From 40adaf51cb318131073d1ba8233d473cc105ecbf Mon Sep 17 00:00:00 2001
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Date: Fri, 18 Nov 2022 10:15:34 +0900
Subject: [PATCH] tracing/eprobe: Fix eprobe filter to make a filter correctly
Since the eprobe filter was defined based on the eprobe's trace event
itself, it doesn't work correctly. Use the original trace event of
the eprobe when making the filter so that the filter works correctly.
Without this fix:
# echo 'e syscalls/sys_enter_openat \
flags_rename=$flags:u32 if flags < 1000' >> dynamic_events
# echo 1 > events/eprobes/sys_enter_openat/enable
[ 114.551550] event trace: Could not enable event sys_enter_openat
-bash: echo: write error: Invalid argument
With this fix:
# echo 'e syscalls/sys_enter_openat \
flags_rename=$flags:u32 if flags < 1000' >> dynamic_events
# echo 1 > events/eprobes/sys_enter_openat/enable
# tail trace
cat-241 [000] ...1. 266.498449: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0
cat-242 [000] ...1. 266.977640: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0
Link: https://lore.kernel.org/all/166823166395.1385292.8931770640212414483.stgit@devnote3/
Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support")
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Tested-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace_eprobe.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index e888446d80fa2..123d2c0a6b688 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -643,7 +643,7 @@ new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file)
INIT_LIST_HEAD(&trigger->list);
if (ep->filter_str) {
- ret = create_event_filter(file->tr, file->event_call,
+ ret = create_event_filter(file->tr, ep->event,
ep->filter_str, false, &filter);
if (ret)
goto error;