Viewing file:  pr95443-1.c (2.79 KB) -rw-r--r--
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/* { dg-do run { target { sysconf && mmap } } } */
/* { dg-options "-O2 -minline-all-stringops" } */
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#ifndef MAP_ANON
#define MAP_ANON 0
#endif
#ifndef MAP_FAILED
#define MAP_FAILED ((void *)-1)
#endif
uint8_t shift[256];
static size_t
__attribute__ ((noclone, noinline))
hash2(const unsigned char *p)
{
return (((size_t)(p)[0] - ((size_t)(p)[-1] << 3)) % sizeof (shift));
}
char *
simple_strstr (const char *haystack, const char *needle)
{
const unsigned char *hs = (const unsigned char *) haystack;
const unsigned char *ne = (const unsigned char *) needle;
size_t ne_len = strlen ((const char*)ne);
size_t hs_len = strnlen ((const char*)hs, ne_len | 512);
if (hs_len < ne_len)
return NULL;
if (memcmp (hs, ne, ne_len) == 0)
return (char *) hs;
const unsigned char *end = hs + hs_len - ne_len;
size_t tmp, shift1;
size_t m1 = ne_len - 1;
size_t offset = 0;
memset (shift, 0, sizeof (shift));
for (int i = 1; i < m1; i++)
shift[hash2 (ne + i)] = i;
shift1 = m1 - shift[hash2 (ne + m1)];
shift[hash2 (ne + m1)] = m1;
while (1)
{
if (__builtin_expect (hs > end, 0))
{
end += strnlen ((const char*)end + m1 + 1, 2048);
if (hs > end)
return NULL;
}
do
{
hs += m1;
tmp = shift[hash2 (hs)];
}
while (tmp == 0 && hs <= end);
hs -= tmp;
if (tmp < m1)
continue;
if (m1 < 15 || memcmp (hs + offset, ne + offset, 8) == 0)
{
if (memcmp (hs, ne, m1) == 0)
return (void *) hs;
offset = (offset >= 8 ? offset : m1) - 8;
}
hs += shift1;
}
}
static int
check_result (const char *s1, const char *s2,
char *exp_result)
{
char *result = simple_strstr (s1, s2);
if (result != exp_result)
return -1;
return 0;
}
void
__attribute__ ((noclone, noinline))
check1 (void)
{
const char s1[] =
"F_BD_CE_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_88_20_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_A7_20_EF_BF_BD";
const char s2[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
char *exp_result;
exp_result = simple_strstr (s1, s2);
if (check_result (s1, s2, exp_result) != 0)
abort ();
}
int
main (void)
{
unsigned char *buf1, *buf2;
size_t page_size = 2 * sysconf(_SC_PAGESIZE);
buf1 = mmap (0, (1 + 1) * page_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (buf1 == MAP_FAILED)
return -1;
if (mprotect (buf1 + 1 * page_size, page_size, PROT_NONE))
return -1;
buf2 = mmap (0, 2 * page_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (buf2 == MAP_FAILED)
return -1;
if (mprotect (buf2 + page_size, page_size, PROT_NONE))
return -1;
memset (buf1, 0xa5, 1 * page_size);
memset (buf2, 0x5a, page_size);
check1 ();
return 0;
}
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