tracing: protect trace_printk from recursion
authorSteven Rostedt <srostedt@redhat.com>
Fri, 17 Apr 2009 20:13:55 +0000 (16:13 -0400)
committerSteven Rostedt <rostedt@goodmis.org>
Fri, 17 Apr 2009 20:21:35 +0000 (16:21 -0400)
commit3189cdb31622f4e40688ce5a6fc5d940b42bc805
tree89f370c0079281c55f37230c17951514c1b508c9
parent261842b7c9099f56de2eb969c8ad65402d68e00e
tracing: protect trace_printk from recursion

trace_printk can be called from any context, including NMIs.
If this happens, then we must test for for recursion before
grabbing any spinlocks.

This patch prevents trace_printk from being called recursively.

[ Impact: prevent hard lockup in lockdep event tracer ]

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
kernel/trace/trace.c