Re: [PATCH] io_uring: Add to traces the req pointer when available

From: Jens Axboe
Date: Tue May 25 2021 - 18:28:27 EST


On 5/25/21 3:48 PM, Olivier Langlois wrote:
> On Tue, 2021-05-25 at 17:26 -0400, Olivier Langlois wrote:
>> but the pointers should be hashed by trace.
>>
>> That would be nice if someone more knowledgeable about the tracing
>> system could jump in and comment about the hash-ptr option and tell
>> when it is applied and when it is not...
>
> My concern about hashing pointers directly in the io_uring code
> directly. It is that by doing so will make it impossible for a
> sufficiently priviledged user to get the raw pointer values without
> reverting back the pointer hashing stuff.
>
> that would not be the right way to address the security concern if the
> tracing subsystem already hash them by default and is configurable to
> display raw pointers if desired.
>
> My issue is that I haven't been able to see hashed pointers output from
> trace.

Just a quick guess, but does it rely on using %p to print the pointers?

--
Jens Axboe