android13/external/ltp/testcases/kernel/syscalls/pipe2/pipe2_04.c

107 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2020 Francis Laniel. All rights reserved.
* Author: Francis Laniel <laniel_francis@privacyrequired.com>
*
* Test Description:
* This Program tests getting and setting the pipe size.
* It also tests what happen when you write to a full pipe depending on whether
* O_NONBLOCK is set or not.
*/
#define _GNU_SOURCE
#include <stdlib.h>
#include <features.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include "lapi/fcntl.h"
#include "tst_test.h"
static int fds[2];
static int flags;
static void test_pipe2(void)
{
int ret;
pid_t pid;
/*
* This ensures parent process is still in non-block mode when
* using -i parameter. Subquent writes hould return -1 and errno
* set to either EAGAIN or EWOULDBLOCK because pipe is already full.
*/
SAFE_FCNTL(fds[1], F_SETFL, flags | O_NONBLOCK);
ret = write(fds[1], "x", 1);
if (ret == -1) {
if (errno == EAGAIN)
tst_res(TPASS | TERRNO, "write failed as expected");
else
tst_brk(TFAIL | TERRNO, "write failed expected EAGAIN but got");
} else {
tst_res(TFAIL, "write() succeeded unexpectedly");
}
pid = SAFE_FORK();
if (!pid) {
SAFE_FCNTL(fds[1], F_SETFL, flags & ~O_NONBLOCK);
SAFE_WRITE(1, fds[1], "x", 1);
}
if (TST_PROCESS_STATE_WAIT(pid, 'S', 1000) < 0)
tst_res(TFAIL, "Child process is not blocked");
else
tst_res(TPASS, "Child process is blocked");
SAFE_KILL(pid, SIGKILL);
SAFE_WAIT(NULL);
}
static void setup(void)
{
int page_size, pipe_size;
char *write_buffer;
SAFE_PIPE2(fds, O_NONBLOCK);
page_size = SAFE_SYSCONF(_SC_PAGESIZE);
flags = SAFE_FCNTL(fds[1], F_GETFL);
if (!(flags & O_NONBLOCK))
tst_brk(TCONF, "O_NONBLOCK flag must be set");
/*
* A pipe has two file descriptors.
* But in the kernel these two file descriptors point to the same pipe.
* So setting size from first file handle set size for the pipe.
*/
SAFE_FCNTL(fds[0], F_SETPIPE_SZ, 0);
/*
* So getting size from the second file descriptor return the size of
* the pipe which was changed before with first file descriptor.
*/
pipe_size = SAFE_FCNTL(fds[1], F_GETPIPE_SZ);
if (pipe_size != page_size)
tst_res(TFAIL, "Pipe size (%d) must be page size (%d)",
pipe_size, page_size);
write_buffer = SAFE_MALLOC(pipe_size);
memset(write_buffer, 'x', pipe_size);
SAFE_WRITE(1, fds[1], write_buffer, pipe_size);
free(write_buffer);
}
static void cleanup(void)
{
if (fds[0] > 0)
SAFE_CLOSE(fds[0]);
if (fds[1] > 0)
SAFE_CLOSE(fds[1]);
}
static struct tst_test test = {
.min_kver = "2.6.35",
.test_all = test_pipe2,
.setup = setup,
.cleanup = cleanup,
.forks_child = 1,
};