linux-kernel - Re: [PATCH] Added MIPS RM9K watchdog driver

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] [day] [month] [year] [list]

Message-ID: <20061102140450.GE16883@linux-mips.org>
Date:	Thu, 2 Nov 2006 14:04:51 +0000
From:	Ralf Baechle <ralf@...ux-mips.org>
To:	Randy Dunlap <rdunlap@...otime.net>
Cc:	Wim Van Sebroeck <wim@...ana.be>,
	Thomas Koeller <thomas@...ller.dyndns.org>,
	Dave Jones <davej@...hat.com>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Sam Ravnborg <sam@...nborg.org>,
	Alexey Dobriyan <adobriyan@...il.com>,
	linux-kernel@...r.kernel.org, linux-mips@...ux-mips.org
Subject: Re: [PATCH] Added MIPS RM9K watchdog driver

On Wed, Nov 01, 2006 at 10:11:25PM -0800, Randy Dunlap wrote:

> > 	wd_regs = ioremap_nocache(rr->start, rr->end + 1 - rr->start);
> > 	if (unlikely(!wd_regs))
> > 		return -ENOMEM;
> 
> There's no way to return the resources on failure?

MIPS drivers (and this one is specific to a particular MIPS SOC) are
generally a bit sloopy about checking of return values of ioremap because
ioremap is only doing some address arithmetic but no allocations that
actually could fail.  So for 64-bit kernels or addresses below 0x20000000
on a 32-bit system ioremap cannot fail.  In the same cases ioremap happens
to be a no-op because where nothing was allocated nothing needs to be
freed.

> > 			if (unlikely(__copy_from_user(&val, (const void __user *) arg,

Note to self, __copy_from_user and gang are generally assume to not
return an error so it might be a good idea to move that unlikely() into
the macro definitions.

  Ralf
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/