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| author | Yonghong Song <yhs@fb.com> | 2020-06-30 10:12:41 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-06-30 22:21:29 +0200 |
| commit | d923021c2ce12acb50dc7086a1bf66eed82adf6a (patch) | |
| tree | ab388fa92b8b8bf4d3be8683567ee1b3788ebbf9 /net/bpf | |
| parent | 01c66c48d4f0825a202d4163800b706a1d2ec7ad (diff) | |
| download | linux-d923021c2ce12acb50dc7086a1bf66eed82adf6a.tar.gz linux-d923021c2ce12acb50dc7086a1bf66eed82adf6a.tar.bz2 linux-d923021c2ce12acb50dc7086a1bf66eed82adf6a.zip | |
bpf: Add tests for PTR_TO_BTF_ID vs. null comparison
Add two tests for PTR_TO_BTF_ID vs. null ptr comparison,
one for PTR_TO_BTF_ID in the ctx structure and the
other for PTR_TO_BTF_ID after one level pointer chasing.
In both cases, the test ensures condition is not
removed.
For example, for this test
struct bpf_fentry_test_t {
struct bpf_fentry_test_t *a;
};
int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
{
if (arg == 0)
test7_result = 1;
return 0;
}
Before the previous verifier change, we have xlated codes:
int test7(long long unsigned int * ctx):
; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
0: (79) r1 = *(u64 *)(r1 +0)
; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
1: (b4) w0 = 0
2: (95) exit
After the previous verifier change, we have:
int test7(long long unsigned int * ctx):
; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
0: (79) r1 = *(u64 *)(r1 +0)
; if (arg == 0)
1: (55) if r1 != 0x0 goto pc+4
; test7_result = 1;
2: (18) r1 = map[id:6][0]+48
4: (b7) r2 = 1
5: (7b) *(u64 *)(r1 +0) = r2
; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
6: (b4) w0 = 0
7: (95) exit
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200630171241.2523875-1-yhs@fb.com
Diffstat (limited to 'net/bpf')
| -rw-r--r-- | net/bpf/test_run.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index bfd4ccd80847..b03c469cd01f 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -147,6 +147,20 @@ int noinline bpf_fentry_test6(u64 a, void *b, short c, int d, void *e, u64 f) return a + (long)b + c + d + (long)e + f; } +struct bpf_fentry_test_t { + struct bpf_fentry_test_t *a; +}; + +int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg) +{ + return (long)arg; +} + +int noinline bpf_fentry_test8(struct bpf_fentry_test_t *arg) +{ + return (long)arg->a; +} + int noinline bpf_modify_return_test(int a, int *b) { *b += 1; @@ -185,6 +199,7 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog, const union bpf_attr *kattr, union bpf_attr __user *uattr) { + struct bpf_fentry_test_t arg = {}; u16 side_effect = 0, ret = 0; int b = 2, err = -EFAULT; u32 retval = 0; @@ -197,7 +212,9 @@ int bpf_prog_test_run_tracing(struct bpf_prog *prog, bpf_fentry_test3(4, 5, 6) != 15 || bpf_fentry_test4((void *)7, 8, 9, 10) != 34 || bpf_fentry_test5(11, (void *)12, 13, 14, 15) != 65 || - bpf_fentry_test6(16, (void *)17, 18, 19, (void *)20, 21) != 111) + bpf_fentry_test6(16, (void *)17, 18, 19, (void *)20, 21) != 111 || + bpf_fentry_test7((struct bpf_fentry_test_t *)0) != 0 || + bpf_fentry_test8(&arg) != 0) goto out; break; case BPF_MODIFY_RETURN: |