Re: [PATCH] tracepoint: don't make assumptions about length of string on task rename

[Sasha Levin <sasha.levin@oracle.com>]

On 08/28/2015 11:02 AM, Steven Rostedt wrote:
> On Fri, 28 Aug 2015 07:06:58 -0400
> Sasha Levin <sasha.levin@oracle.com> wrote:
> 
>> While the dest comm string size is assured to be at least TASK_COMM_LEN long,
>> doing a memcpy() also adds the assumption that the source is at least that
>> long as well, which isn't assured, and isn't true in cases such as:
>>
>> 	set_task_comm(worker->task, "kworker/dying");
>>
>> This leads to accessing invalid memory.
>>
>> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> 
> Acked-by: Steven Rostedt <rostedt@goodmis.org>
> 
> Should this go to stable as well?

Yup.

> Also, as the memcpy was just faster than a strcpy, the static length
> was used. Perhaps we should convert that to a dynamic length string.
> But that should be a separate patch as this one fixes a possible bug,
> and the conversion to a dynamic string is just an enhancement.

That'll slow things down for the common case, no?


Thanks,
Sasha