lkml.org 
[lkml]   [2022]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] rtla: fix double free
From
On 7/25/22 16:56, Steven Rostedt wrote:
> On Mon, 25 Jul 2022 15:46:40 +0200
> Andreas Schwab <schwab@suse.de> wrote:
>
>> On Jul 25 2022, Daniel Bristot de Oliveira wrote:
>>
>>> Hi Andreas
>>>
>>> On 7/25/22 15:10, Andreas Schwab wrote:
>>>> Don't call trace_instance_destroy in trace_instance_init when it fails,
>>>> this is done by the caller.
>>>
>>> Regarding the Subject, are you seeing a double-free error, or it is just an
>>> optimization?
>>
>> A double free nowadays is almost always an error, due to better malloc
>> checking.
>>
>>> AFAICS, trace_instance_destroy() checks the pointers before calling free().
>>
>> That doesn't help when the pointer is not cleared afterwards. Do you
>> prefer that?
>>
>>> Why am I asking? because if it is a double-free bug, we need to add the "Fixes:"
>>> tag,
>>
>> It's the first time I tried running rtla, so I don't know whether it is
>> a regression, but from looking at the history it appears to have been
>> introduced already in commit 0605bf009f18 ("rtla: Add osnoise tool")
>>
>
> I think the real fix is to make trace_instance_destroy() be able to be
> called more than once.
>
> void trace_instance_destroy(struct trace_instance *trace)
> {
> if (trace->inst) {
> disable_tracer(trace->inst);
> destroy_instance(trace->inst);
> trace->inst = NULL
ah! right, it was missing this... ^^^
-- Daniel

\
 
 \ /
  Last update: 2022-07-25 17:24    [W:0.769 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site