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authorSteven Rostedt <srostedt@redhat.com>2009-04-28 11:39:34 -0400
committerSteven Rostedt <rostedt@goodmis.org>2009-04-28 11:39:34 -0400
commitcd891ae0305601bdb4d2e7e85282961c4ff256cd (patch)
treeb425f3c4eba7bd80eb0566d3b233503a9f76cc9d
parent701970b3a83cc639c1ec8fc6f40a7871cb99426f (diff)
downloadlinux-cd891ae0305601bdb4d2e7e85282961c4ff256cd.tar.bz2
tracing: convert ftrace_dump spinlocks to raw
ftrace_dump is used for printing out the contents of the ftrace ring buffer to the console on failure. Currently it uses a spinlock to synchronize the output from multiple failures on different CPUs. This spin lock currently is a normal spinlock and can cause issues with lockdep and lock tracing. This patch converts it to raw since it is for error handling only. The lock is local to the ftrace_dump and is not used by any other infrastructure. [ Impact: prevent ftrace_dump from locking up by internal tracing ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b6183bc9ecae..5d704a41f836 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4114,7 +4114,8 @@ trace_printk_seq(struct trace_seq *s)
static void __ftrace_dump(bool disable_tracing)
{
- static DEFINE_SPINLOCK(ftrace_dump_lock);
+ static raw_spinlock_t ftrace_dump_lock =
+ (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
/* use static because iter can be a bit big for the stack */
static struct trace_iterator iter;
unsigned int old_userobj;
@@ -4123,7 +4124,8 @@ static void __ftrace_dump(bool disable_tracing)
int cnt = 0, cpu;
/* only one dump */
- spin_lock_irqsave(&ftrace_dump_lock, flags);
+ local_irq_save(flags);
+ __raw_spin_lock(&ftrace_dump_lock);
if (dump_ran)
goto out;
@@ -4195,7 +4197,8 @@ static void __ftrace_dump(bool disable_tracing)
}
out:
- spin_unlock_irqrestore(&ftrace_dump_lock, flags);
+ __raw_spin_unlock(&ftrace_dump_lock);
+ local_irq_restore(flags);
}
/* By default: disable tracing after the dump */