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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/kernel/signal_32.c | |
| parent | powerpc/64: Bump SIGSTKSZ and MINSIGSTKSZ (diff) | |
| download | linux-2896b2dff49d0377e4372f470dcddbcb26f2be59.tar.gz linux-2896b2dff49d0377e4372f470dcddbcb26f2be59.tar.bz2 linux-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/kernel/signal_32.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index d84c434b2b78..157a7403e3eb 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -233,6 +233,12 @@ struct rt_sigframe { int abigap[56]; }; +unsigned long get_min_sigframe_size_32(void) +{ + return max(sizeof(struct rt_sigframe) + __SIGNAL_FRAMESIZE + 16, + sizeof(struct sigframe) + __SIGNAL_FRAMESIZE); +} + /* * Save the current user registers on the user stack. * We only save the altivec/spe registers if the process has used |