From 638cc92651d52087ea7e22c3cee5dfaa472e835b Mon Sep 17 00:00:00 2001 From: Siddh Raman Pant Date: Thu, 18 Apr 2024 18:58:06 +0530 Subject: [PATCH] Revert "tracing/trigger: Fix to return error if failed to alloc snapshot" This reverts commit bcf4a115a5068f3331fafb8c176c1af0da3d8b19 which is commit 0958b33ef5a04ed91f61cef4760ac412080c4e08 upstream. The change has an incorrect assumption about the return value because in the current stable trees for versions 5.15 and before, the following commit responsible for making 0 a success value is not present: b8cc44a4d3c1 ("tracing: Remove logic for registering multiple event triggers at a time") The return value should be 0 on failure in the current tree, because in the functions event_trigger_callback() and event_enable_trigger_func(), we have: ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); /* * The above returns on success the # of functions enabled, * but if it didn't find any functions it returns zero. * Consider no functions a failure too. */ if (!ret) { ret = -ENOENT; Cc: stable@kernel.org # 5.15, 5.10, 5.4, 4.19 Signed-off-by: Siddh Raman Pant Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 34925d01baf3ee62ab21c21efd9e2c44c24c004a) Signed-off-by: Vegard Nossum --- kernel/trace/trace_events_trigger.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 871ea0fa78bb..40c1a2dd48f0 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1127,10 +1127,8 @@ register_snapshot_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) { - int ret = tracing_alloc_snapshot_instance(file->tr); - - if (ret < 0) - return ret; + if (tracing_alloc_snapshot_instance(file->tr) != 0) + return 0; return register_trigger(glob, ops, data, file); }