All of lore.kernel.org
 help / color / mirror / Atom feed
From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-mm@kvack.org, Catalin Marinas <catalin.marinas@arm.com>,
	x86@kernel.org, Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH] x86/dumpstack/64: Don't evaluate exception stacks before setup
Date: Wed, 23 Oct 2019 21:43:36 +0300	[thread overview]
Message-ID: <20191023184336.GL12121@uranus.lan> (raw)
In-Reply-To: <20191023183140.GC2963@bombadil.infradead.org>

On Wed, Oct 23, 2019 at 11:31:40AM -0700, Matthew Wilcox wrote:
> On Wed, Oct 23, 2019 at 08:05:49PM +0200, Thomas Gleixner wrote:
> > Prevent this by checking the validity of the cea_exception_stack base
> > address and bailing out if it is zero.
> 
> Could also initialise cea_exception_stack to -1?  That would lead to it
> being caught by ...
> 
> >  	end = begin + sizeof(struct cea_exception_stacks);
> >  	/* Bail if @stack is outside the exception stack area. */
> >  	if (stk < begin || stk >= end)
> 
> this existing check.

As to me this would be a hack and fragile :/ In turn the current explicit
test Thomas made is a way more readable.


  reply	other threads:[~2019-10-23 18:43 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-19 11:44 [BUG -tip] kmemleak and stacktrace cause page faul Cyrill Gorcunov
2019-10-22 14:23 ` Cyrill Gorcunov
2019-10-22 14:56   ` Cyrill Gorcunov
2019-10-23 13:21     ` Thomas Gleixner
2019-10-23 13:32       ` Cyrill Gorcunov
2019-10-23 13:38         ` Thomas Gleixner
2019-10-23 13:44           ` Cyrill Gorcunov
2019-10-23 13:47       ` Thomas Gleixner
2019-10-23 13:53         ` Cyrill Gorcunov
2019-10-23 13:59         ` Cyrill Gorcunov
2019-10-23 18:05           ` [PATCH] x86/dumpstack/64: Don't evaluate exception stacks before setup Thomas Gleixner
2019-10-23 18:31             ` Matthew Wilcox
2019-10-23 18:43               ` Cyrill Gorcunov [this message]
2019-10-23 21:27               ` Thomas Gleixner
2019-10-23 19:17             ` Josh Poimboeuf
2019-11-04 23:56             ` [tip: x86/urgent] " tip-bot2 for Thomas Gleixner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191023184336.GL12121@uranus.lan \
    --to=gorcunov@gmail.com \
    --cc=catalin.marinas@arm.com \
    --cc=jpoimboe@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=willy@infradead.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.