Commit 1f9f4f47 authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google)
Browse files

tracing/probes: Fix to add NULL check for BTF APIs 

Since find_btf_func_param() abd btf_type_by_id() can return NULL,
the caller must check the return value correctly.

Link: https://lore.kernel.org/all/169024903951.395371.11361556840733470934.stgit@devnote2/



Fixes: b576e097 ("tracing/probes: Support function parameters if BTF is available")
Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 6eaae198

kernel/trace/trace_probe.c

+4 −4
Original line number Diff line number Diff line
@@ -386,12 +386,12 @@ static const struct btf_type *find_btf_func_proto(const char *funcname) 


	/* Get BTF_KIND_FUNC type */

	t = btf_type_by_id(btf, id);

	if (!btf_type_is_func(t))

	if (!t || !btf_type_is_func(t))

		return ERR_PTR(-ENOENT);



	/* The type of BTF_KIND_FUNC is BTF_KIND_FUNC_PROTO */

	t = btf_type_by_id(btf, t->type);

	if (!btf_type_is_func_proto(t))

	if (!t || !btf_type_is_func_proto(t))

		return ERR_PTR(-ENOENT);



	return t;
@@ -443,7 +443,7 @@ static int parse_btf_arg(const char *varname, struct fetch_insn *code, 
	if (!ctx->params) {

		params = find_btf_func_param(ctx->funcname, &ctx->nr_params,

					     ctx->flags & TPARG_FL_TPOINT);

		if (IS_ERR(params)) {

		if (IS_ERR_OR_NULL(params)) {

			trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);

			return PTR_ERR(params);

		}
@@ -1273,7 +1273,7 @@ const char **traceprobe_expand_meta_args(int argc, const char *argv[], 


	params = find_btf_func_param(ctx->funcname, &nr_params,

				     ctx->flags & TPARG_FL_TPOINT);

	if (IS_ERR(params)) {

	if (IS_ERR_OR_NULL(params)) {

		if (args_idx != -1) {

			/* $arg* requires BTF info */

			trace_probe_log_err(0, NOSUP_BTFARG);