Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3132e107 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
Browse files

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: 09ae7234 "tracing: Add trace_puts() for even faster trace_printk() tracing"
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 71485c45

kernel/trace/trace.c

+6 −0
Original line number Diff line number Diff line
@@ -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,