Bug 20305 - x86_64: MINSIGSTKSZ too small for AVX-512F support
Summary: x86_64: MINSIGSTKSZ too small for AVX-512F support
Status: RESOLVED MOVED
Alias: None
Product: glibc
Classification: Unclassified
Component: libc (show other bugs)
Version: 2.24
: P2 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-06-28 11:32 UTC by Florian Weimer
Modified: 2016-09-09 16:13 UTC (History)
2 users (show)

See Also:
Host:
Target: x86_64
Build:
Last reconfirmed:
fweimer: security-


Attachments
tst-minsigstksz.c (617 bytes, text/plain)
2016-06-28 11:32 UTC, Florian Weimer
Details

Note You need to log in before you can comment on or make changes to this bug.
Description Florian Weimer 2016-06-28 11:32:46 UTC
Created attachment 9368 [details]
tst-minsigstksz.c

The attached test case fails on a system with AVX512 support (both hardware and kernel) with the following error:

tst-minsigstksz: changed byte 1376 bytes below configured stack
Comment 1 Florian Weimer 2016-06-28 11:35:59 UTC
As a possible fix, the kernel could refuse to save FPU state to the signal handler stack if the specified stack is not large enough.

I do not see a good way to fix this in glibc.  Increasing MINSIGSTKSZ has potential impact on ABI.
Comment 2 Florian Weimer 2016-08-22 15:02:39 UTC
I filed a kernel bug: https://bugzilla.kernel.org/show_bug.cgi?id=153531