blob: 6d629c8d0ed7881647f6ddbe96cfdaa4f0143204 [file] [log] [blame]
From 098507ae3ec2331476fb52e85d4040c1cc6d0ef4 Mon Sep 17 00:00:00 2001
From: Romain Izard <romain.izard.pro@gmail.com>
Date: Tue, 4 Mar 2014 10:09:39 +0100
Subject: trace: module: Maintain a valid user count
From: Romain Izard <romain.izard.pro@gmail.com>
commit 098507ae3ec2331476fb52e85d4040c1cc6d0ef4 upstream.
The replacement of the 'count' variable by two variables 'incs' and
'decs' to resolve some race conditions during module unloading was done
in parallel with some cleanup in the trace subsystem, and was integrated
as a merge.
Unfortunately, the formula for this replacement was wrong in the tracing
code, and the refcount in the traces was not usable as a result.
Use 'count = incs - decs' to compute the user count.
Link: http://lkml.kernel.org/p/1393924179-9147-1-git-send-email-romain.izard.pro@gmail.com
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Fixes: c1ab9cab7509 "merge conflict resolution"
Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/trace/events/module.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/trace/events/module.h
+++ b/include/trace/events/module.h
@@ -78,7 +78,7 @@ DECLARE_EVENT_CLASS(module_refcnt,
TP_fast_assign(
__entry->ip = ip;
- __entry->refcnt = __this_cpu_read(mod->refptr->incs) + __this_cpu_read(mod->refptr->decs);
+ __entry->refcnt = __this_cpu_read(mod->refptr->incs) - __this_cpu_read(mod->refptr->decs);
__assign_str(name, mod->name);
),