diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-01-23 18:27:59 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2014-01-23 18:27:59 +0100 |
| commit | 3132e107d608f8753240d82d61303c500fd515b4 (patch) | |
| tree | 2539c98c79927f04ebc1a2ab3ee1517a284c67b1 /kernel | |
| parent | tracing: Fix formatting of trace README file (diff) | |
| download | linux-3132e107d608f8753240d82d61303c500fd515b4.tar.xz linux-3132e107d608f8753240d82d61303c500fd515b4.zip | |
tracing: Check if tracing is enabled in trace_puts()
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.
Cc: stable@vger.kernel.org # 3.10+
Fixes: 09ae72348ecc "tracing: Add trace_puts() for even faster trace_printk() tracing"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7857ea9b3b9c..815c878f409b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -455,6 +455,9 @@ 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 */ local_save_flags(irq_flags); @@ -495,6 +498,9 @@ 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; + local_save_flags(irq_flags); buffer = global_trace.trace_buffer.buffer; event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, |