Re: [PATCH v2 05/10] tracing/boot: Show correct histogram error command
From: Masami Hiramatsu
Date: Mon Aug 09 2021 - 20:48:49 EST
On Tue, 10 Aug 2021 00:48:26 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
> Since trigger_process_regex() modifies given trigger actions
> while parsing, the error message couldn't show what command
> was passed to the trigger_process_regex() when it returns
> an error.
>
> To fix that, show the backed up trigger action command
> instead of parsed buffer.
>
> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> ---
> kernel/trace/trace_boot.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
> index 69558f149620..cfe4a415b468 100644
> --- a/kernel/trace/trace_boot.c
> +++ b/kernel/trace/trace_boot.c
> @@ -422,6 +422,7 @@ trace_boot_init_histograms(struct trace_event_file *file,
> {
> struct xbc_node *node;
> const char *p;
> + char *tmp;
>
> xbc_node_for_each_subkey(hnode, node) {
> p = xbc_node_get_data(node);
> @@ -429,15 +430,19 @@ trace_boot_init_histograms(struct trace_event_file *file,
> continue;
> /* All digit started node should be instances. */
> if (trace_boot_compose_hist_cmd(node, buf, size) == 0) {
> + tmp = kstrdup(buf, GFP_KERNEL);
> if (trigger_process_regex(file, buf) < 0)
> - pr_err("Failed to apply hist trigger: %s\n", buf);
> + pr_err("Failed to apply hist trigger: %s\n", tmp);
> + kfree(tmp);
> }
> }
>
> if (xbc_node_find_child(hnode, "keys")) {
> if (trace_boot_compose_hist_cmd(hnode, buf, size) == 0)
> + tmp = kstrdup(buf, GFP_KERNEL);
> if (trigger_process_regex(file, buf) < 0)
> - pr_err("Failed to apply hist trigger: %s\n", buf);
> + pr_err("Failed to apply hist trigger: %s\n", tmp);
> + kfree(tmp);
And this lacks '{}' for the 2nd if...
> }
> }
> #else
> @@ -488,7 +493,7 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
> if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
> pr_err("action string is too long: %s\n", p);
> else if (trigger_process_regex(file, buf) < 0)
> - pr_err("Failed to apply an action: %s\n", buf);
> + pr_err("Failed to apply an action: %s\n", p);
> }
> anode = xbc_node_find_child(enode, "hist");
> if (anode)
>
--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>