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  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:	Thu, 17 Mar 2016 20:17:59 -0400
From:	Chris Metcalf <>
To:	<>, Peter Zijlstra <>
CC:	Russell King <>,
	Thomas Gleixner <>,
	Aaron Tomlin <>,
	Ingo Molnar <>, Andrew Morton <>,
	Daniel Thompson <>, <>,
Subject: Re: [PATCH v2 1/4] nmi_backtrace: add more trigger_*_cpu_backtrace()

On 3/17/2016 6:55 PM, Paul E. McKenney wrote:
> The RCU stall-warn stack traces can be ugly, agreed.
> That said, RCU used to use NMI-based stack traces, but switched to the
> current scheme due to the NMIs having the unfortunate habit of locking
> things up, which IIRC often meant no stack traces at all.  If I recall
> correctly, one of the problems was self-deadlock in printk().

Steven Rostedt enabled the per_cpu printk func support in June 2014, and
the nmi_backtrace code uses it to just capture printk output to percpu
buffers, so I think it's going to be a lot more robust than earlier attempts.

Chris Metcalf, Mellanox Technologies

Powered by blists - more mailing lists