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| author |   Nicholas Piggin <npiggin@gmail.com> | 2022-03-08 04:27:34 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-05-19 23:11:26 +1000 |
| commit | 2896b2dff49d0377e4372f470dcddbcb26f2be59 (patch) | |
| tree | 854ce287fc7cb79a46ba739fb5981a5a67f2a003 /arch/powerpc/include | |
| parent | powerpc/64: Bump SIGSTKSZ and MINSIGSTKSZ (diff) | |
| download | linux-dev-2896b2dff49d0377e4372f470dcddbcb26f2be59.tar.xz linux-dev-2896b2dff49d0377e4372f470dcddbcb26f2be59.zip | |
powerpc/signal: Report minimum signal frame size to userspace via AT_MINSIGSTKSZ
Implement the AT_MINSIGSTKSZ AUXV entry, allowing userspace to
dynamically size stack allocations in a manner forward-compatible with
new processor state saved in the signal frame
For now these statically find the maximum signal frame size rather than
doing any runtime testing of features to minimise the size.
glibc 2.34 will take advantage of this, as will applications that use
use _SC_MINSIGSTKSZ and _SC_SIGSTKSZ.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
References: 94b07c1f8c39 ("arm64: signal: Report signal frame size to userspace via auxv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220307182734.289289-2-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/elf.h | 14 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/signal.h | 5 | ||||
| -rw-r--r-- | arch/powerpc/include/uapi/asm/auxvec.h | 4 |
3 files changed, 21 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/elf.h b/arch/powerpc/include/asm/elf.h index 971589a21bc0..79f1c480b5eb 100644 --- a/arch/powerpc/include/asm/elf.h +++ b/arch/powerpc/include/asm/elf.h @@ -160,7 +160,7 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm, * even if DLINFO_ARCH_ITEMS goes to zero or is undefined. * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */ -#define ARCH_DLINFO \ +#define COMMON_ARCH_DLINFO \ do { \ /* Handle glibc compatibility. */ \ NEW_AUX_ENT(AT_IGNOREPPC, AT_IGNOREPPC); \ @@ -173,6 +173,18 @@ do { \ ARCH_DLINFO_CACHE_GEOMETRY; \ } while (0) +#define ARCH_DLINFO \ +do { \ + COMMON_ARCH_DLINFO; \ + NEW_AUX_ENT(AT_MINSIGSTKSZ, get_min_sigframe_size()); \ +} while (0) + +#define COMPAT_ARCH_DLINFO \ +do { \ + COMMON_ARCH_DLINFO; \ + NEW_AUX_ENT(AT_MINSIGSTKSZ, get_min_sigframe_size_compat()); \ +} while (0) + /* Relocate the kernel image to @final_address */ void relocate(unsigned long final_address); diff --git a/arch/powerpc/include/asm/signal.h b/arch/powerpc/include/asm/signal.h index 99e1c6de27bc..922d43700fb4 100644 --- a/arch/powerpc/include/asm/signal.h +++ b/arch/powerpc/include/asm/signal.h @@ -9,4 +9,9 @@ struct pt_regs; void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags); +unsigned long get_min_sigframe_size_32(void); +unsigned long get_min_sigframe_size_64(void); +unsigned long get_min_sigframe_size(void); +unsigned long get_min_sigframe_size_compat(void); + #endif /* _ASM_POWERPC_SIGNAL_H */ diff --git a/arch/powerpc/include/uapi/asm/auxvec.h b/arch/powerpc/include/uapi/asm/auxvec.h index 7af21dc0e320..aa7c16215453 100644 --- a/arch/powerpc/include/uapi/asm/auxvec.h +++ b/arch/powerpc/include/uapi/asm/auxvec.h @@ -48,6 +48,8 @@ #define AT_L3_CACHESIZE 46 #define AT_L3_CACHEGEOMETRY 47 -#define AT_VECTOR_SIZE_ARCH 14 /* entries in ARCH_DLINFO */ +#define AT_MINSIGSTKSZ 51 /* stack needed for signal delivery */ + +#define AT_VECTOR_SIZE_ARCH 15 /* entries in ARCH_DLINFO */ #endif |