[PATCH v4 05/10] tracing/boot: Show correct histogram error command

Masami Hiramatsu
2021-08-10T02:07:53Z

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@kernel.org>
---
Changes in v4:
- Fix to add braces for if block.
---
kernel/trace/trace_boot.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 1a2b270e9cda..1060b0446032 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 +430,20 @@ 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)
+ 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);
+ }
}
}
#else
@@ -488,7 +494,7 @@ 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)