* [PATCH v4 0/3] kallsyms: remove special handling for CONFIG_ARM
@ 2016-02-09 15:13 Ard Biesheuvel
2016-02-09 15:13 ` [PATCH v4 1/3] ARM: move .vectors and .stubs sections back into the kernel VMA Ard Biesheuvel
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: Ard Biesheuvel @ 2016-02-09 15:13 UTC (permalink / raw)
To: linux-arm-kernel
The kallsyms symbol address table generation contains a workaround for
CONFIG_ARM to address an issue with perf when it sees symbols whose
addresses are close to 0x0. The workaround is only enabled if XIP_KERNEL=n,
not because the issue itself only exists in that case, but because the
chosen workaround cannot deal with [_stext,_etext] living below PAGE_OFFSET.
So let's fix this properly, by emitting the stubs symbols at a more reasonable
offset, which is more likely to be the actual location of the vectors and stubs
sections at runtime, and will prevent the symbols from being mistaken for
userland symbols by perf.
Changes since v3:
- rebased onto -next, which contains a patch that moves the XIP handling to a
separate linker script (patch #1)
Changes since v2:
- Move back to the original arrangement, where .stubs follows .vectors, and both
are emitted outside of the ordinary kernel VMA space
- Move .vectors and .stubs sections to VMA 0xffff0000/0xffff1000, respectively.
As Russell pointed out, this is the most reasonable value, since modern CPUs
actually execute the vectors and stubs from there, and it fixes the kallsyms
perf issue all the same.
- Rebased onto latest -next, which contains related ARM patch 8514/1, and
updated kallsyms base relative patches (queued via akpm's tree)
Changes since v1:
- added Nico's ack
- use PROVIDE() for vector_fiq_offset since vector_fiq itself is not always
defined
- put __stubs_start/_end inside the section definition so that the value of the
start symbol equals the start of the section after alignment (fixes an issue
on XIP spotted by Chris)
Patch #1 moves the .stubs and .vectors section back into the kernel VMA, while
preserving the guaranteed virtual offset of 4 KB. This results in all symbols
that kallsyms sees to be in a reasonable interval.
Patch #2 removes the special case for CONFIG_ARM && !CONFIG_XIP_KERNEL in the
invocation of scripts/kallsyms
Patch #3 removes the now unused --page-offset command line argument handling
from scripts/kallsyms.c
Ard Biesheuvel (3):
ARM: move .vectors and .stubs sections back into the kernel VMA
kallsyms: remove special lower address limit for CONFIG_ARM
kallsyms: remove --page-offset command line option
arch/arm/kernel/entry-armv.S | 3 +--
arch/arm/kernel/vmlinux-xip.lds.S | 6 ++++--
arch/arm/kernel/vmlinux.lds.S | 6 ++++--
scripts/kallsyms.c | 8 --------
scripts/link-vmlinux.sh | 4 ----
5 files changed, 9 insertions(+), 18 deletions(-)
--
2.5.0
^ permalink raw reply [flat|nested] 9+ messages in thread* [PATCH v4 1/3] ARM: move .vectors and .stubs sections back into the kernel VMA 2016-02-09 15:13 [PATCH v4 0/3] kallsyms: remove special handling for CONFIG_ARM Ard Biesheuvel @ 2016-02-09 15:13 ` Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 2/3] kallsyms: remove special lower address limit for CONFIG_ARM Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 3/3] kallsyms: remove --page-offset command line option Ard Biesheuvel 2 siblings, 0 replies; 9+ messages in thread From: Ard Biesheuvel @ 2016-02-09 15:13 UTC (permalink / raw) To: linux-arm-kernel Commit b9b32bf70f2f ("ARM: use linker magic for vectors and vector stubs") updated the linker script to emit the .vectors and .stubs sections into a VMA range that is zero based and disjoint from the normal static kernel region. The reason for that was that this way, the sections can be placed exactly 4 KB apart, while the payload of the .vectors section is only 32 bytes. Since the symbols that are part of the .stubs section are emitted into the kallsyms table, they appear with zero based addresses as well, e.g., 00001004 t vector_rst 00001020 t vector_irq 000010a0 t vector_dabt 00001120 t vector_pabt 000011a0 t vector_und 00001220 t vector_addrexcptn 00001240 t vector_fiq 00001240 T vector_fiq_offset