2024-05-27 09:46:48

by Carlos López

Subject: [PATCH v2] tracing/probes: fix error check in parse_btf_field()

btf_find_struct_member() might return NULL or an error via the
ERR_PTR() macro. However, its caller in parse_btf_field() only checks
for the NULL condition. Fix this by using IS_ERR() and returning the
error up the stack.

Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access")
Signed-off-by: Carlos López <[email protected]>
---
v2: added call to trace_probe_log_err()

kernel/trace/trace_probe.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 5e263c141574..39877c80d6cb 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -554,6 +554,10 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
anon_offs = 0;
field = btf_find_struct_member(ctx->btf, type, fieldname,
&anon_offs);
+ if (IS_ERR(field)) {
+ trace_probe_log_err(ctx->offset, BAD_BTF_TID);
+ return PTR_ERR(field);
+ }
if (!field) {
trace_probe_log_err(ctx->offset, NO_BTF_FIELD);
return -ENOENT;
--
2.35.3

2024-05-27 12:31:56

by Masami Hiramatsu

Subject: Re: [PATCH v2] tracing/probes: fix error check in parse_btf_field()

On Mon, 27 May 2024 11:43:52 +0200
Carlos López <[email protected]> wrote:

> btf_find_struct_member() might return NULL or an error via the
> ERR_PTR() macro. However, its caller in parse_btf_field() only checks
> for the NULL condition. Fix this by using IS_ERR() and returning the
> error up the stack.
>

Thanks for updating! This version looks good to me.
Let me pick this to probes/fixes.

Thank you,


> Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access")
> Signed-off-by: Carlos López <[email protected]>
> ---
> v2: added call to trace_probe_log_err()
>
> kernel/trace/trace_probe.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 5e263c141574..39877c80d6cb 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -554,6 +554,10 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
> anon_offs = 0;
> field = btf_find_struct_member(ctx->btf, type, fieldname,
> &anon_offs);
> + if (IS_ERR(field)) {
> + trace_probe_log_err(ctx->offset, BAD_BTF_TID);
> + return PTR_ERR(field);
> + }
> if (!field) {
> trace_probe_log_err(ctx->offset, NO_BTF_FIELD);
> return -ENOENT;
> --
> 2.35.3
>


--
Masami Hiramatsu (Google) <[email protected]>