Adding support to use get_func_[arg|arg_cnt] helpers in raw_tp/tp_btf programs.
We can use get_func_[arg|ret|arg_cnt] helpers in fentry/fexit/fmod_ret programs currently. If we try to use get_func_[arg|arg_cnt] helpers in raw_tp/tp_btf programs, verifier will fail to load the program with: ; __u64 cnt = bpf_get_func_arg_cnt(ctx); 3: (85) call bpf_get_func_arg_cnt#185 unknown func bpf_get_func_arg_cnt#185 Adding get_func_[arg|arg_cnt] helpers in raw_tp_prog_func_proto and tracing_prog_func_proto for raw tracepoint. Adding 1 arg on ctx of raw tracepoint program and make it stores number of arguments on ctx-8, so it's easy to verify argument index and find argument's position. Signed-off-by: KaFai Wan <[email protected]> --- kernel/trace/bpf_trace.c | 17 ++++++++++++++--- net/bpf/test_run.c | 13 +++++-------- 2 files changed, 19 insertions(+), 11 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 52c432a44aeb..eb4c56013493 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1892,6 +1892,10 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_stackid_proto_raw_tp; case BPF_FUNC_get_stack: return &bpf_get_stack_proto_raw_tp; + case BPF_FUNC_get_func_arg: + return &bpf_get_func_arg_proto; + case BPF_FUNC_get_func_arg_cnt: + return &bpf_get_func_arg_cnt_proto; case BPF_FUNC_get_attach_cookie: return &bpf_get_attach_cookie_proto_tracing; default: @@ -1950,10 +1954,16 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_d_path: return &bpf_d_path_proto; case BPF_FUNC_get_func_arg: + if (prog->type == BPF_PROG_TYPE_TRACING && + prog->expected_attach_type == BPF_TRACE_RAW_TP) + return &bpf_get_func_arg_proto; return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL; case BPF_FUNC_get_func_ret: return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL; case BPF_FUNC_get_func_arg_cnt: + if (prog->type == BPF_PROG_TYPE_TRACING && + prog->expected_attach_type == BPF_TRACE_RAW_TP) + return &bpf_get_func_arg_cnt_proto; return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL; case BPF_FUNC_get_attach_cookie: if (prog->type == BPF_PROG_TYPE_TRACING && @@ -2312,7 +2322,7 @@ void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) #define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__) #define SARG(X) u64 arg##X -#define COPY(X) args[X] = arg##X +#define COPY(X) args[X + 1] = arg##X #define __DL_COM (,) #define __DL_SEM (;) @@ -2323,9 +2333,10 @@ void __bpf_trace_run(struct bpf_raw_tp_link *link, u64 *args) void bpf_trace_run##x(struct bpf_raw_tp_link *link, \ REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \ { \ - u64 args[x]; \ + u64 args[x + 1]; \ + args[0] = x; \ REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \ - __bpf_trace_run(link, args); \ + __bpf_trace_run(link, args + 1); \ } \ EXPORT_SYMBOL_GPL(bpf_trace_run##x) BPF_TRACE_DEFN_x(1); diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index aaf13a7d58ed..8cb285187270 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -760,6 +760,7 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog, void __user *ctx_in = u64_to_user_ptr(kattr->test.ctx_in); __u32 ctx_size_in = kattr->test.ctx_size_in; struct bpf_raw_tp_test_run_info info; + u64 args[MAX_BPF_FUNC_ARGS + 1] = {}; int cpu = kattr->test.cpu, err = 0; int current_cpu; @@ -776,14 +777,11 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog, if ((kattr->test.flags & BPF_F_TEST_RUN_ON_CPU) == 0 && cpu != 0) return -EINVAL; - if (ctx_size_in) { - info.ctx = memdup_user(ctx_in, ctx_size_in); - if (IS_ERR(info.ctx)) - return PTR_ERR(info.ctx); - } else { - info.ctx = NULL; - } + if (ctx_size_in && copy_from_user(args + 1, ctx_in, ctx_size_in)) + return -EFAULT; + args[0] = ctx_size_in / sizeof(u64); + info.ctx = args + 1; info.prog = prog; current_cpu = get_cpu(); @@ -807,7 +805,6 @@ int bpf_prog_test_run_raw_tp(struct bpf_prog *prog, copy_to_user(&uattr->test.retval, &info.retval, sizeof(u32))) err = -EFAULT; - kfree(info.ctx); return err; } -- 2.43.0
