glibc/sysdeps/powerpc/tst-stack-align.h
H.J. Lu 79aec84102 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>
2021-05-24 07:42:12 -07:00

34 lines
1.4 KiB
C

/* Check stack alignment. PowerPC version.
Copyright (C) 2005-2021 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/>. */
#define TEST_STACK_ALIGN_INIT() \
({ \
/* Altivec __vector int etc. needs 16byte aligned stack. \
Instead of using altivec.h here, use aligned attribute instead. */ \
struct _S \
{ \
int _i __attribute__((aligned (16))); \
int _j[3]; \
} _s = { ._i = 18, ._j[0] = 19, ._j[1] = 20, ._j[2] = 21 }; \
printf ("__vector int: { %d, %d, %d, %d } %p %zu\n", _s._i, _s._j[0], \
_s._j[1], _s._j[2], &_s, __alignof (_s)); \
is_aligned (&_s, __alignof (_s)); \
})
#include_next <tst-stack-align.h>