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
Cc: Andrii Nakryiko <andriin@xxxxxx>
Cc: John Fastabend <john.fastabend@xxxxxxxxx>
Cc: Wenbo Zhang <ethercflow@xxxxxxxxx>
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
net/bpf/test_run.c | 19 +++++++++++++++-
.../selftests/bpf/prog_tests/fentry_fexit.c | 2 +-
.../testing/selftests/bpf/progs/fentry_test.c | 22 +++++++++++++++++++
.../testing/selftests/bpf/progs/fexit_test.c | 22 +++++++++++++++++++
4 files changed, 63 insertions(+), 2 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:
diff --git a/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c b/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c
index 83493bd5745c..109d0345a2be 100644
--- a/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c
+++ b/tools/testing/selftests/bpf/prog_tests/fentry_fexit.c
@@ -36,7 +36,7 @@ void test_fentry_fexit(void)
fentry_res = (__u64 *)fentry_skel->bss;
fexit_res = (__u64 *)fexit_skel->bss;
printf("%lld\n", fentry_skel->bss->test1_result);
- for (i = 0; i < 6; i++) {
+ for (i = 0; i < 8; i++) {
CHECK(fentry_res[i] != 1, "result",
"fentry_test%d failed err %lld\n", i + 1, fentry_res[i]);
CHECK(fexit_res[i] != 1, "result",
diff --git a/tools/testing/selftests/bpf/progs/fentry_test.c b/tools/testing/selftests/bpf/progs/fentry_test.c
index 9365b686f84b..5f645fdaba6f 100644
--- a/tools/testing/selftests/bpf/progs/fentry_test.c
+++ b/tools/testing/selftests/bpf/progs/fentry_test.c
@@ -55,3 +55,25 @@ int BPF_PROG(test6, __u64 a, void *b, short c, int d, void * e, __u64 f)
e == (void *)20 && f == 21;
return 0;
}
+
+struct bpf_fentry_test_t {
+ struct bpf_fentry_test_t *a;
+};
+
+__u64 test7_result = 0;
+SEC("fentry/bpf_fentry_test7")
+int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
+{
+ if (arg == 0)
+ test7_result = 1;
+ return 0;
+}
+
+__u64 test8_result = 0;
+SEC("fentry/bpf_fentry_test8")
+int BPF_PROG(test8, struct bpf_fentry_test_t *arg)
+{
+ if (arg->a == 0)
+ test8_result = 1;
+ return 0;
+}
diff --git a/tools/testing/selftests/bpf/progs/fexit_test.c b/tools/testing/selftests/bpf/progs/fexit_test.c
index bd1e17d8024c..0952affb22a6 100644
--- a/tools/testing/selftests/bpf/progs/fexit_test.c
+++ b/tools/testing/selftests/bpf/progs/fexit_test.c
@@ -56,3 +56,25 @@ int BPF_PROG(test6, __u64 a, void *b, short c, int d, void *e, __u64 f, int ret)
e == (void *)20 && f == 21 && ret == 111;
return 0;
}
+
+struct bpf_fentry_test_t {
+ struct bpf_fentry_test *a;
+};
+
+__u64 test7_result = 0;
+SEC("fexit/bpf_fentry_test7")
+int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
+{
+ if (arg == 0)
+ test7_result = 1;
+ return 0;
+}
+
+__u64 test8_result = 0;
+SEC("fexit/bpf_fentry_test8")
+int BPF_PROG(test8, struct bpf_fentry_test_t *arg)
+{
+ if (arg->a == 0)
+ test8_result = 1;
+ return 0;
+}
--
2.24.1
