dlan17/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

selftests/bpf: Fix cgroup_xattr/read_cgroupfs_xattr

Browse Source 
cgroup_xattr/read_cgroupfs_xattr has two issues:

1. cgroup_xattr/read_cgroupfs_xattr messes up lo without creating a netns
   first. This causes issue with other tests.

   Fix this by using a different hook (lsm.s/file_open) and not messing
   with lo.

2. cgroup_xattr/read_cgroupfs_xattr sets up cgroups without proper
   mount namespaces.

   Fix this by using the existing cgroup helpers. A new helper
   set_cgroup_xattr() is added to set xattr on cgroup files.

Fixes: f4fba2d6d2 ("selftests/bpf: Add tests for bpf_cgroup_read_xattr")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Closes: https://lore.kernel.org/bpf/CAADnVQ+iqMi2HEj_iH7hsx+XJAsqaMWqSDe4tzcGAnehFWA9Sw@mail.gmail.com/
Signed-off-by: Song Liu <song@kernel.org>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Tested-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/r/20250627191221.765921-1-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Song Liu
2025-06-27 14:34:08 -07:00
committed by Alexei Starovoitov
parent a5a7b25d75
commit bacdf5a0e6
4 changed files with 49 additions and 97 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tools/testing/selftests/bpf/cgroup_helpers.c
+21
View File
@@ -4,6 +4,7 @@
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/xattr.h>
#include <linux/limits.h>
#include <stdio.h>
#include <stdlib.h>
@@ -318,6 +319,26 @@ int join_parent_cgroup(const char *relative_path)
return join_cgroup_from_top(cgroup_path);
}
/**
* set_cgroup_xattr() - Set xattr on a cgroup dir
* @relative_path: The cgroup path, relative to the workdir, to set xattr
* @name: xattr name
* @value: xattr value
*
* This function set xattr on cgroup dir.
*
* On success, it returns 0, otherwise on failure it returns -1.
*/
int set_cgroup_xattr(const char *relative_path,
const char *name,
const char *value)
{
char cgroup_path[PATH_MAX + 1];
format_cgroup_path(cgroup_path, relative_path);
return setxattr(cgroup_path, name, value, strlen(value) + 1, 0);
}
/**
* __cleanup_cgroup_environment() - Delete temporary cgroups
*
tools/testing/selftests/bpf/cgroup_helpers.h
+4
View File
@@ -26,6 +26,10 @@ int join_cgroup(const char *relative_path);
int join_root_cgroup(void);
int join_parent_cgroup(const char *relative_path);
int set_cgroup_xattr(const char *relative_path,
const char *name,
const char *value);
int setup_cgroup_environment(void);
void cleanup_cgroup_environment(void);
tools/testing/selftests/bpf/prog_tests/cgroup_xattr.c
+22 -95
View File
@@ -7,133 +7,60 @@
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/xattr.h>
#include <test_progs.h>
#include "cgroup_helpers.h"
#include "read_cgroupfs_xattr.skel.h"
#include "cgroup_read_xattr.skel.h"
#define CGROUP_FS_ROOT "/sys/fs/cgroup/"
#define CGROUP_FS_PARENT CGROUP_FS_ROOT "foo/"
#define CGROUP_FS_PARENT "foo/"
#define CGROUP_FS_CHILD CGROUP_FS_PARENT "bar/"
static int move_pid_to_cgroup(const char *cgroup_folder, pid_t pid)
{
char filename[128];
char pid_str[64];
int procs_fd;
int ret;
snprintf(filename, sizeof(filename), "%scgroup.procs", cgroup_folder);
snprintf(pid_str, sizeof(pid_str), "%d", pid);
procs_fd = open(filename, O_WRONLY | O_APPEND);
if (!ASSERT_OK_FD(procs_fd, "open"))
return -1;
ret = write(procs_fd, pid_str, strlen(pid_str));
close(procs_fd);
if (!ASSERT_GT(ret, 0, "write cgroup.procs"))
return -1;
return 0;
}
