glibc/string/test-memcpy-support.h
John David Anglin 409a735816 String: test-memcpy used unaligned types for buffers [BZ 28572]
commit d585ba47fc
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Mon Nov 1 00:49:48 2021 -0500

    string: Make tests birdirectional test-memcpy.c

Add tests that had src/dst non 4-byte aligned. Since src/dst are
initialized/compared as uint32_t type which is 4-byte aligned this can
break on some targets.

Fix the issue by specifying a new non-aligned 4-byte
`unaligned_uint32_t` for src/dst.

Another alternative is to rely on memcpy/memcmp for
initializing/testing src/dst. Using memcpy for initializing in memcpy
tests, however, could lead to future bugs.

Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
2021-12-07 22:19:50 -06:00

170 lines
4.8 KiB
C

/* Support for testing and measuring memcpy functions.
Copyright (C) 1999-2021 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/>. */
/* This fail contains the actual memcpy test functions. It is included
in test-memcpy.c and test-memcpy-large.c. They are split because
the tests take a long time to run and splitting them allows for
simpler parallel testing. */
#ifndef MEMCPY_RESULT
#define MEMCPY_RESULT(dst, len) dst
#define MIN_PAGE_SIZE 131072
#define TEST_MAIN
#define TEST_NAME "memcpy"
#define TIMEOUT (8 * 60)
#include "test-string.h"
char *simple_memcpy (char *, const char *, size_t);
char *builtin_memcpy (char *, const char *, size_t);
IMPL (simple_memcpy, 0)
IMPL (builtin_memcpy, 0)
IMPL (memcpy, 1)
char *
simple_memcpy (char *dst, const char *src, size_t n)
{
char *ret = dst;
while (n--)
*dst++ = *src++;
return ret;
}
char *
builtin_memcpy (char *dst, const char *src, size_t n)
{
return __builtin_memcpy (dst, src, n);
}
#endif
typedef char *(*proto_t) (char *, const char *, size_t);
typedef uint32_t __attribute__ ((may_alias, aligned (1))) unaligned_uint32_t;
static void
do_one_test (impl_t *impl, char *dst, const char *src, size_t len)
{
size_t i;
/* Must clear the destination buffer set by the previous run. */
for (i = 0; i < len; i++)
dst[i] = 0;
if (CALL (impl, dst, src, len) != MEMCPY_RESULT (dst, len))
{
error (0, 0, "Wrong result in function %s %p %p", impl->name,
CALL (impl, dst, src, len), MEMCPY_RESULT (dst, len));
ret = 1;
return;
}
if (memcmp (dst, src, len) != 0)
{
error (0, 0,
"Wrong result in function %s dst %p \"%.*s\" src %p \"%.*s\" len "
"%zu",
impl->name, dst, (int)len, dst, src, (int)len, src, len);
ret = 1;
return;
}
}
static void
do_test (size_t align1, size_t align2, size_t len)
{
size_t i, j, repeats;
char *s1, *s2;
align1 &= 4095;
if (align1 + len >= page_size)
return;
align2 &= 4095;
if (align2 + len >= page_size)
return;
s1 = (char *)(buf1 + align1);
s2 = (char *)(buf2 + align2);
for (repeats = 0; repeats < 2; ++repeats)
{
for (i = 0, j = 1; i < len; i++, j += 23)
s1[i] = j;
FOR_EACH_IMPL (impl, 0)
do_one_test (impl, s2, s1, len);
}
}
static void
do_test1 (size_t align1, size_t align2, size_t size)
{
void *large_buf;
size_t mmap_size, region_size;
align1 &= (page_size - 1);
if (align1 == 0)
align1 = page_size;
align2 &= (page_size - 1);
if (align2 == 0)
align2 = page_size;
region_size = (size + page_size - 1) & (~(page_size - 1));
mmap_size = region_size * 2 + 3 * page_size;
large_buf = mmap (NULL, mmap_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (large_buf == MAP_FAILED)
{
puts ("Failed to allocate large_buf, skipping do_test");
return;
}
if (mprotect (large_buf + region_size + page_size, page_size, PROT_NONE))
error (EXIT_FAILURE, errno, "mprotect failed");
size_t array_size = size / sizeof (uint32_t);
unaligned_uint32_t *dest = large_buf + align1;
unaligned_uint32_t *src = large_buf + region_size + 2 * page_size + align2;
size_t i;
size_t repeats;
for (repeats = 0; repeats < 2; repeats++)
{
for (i = 0; i < array_size; i++)
src[i] = (uint32_t)i;
FOR_EACH_IMPL (impl, 0)
{
memset (dest, -1, size);
CALL (impl, (char *)dest, (char *)src, size);
if (memcmp (src, dest, size))
{
for (i = 0; i < array_size; i++)
if (dest[i] != src[i])
{
error (0, 0,
"Wrong result in function %s dst \"%p\" src \"%p\" "
"offset \"%zd\"",
impl->name, dest, src, i);
ret = 1;
munmap ((void *)large_buf, mmap_size);
return;
}
}
}
dest = large_buf + region_size + 2 * page_size + align1;
src = large_buf + align2;
}
munmap ((void *)large_buf, mmap_size);
}