Re: [PATCH 4/8] tracing: probe-events: Log errro for exceeding the number of arguments

Masami Hiramatsu
2025-03-03T02:17:26Z

On Wed, 26 Feb 2025 15:19:10 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:

> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Add error message when the number of arguments exceeeds the limitation.
>

Hmm, this is not a fix patch so this should be handled as enhancement.
I'll drop this from probes/fixes.

Thanks,

> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
> kernel/trace/trace_eprobe.c | 2 ++
> kernel/trace/trace_fprobe.c | 5 ++++-
> kernel/trace/trace_kprobe.c | 5 ++++-
> kernel/trace/trace_probe.h | 1 +
> kernel/trace/trace_uprobe.c | 9 +++++++--
> 5 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
> index 82fd637cfc19..af9fa0632b57 100644
> --- a/kernel/trace/trace_eprobe.c
> +++ b/kernel/trace/trace_eprobe.c
> @@ -913,6 +913,8 @@ static int __trace_eprobe_create(int argc, const char *argv[])
> }
>
> if (argc - 2 > MAX_TRACE_ARGS) {
> + trace_probe_log_set_index(2);
> + trace_probe_log_err(0, TOO_MANY_ARGS);
> ret = -E2BIG;
> goto error;
> }
> diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
> index e27305d31fc5..372936163c21 100644
> --- a/kernel/trace/trace_fprobe.c
> +++ b/kernel/trace/trace_fprobe.c
> @@ -1201,8 +1201,11 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
> argc = new_argc;
> argv = new_argv;
> }
> - if (argc > MAX_TRACE_ARGS)
> + if (argc > MAX_TRACE_ARGS) {
> + trace_probe_log_set_index(2);
> + trace_probe_log_err(0, TOO_MANY_ARGS);
> return -E2BIG;
> + }
>
> ret = traceprobe_expand_dentry_args(argc, argv, &dbuf);
> if (ret)
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index d8d5f18a141a..8287b175667f 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -1007,8 +1007,11 @@ static int trace_kprobe_create_internal(int argc, const char *argv[],
> argc = new_argc;
> argv = new_argv;
> }
> - if (argc > MAX_TRACE_ARGS)
> + if (argc > MAX_TRACE_ARGS) {
> + trace_probe_log_set_index(2);
> + trace_probe_log_err(0, TOO_MANY_ARGS);
> return -E2BIG;
> + }
>
> ret = traceprobe_expand_dentry_args(argc, argv, &dbuf);
> if (ret)
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index c47ca002347a..6075afc8ea67 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -546,6 +546,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
> C(BAD_BTF_TID, "Failed to get BTF type info."),\
> C(BAD_TYPE4STR, "This type does not fit for string."),\
> C(NEED_STRING_TYPE, "$comm and immediate-string only accepts string type"),\
> + C(TOO_MANY_ARGS, "Too many arguments are specified"), \
> C(TOO_MANY_EARGS, "Too many entry arguments specified"),
>
> #undef C
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index ccc762fbb69c..3386439ec9f6 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -562,8 +562,14 @@ static int __trace_uprobe_create(int argc, const char **argv)
>
> if (argc < 2)
> return -ECANCELED;
> - if (argc - 2 > MAX_TRACE_ARGS)
> +
> + trace_probe_log_init("trace_uprobe", argc, argv);
> +
> + if (argc - 2 > MAX_TRACE_ARGS) {
> + trace_probe_log_set_index(2);
> + trace_probe_log_err(0, TOO_MANY_ARGS);
> return -E2BIG;
> + }
>
> if (argv[0][1] == ':')
> event = &argv[0][2];
> @@ -582,7 +588,6 @@ static int __trace_uprobe_create(int argc, const char **argv)
> return -ECANCELED;
> }
>
> - trace_probe_log_init("trace_uprobe", argc, argv);
> trace_probe_log_set_index(1); /* filename is the 2nd argument */
>
> *arg++ = '\0';
>

--
Masami Hiramatsu (Google) <mhiramat@kernel.org>