[PATCH v2 4/7] tracing: Split the event string parsing logic into a dedicated function
From: Thomas Weißschuh <hidden>
Date: 2026-09-08 06:22:20
Also in:
linux-doc, lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
This new function can be tested with a KUnit test to prevent regressions when adding new fields to the format. Signed-off-by: Thomas Weißschuh <redacted> --- kernel/trace/trace_events.c | 61 +++++++++++++++++++++++++-------------------- 1 file changed, 34 insertions(+), 27 deletions(-)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 88d0212ff2ca..4104ccbebf4a 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c@@ -1440,25 +1440,18 @@ static int __ftrace_set_clr_event(struct trace_array *tr, const char *match, return ret; } -int ftrace_set_clr_event(struct trace_array *tr, const char *arg_buf, int set) +static void +ftrace_parse_event_string(char *buf, char **match, char **sub, char **event, char **mod) { - char *event = NULL, *sub = NULL, *match, *mod; - char *buf; - - if (!tr) - return -ENOENT; - - char *dupped_buf __free(kfree) = kstrdup(arg_buf, GFP_KERNEL); - if (!dupped_buf) - return -ENOMEM; - buf = dupped_buf; + *event = NULL; + *sub = NULL; /* Modules events can be appended with :mod:<module> */ - mod = strstr(buf, ":mod:"); - if (mod) { - *mod = '\0'; + *mod = strstr(buf, ":mod:"); + if (*mod) { + **mod = '\0'; /* move to the module name */ - mod += 5; + *mod += 5; } /*
@@ -1473,21 +1466,35 @@ int ftrace_set_clr_event(struct trace_array *tr, const char *arg_buf, int set) * the name <name> or any event that matches <name> */ - match = strsep(&buf, ":"); + *match = strsep(&buf, ":"); if (buf) { - sub = match; - event = buf; - match = NULL; - - if (!strlen(sub) || strcmp(sub, "*") == 0) - sub = NULL; - if (!strlen(event) || strcmp(event, "*") == 0) - event = NULL; - } else if (mod) { + *sub = *match; + *event = buf; + *match = NULL; + + if (!strlen(*sub) || strcmp(*sub, "*") == 0) + *sub = NULL; + if (!strlen(*event) || strcmp(*event, "*") == 0) + *event = NULL; + } else if (*mod) { /* Allow wildcard for no length or star */ - if (!strlen(match) || strcmp(match, "*") == 0) - match = NULL; + if (!strlen(*match) || strcmp(*match, "*") == 0) + *match = NULL; } +} + +int ftrace_set_clr_event(struct trace_array *tr, const char *arg_buf, int set) +{ + char *event, *sub, *match, *mod; + + if (!tr) + return -ENOENT; + + char *dupped_buf __free(kfree) = kstrdup(arg_buf, GFP_KERNEL); + if (!dupped_buf) + return -ENOMEM; + + ftrace_parse_event_string(dupped_buf, &match, &sub, &event, &mod); return __ftrace_set_clr_event(tr, match, sub, event, set, mod); }
--
2.55.0