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From: Chen Gang <gang.chen@asianux.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Chen Gang <gang.chen@asianux.com>,
	Mike Frysinger <vapier@gentoo.org>,
	Anton Vorontsov <anton.vorontsov@linaro.org>,
	Richard Kuo <rkuo@codeaurora.org>,
	Jesper Nilsson <jesper.nilsson@axis.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	David Miller <davem@davemloft.net>,
	"uclinux-dist-devel@blackfin.uclinux.org"
	<uclinux-dist-devel@blackfin.uclinux.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Linux-Arch <linux-arch@vger.kernel.org>
Subject: Re: [PATCH] arch: blackfin: kernel: memory overflow, 'namebuf' length need be more than 256
Date: Wed, 29 May 2013 20:06:31 +0800	[thread overview]
Message-ID: <51A5EF47.4080101@asianux.com> (raw)
In-Reply-To: <CAMuHMdV17ZuCAdZq4vc+Av=r4b02OvjiEeRPxkq=7VrO3C7MSA@mail.gmail.com>

On 05/29/2013 07:30 PM, Geert Uytterhoeven wrote:
>>  void show_regs(struct pt_regs *fp)
>> >  {
>> > -       char buf[150];
>> > +       char buf[512];
> This will increase stack usage a lot. And this function calls decode_address(),
> which allocates another buffer on the stack.
> 

Can it have a risk to cause the related stack used up ? (excuse me, I
don't know the system or thread stack size of blackfin).

If so, we really need save some byes (e.g. buf[300] ...), at least. But
I'm not sure whether it still has the risk too.


> However, as this is in debug code which is (never?) called concurrently, both
> buffers can be made static?
> 

trap_c() may call show_regs(), and can multiple traps occur at the same
time ?

It seems it can (but I am not quite sure): for trap_c() only use stack
variables, and "cpu = raw_smp_processor_id()".



Thanks.
-- 
Chen Gang

Asianux Corporation

  reply	other threads:[~2013-05-29 12:07 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-29  9:43 [PATCH] arch: blackfin: kernel: sprintf(), need avoid NUL for '%s' Chen Gang
2013-05-29  9:43 ` Chen Gang
2013-05-29 10:07 ` [PATCH] arch: blackfin: kernel: memory overflow, 'namebuf' length need be more than 256 Chen Gang
2013-05-29 11:30   ` Geert Uytterhoeven
2013-05-29 12:06     ` Chen Gang [this message]
2013-06-16  3:02 ` [PATCH] arch: blackfin: kernel: sprintf(), need avoid NUL for '%s' Mike Frysinger
2013-06-16  3:02   ` Mike Frysinger
2013-06-17  1:13   ` Chen Gang
2013-06-17  1:13     ` Chen Gang

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