diff options
| -rw-r--r-- | include/uapi/linux/bpf.h | 7 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 43 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 15 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 7 |
4 files changed, 72 insertions, 0 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 3544ec5234f0..89688f16ad60 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4841,6 +4841,12 @@ union bpf_attr { * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier. * **-EDEADLK** if callback_fn tried to call bpf_timer_cancel() on its * own timer which would have led to a deadlock otherwise. + * + * u64 bpf_get_func_ip(void *ctx) + * Description + * Get address of the traced function (for tracing programs). + * Return + * Address of the traced function. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5016,6 +5022,7 @@ union bpf_attr { FN(timer_set_callback), \ FN(timer_start), \ FN(timer_cancel), \ + FN(get_func_ip), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 344ee67265cc..ceef190514e4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6161,6 +6161,27 @@ static int check_bpf_snprintf_call(struct bpf_verifier_env *env, return err; } +static int check_get_func_ip(struct bpf_verifier_env *env) +{ + enum bpf_attach_type eatype = env->prog->expected_attach_type; + enum bpf_prog_type type = resolve_prog_type(env->prog); + int func_id = BPF_FUNC_get_func_ip; + + if (type == BPF_PROG_TYPE_TRACING) { + if (eatype != BPF_TRACE_FENTRY && eatype != BPF_TRACE_FEXIT && + eatype != BPF_MODIFY_RETURN) { + verbose(env, "func %s#%d supported only for fentry/fexit/fmod_ret programs\n", + func_id_name(func_id), func_id); + return -ENOTSUPP; + } + return 0; + } + + verbose(env, "func %s#%d not supported for program type %d\n", + func_id_name(func_id), func_id, type); + return -ENOTSUPP; +} + static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { @@ -6439,6 +6460,12 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn if (func_id == BPF_FUNC_get_stackid || func_id == BPF_FUNC_get_stack) env->prog->call_get_stack = true; + if (func_id == BPF_FUNC_get_func_ip) { + if (check_get_func_ip(env)) + return -ENOTSUPP; + env->prog->call_get_func_ip = true; + } + if (changes_data) clear_all_pkt_pointers(env); return 0; @@ -12632,6 +12659,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) { struct bpf_prog *prog = env->prog; bool expect_blinding = bpf_jit_blinding_enabled(prog); + enum bpf_prog_type prog_type = resolve_prog_type(prog); struct bpf_insn *insn = prog->insnsi; const struct bpf_func_proto *fn; const int insn_cnt = prog->len; @@ -12998,6 +13026,21 @@ patch_map_ops_generic: continue; } + /* Implement bpf_get_func_ip inline. */ + if (prog_type == BPF_PROG_TYPE_TRACING && + insn->imm == BPF_FUNC_get_func_ip) { + /* Load IP address from ctx - 8 */ + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8); + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1); + if (!new_prog) + return -ENOMEM; + + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } + patch_call_imm: fn = env->ops->get_func_proto(insn->imm, env->prog); /* all functions that have prototype and verifier allowed diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 6c77d25137e0..3e71503eeb23 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -948,6 +948,19 @@ const struct bpf_func_proto bpf_snprintf_btf_proto = { .arg5_type = ARG_ANYTHING, }; +BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx) +{ + /* This helper call is inlined by verifier. */ + return ((u64 *)ctx)[-1]; +} + +static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { + .func = bpf_get_func_ip_tracing, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1058,6 +1071,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_for_each_map_elem_proto; case BPF_FUNC_snprintf: return &bpf_snprintf_proto; + case BPF_FUNC_get_func_ip: + return &bpf_get_func_ip_proto_tracing; default: return bpf_base_func_proto(func_id); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 3544ec5234f0..89688f16ad60 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4841,6 +4841,12 @@ union bpf_attr { * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier. * **-EDEADLK** if callback_fn tried to call bpf_timer_cancel() on its * own timer which would have led to a deadlock otherwise. + * + * u64 bpf_get_func_ip(void *ctx) + * Description + * Get address of the traced function (for tracing programs). + * Return + * Address of the traced function. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5016,6 +5022,7 @@ union bpf_attr { FN(timer_set_callback), \ FN(timer_start), \ FN(timer_cancel), \ + FN(get_func_ip), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper |