[v2] tracing: fprobe-event: Fix to check tracepoint event and return
Commit Message
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fix to check the tracepoint event is not valid with $retval.
The commit 08c9306fc2e3 ("tracing/fprobe-event: Assume fprobe is
a return event by $retval") introduced automatic return probe
conversion with $retval. But since tracepoint event does not
support return probe, $retval is not acceptable.
Without this fix, ftracetest, tprobe_syntax_errors.tc fails;
[22] Tracepoint probe event parser error log check [FAIL]
----
# tail 22-tprobe_syntax_errors.tc-log.mRKroL
+ ftrace_errlog_check trace_fprobe t kfree ^$retval dynamic_events
+ printf %s t kfree
+ wc -c
+ pos=8
+ printf %s t kfree ^$retval
+ tr -d ^
+ command=t kfree $retval
+ echo Test command: t kfree $retval
Test command: t kfree $retval
+ echo
----
So 't kfree $retval' should fail (tracepoint doesn't support
return probe) but passed it.
Fixes: 08c9306fc2e3 ("tracing/fprobe-event: Assume fprobe is a return event by $retval")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
Changes in v2:
- update the patch description to show what test fails.
---
kernel/trace/trace_fprobe.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
@@ -927,11 +927,12 @@ static int parse_symbol_and_return(int argc, const char *argv[],
for (i = 2; i < argc; i++) {
tmp = strstr(argv[i], "$retval");
if (tmp && !isalnum(tmp[7]) && tmp[7] != '_') {
+ if (is_tracepoint) {
+ trace_probe_log_set_index(i);
+ trace_probe_log_err(tmp - argv[i], RETVAL_ON_PROBE);
+ return -EINVAL;
+ }
*is_return = true;
- /*
- * NOTE: Don't check is_tracepoint here, because it will
- * be checked when the argument is parsed.
- */
break;
}
}