As this confuses perf when it accesses the kallsyms tables, commit 7122c3e9154b ("scripts/link-vmlinux.sh: only filter kernel symbols for arm") implemented a somewhat ugly special case for ARM, where the value of CONFIG_PAGE_OFFSET is passed to scripts/kallsyms, and symbols whose addresses are below it are filtered out. Note that this special case only applies to CONFIG_XIP_KERNEL=n, not because the issue the patch addresses exists only in that case, but because finding a limit below which to apply the filtering is not entirely straightforward. Since the .vectors and .stubs sections contain position independent code that is never executed in place, we can emit it at its most likely runtime VMA (for more recent CPUs), which is 0xffff0000 for the vector table and 0xffff1000 for the stubs. Not only does this fix the perf issue with kallsyms, allowing us to drop the special case in scripts/kallsyms entirely, it also gives debuggers a more realistic view of the address space, and setting breakpoints or single stepping through code in the vector table or the stubs is more likely to work as expected on CPUs that use a high vector address. E.g., 00001240 A vector_fiq_offset ... c0c35000 T __init_begin c0c35000 T __vectors_start c0c35020 T __stubs_start c0c35020 T __vectors_end c0c352e0 T _sinittext c0c352e0 T __stubs_end ... ffff1004 t vector_rst ffff1020 t vector_irq ffff10a0 t vector_dabt ffff1120 t vector_pabt ffff11a0 t vector_und ffff1220 t vector_addrexcptn ffff1240 T vector_fiq (Note that vector_fiq_offset is now an absolute symbol, which kallsyms already ignores by default) The LMA footprint is identical with or without this change, only the VMAs are different: Before: Idx Name Size VMA LMA File off Algn ... 14 .notes 00000024 c0c34020 c0c34020 00a34020 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 15 .vectors 00000020 00000000 c0c35000 00a40000 2**1 CONTENTS, ALLOC, LOAD, READONLY, CODE 16 .stubs 000002c0 00001000 c0c35020 00a41000 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE 17 .init.text 0006b1b8 c0c352e0 c0c352e0 00a452e0 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE ... After: Idx Name Size VMA LMA File off Algn ... 14 .notes 00000024 c0c34020 c0c34020 00a34020 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 15 .vectors 00000020 ffff0000 c0c35000 00a40000 2**1 CONTENTS, ALLOC, LOAD, READONLY, CODE 16 .stubs 000002c0 ffff1000 c0c35020 00a41000 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE 17 .init.text 0006b1b8 c0c352e0 c0c352e0 00a452e0 2**5 CONTENTS, ALLOC, LOAD, READONLY, CODE ... Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Chris Brandt <chris.brandt@renesas.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/kernel/entry-armv.S | 3 +-- arch/arm/kernel/vmlinux-xip.lds.S | 6 ++++-- arch/arm/kernel/vmlinux.lds.S | 6 ++++-- 3 files changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 788e40c1254f..e2550500486d 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -1201,8 +1201,7 @@ vector_addrexcptn: .long __fiq_svc @ e .long __fiq_svc @ f - .globl vector_fiq_offset - .equ vector_fiq_offset, vector_fiq + .globl vector_fiq .section .vectors, "ax", %progbits .L__vectors_start: diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S index 6f59ef290289..7b1ded6fb628 100644 --- a/arch/arm/kernel/vmlinux-xip.lds.S +++ b/arch/arm/kernel/vmlinux-xip.lds.S @@ -154,19 +154,21 @@ SECTIONS * only thing that matters is their relative offsets */ __vectors_start = .; - .vectors 0 : AT(__vectors_start) { + .vectors 0xffff0000 : AT(__vectors_start) { *(.vectors) } . = __vectors_start + SIZEOF(.vectors); __vectors_end = .; __stubs_start = .; - .stubs 0x1000 : AT(__stubs_start) { + .stubs ADDR(.vectors) + 0x1000 : AT(__stubs_start) { *(.stubs) } . = __stubs_start + SIZEOF(.stubs); __stubs_end = .; + PROVIDE(vector_fiq_offset = vector_fiq - ADDR(.vectors)); + INIT_TEXT_SECTION(8) .exit.text : { ARM_EXIT_KEEP(EXIT_TEXT) diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index cdc84693091b..e087a2ed112b 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -164,19 +164,21 @@ SECTIONS * only thing that matters is their