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| author | H.J. Lu <hjl.tools@gmail.com> | 2021-05-23 09:15:52 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2021-05-24 07:42:12 -0700 |
| commit | 79aec841029c160a85f46564f8bad132af008e30 (patch) | |
| tree | af636da51359f8ff5d18d700b51067e1196b37c0 /sysdeps/x86 | |
| parent | 1b992204f68af851e905c16016756fd4421e1934 (diff) | |
| download | glibc-79aec841029c160a85f46564f8bad132af008e30.zip glibc-79aec841029c160a85f46564f8bad132af008e30.tar.gz glibc-79aec841029c160a85f46564f8bad132af008e30.tar.bz2 | |
Properly check stack alignment [BZ #27901]
1. Replace
if ((((uintptr_t) &_d) & (__alignof (double) - 1)) != 0)
which may be optimized out by compiler, with
int
__attribute__ ((weak, noclone, noinline))
is_aligned (void *p, int align)
{
return (((uintptr_t) p) & (align - 1)) != 0;
}
2. Add TEST_STACK_ALIGN_INIT to TEST_STACK_ALIGN.
3. Add a common TEST_STACK_ALIGN_INIT to check 16-byte stack alignment
for both i386 and x86-64.
4. Update powerpc to use TEST_STACK_ALIGN_INIT.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'sysdeps/x86')
| -rw-r--r-- | sysdeps/x86/tst-stack-align.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/sysdeps/x86/tst-stack-align.h b/sysdeps/x86/tst-stack-align.h new file mode 100644 index 0000000..578d5c4 --- /dev/null +++ b/sysdeps/x86/tst-stack-align.h @@ -0,0 +1,28 @@ +/* Check stack alignment. X86 version. + Copyright (C) 2021 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 + <https://www.gnu.org/licenses/>. */ + +typedef struct { int i[16]; } int_al16 __attribute__((aligned (16))); + +#define TEST_STACK_ALIGN_INIT() \ + ({ \ + int_al16 _m; \ + printf ("int_al16: %p %zu\n", &_m, __alignof (int_al16)); \ + is_aligned (&_m, __alignof (int_al16)); \ + }) + +#include_next <tst-stack-align.h> |