path: root/kernel
diff options
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2014-01-23 12:27:59 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-13 13:47:59 -0800
commitf74bb7400b79ea730fc5626dc9172d1c236a7498 (patch)
treee22fc88ba5a03021c1330b6bf8691fc20392eff2 /kernel
parentfb23eaf401bf37602ff9a222d99980ea4d219765 (diff)
tracing: Check if tracing is enabled in trace_puts()
commit 3132e107d608f8753240d82d61303c500fd515b4 upstream. If trace_puts() is used very early in boot up, it can crash the machine if it is called before the ring buffer is allocated. If a trace_printk() is used with no arguments, then it will be converted into a trace_puts() and suffer the same fate. Fixes: 09ae72348ecc "tracing: Add trace_puts() for even faster trace_printk() tracing" Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b7f5471ae51..6dbdf277c8f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -424,6 +424,9 @@ int __trace_puts(unsigned long ip, const char *str, int size)
unsigned long irq_flags;
int alloc;
+ if (unlikely(tracing_selftest_running || tracing_disabled))
+ return 0;
alloc = sizeof(*entry) + size + 2; /* possible \n added */
@@ -464,6 +467,9 @@ int __trace_bputs(unsigned long ip, const char *str)
unsigned long irq_flags;
int size = sizeof(struct bputs_entry);
+ if (unlikely(tracing_selftest_running || tracing_disabled))
+ return 0;
buffer = global_trace.trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,