glibc/string/test-memchr.c
Adhemerval Zanella 3abeeec5f4 Fix i686 memchr overflow calculation (BZ#21182)
This patch fixes the regression added by 23d2770 for final address
overflow calculation.  The subtraction of the considered size (16)
at line 120 is at wrong place, for sizes less than 16 subsequent
overflow check will not take in consideration an invalid size (since
the subtraction will be negative).  Also, the lea instruction also
does not raise the carry flag (CF) that is used in subsequent jbe
to check for overflow.

The fix is to follow x86_64 logic from 3daef2c where the overflow
is first check and a sub instruction is issued.  In case of resulting
negative size, CF will be set by the sub instruction and a NULL
result will be returned.  The patch also add similar tests reported
in bug report.

Checked on i686-linux-gnu and x86_64-linux-gnu.

	* string/test-memchr.c (do_test): Add BZ#21182 checks for address
	near end of a page.
	* sysdeps/i386/i686/multiarch/memchr-sse2.S (__memchr): Fix
	overflow calculation.
2017-03-29 09:54:14 -03:00

224 lines
5.3 KiB
C

/* Test memchr functions.
Copyright (C) 1999-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Written by Jakub Jelinek <jakub@redhat.com>, 1999.
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
<http://www.gnu.org/licenses/>. */
#define TEST_MAIN
#ifndef WIDE
# define TEST_NAME "memchr"
#else
# define TEST_NAME "wmemchr"
#endif /* WIDE */
#include "test-string.h"
#include <stdint.h>
#ifndef WIDE
# define MEMCHR memchr
# define CHAR char
# define UCHAR unsigned char
# define SIMPLE_MEMCHR simple_memchr
# define BIG_CHAR CHAR_MAX
# define SMALL_CHAR 127
#else
# include <wchar.h>
# define MEMCHR wmemchr
# define CHAR wchar_t
# define UCHAR wchar_t
# define SIMPLE_MEMCHR simple_wmemchr
# define BIG_CHAR WCHAR_MAX
# define SMALL_CHAR 1273
#endif /* WIDE */
typedef CHAR *(*proto_t) (const CHAR *, int, size_t);
CHAR *SIMPLE_MEMCHR (const CHAR *, int, size_t);
IMPL (SIMPLE_MEMCHR, 0)
IMPL (MEMCHR, 1)
CHAR *
SIMPLE_MEMCHR (const CHAR *s, int c, size_t n)
{
while (n--)
if (*s++ == (CHAR) c)
return (CHAR *) s - 1;
return NULL;
}
static void
do_one_test (impl_t *impl, const CHAR *s, int c, size_t n, CHAR *exp_res)
{
CHAR *res = CALL (impl, s, c, n);
if (res != exp_res)
{
error (0, 0, "Wrong result in function %s %p %p", impl->name,
res, exp_res);
ret = 1;
return;
}
}
static void
do_test (size_t align, size_t pos, size_t len, size_t n, int seek_char)
{
size_t i;
CHAR *result;
if ((align + len) * sizeof (CHAR) >= page_size)
return;
CHAR *buf = (CHAR *) (buf1);
for (i = 0; i < len; ++i)
{
buf[align + i] = 1 + 23 * i % SMALL_CHAR;
if (buf[align + i] == seek_char)
buf[align + i] = seek_char + 1;
}
buf[align + len] = 0;
if (pos < len)
{
buf[align + pos] = seek_char;
buf[align + len] = -seek_char;
result = (CHAR *) (buf + align + pos);
}
else
{
result = NULL;
buf[align + len] = seek_char;
}
FOR_EACH_IMPL (impl, 0)
do_one_test (impl, (CHAR *) (buf + align), seek_char, n, result);
}
static void
do_random_tests (void)
{
size_t i, j, n, align, pos, len;
int seek_char;
CHAR *result;
UCHAR *p = (UCHAR *) (buf1 + page_size) - 512;
for (n = 0; n < ITERATIONS; n++)
{
align = random () & 15;
pos = random () & 511;
if (pos + align >= 512)
pos = 511 - align - (random () & 7);
len = random () & 511;
if (pos >= len)
len = pos + (random () & 7);
if (len + align >= 512)
len = 512 - align - (random () & 7);
seek_char = random () & BIG_CHAR;
j = len + align + 64;
if (j > 512)
j = 512;
for (i = 0; i < j; i++)
{
if (i == pos + align)
p[i] = seek_char;
else
{
p[i] = random () & BIG_CHAR;
if (i < pos + align && p[i] == seek_char)
p[i] = seek_char + 13;
}
}
if (pos < len)
{
size_t r = random ();
if ((r & 31) == 0)
len = ~(uintptr_t) (p + align) - ((r >> 5) & 31);
result = (CHAR *) (p + pos + align);
}
else
result = NULL;
FOR_EACH_IMPL (impl, 1)
if (CALL (impl, (CHAR *) (p + align), seek_char, len) != result)
{
error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %d, %zd, %zd) %p != %p, p %p",
n, impl->name, align, seek_char, len, pos,
CALL (impl, (CHAR *) (p + align), seek_char, len),
result, p);
ret = 1;
}
}
}
int
test_main (void)
{
size_t i, j;
test_init ();
printf ("%20s", "");
FOR_EACH_IMPL (impl, 0)
printf ("\t%s", impl->name);
putchar ('\n');
for (i = 1; i < 8; ++i)
{
do_test (0, 16 << i, 2048, 2048, 23);
do_test (i, 64, 256, 256, 23);
do_test (0, 16 << i, 2048, 2048, 0);
do_test (i, 64, 256, 256, 0);
/* Check for large input sizes and for these cases we need to
make sure the byte is within the size range (that's why
7 << i must be smaller than 2048). */
do_test (0, 7 << i, 2048, SIZE_MAX, 23);
do_test (0, 2048 - i, 2048, SIZE_MAX, 23);
do_test (i, 64, 256, SIZE_MAX, 23);
do_test (0, 7 << i, 2048, SIZE_MAX, 0);
do_test (0, 2048 - i, 2048, SIZE_MAX, 0);
do_test (i, 64, 256, SIZE_MAX, 0);
}
for (i = 1; i < 64; ++i)
{
for (j = 1; j < 64; j++)
{
do_test (0, 64 - j, 64, SIZE_MAX, 23);
do_test (i, 64 - j, 64, SIZE_MAX, 23);
}
}
for (i = 1; i < 32; ++i)
{
do_test (0, i, i + 1, i + 1, 23);
do_test (0, i, i + 1, i + 1, 0);
}
/* BZ#21182 - wrong overflow calculation for i686 implementation
with address near end of the page. */
for (i = 2; i < 16; ++i)
/* page_size is in fact getpagesize() * 2. */
do_test (page_size / 2 - i, i, i, 1, 0x9B);
do_random_tests ();
return ret;
}
#include <support/test-driver.c>