static void reset_cgroups_and_lo(void)
{
rmdir(CGROUP_FS_CHILD);
rmdir(CGROUP_FS_PARENT);
system("ip addr del 1.1.1.1/32 dev lo");
system("ip link set dev lo down");
}
#define TMP_FILE "/tmp/selftests_cgroup_xattr"
static const char xattr_value_a[] = "bpf_selftest_value_a";
static const char xattr_value_b[] = "bpf_selftest_value_b";
static const char xattr_name[] = "user.bpf_test";
static int setup_cgroups_and_lo(void)
{
int err;
err = mkdir(CGROUP_FS_PARENT, 0755);
if (!ASSERT_OK(err, "mkdir 1"))
goto error;
err = mkdir(CGROUP_FS_CHILD, 0755);
if (!ASSERT_OK(err, "mkdir 2"))
goto error;
err = setxattr(CGROUP_FS_PARENT, xattr_name, xattr_value_a,
strlen(xattr_value_a) + 1, 0);
if (!ASSERT_OK(err, "setxattr 1"))
goto error;
err = setxattr(CGROUP_FS_CHILD, xattr_name, xattr_value_b,
strlen(xattr_value_b) + 1, 0);
if (!ASSERT_OK(err, "setxattr 2"))
goto error;
err = system("ip link set dev lo up");
if (!ASSERT_OK(err, "lo up"))
goto error;
err = system("ip addr add 1.1.1.1 dev lo");
if (!ASSERT_OK(err, "lo addr v4"))
goto error;
err = write_sysctl("/proc/sys/net/ipv4/ping_group_range", "0 0");
if (!ASSERT_OK(err, "write_sysctl"))
goto error;
return 0;
error:
reset_cgroups_and_lo();
return err;
}
static void test_read_cgroup_xattr(void)
{
struct sockaddr_in sa4 = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
};
int tmp_fd, parent_cgroup_fd = -1, child_cgroup_fd = -1;
struct read_cgroupfs_xattr *skel = NULL;
pid_t pid = gettid();
int sock_fd = -1;
int connect_fd = -1;
if (!ASSERT_OK(setup_cgroups_and_lo(), "setup_cgroups_and_lo"))
parent_cgroup_fd = test__join_cgroup(CGROUP_FS_PARENT);
if (!ASSERT_OK_FD(parent_cgroup_fd, "create parent cgroup"))
return;
if (!ASSERT_OK(move_pid_to_cgroup(CGROUP_FS_CHILD, pid),
"move_pid_to_cgroup"))
if (!ASSERT_OK(set_cgroup_xattr(CGROUP_FS_PARENT, xattr_name, xattr_value_a),
"set parent xattr"))
goto out;
child_cgroup_fd = test__join_cgroup(CGROUP_FS_CHILD);
if (!ASSERT_OK_FD(child_cgroup_fd, "create child cgroup"))
goto out;
if (!ASSERT_OK(set_cgroup_xattr(CGROUP_FS_CHILD, xattr_name, xattr_value_b),
"set child xattr"))
goto out;
skel = read_cgroupfs_xattr__open_and_load();
if (!ASSERT_OK_PTR(skel, "read_cgroupfs_xattr__open_and_load"))
goto out;
skel->bss->target_pid = pid;
skel->bss->target_pid = gettid();
if (!ASSERT_OK(read_cgroupfs_xattr__attach(skel), "read_cgroupfs_xattr__attach"))
goto out;
sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
if (!ASSERT_OK_FD(sock_fd, "sock create"))
goto out;
connect_fd = connect(sock_fd, &sa4, sizeof(sa4));
if (!ASSERT_OK_FD(connect_fd, "connect 1"))
goto out;
close(connect_fd);
tmp_fd = open(TMP_FILE, O_RDONLY | O_CREAT);
ASSERT_OK_FD(tmp_fd, "open tmp file");
close(tmp_fd);
ASSERT_TRUE(skel->bss->found_value_a, "found_value_a");
ASSERT_TRUE(skel->bss->found_value_b, "found_value_b");
out:
close(connect_fd);
close(sock_fd);
close(child_cgroup_fd);
close(parent_cgroup_fd);
read_cgroupfs_xattr__destroy(skel);
move_pid_to_cgroup(CGROUP_FS_ROOT, pid);
reset_cgroups_and_lo();
unlink(TMP_FILE);
}
void test_cgroup_xattr(void)
tools/testing/selftests/bpf/progs/read_cgroupfs_xattr.c
+2 -2
View File
@@ -17,8 +17,8 @@ static const char expected_value_b[] = "bpf_selftest_value_b";
bool found_value_a;
bool found_value_b;
SEC("lsm.s/socket_connect")
int BPF_PROG(test_socket_connect)
SEC("lsm.s/file_open")
int BPF_PROG(test_file_open)
{
u64 cgrp_id = bpf_get_current_cgroup_id();
struct cgroup_subsys_state *css, *tmp;