linux-stable/tools/testing/selftests/bpf/prog_tests/test_bpffs.c
Alexei Starovoitov edb65ee5aa selftests/bpf: Add bpffs preload test.
Add a test that mounts two bpffs instances and checks progs.debug
and maps.debug for sanity data.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200819042759.51280-5-alexei.starovoitov@gmail.com
2020-08-20 16:02:36 +02:00

94 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#define _GNU_SOURCE
#include <sched.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <test_progs.h>
#define TDIR "/sys/kernel/debug"
static int read_iter(char *file)
{
/* 1024 should be enough to get contiguous 4 "iter" letters at some point */
char buf[1024];
int fd, len;
fd = open(file, 0);
if (fd < 0)
return -1;
while ((len = read(fd, buf, sizeof(buf))) > 0)
if (strstr(buf, "iter")) {
close(fd);
return 0;
}
close(fd);
return -1;
}
static int fn(void)
{
int err, duration = 0;
err = unshare(CLONE_NEWNS);
if (CHECK(err, "unshare", "failed: %d\n", errno))
goto out;
err = mount("", "/", "", MS_REC | MS_PRIVATE, NULL);
if (CHECK(err, "mount /", "failed: %d\n", errno))
goto out;
err = umount(TDIR);
if (CHECK(err, "umount " TDIR, "failed: %d\n", errno))
goto out;
err = mount("none", TDIR, "tmpfs", 0, NULL);
if (CHECK(err, "mount", "mount root failed: %d\n", errno))
goto out;
err = mkdir(TDIR "/fs1", 0777);
if (CHECK(err, "mkdir "TDIR"/fs1", "failed: %d\n", errno))
goto out;
err = mkdir(TDIR "/fs2", 0777);
if (CHECK(err, "mkdir "TDIR"/fs2", "failed: %d\n", errno))
goto out;
err = mount("bpf", TDIR "/fs1", "bpf", 0, NULL);
if (CHECK(err, "mount bpffs "TDIR"/fs1", "failed: %d\n", errno))
goto out;
err = mount("bpf", TDIR "/fs2", "bpf", 0, NULL);
if (CHECK(err, "mount bpffs " TDIR "/fs2", "failed: %d\n", errno))
goto out;
err = read_iter(TDIR "/fs1/maps.debug");
if (CHECK(err, "reading " TDIR "/fs1/maps.debug", "failed\n"))
goto out;
err = read_iter(TDIR "/fs2/progs.debug");
if (CHECK(err, "reading " TDIR "/fs2/progs.debug", "failed\n"))
goto out;
out:
umount(TDIR "/fs1");
umount(TDIR "/fs2");
rmdir(TDIR "/fs1");
rmdir(TDIR "/fs2");
umount(TDIR);
exit(err);
}
void test_test_bpffs(void)
{
int err, duration = 0, status = 0;
pid_t pid;
pid = fork();
if (CHECK(pid == -1, "clone", "clone failed %d", errno))
return;
if (pid == 0)
fn();
err = waitpid(pid, &status, 0);
if (CHECK(err == -1 && errno != ECHILD, "waitpid", "failed %d", errno))
return;
if (CHECK(WEXITSTATUS(status), "bpffs test ", "failed %d", WEXITSTATUS(status)))
return;
}