[PATCH] tracing/probe: Fix same probe event argument matching

From: Srikar Dronamraju
Date: Tue Sep 24 2019 - 07:49:20 EST


Commit fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event")
tries to reject a event which matches an already existing probe.

However it currently continues to match arguments and rejects adding a
probe even when the arguments don't match. Fix this by only rejecting a
probe if and only if all the arguments match.

Fixes: fe60b0ce8e73 ("tracing/probe: Reject exactly same probe event")
Signed-off-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 5 +++--
kernel/trace/trace_uprobe.c | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index a6697e28ddda..402dc3ce88d3 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -549,10 +549,11 @@ static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
for (i = 0; i < orig->tp.nr_args; i++) {
if (strcmp(orig->tp.args[i].comm,
comp->tp.args[i].comm))
- continue;
+ break;
}

- return true;
+ if (i == orig->tp.nr_args)
+ return true;
}

return false;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 34dd6d0016a3..dd884341f5c5 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -431,10 +431,11 @@ static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
for (i = 0; i < orig->tp.nr_args; i++) {
if (strcmp(orig->tp.args[i].comm,
comp->tp.args[i].comm))
- continue;
+ break;
}

- return true;
+ if (i == orig->tp.nr_args)
+ return true;
}

return false;
--
2.18.1