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/*
* Check decoding of kcmp syscall.
*
* Copyright (c) 2016-2017 Eugene Syromyatnikov <evgsyr@gmail.com>
* Copyright (c) 2016-2021 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#include "scno.h"
#include "pidns.h"
#include <fcntl.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <linux/kcmp.h>
#ifndef SKIP_IF_PROC_IS_UNAVAILABLE
# define SKIP_IF_PROC_IS_UNAVAILABLE
#endif
#ifndef VERBOSE_FD
# define VERBOSE_FD 0
#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)
{
const char *path = NULL;
#if VERBOSE_FD
if (pid == getpid()) {
switch (fd)
{
case NULL_FD:
path = null_path;
break;
case ZERO_FD:
path = zero_path;
break;
}
}
#endif
if (path)
printf("%s%d<%s>", prefix, fd, path);
else
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);
const char *pid_str = pidns_pid2str(PT_TGID);
pidns_print_leader();
printf("kcmp(%d%s, %d%s, ",
(int) pid1, (int) pid1 == getpid() ? pid_str : "",
(int) pid2, (int) pid2 == getpid() ? pid_str : "");
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)
{
SKIP_IF_PROC_IS_UNAVAILABLE;
PIDNS_TEST_INIT;
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;
TAIL_ALLOC_OBJECT_CONST_PTR(struct kcmp_epoll_slot, 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(getpid(), getpid(), 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 (unsigned int i = 0; i < ARRAY_SIZE(slot_data); ++i) {
memcpy(slot, slot_data + i, sizeof(*slot));
do_kcmp(getpid(), -1, ARG_STR(KCMP_EPOLL_TFD), NULL_FD,
(uintptr_t) slot, 1);
}
pidns_print_leader();
puts("+++ exited with 0 +++");
return 0;
}
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