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>

1 files changed, 0 insertions, 46 deletions

diff --git a/sysdeps/x86_64/tst-stack-align.h b/sysdeps/x86_64/tst-stack-align.h
deleted file mode 100644
index b3f93f7cab..0000000000
--- a/sysdeps/x86_64/tst-stack-align.h
+++ /dev/null
@@ -1,46 +0,0 @@
-/* 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
-   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/>.  */
-
-#include <stdio.h>
-#include <stdint.h>
-
-#define TEST_STACK_ALIGN() \
-  ({									     \
-    /* AMD64 ABI mandates 16byte aligned stack.				     \
-       Unfortunately, current GCC doesn't support __int128 or __float128     \
-       types, so use aligned attribute instead.  */			     \
-    struct _S								     \
-      {									     \
-        int _i __attribute__((aligned (16)));				     \
-	int _pad[3];							     \
-      } _s = { ._i = 18 };						     \
-    double _d = 12.0;							     \
-    long double _ld = 15.0;						     \
-    int _ret = 0;							     \
-    printf ("__int128:  %d %p %zu\n", _s._i, &_s, __alignof (_s));	     \
-    if ((((uintptr_t) &_s) & (__alignof (_s) - 1)) != 0)		     \
-      _ret = 1;								     \
-									     \
-    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;								     \
-    })