diff options
| author | Carlos O'Donell <carlos@systemhalted.org> | 2018-01-24 20:35:22 -0800 |
|---|---|---|
| committer | Carlos O'Donell <carlos@systemhalted.org> | 2018-01-25 23:43:46 -0800 |
| commit | 2ec0e7eade0ea1258acd5c6f5e5e9bfaeb5041a8 (patch) | |
| tree | 9d069618e0132fa31ab0c39eda4c95f14d50a1b0 /bits | |
| parent | 47c4b4b060db0290022dcc37cab7b5ff4bdb5c32 (diff) | |
Revert Intel CET changes to __jmp_buf_tag (Bug 22743)
In commit cba595c350e52194e10c0006732e1991e3d0803b and commit
f81ddabffd76ac9dd600b02adbf3e1dac4bb10ec, ABI compatibility with
applications was broken by increasing the size of the on-stack
allocated __pthread_unwind_buf_t beyond the oringal size.
Applications only have the origianl space available for
__pthread_unwind_register, and __pthread_unwind_next to use,
any increase in the size of __pthread_unwind_buf_t causes these
functions to write beyond the original structure into other
on-stack variables leading to segmentation faults in common
applications like vlc. The only workaround is to version those
functions which operate on the old sized objects, but this must
happen in glibc 2.28.
Thank you to Andrew Senkevich, H.J. Lu, and Aurelien Jarno, for
submitting reports and tracking the issue down.
The commit reverts the above mentioned commits and testing on
x86_64 shows that the ABI compatibility is restored. A tst-cleanup1
regression test linked with an older glibc now passes when run
with the newly built glibc. Previously a tst-cleanup1 linked with
an older glibc would segfault when run with an affected glibc build.
Tested on x86_64 with no regressions.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'bits')
| -rw-r--r-- | bits/types/__cancel_jmp_buf_tag.h | 28 |
1 files changed, 0 insertions, 28 deletions
diff --git a/bits/types/__cancel_jmp_buf_tag.h b/bits/types/__cancel_jmp_buf_tag.h deleted file mode 100644 index 62f5c61f83..0000000000 --- a/bits/types/__cancel_jmp_buf_tag.h +++ /dev/null @@ -1,28 +0,0 @@ -/* Define struct __cancel_jmp_buf_tag. - Copyright (C) 2017-2018 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#ifndef ____cancel_jmp_buf_tag_defined -#define ____cancel_jmp_buf_tag_defined 1 - -struct __cancel_jmp_buf_tag - { - __jmp_buf __cancel_jmp_buf; - int __mask_was_saved; - }; - -#endif |