Messages in this thread Patch in this message | | | Date | Tue, 26 Nov 2013 07:58:59 -0500 | From | Steven Rostedt <> | Subject | Re: [BUG] 3.13-rc1 kernel crash when enable all tracepoints |
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On Tue, 26 Nov 2013 12:38:53 +0800 Jovi Zhangwei <jovi.zhangwei@gmail.com> wrote:
> Hi, > > I'm not sure this issue already be fixed or not, it can be reproduced > permanently. > > (I didn't use git-bisect yet, you guys might can understand it quickly) > > #echo 1 > /sys/kernel/debug/tracing/events/enable > > [ 160.472176] BUG: unable to handle kernel NULL pointer dereference > at (null) > [ 160.472176] IP: [<ffffffff8132ae40>] strlen+0x0/0x30
I hit this bug last night when testing a fix for another bug. I have a patch for this too, and will send it out after I put it through my tests.
You can try it out.
-- Steve
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 52594b2..bdac88c 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -372,7 +372,8 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call) \ __data_size += (len) * sizeof(type); #undef __string -#define __string(item, src) __dynamic_array(char, item, strlen(src) + 1) +#define __string(item, src) __dynamic_array(char, item, \ + strlen((src) ? (src) : "(null)") + 1) #undef DECLARE_EVENT_CLASS #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ @@ -501,7 +502,7 @@ static inline notrace int ftrace_get_offsets_##call( \ #undef __assign_str #define __assign_str(dst, src) \ - strcpy(__get_str(dst), src); + strcpy(__get_str(dst), (src) ? (src) : "(null)"); #undef TP_fast_assign #define TP_fast_assign(args...) args
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