linux-kernel - Re: [PATCH v2] lockdep: Show address of "struct lockdep_map" at print

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 27 Mar 2018 13:23:57 -0700 (PDT)
From:   David Rientjes <rientjes@...gle.com>
To:     Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
cc:     peterz@...radead.org, mhocko@...e.com, mingo@...hat.com,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org, bp@...e.de,
        tglx@...utronix.de
Subject: Re: [PATCH v2] lockdep: Show address of "struct lockdep_map" at
 print_lock().

On Tue, 27 Mar 2018, Tetsuo Handa wrote:

> Since "struct lockdep_map" is embedded into lock objects, we can know
> which instance of a lock object is acquired using hlock->instance field.
> This will help finding which threads are causing a lock contention.
> 
> Currently, print_lock() is printing hlock->acquire_ip field in both
> "[<%px>]" and "%pS" format. But "[<%px>]" is little useful nowadays, for
> we use scripts/faddr2line which receives "%pS" for finding the location
> in the source code. And I want to reduce amount of output, for
> debug_show_all_locks() might print a lot.
> 
> Therefore, this patch replaces "[<%px>]" for printing hlock->acquire_ip
> field with "%p" for printing hlock->instance field.
> 
> [  251.305475] 3 locks held by a.out/31106:
> [  251.308949]  #0: 00000000b0f753ba (&mm->mmap_sem){++++}, at: copy_process.part.41+0x10d5/0x1fe0
> [  251.314283]  #1: 00000000ef64d539 (&mm->mmap_sem/1){+.+.}, at: copy_process.part.41+0x10fe/0x1fe0
> [  251.319618]  #2: 00000000b41a282e (&mapping->i_mmap_rwsem){++++}, at: copy_process.part.41+0x12f2/0x1fe0
> 
> Signed-off-by: Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Cc: Ingo Molnar <mingo@...hat.com>
> Cc: Borislav Petkov <bp@...e.de>
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: David Rientjes <rientjes@...gle.com>
> Cc: Michal Hocko <mhocko@...e.com>

Acked-by: David Rientjes <rientjes@...gle.com>