From: Steven Rostedt (VMware) Date: Thu, 9 Aug 2018 19:37:59 +0000 (-0400) Subject: uprobes: Use synchronize_rcu() not synchronize_sched() X-Git-Tag: v4.9.126~33 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0ef606320567f081475f57224639efb40bfddd69;p=platform%2Fkernel%2Flinux-amlogic.git uprobes: Use synchronize_rcu() not synchronize_sched() commit 016f8ffc48cb01d1e7701649c728c5d2e737d295 upstream. While debugging another bug, I was looking at all the synchronize*() functions being used in kernel/trace, and noticed that trace_uprobes was using synchronize_sched(), with a comment to synchronize with {u,ret}_probe_trace_func(). When looking at those functions, the data is protected with "rcu_read_lock()" and not with "rcu_read_lock_sched()". This is using the wrong synchronize_*() function. Link: http://lkml.kernel.org/r/20180809160553.469e1e32@gandalf.local.home Cc: stable@vger.kernel.org Fixes: 70ed91c6ec7f8 ("tracing/uprobes: Support ftrace_event_file base multibuffer") Acked-by: Oleg Nesterov Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 7882629..f0ab801 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -969,7 +969,7 @@ probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file) list_del_rcu(&link->list); /* synchronize with u{,ret}probe_trace_func */ - synchronize_sched(); + synchronize_rcu(); kfree(link); if (!list_empty(&tu->tp.files))