relative offsets */ __vectors_start = .; - .vectors 0 : AT(__vectors_start) { + .vectors 0xffff0000 : AT(__vectors_start) { *(.vectors) } . = __vectors_start + SIZEOF(.vectors); __vectors_end = .; __stubs_start = .; - .stubs 0x1000 : AT(__stubs_start) { + .stubs ADDR(.vectors) + 0x1000 : AT(__stubs_start) { *(.stubs) } . = __stubs_start + SIZEOF(.stubs); __stubs_end = .; + PROVIDE(vector_fiq_offset = vector_fiq - ADDR(.vectors)); + INIT_TEXT_SECTION(8) .exit.text : { ARM_EXIT_KEEP(EXIT_TEXT) -- 2.5.0 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v4 2/3] kallsyms: remove special lower address limit for CONFIG_ARM 2016-02-09 15:13 [PATCH v4 0/3] kallsyms: remove special handling for CONFIG_ARM Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 1/3] ARM: move .vectors and .stubs sections back into the kernel VMA Ard Biesheuvel @ 2016-02-09 15:13 ` Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 3/3] kallsyms: remove --page-offset command line option Ard Biesheuvel 2 siblings, 0 replies; 9+ messages in thread From: Ard Biesheuvel @ 2016-02-09 15:13 UTC (permalink / raw) To: linux-arm-kernel Now that we no longer emit .stubs symbols into a section VMA loaded at absolute address 0x1000, we can drop the ARM-specific override that sets a lower limit based on CONFIG_PAGE_OFFSET, below which symbols are filtered from the kallsyms output. Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Chris Brandt <chris.brandt@renesas.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- scripts/link-vmlinux.sh | 4 ---- 1 file changed, 4 deletions(-) diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh index b0281f32f075..4846ecb9764c 100755 --- a/scripts/link-vmlinux.sh +++ b/scripts/link-vmlinux.sh @@ -82,10 +82,6 @@ kallsyms() kallsymopt="${kallsymopt} --all-symbols" fi - if [ -n "${CONFIG_ARM}" ] && [ -z "${CONFIG_XIP_KERNEL}" ] && [ -n "${CONFIG_PAGE_OFFSET}" ]; then - kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET" - fi - if [ -n "${CONFIG_X86_64}" ] && [ -n "${CONFIG_SMP}" ]; then kallsymopt="${kallsymopt} --absolute-percpu" fi -- 2.5.0 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v4 3/3] kallsyms: remove --page-offset command line option 2016-02-09 15:13 [PATCH v4 0/3] kallsyms: remove special handling for CONFIG_ARM Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 1/3] ARM: move .vectors and .stubs sections back into the kernel VMA Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 2/3] kallsyms: remove special lower address limit for CONFIG_ARM Ard Biesheuvel @ 2016-02-09 15:13 ` Ard Biesheuvel 2016-02-09 16:09 ` Chris Brandt 2 siblings, 1 reply; 9+ messages in thread From: Ard Biesheuvel @ 2016-02-09 15:13 UTC (permalink / raw) To: linux-arm-kernel The --page-offset command line option was only used for ARM, to filter symbol addresses below CONFIG_PAGE_OFFSET. This is no longer needed, so remove the functionality altogether. Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Chris Brandt <chris.brandt@renesas.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- scripts/kallsyms.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 02473b71643b..32c8d43590af 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -63,7 +63,6 @@ static unsigned int table_size, table_cnt; static int all_symbols = 0; static int absolute_percpu = 0; static char symbol_prefix_char = '\0'; -static unsigned long long kernel_start_addr = 0; static int base_relative = 0; int token_profit[0x10000]; @@ -228,10 +227,6 @@ static int symbol_valid(struct sym_entry *s) int i; char *sym_name = (char *)s->sym + 1; - - if (s->addr < kernel_start_addr) - return 0; - /* skip prefix char */ if (symbol_prefix_char && *sym_name == symbol_prefix_char) sym_name++; @@ -774,9 +769,6 @@ int main(int argc, char **argv) if ((*p == '"' && *(p+2) == '"') || (*p == '\'' && *(p+2) == '\'')) p++; symbol_prefix_char = *p; - } else if (strncmp(argv[i], "--page-offset=", 14) == 0) { - const char *p = &argv[i][14]; - kernel_start_addr = strtoull(p, NULL, 16); } else if (strcmp(argv[i], "--base-relative") == 0) base_relative = 1; else -- 2.5.0 ^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v4 3/3] kallsyms: remove --page-offset command line option 2016-02-09 15:13 ` [PATCH v4 3/3] kallsyms: remove --page-offset command line option Ard Biesheuvel @ 2016-02-09 16:09 ` Chris Brandt 2016-02-09 16:17 ` Ard Biesheuvel 0 siblings, 1 reply; 9+ messages in thread From: Chris Brandt @ 2016-02-09 16:09 UTC (permalink / raw) To: linux-arm-kernel On 9 Feb 2016, Ard Biesheuvel wrote: >diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c >index 02473b71643b..32c8d43590af 100644 >--- a/scripts/kallsyms.c >+++ b/scripts/kallsyms.c >@@ -63,7 +63,6 @@ static unsigned int table_size, table_cnt; > static int all_symbols = 0; > static int absolute_percpu = 0; > static char symbol_prefix_char = '\0'; >-static unsigned long long kernel_start_addr = 0; > static int base_relative = 0; You removed kernel_start_addr, but you didn't remove all the instances of it in the file (you did remove them all in V2 though). So, now I get: CC scripts/mod/devicetable-offsets.s ../scripts/kallsyms.c: In function 'record_relative_base': ../scripts/kallsyms.c:740:6: error: 'kernel_start_addr' undeclared (first use in this function) if (kernel_start_addr > 0) { ^ ../scripts/kallsyms.c:740:6: note: each undeclared identifier is reported only once for each function it appears in make[2]: *** [scripts/kallsyms] Error 1 Chris ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v4 3/3] kallsyms: remove --page-offset command line option 2016-02-09 16:09 ` Chris Brandt @ 2016-02-09 16:17 ` Ard Biesheuvel 2016-02-09 19:28 ` Nicolas Pitre 0 siblings, 1 reply; 9+ messages in thread From: Ard Biesheuvel @ 2016-02-09 16:17 UTC (permalink / raw) To: linux-arm-kernel On 9 February 2016 at 17:09, Chris Brandt <Chris.Brandt@renesas.com> wrote: > On 9 Feb 2016, Ard Biesheuvel wrote: > >>diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c >>index 02473b71643b..32c8d43590af 100644 >>--- a/scripts/kallsyms.c >>+++ b/scripts/kallsyms.c >>@@ -63,7 +63,6 @@ static unsigned int table_size, table_cnt; >> static int all_symbols = 0; >> static int absolute_percpu = 0; >> static char symbol_prefix_char = '\0'; >>-static unsigned long long kernel_start_addr = 0; >> static int base_relative = 0; > > > > You removed kernel_start_addr, but you didn't remove all the instances of it in the file (you did remove them all in V2 though). > > So, now I get: > > CC scripts/mod/devicetable-offsets.s > ../scripts/kallsyms.c: In function 'record_relative_base': > ../scripts/kallsyms.c:740:6: error: 'kernel_start_addr' undeclared (first use in this function) > if (kernel_start_addr > 0) { > ^ > ../scripts/kallsyms.c:740:6: note: each undeclared identifier is reported only once for each function it appears in > make[2]: *** [scripts/kallsyms] Error 1 > That is because this patch http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table-v5.patch is also in flight, via akpm's tree, and is expected to hit -next tomorrow. That patch removes this reference (or alternatively, will not introduce it anymore if akpm decides to fold it into http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table.patch before submitting it) Going forward, it probably makes sense to only submit #1 of this series for v4.6, and queue the remaining two after the merge window. Thanks for testing btw, Ard. ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v4 3/3] kallsyms: remove --page-offset command line option 2016-02-09 16:17 ` Ard Biesheuvel @ 2016-02-09 19:28 ` Nicolas Pitre 2016-02-09 20:18 ` Ard Biesheuvel 0 siblings, 1 reply; 9+ messages in thread From: Nicolas Pitre @ 2016-02-09 19:28 UTC (permalink / raw) To: linux-arm-kernel On Tue, 9 Feb 2016, Ard Biesheuvel wrote: > On 9 February 2016 at 17:09, Chris Brandt <Chris.Brandt@renesas.com> wrote: > > On 9 Feb 2016, Ard Biesheuvel wrote: > > > >>diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c > >>index 02473b71643b..32c8d43590af 100644 > >>--- a/scripts/kallsyms.c > >>+++ b/scripts/kallsyms.c > >>@@ -63,7 +63,6 @@ static unsigned int table_size, table_cnt; > >> static int all_symbols = 0; > >> static int absolute_percpu = 0; > >> static char symbol_prefix_char = '\0'; > >>-static unsigned long long kernel_start_addr = 0; > >> static int base_relative = 0; > > > > > > > > You removed kernel_start_addr, but you didn't remove all the instances of it in the file (you did remove them all in V2 though). > > > > So, now I get: > > > > CC scripts/mod/devicetable-offsets.s > > ../scripts/kallsyms.c: In function 'record_relative_base': > > ../scripts/kallsyms.c:740:6: error: 'kernel_start_addr' undeclared (first use in this function) > > if (kernel_start_addr > 0) { > > ^ > > ../scripts/kallsyms.c:740:6: note: each undeclared identifier is reported only once for each function it appears in > > make[2]: *** [scripts/kallsyms] Error 1 > > > > That is because this patch > > http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table-v5.patch > > is also in flight, via akpm's tree, and is expected to hit -next > tomorrow. That patch removes this reference (or alternatively, will > not introduce it anymore if akpm decides to fold it into > http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table.patch > before submitting it) > > Going forward, it probably makes sense to only submit #1 of this > series for v4.6, and queue the remaining two after the merge window. Well... If akpm agrees, you could get those patches back and create a tree of your own with all ACKs for this work to avoi all this patch ordering dependency nightmare (including the work that depends on this) and submit it upstream (to Linus maybe?) while having it merged in linux-next in the mean time. Nicolas ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v4 3/3] kallsyms: remove --page-offset command line option 2016-02-09 19:28 ` Nicolas Pitre @ 2016-02-09 20:18 ` Ard Biesheuvel 2016-02-09 20:45 ` Nicolas Pitre 0 siblings, 1 reply; 9+ messages in thread From: Ard Biesheuvel @ 2016-02-09 20:18 UTC (permalink / raw) To: linux-arm-kernel On 9 February 2016 at 20:28, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > On Tue, 9 Feb 2016, Ard Biesheuvel wrote: > >> On 9 February 2016 at 17:09, Chris Brandt <Chris.Brandt@renesas.com> wrote: >> > On 9 Feb 2016, Ard Biesheuvel wrote: >> > >> >>diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c >> >>index 02473b71643b..32c8d43590af 100644 >> >>--- a/scripts/kallsyms.c >> >>+++ b/scripts/kallsyms.c >> >>@@ -63,7 +63,6 @@ static unsigned int table_size, table_cnt; >> >> static int all_symbols = 0; >> >> static int absolute_percpu = 0; >> >> static char symbol_prefix_char = '\0'; >> >>-static unsigned long long kernel_start_addr = 0; >> >> static int base_relative = 0; >> > >> > >> > >> > You removed kernel_start_addr, but you didn't remove all the instances of it in the file (you did remove them all in V2 though). >> > >> > So, now I get: >> > >> > CC scripts/mod/devicetable-offsets.s >> > ../scripts/kallsyms.c: In function 'record_relative_base': >> > ../scripts/kallsyms.c:740:6: error: 'kernel_start_addr' undeclared (first use in this function) >> > if (kernel_start_addr > 0) { >> > ^ >> > ../scripts/kallsyms.c:740:6: note: each undeclared identifier is reported only once for each function it appears in >> > make[2]: *** [scripts/kallsyms] Error 1 >> > >> >> That is because this patch >> >> http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table-v5.patch >> >> is also in flight, via akpm's tree, and is expected to hit -next >> tomorrow. That patch removes this reference (or alternatively, will >> not introduce it anymore if akpm decides to fold it into >> http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table.patch >> before submitting it) >> >> Going forward, it probably makes sense to only submit #1 of this >> series for v4.6, and queue the remaining two after the merge window. > > Well... If akpm agrees, you could get those patches back and create a > tree of your own with all ACKs for this work to avoi all this patch > ordering dependency nightmare (including the work that depends on this) > and submit it upstream (to Linus maybe?) while having it merged in > linux-next in the mean time. > All these changes are related to my KASLR series for arm64 in one way or the other, some of which is en route via akpm's tree (including the generic kallsyms changes that these patches are based on) and some via Catalin's tree. If Russell is ok to take this #1 for v4.6, I am happy to sit on the remaining two for a while (which essentially only remove dead code once #1 is applied) Thanks, Ard. ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v4 3/3] kallsyms: remove --page-offset command line option 2016-02-09 20:18 ` Ard Biesheuvel @ 2016-02-09 20:45 ` Nicolas Pitre 0 siblings, 0 replies; 9+ messages in thread From: Nicolas Pitre @ 2016-02-09 20:45 UTC (permalink / raw) To: linux-arm-kernel On Tue, 9 Feb 2016, Ard Biesheuvel wrote: > On 9 February 2016 at 20:28, Nicolas Pitre <nicolas.pitre@linaro.org> wrote: > > On Tue, 9 Feb 2016, Ard Biesheuvel wrote: > > > >> On 9 February 2016 at 17:09, Chris Brandt <Chris.Brandt@renesas.com> wrote: > >> > On 9 Feb 2016, Ard Biesheuvel wrote: > >> > > >> >>diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c > >> >>index 02473b71643b..32c8d43590af 100644 > >> >>--- a/scripts/kallsyms.c > >> >>+++ b/scripts/kallsyms.c > >> >>@@ -63,7 +63,6 @@ static unsigned int table_size, table_cnt; > >> >> static int all_symbols = 0; > >> >> static int absolute_percpu = 0; > >> >> static char symbol_prefix_char = '\0'; > >> >>-static unsigned long long kernel_start_addr = 0; > >> >> static int base_relative = 0; > >> > > >> > > >> > > >> > You removed kernel_start_addr, but you didn't remove all the instances of it in the file (you did remove them all in V2 though). > >> > > >> > So, now I get: > >> > > >> > CC scripts/mod/devicetable-offsets.s > >> > ../scripts/kallsyms.c: In function 'record_relative_base': > >> > ../scripts/kallsyms.c:740:6: error: 'kernel_start_addr' undeclared (first use in this function) > >> > if (kernel_start_addr > 0) { > >> > ^ > >> > ../scripts/kallsyms.c:740:6: note: each undeclared identifier is reported only once for each function it appears in > >> > make[2]: *** [scripts/kallsyms] Error 1 > >> > > >> > >> That is because this patch > >> > >> http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table-v5.patch > >> > >> is also in flight, via akpm's tree, and is expected to hit -next > >> tomorrow. That patch removes this reference (or alternatively, will > >> not introduce it anymore if akpm decides to fold it into > >> http://ozlabs.org/~akpm/mmots/broken-out/kallsyms-add-support-for-relative-offsets-in-kallsyms-address-table.patch > >> before submitting it) > >> > >> Going forward, it probably makes sense to only submit #1 of this > >> series for v4.6, and queue the remaining two after the merge window. > > > > Well... If akpm agrees, you could get those patches back and create a > > tree of your own with all ACKs for this work to avoi all this patch > > ordering dependency nightmare (including the work that depends on this) > > and submit it upstream (to Linus maybe?) while having it merged in > > linux-next in the mean time. > > > > All these changes are related to my KASLR series for arm64 in one way > or the other, some of which is en route via akpm's tree (including the > generic kallsyms changes that these patches are based on) and some via > Catalin's tree. If Russell is ok to take this #1 for v4.6, I am happy > to sit on the remaining two for a while (which essentially only remove > dead code once #1 is applied) OK makes sense. Nicolas ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2016-02-09 20:45 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-02-09 15:13 [PATCH v4 0/3] kallsyms: remove special handling for CONFIG_ARM Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 1/3] ARM: move .vectors and .stubs sections back into the kernel VMA Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 2/3] kallsyms: remove special lower address limit for CONFIG_ARM Ard Biesheuvel 2016-02-09 15:13 ` [PATCH v4 3/3] kallsyms: remove --page-offset command line option Ard Biesheuvel 2016-02-09 16:09 ` Chris Brandt 2016-02-09 16:17 ` Ard Biesheuvel 2016-02-09 19:28 ` Nicolas Pitre 2016-02-09 20:18 ` Ard Biesheuvel 2016-02-09 20:45 ` Nicolas Pitre
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