strace/tests/pread64-pwrite64.c
Dmitry V. Levin ff2b853e7f tests/pread64-pwrite64.c: robustify against os specific issues
Do not assume that pwrite64 syscall fails when only part of the
specified memory buffer is accessible.  With some kernels, one
accessible byte at the end of page is enough for pwrite64 syscall
to return 1.

* tests/pread64-pwrite64.c (main): Tweak the test that can lead
to a partial write.
2016-05-18 09:26:01 +00:00

224 lines
6.1 KiB
C

/*
* Check decoding of pread64 and pwrite64 syscalls.
*
* Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "tests.h"
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static void
dump_str(const char *str, const unsigned int len)
{
static const char dots[16] = "................";
unsigned int i;
for (i = 0; i < len; i += 16) {
unsigned int n = len - i > 16 ? 16 : len - i;
const char *dump = hexdump_memdup(str + i, n);
tprintf(" | %05x %-49s %-16.*s |\n",
i, dump, n, dots);
free((void *) dump);
}
}
static void
print_hex(const char *str, const unsigned int len)
{
const unsigned char *ustr = (const unsigned char *) str;
unsigned int i;
for (i = 0; i < len; ++i) {
unsigned int c = ustr[i];
switch (c) {
case '\t':
tprintf("\\t"); break;
case '\n':
tprintf("\\n"); break;
case '\v':
tprintf("\\v"); break;
case '\f':
tprintf("\\f"); break;
case '\r':
tprintf("\\r"); break;
default:
tprintf("\\%o", ustr[i]);
}
}
}
static void
test_dump(const unsigned int len)
{
static char *buf;
if (buf) {
size_t ps1 = get_page_size() - 1;
buf = (void *) (((size_t) buf + ps1) & ~ps1) - len;
} else {
buf = tail_alloc(len);
}
const off_t offset = 0xdefaceddeadbeefLL + len;
long rc = pread(0, buf, len, offset);
if (rc != (int) len)
perror_msg_and_fail("pread64: expected %d, returned %ld",
len, rc);
tprintf("%s(%d, \"", "pread64", 0);
print_hex(buf, len);
tprintf("\", %d, %lld) = %ld\n", len, (long long) offset, rc);
dump_str(buf, len);
unsigned int i;
for (i = 0; i < len; ++i)
buf[i] = i;
rc = pwrite(1, buf, len, offset);
if (rc != (int) len)
perror_msg_and_fail("pwrite64: expected %d, returned %ld",
len, rc);
tprintf("%s(%d, \"", "pwrite64", 1);
print_hex(buf, len);
tprintf("\", %d, %lld) = %ld\n", len, (long long) offset, rc);
dump_str(buf, len);
if (!len)
buf = 0;
}
int
main(void)
{
tprintf("%s", "");
static char tmp[] = "pread64-pwrite64-tmpfile";
if (open(tmp, O_CREAT|O_RDONLY|O_TRUNC, 0600) != 0)
perror_msg_and_fail("creat: %s", tmp);
if (open(tmp, O_WRONLY) != 1)
perror_msg_and_fail("open: %s", tmp);
char *nil = tail_alloc(1);
*nil = '\0';
static const char w_c[] = "0123456789abcde";
const unsigned int w_len = LENGTH_OF(w_c);
const char *w_d = hexdump_strdup(w_c);
const void *w = tail_memdup(w_c, w_len);
static const char r0_c[] = "01234567";
const char *r0_d = hexdump_strdup(r0_c);
const unsigned int r0_len = (w_len + 1) / 2;
void *r0 = tail_alloc(r0_len);
static const char r1_c[] = "89abcde";
const char *r1_d = hexdump_strdup(r1_c);
const unsigned int r1_len = w_len - r0_len;
void *r1 = tail_alloc(w_len);
void *efault = r1 - get_page_size();
long rc;
rc = pwrite(1, w, 0, 0);
if (rc)
perror_msg_and_fail("pwrite64: expected 0, returned %ld", rc);
tprintf("pwrite64(1, \"\", 0, 0) = 0\n");
rc = pwrite(1, efault, 1, 0);
if (rc != -1)
perror_msg_and_fail("pwrite64: expected -1 EFAULT"
", returned %ld", rc);
tprintf("pwrite64(1, %p, 1, 0) = -1 EFAULT (%m)\n", efault);
rc = pwrite(1, nil, 1, -3);
if (rc != -1)
perror_msg_and_fail("pwrite64: expected -1, returned %ld", rc);
tprintf("pwrite64(1, \"\\0\", 1, -3) = -1 EINVAL (%m)\n");
rc = pwrite(1, w, w_len, 0);
if (rc != (int) w_len)
perror_msg_and_fail("pwrite64: expected %u, returned %ld",
w_len, rc);
tprintf("pwrite64(1, \"%s\", %u, 0) = %ld\n"
" | 00000 %-49s %-16s |\n",
w_c, w_len, rc, w_d, w_c);
close(1);
rc = pread(0, r0, 0, 0);
if (rc)
perror_msg_and_fail("pread64: expected 0, returned %ld", rc);
tprintf("pread64(0, \"\", 0, 0) = 0\n");
rc = pread(0, efault, 1, 0);
if (rc != -1)
perror_msg_and_fail("pread64: expected -1, returned %ld", rc);
tprintf("pread64(0, %p, 1, 0) = -1 EFAULT (%m)\n", efault);
rc = pread(0, efault, 2, -7);
if (rc != -1)
perror_msg_and_fail("pread64: expected -1, returned %ld", rc);
tprintf("pread64(0, %p, 2, -7) = -1 EINVAL (%m)\n", efault);
rc = pread(0, r0, r0_len, 0);
if (rc != (int) r0_len)
perror_msg_and_fail("pread64: expected %u, returned %ld",
r0_len, rc);
tprintf("pread64(0, \"%s\", %u, 0) = %ld\n"
" | 00000 %-49s %-16s |\n",
r0_c, r0_len, rc, r0_d, r0_c);
rc = pread(0, r1, w_len, r0_len);
if (rc != (int) r1_len)
perror_msg_and_fail("pread64: expected %u, returned %ld",
r1_len, rc);
tprintf("pread64(0, \"%s\", %u, %u) = %ld\n"
" | 00000 %-49s %-16s |\n",
r1_c, w_len, r0_len, rc, r1_d, r1_c);
close(0);
if (open("/dev/zero", O_RDONLY))
perror_msg_and_fail("open");
if (open("/dev/null", O_WRONLY) != 1)
perror_msg_and_fail("open");
unsigned int i;
for (i = 0; i <= 32; ++i)
test_dump(i);
tprintf("+++ exited with 0 +++\n");
return 0;
}