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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/generic | |
| 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/generic')
| -rw-r--r-- | sysdeps/generic/tst-stack-align.h | 40 |
1 files changed, 26 insertions, 14 deletions
diff --git a/sysdeps/generic/tst-stack-align.h b/sysdeps/generic/tst-stack-align.h index b41f9d3..6f7c426 100644 --- a/sysdeps/generic/tst-stack-align.h +++ b/sysdeps/generic/tst-stack-align.h @@ -1,4 +1,5 @@ -/* Copyright (C) 2003-2021 Free Software Foundation, Inc. +/* Check stack alignment. Generic version. + Copyright (C) 2003-2021 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 @@ -18,17 +19,28 @@ #include <stdio.h> #include <stdint.h> +int +__attribute__ ((weak, noclone, noinline)) +is_aligned (void *p, int align) +{ + return (((uintptr_t) p) & (align - 1)) != 0; +} + +#ifndef TEST_STACK_ALIGN_INIT +# define TEST_STACK_ALIGN_INIT() 0 +#endif + #define TEST_STACK_ALIGN() \ - ({ \ - double _d = 12.0; \ - long double _ld = 15.0; \ - int _ret = 0; \ - printf ("double: %g %p %zu\n", _d, &_d, __alignof (double)); \ - if ((((uintptr_t) &_d) & (__alignof (double) - 1)) != 0) \ - _ret = 1; \ - \ - printf ("ldouble: %Lg %p %zu\n", _ld, &_ld, __alignof (long double)); \ - if ((((uintptr_t) &_ld) & (__alignof (long double) - 1)) != 0) \ - _ret = 1; \ - _ret; \ - }) + ({ \ + double _d = 12.0; \ + long double _ld = 15.0; \ + int _ret = TEST_STACK_ALIGN_INIT (); \ + \ + printf ("double: %g %p %zu\n", _d, &_d, __alignof (double)); \ + _ret += is_aligned (&_d, __alignof (double)); \ + \ + printf ("ldouble: %Lg %p %zu\n", _ld, &_ld, \ + __alignof (long double)); \ + _ret += is_aligned (&_ld, __alignof (long double)); \ + _ret; \ + }) |