diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2023-12-15 10:12:20 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-12-15 16:25:55 -0800 |
| commit | 2cd3e3772e41377f32d6eea643e0590774e9187c (patch) | |
| tree | 6731bd8786a091dbf2e2447952df2b5d908efec6 /net/bpf | |
| parent | e72d88d18df4e03c80e64c2535f70c64f1dc6fc1 (diff) | |
x86/cfi,bpf: Fix bpf_struct_ops CFI
BPF struct_ops uses __arch_prepare_bpf_trampoline() to write
trampolines for indirect function calls. These tramplines much have
matching CFI.
In order to obtain the correct CFI hash for the various methods, add a
matching structure that contains stub functions, the compiler will
generate correct CFI which we can pilfer for the trampolines.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20231215092707.566977112@infradead.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net/bpf')
| -rw-r--r-- | net/bpf/bpf_dummy_struct_ops.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c index 2748f9d77b18..8906f7bdf4a9 100644 --- a/net/bpf/bpf_dummy_struct_ops.c +++ b/net/bpf/bpf_dummy_struct_ops.c @@ -12,6 +12,11 @@ extern struct bpf_struct_ops bpf_bpf_dummy_ops; /* A common type for test_N with return value in bpf_dummy_ops */ typedef int (*dummy_ops_test_ret_fn)(struct bpf_dummy_ops_state *state, ...); +static int dummy_ops_test_ret_function(struct bpf_dummy_ops_state *state, ...) +{ + return 0; +} + struct bpf_dummy_ops_test_args { u64 args[MAX_BPF_FUNC_ARGS]; struct bpf_dummy_ops_state state; @@ -62,7 +67,7 @@ static int dummy_ops_copy_args(struct bpf_dummy_ops_test_args *args) static int dummy_ops_call_op(void *image, struct bpf_dummy_ops_test_args *args) { - dummy_ops_test_ret_fn test = (void *)image; + dummy_ops_test_ret_fn test = (void *)image + cfi_get_offset(); struct bpf_dummy_ops_state *state = NULL; /* state needs to be NULL if args[0] is 0 */ @@ -119,6 +124,7 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr, op_idx = prog->expected_attach_type; err = bpf_struct_ops_prepare_trampoline(tlinks, link, &st_ops->func_models[op_idx], + &dummy_ops_test_ret_function, image, image + PAGE_SIZE); if (err < 0) goto out; @@ -219,6 +225,28 @@ static void bpf_dummy_unreg(void *kdata) { } +static int bpf_dummy_test_1(struct bpf_dummy_ops_state *cb) +{ + return 0; +} + +static int bpf_dummy_test_2(struct bpf_dummy_ops_state *cb, int a1, unsigned short a2, + char a3, unsigned long a4) +{ + return 0; +} + +static int bpf_dummy_test_sleepable(struct bpf_dummy_ops_state *cb) +{ + return 0; +} + +static struct bpf_dummy_ops __bpf_bpf_dummy_ops = { + .test_1 = bpf_dummy_test_1, + .test_2 = bpf_dummy_test_2, + .test_sleepable = bpf_dummy_test_sleepable, +}; + struct bpf_struct_ops bpf_bpf_dummy_ops = { .verifier_ops = &bpf_dummy_verifier_ops, .init = bpf_dummy_init, @@ -227,4 +255,5 @@ struct bpf_struct_ops bpf_bpf_dummy_ops = { .reg = bpf_dummy_reg, .unreg = bpf_dummy_unreg, .name = "bpf_dummy_ops", + .cfi_stubs = &__bpf_bpf_dummy_ops, }; |