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/*
* Check decoding of kcmp syscall.
*
* Copyright (c) 2016-2017 Eugene Syromyatnikov <evgsyr@gmail.com>
* 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 <asm/unistd.h>
#include "scno.h"
#ifdef __NR_kcmp
# include <fcntl.h>
# include <stdarg.h>
# include <stdint.h>
# include <stdio.h>
# include <string.h>
# include <unistd.h>
# ifndef VERBOSE_FD
# define VERBOSE_FD 0
# endif
/*
* We prefer to use system headers in order to catch some possible deviations in
* system's headers from our perception of reality, but happy to include our own
* definitions as well.
*/
# ifdef HAVE_LINUX_KCMP_H
# include <linux/kcmp.h>
# else
# define KCMP_FILE 0
# define KCMP_VM 1
# define KCMP_FILES 2
# define KCMP_FS 3
# define KCMP_SIGHAND 4
# define KCMP_IO 5
# define KCMP_SYSVSEM 6
# endif
/* All other kcmp types have been added atomically */
# define KCMP_EPOLL_TFD 7
# ifndef HAVE_STRUCT_KCMP_EPOLL_SLOT
struct kcmp_epoll_slot {
uint32_t efd;
uint32_t tfd;
uint32_t toff;
};
# endif
static const kernel_ulong_t kcmp_max_type = KCMP_EPOLL_TFD;
static const char null_path[] = "/dev/null";
static const char zero_path[] = "/dev/zero";
# define NULL_FD 23
# define ZERO_FD 42
static void
printpidfd(const char *prefix, pid_t pid, unsigned fd)
{
printf("%s%d", prefix, fd);
}
/*
* Last argument is optional and is used as follows:
* * When type is KCMP_EPOLL_TFD, it signalises whether idx2 is a valid
* pointer.
*/
static void
do_kcmp(kernel_ulong_t pid1, kernel_ulong_t pid2, kernel_ulong_t type,
const char *type_str, kernel_ulong_t idx1, kernel_ulong_t idx2, ...)
{
long rc;
const char *errstr;
rc = syscall(__NR_kcmp, pid1, pid2, type, idx1, idx2);
errstr = sprintrc(rc);
printf("kcmp(%d, %d, ", (int) pid1, (int) pid2);
if (type_str)
printf("%s", type_str);
else
printf("%#x /* KCMP_??? */", (int) type);
if (type == KCMP_FILE) {
printpidfd(", ", pid1, idx1);
printpidfd(", ", pid2, idx2);
} else if (type == KCMP_EPOLL_TFD) {
va_list ap;
int valid_ptr;
va_start(ap, idx2);
valid_ptr = va_arg(ap, int);
va_end(ap);
printpidfd(", ", pid1, idx1);
printf(", ");
if (valid_ptr) {
struct kcmp_epoll_slot *slot =
(struct kcmp_epoll_slot *) (uintptr_t) idx2;
printpidfd("{efd=", pid2, slot->efd);
printpidfd(", tfd=", pid2, slot->tfd);
printf(", toff=%llu}", (unsigned long long) slot->toff);
} else {
if (idx2)
printf("%#llx", (unsigned long long) idx2);
else
printf("NULL");
}
} else if (type > kcmp_max_type) {
printf(", %#llx, %#llx",
(unsigned long long) idx1, (unsigned long long) idx2);
}
printf(") = %s\n", errstr);
}
int
main(void)
{
static const kernel_ulong_t bogus_pid1 =
(kernel_ulong_t) 0xdeadca75face1057ULL;
static const kernel_ulong_t bogus_pid2 =
(kernel_ulong_t) 0xdefaced1defaced2ULL;
static const kernel_ulong_t bogus_type =
(kernel_ulong_t) 0xbadc0dedda7adeadULL;
static const kernel_ulong_t bogus_idx1 =
(kernel_ulong_t) 0xdec0ded3dec0ded4ULL;
static const kernel_ulong_t bogus_idx2 =
(kernel_ulong_t) 0xba5e1e55deadc0deULL;
static const struct kcmp_epoll_slot slot_data[] = {
{ 0xdeadc0de, 0xfacef157, 0xbadc0ded },
{ NULL_FD, ZERO_FD, 0 },
{ 0, 0, 0 },
};
static kernel_ulong_t ptr_check =
F8ILL_KULONG_SUPPORTED ? F8ILL_KULONG_MASK : 0;
int fd;
unsigned i;
struct kcmp_epoll_slot *slot = tail_alloc(sizeof(*slot));
/* Open some files to test printpidfd */
fd = open(null_path, O_RDONLY);
if (fd < 0)
perror_msg_and_fail("open(\"%s\")", null_path);
if (fd != NULL_FD) {
if (dup2(fd, NULL_FD) < 0)
perror_msg_and_fail("dup2(fd, NULL_FD)");
close(fd);
}
fd = open(zero_path, O_RDONLY);
if (fd < 0)
perror_msg_and_fail("open(\"%s\")", zero_path);
if (fd != ZERO_FD) {
if (dup2(fd, ZERO_FD) < 0)
perror_msg_and_fail("dup2(fd, ZERO_FD)");
close(fd);
}
close(0);
/* Invalid values */
do_kcmp(bogus_pid1, bogus_pid2, bogus_type, NULL, bogus_idx1,
bogus_idx2);
do_kcmp(F8ILL_KULONG_MASK, F8ILL_KULONG_MASK, kcmp_max_type + 1, NULL,
0, 0);
/* KCMP_FILE is the only type which has additional args */
do_kcmp(3141592653U, 2718281828U, ARG_STR(KCMP_FILE), bogus_idx1,
bogus_idx2);
do_kcmp(-1, -1, ARG_STR(KCMP_FILE), NULL_FD, ZERO_FD);
/* Types without additional args */
do_kcmp(-1, -1, ARG_STR(KCMP_VM), bogus_idx1, bogus_idx2);
do_kcmp(-1, -1, ARG_STR(KCMP_FILES), bogus_idx1, bogus_idx2);
do_kcmp(-1, -1, ARG_STR(KCMP_FS), bogus_idx1, bogus_idx2);
do_kcmp(-1, -1, ARG_STR(KCMP_SIGHAND), bogus_idx1, bogus_idx2);
do_kcmp(-1, -1, ARG_STR(KCMP_IO), bogus_idx1, bogus_idx2);
do_kcmp(-1, -1, ARG_STR(KCMP_SYSVSEM), bogus_idx1, bogus_idx2);
/* KCMP_EPOLL_TFD checks */
do_kcmp(-1, -1, ARG_STR(KCMP_EPOLL_TFD),
F8ILL_KULONG_MASK | 2718281828U, ptr_check, 0);
do_kcmp(-1, -1, ARG_STR(KCMP_EPOLL_TFD),
3141592653U, (uintptr_t) slot + 1, 0);
for (i = 0; i < ARRAY_SIZE(slot_data); i++) {
memcpy(slot, slot_data + i, sizeof(*slot));
do_kcmp(getpid(), getppid(), ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
(uintptr_t) slot, 1);
}
puts("+++ exited with 0 +++");
return 0;
}
#else
SKIP_MAIN_UNDEFINED("__NR_kcmp");
#endif
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