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/*
* Test --decode-fds=eventfd option.
*
* Copyright (c) 2024 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#ifdef HAVE_SYS_EVENTFD_H
# include "scno.h"
# include "xmalloc.h"
# include <inttypes.h>
# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <unistd.h>
# include <sys/eventfd.h>
static long
k_eventfd(const unsigned int value, const unsigned int flags)
{
const kernel_ulong_t fill = (kernel_ulong_t) 0xdefaced00000000ULL;
const kernel_ulong_t bad = (kernel_ulong_t) 0xbadc0dedbadc0dedULL;
const kernel_ulong_t arg1 = fill | value;
const kernel_ulong_t arg2 = fill | flags;
return syscall(__NR_eventfd2, arg1, arg2, bad, bad, bad, bad);
}
struct fdinfo {
const char *search_pfx;
size_t search_pfx_len;
void *data;
bool avail;
};
static void
parse_fdinfo_efd_id(const char *value, void *data)
{
int *efd_id = data;
*efd_id = (int) strtol(value, NULL, 10);
if (*efd_id < 0)
*efd_id = -1;
}
static size_t
procfs_check_avail_efd_data(pid_t pid, int fd, struct fdinfo *fdinfo_lines,
size_t fdinfo_array_size)
{
char *fdinfo_path = xasprintf("/proc/%u/fdinfo/%u", pid, fd);
FILE *f = fopen(fdinfo_path, "r");
if (!f)
perror_msg_and_skip("fopen: %s", fdinfo_path);
free(fdinfo_path);
char *line = NULL;
size_t sz = 0;
size_t matches = 0;
while (getline(&line, &sz, f) > 0) {
for (size_t i = 0; i < fdinfo_array_size; i++) {
const char *search_pfx = fdinfo_lines[i].search_pfx;
size_t search_pfx_len = fdinfo_lines[i].search_pfx_len;
if (strncmp(line, search_pfx, search_pfx_len))
continue;
if (fdinfo_lines[i].data) {
const char *value = line + search_pfx_len;
parse_fdinfo_efd_id(value, fdinfo_lines[i].data);
}
fdinfo_lines[i].avail = true;
matches++;
break;
}
}
free(line);
fclose(f);
return matches;
}
static void
print_eventfd_details(struct fdinfo *fdinfo_lines,
uint64_t efd_counter, int efd_semaphore)
{
if (fdinfo_lines[0].avail) {
printf("<{eventfd-count=%#" PRIx64, efd_counter);
int efd_id = *(int *) fdinfo_lines[1].data;
if (efd_id != -1) {
printf(", eventfd-id=%d", efd_id);
if (fdinfo_lines[2].avail)
printf(", eventfd-semaphore=%d", efd_semaphore);
}
printf("}>");
}
}
int
main(void)
{
static const char efd_counter_pfx[] = "eventfd-count:";
static const char efd_id_pfx[] = "eventfd-id:";
static const char efd_semaphore_pfx[] = "eventfd-semaphore:";
const pid_t pid = getpid();
const unsigned int u = 5;
uint64_t efd_counter = u;
int efd_id = -1;
int efd_semaphore = 0;
struct fdinfo fdinfo_lines[] = {
{
.search_pfx = efd_counter_pfx,
.search_pfx_len = sizeof(efd_counter_pfx) - 1,
},
{
.search_pfx = efd_id_pfx,
.search_pfx_len = sizeof(efd_id_pfx) - 1,
.data = (void *) &efd_id,
},
{
.search_pfx = efd_semaphore_pfx,
.search_pfx_len = sizeof(efd_semaphore_pfx) - 1,
}
};
size_t fdinfo_array_size = ARRAY_SIZE(fdinfo_lines);
int efd0 = k_eventfd(u, 0);
if (efd0 < 0)
perror_msg_and_skip("eventfd");
procfs_check_avail_efd_data(pid, efd0, fdinfo_lines, fdinfo_array_size);
printf("eventfd2(%u, 0) = %d", u, efd0);
print_eventfd_details(fdinfo_lines, efd_counter, efd_semaphore);
printf("\n");
uint64_t read_efd_count;
if (read(efd0, &read_efd_count, sizeof(read_efd_count))
!= sizeof(read_efd_count))
perror_msg_and_fail("read");
efd_counter -= read_efd_count;
printf("fchdir(%d", efd0);
print_eventfd_details(fdinfo_lines, efd_counter, efd_semaphore);
printf(") = %s\n", sprintrc(fchdir(efd0)));
efd_counter = u;
efd_id = -1;
efd_semaphore = 1;
fdinfo_lines[0].avail = false;
fdinfo_lines[1].avail = false;
fdinfo_lines[2].avail = false;
int efd1 = k_eventfd(u, EFD_SEMAPHORE);
if (efd1 < 0)
perror_msg_and_skip("eventfd");
procfs_check_avail_efd_data(pid, efd1, fdinfo_lines, fdinfo_array_size);
printf("eventfd2(%u, EFD_SEMAPHORE) = %d", u, efd1);
print_eventfd_details(fdinfo_lines, efd_counter, efd_semaphore);
printf("\n");
if (read(efd1, &read_efd_count, sizeof(read_efd_count))
!= sizeof(read_efd_count))
perror_msg_and_fail("read");
efd_counter -= read_efd_count;
printf("fchdir(%d", efd1);
print_eventfd_details(fdinfo_lines, efd_counter, efd_semaphore);
printf(") = %s\n", sprintrc(fchdir(efd1)));
close(efd1);
close(efd0);
return 0;
}
#else
SKIP_MAIN_UNDEFINED("HAVE_SYS_EVENTFD_H")
#endif
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