasan, Max Filippov, Michael Ellerman, Rich Felker,
Thomas Gleixner, Yoshinori Sato
This reverts commit c33c28f9f6e017702374e1ab907dfa5a63db5301.
efi_tpm_eventlog_init() runs from efi_config_parse_tables() during early
EFI initialization, before memblock_allow_resize(). At that point
memblock_reserve() either succeeds or panics, never returning an error.
Therefore the return value check is unreachable, so restore the original
unconditional memblock_reserve().
No functional change.
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
drivers/firmware/efi/tpm.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
index cdd431027065..288bcf7a5b99 100644
--- a/drivers/firmware/efi/tpm.c
+++ b/drivers/firmware/efi/tpm.c
@@ -61,12 +61,7 @@ int __init efi_tpm_eventlog_init(void)
}
tbl_size = sizeof(*log_tbl) + log_tbl->size;
- if (memblock_reserve(efi.tpm_log, tbl_size)) {
- pr_err("TPM Event Log memblock reserve fails (0x%lx, 0x%x)\n",
- efi.tpm_log, tbl_size);
- ret = -ENOMEM;
- goto out;
- }
+ memblock_reserve(efi.tpm_log, tbl_size);
if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) {
pr_info("TPM Final Events table not present\n");
--
2.43.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
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2026-07-06 16:37 [PATCH v2 0/5] treewide: remove unreachable memblock_reserve() return value checks in early boot Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 1/5] x86/setup: remove unreachable memblock_reserve() return value check Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 2/5] sh: " Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 3/5] powerpc/fadump: remove unreachable memblock_reserve() return value checks Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 4/5] xtensa: " Sang-Heon Jeon
2026-07-06 16:37 ` [PATCH v2 5/5] Revert "tpm: do not ignore memblock_reserve return value" Sang-Heon Jeon
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