linux-kernel - Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code

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Message-ID: <20160818132507.GD22490@lerouge>
Date:	Thu, 18 Aug 2016 15:25:09 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Josh Poimboeuf <jpoimboe@...hat.com>
Cc:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>,
	"H . Peter Anvin" <hpa@...or.com>, x86@...nel.org,
	linux-kernel@...r.kernel.org,
	Andy Lutomirski <luto@...capital.net>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Brian Gerst <brgerst@...il.com>,
	Kees Cook <keescook@...omium.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Byungchul Park <byungchul.park@....com>,
	Nilay Vaish <nilayvaish@...il.com>
Subject: Re: [PATCH v4 00/57] x86/dumpstack: rewrite x86 stack dump code

On Thu, Aug 18, 2016 at 08:05:40AM -0500, Josh Poimboeuf wrote:
> 
> The x86 stack dump code is a bit of a mess.  dump_trace() uses
> callbacks, and each user of it seems to have slightly different
> requirements, so there are several slightly different callbacks floating
> around.
> 
> Also there are some upcoming features which will require more changes to
> the stack dump code: reliable stack detection for live patching,
> hardened user copy, and the DWARF unwinder.  Each of those features
> would at least need more callbacks and/or callback interfaces, resulting
> in a much bigger mess than what we have today.
> 
> Before doing all that, we should try to clean things up and replace
> dump_trace() with something cleaner and more flexible.
> 
> The new unwinder is a simple state machine which was heavily inspired by
> a suggestion from Andy Lutomirski:
> 
>   https://lkml.kernel.org/r/CALCETrUbNTqaM2LRyXGRx=kVLRPeY5A3Pc6k4TtQxF320rUT=w@mail.gmail.com
> 
> It's also similar to the libunwind API:
> 
>   http://www.nongnu.org/libunwind/man/libunwind(3).html
> 
> Some if its advantages:
> 
> - simplicity: no more callback sprawl and less code duplication.
> 
> - flexibility: allows the caller to stop and inspect the stack state at
>   each step in the unwinding process.
> 
> - modularity: the unwinder code, console stack dump code, and stack
>   metadata analysis code are all better separated so that changing one
>   of them shouldn't have much of an impact on any of the others.
> 
> ----
> 
> Josh Poimboeuf (57):

I am personally unable to review a 57 patches series.

Any chance you could split it into self-contained steps? In general doing so
increase the chances for reviews, accelerate merging, improve maintainance...

Thanks.