Commit 58f6e384 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Steven Rostedt (VMware)
Browse files

ftrace,bug: Improve traceoff_on_warn 

While doing some tracing, I found a huge portion of the per-cpu buffer
was taken by printk/serial output because we're disabling the trace far
too late (after printing the CUT string).

Improve matters for architectures that have GENERIC_BUG + _BUG_FLAGS by
killing the tracer in the exception handler before printing anything
much.

Link: https://lkml.kernel.org/r/20200528145240.GF706495@hirez.programming.kicks-ass.net



Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent bea24f76

lib/bug.c

+3 −0
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ 
#include <linux/bug.h>

#include <linux/sched.h>

#include <linux/rculist.h>

#include <linux/ftrace.h>



extern struct bug_entry __start___bug_table[], __stop___bug_table[];
@@ -153,6 +154,8 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) 
	if (!bug)

		return BUG_TRAP_TYPE_NONE;



	disable_trace_on_warning();



	file = NULL;

	line = 0;

	warning = 0;