From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
The variable $comm is hard coded as a string, which is true for both
kprobes and uprobes, but for event probes (eprobes) it is a field name. In
most cases the "comm" field would be a string, but there's no guarantee of
that fact.
Do not assume that comm is a string. Not to mention, it currently forces
comm fields to fault, as string processing for event probes is currently
broken.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_probe.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index dec657af363c..23dcd52ad45c 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -622,9 +622,10 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
/*
* Since $comm and immediate string can not be dereferenced,
- * we can find those by strcmp.
+ * we can find those by strcmp. But ignore for eprobes.
*/
- if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) {
+ if (!(flags & TPARG_FL_TPOINT) &&
+ strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) {
/* The type of $comm must be "string", and not an array. */
if (parg->count || (t && strcmp(t, "string")))
goto out;
--
2.35.1
