Re: [PATCH] tracing/ftrace: fix the check on nopped sites

From: Zhaolei
Date: Tue Mar 17 2009 - 23:38:37 EST


* From: "Steven Rostedt" <rostedt@xxxxxxxxxxx>
>
>
> On Mon, 16 Mar 2009, Frederic Weisbecker wrote:
>
>> Impact: fix a dynamic tracing failure
>>
>> Recently, the function and function graph tracers failed to use dynamic
>> tracing after the following commit:
>>
>> fa9d13cf135efbd454453a53b6299976bea245a9
>> (ftrace: don't try to __ftrace_replace_code on !FTRACE_FL_CONVERTED rec)
>>
>> The patch is right except a mistake on the check for the FTRACE_FL_CONVERTED
>> flag. The code patching is aborted in case of successfully nopped sites.
>> What we want is the opposite: ignore the callsites that haven't been nopped.
>>
>> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
>> ---
>> kernel/trace/ftrace.c | 2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
>> index 90d5729..7847806 100644
>> --- a/kernel/trace/ftrace.c
>> +++ b/kernel/trace/ftrace.c
>> @@ -537,7 +537,7 @@ static void ftrace_replace_code(int enable)
>> */
>> if (rec->flags & FTRACE_FL_FREE ||
>> rec->flags & FTRACE_FL_FAILED ||
>> - rec->flags & FTRACE_FL_CONVERTED)
>> + !(rec->flags & FTRACE_FL_CONVERTED))
>> continue;
>>
>> /* ignore updates to this record's mcount site */
>> --
Hello,

Sorry for my fault.

B.R.
Zhaolei
>
> Heh, I just found this bug too, and wrote a patch. But you posted before I
> did, so I'll let you have it ;-)
>
> Acked-by: Steven Rostedt <srostedt@xxxxxxxxxx>
>
> -- Steve
>
>
>èº{.nÇ+?·?®?­?+%?Ëlzwm?éb?맲æìr¸?zX§»®w¥?{ayºÊ?Ú?ë,j­¢f£¢·h??àz¹®w¥¢¸ ¢·¦j:+v?¨?wèjØm¶?ÿ¾«?êçzZ+?ù???Ý¢j"?ú!¶iO?æ¬z·?vØ^¶m§ÿðà nÆ?àþY&?