diff options
author | Hao Sun <sunhao.th@gmail.com> | 2022-12-22 05:44:14 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-24 09:19:55 +0300 |
commit | 3093027183f2846365a76b2fb1e1309f1960084a (patch) | |
tree | 0ee3780b2ce65f2b2bbf872426396183cec46eae /tools/testing | |
parent | c7c36bb6eafd3f349d2371a1c6f2a3a72400acbc (diff) | |
download | linux-3093027183f2846365a76b2fb1e1309f1960084a.tar.xz |
selftests/bpf: check null propagation only neither reg is PTR_TO_BTF_ID
[ Upstream commit cedebd74cf3883f0384af9ec26b4e6f8f1964dd4 ]
Verify that nullness information is not porpagated in the branches
of register to register JEQ and JNE operations if one of them is
PTR_TO_BTF_ID. Implement this in C level so we can use CO-RE.
Signed-off-by: Hao Sun <sunhao.th@gmail.com>
Suggested-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20221222024414.29539-2-sunhao.th@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools/testing')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/jeq_infer_not_null.c | 9 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/jeq_infer_not_null_fail.c | 42 |
2 files changed, 51 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/jeq_infer_not_null.c b/tools/testing/selftests/bpf/prog_tests/jeq_infer_not_null.c new file mode 100644 index 000000000000..3add34df5767 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/jeq_infer_not_null.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <test_progs.h> +#include "jeq_infer_not_null_fail.skel.h" + +void test_jeq_infer_not_null(void) +{ + RUN_TESTS(jeq_infer_not_null_fail); +} diff --git a/tools/testing/selftests/bpf/progs/jeq_infer_not_null_fail.c b/tools/testing/selftests/bpf/progs/jeq_infer_not_null_fail.c new file mode 100644 index 000000000000..f46965053acb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/jeq_infer_not_null_fail.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include "bpf_misc.h" + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 1); + __type(key, u64); + __type(value, u64); +} m_hash SEC(".maps"); + +SEC("?raw_tp") +__failure __msg("R8 invalid mem access 'map_value_or_null") +int jeq_infer_not_null_ptr_to_btfid(void *ctx) +{ + struct bpf_map *map = (struct bpf_map *)&m_hash; + struct bpf_map *inner_map = map->inner_map_meta; + u64 key = 0, ret = 0, *val; + + val = bpf_map_lookup_elem(map, &key); + /* Do not mark ptr as non-null if one of them is + * PTR_TO_BTF_ID (R9), reject because of invalid + * access to map value (R8). + * + * Here, we need to inline those insns to access + * R8 directly, since compiler may use other reg + * once it figures out val==inner_map. + */ + asm volatile("r8 = %[val];\n" + "r9 = %[inner_map];\n" + "if r8 != r9 goto +1;\n" + "%[ret] = *(u64 *)(r8 +0);\n" + : [ret] "+r"(ret) + : [inner_map] "r"(inner_map), [val] "r"(val) + : "r8", "r9"); + + return ret; +} |