2024-02-26 04:02:50

by Masami Hiramatsu

Subject: [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init

From: Masami Hiramatsu (Google) <[email protected]>

Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init().
This is a cleanup, so the behavior is not changed.

Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
---
kernel/trace/trace_eprobe.c | 2 +-
kernel/trace/trace_probe.c | 10 ++++++----
kernel/trace/trace_probe.h | 2 +-
kernel/trace/trace_uprobe.c | 2 +-
4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 03c851f57969..eb72def7410f 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -220,7 +220,7 @@ static struct trace_eprobe *alloc_event_probe(const char *group,
if (!ep->event_system)
goto error;

- ret = trace_probe_init(&ep->tp, this_event, group, false);
+ ret = trace_probe_init(&ep->tp, this_event, group, false, nargs);
if (ret < 0)
goto error;

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 67a0b9cbb648..93f36f8a108e 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1423,9 +1423,6 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
struct probe_arg *parg = &tp->args[i];
const char *body;

- /* Increment count for freeing args in error case */
- tp->nr_args++;
-
body = strchr(arg, '=');
if (body) {
if (body - arg > MAX_ARG_NAME_LEN) {
@@ -1810,7 +1807,7 @@ void trace_probe_cleanup(struct trace_probe *tp)
}

int trace_probe_init(struct trace_probe *tp, const char *event,
- const char *group, bool alloc_filter)
+ const char *group, bool alloc_filter, int nargs)
{
struct trace_event_call *call;
size_t size = sizeof(struct trace_probe_event);
@@ -1846,6 +1843,11 @@ int trace_probe_init(struct trace_probe *tp, const char *event,
goto error;
}

+ tp->nr_args = nargs;
+ /* Make sure pointers in args[] are NULL */
+ if (nargs)
+ memset(tp->args, 0, sizeof(tp->args[0]) * nargs);
+
return 0;

error:
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index c1877d018269..ed8d1052f8a7 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -338,7 +338,7 @@ static inline bool trace_probe_has_single_file(struct trace_probe *tp)
}

int trace_probe_init(struct trace_probe *tp, const char *event,
- const char *group, bool alloc_filter);
+ const char *group, bool alloc_filter, int nargs);
void trace_probe_cleanup(struct trace_probe *tp);
int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
void trace_probe_unlink(struct trace_probe *tp);
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index a84b85d8aac1..796ebcae9b38 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -337,7 +337,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
if (!tu)
return ERR_PTR(-ENOMEM);

- ret = trace_probe_init(&tu->tp, event, group, true);
+ ret = trace_probe_init(&tu->tp, event, group, true, nargs);
if (ret < 0)
goto error;

2024-03-01 03:35:54

by Steven Rostedt

Subject: Re: [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init

On Mon, 26 Feb 2024 12:58:23 +0900
"Masami Hiramatsu (Google)" <[email protected]> wrote:

> From: Masami Hiramatsu (Google) <[email protected]>
>
> Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init().
> This is a cleanup, so the behavior is not changed.

The change is fine, but the change log does not say why this was done.

Reviewed-by: Steven Rostedt (Google) <[email protected]>

-- Steve


>
> Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> ---

2024-03-03 15:48:36

by Masami Hiramatsu

Subject: Re: [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init

On Thu, 29 Feb 2024 22:37:53 -0500
Steven Rostedt <[email protected]> wrote:

> On Mon, 26 Feb 2024 12:58:23 +0900
> "Masami Hiramatsu (Google)" <[email protected]> wrote:
>
> > From: Masami Hiramatsu (Google) <[email protected]>
> >
> > Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init().
> > This is a cleanup, so the behavior is not changed.
>
> The change is fine, but the change log does not say why this was done.

This change is to get the number of trace_probe arguments while parsing
the argument strings.

Thank you,

>
> Reviewed-by: Steven Rostedt (Google) <[email protected]>
>
> -- Steve
>
>
> >
> > Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
> > ---


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