Messages in this thread | | | Date | Thu, 26 Nov 2020 18:44:18 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 2/4] x86/elf: Support a new ELF aux vector AT_MINSIGSTKSZ |
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On Thu, Nov 19, 2020 at 11:02:35AM -0800, Chang S. Bae wrote: > Historically, signal.h defines MINSIGSTKSZ (2KB) and SIGSTKSZ (8KB), for > use by all architectures with sigaltstack(2). Over time, the hardware state > size grew, but these constants did not evolve. Today, literal use of these > constants on several architectures may result in signal stack overflow, and > thus user data corruption. > > A few years ago, the ARM team addressed this issue by establishing > getauxval(AT_MINSIGSTKSZ), such that the kernel can supply at runtime value > that is an appropriate replacement on the current and future hardware. > > Add getauxval(AT_MINSIGSTKSZ) support to x86, analogous to the support > added for ARM in commit 94b07c1f8c39 ("arm64: signal: Report signal frame > size to userspace via auxv").
I don't see it documented here:
https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/man3/getauxval.3
Dunno, now that two architectures will have it, maybe that is good enough reason to document it.
Adding Michael.
-- Regards/Gruss, Boris.
SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG Nürnberg
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