linux_dsm_epyc7002/tools/testing/selftests/bpf/prog_tests/spinlock.c
Yonghong Song d6f1837107 selftests/bpf: fix segfault of test_progs when prog loading failed
The test_progs subtests, test_spin_lock() and test_map_lock(),
requires BTF present to run successfully.
Currently, when BTF failed to load, test_progs will segfault,
  $ ./test_progs
  ...
  12: (bf) r1 = r8
  13: (85) call bpf_spin_lock#93
  map 'hash_map' has to have BTF in order to use bpf_spin_lock

  libbpf: -- END LOG --
  libbpf: failed to load program 'map_lock_demo'
  libbpf: failed to load object './test_map_lock.o'
  test_map_lock:bpf_prog_load errno 13
  Segmentation fault

The segfault is caused by uninitialized variable "obj", which
is used in bpf_object__close(obj), when bpf prog failed to load.

Initializing variable "obj" to NULL in two occasions fixed the problem.
  $ ./test_progs
  ...
  Summary: 219 PASSED, 2 FAILED

Fixes: b4d4556c32 ("selftests/bpf: add bpf_spin_lock verifier tests")
Fixes: ba72a7b4ba ("selftests/bpf: test for BPF_F_LOCK")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-12 21:55:54 +01:00

30 lines
716 B
C

// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
void test_spinlock(void)
{
const char *file = "./test_spin_lock.o";
pthread_t thread_id[4];
struct bpf_object *obj = NULL;
int prog_fd;
int err = 0, i;
void *ret;
err = bpf_prog_load(file, BPF_PROG_TYPE_CGROUP_SKB, &obj, &prog_fd);
if (err) {
printf("test_spin_lock:bpf_prog_load errno %d\n", errno);
goto close_prog;
}
for (i = 0; i < 4; i++)
assert(pthread_create(&thread_id[i], NULL,
&spin_lock_thread, &prog_fd) == 0);
for (i = 0; i < 4; i++)
assert(pthread_join(thread_id[i], &ret) == 0 &&
ret == (void *)&prog_fd);
goto close_prog_noerr;
close_prog:
error_cnt++;
close_prog_noerr:
bpf_object__close(obj);
}