From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Salter Subject: Re: sys_kcmp (was: Re: [PATCH 1/2] ARM: add finit_module syscall to ARM) Date: Mon, 24 Sep 2012 14:16:09 -0400 Message-ID: <1348510573.20929.44.camel@deneb.redhat.com> References: <20120922114549.GA11610@moon> <20120922132046.GA4260@flint.arm.linux.org.uk> <20120922114723.d7f07fb6.akpm@linux-foundation.org> <1348503709.20929.40.camel@deneb.redhat.com> <20120924164942.GH16532@moon> <20120924174256.GD24172@moon> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:45779 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756754Ab2IXSQb (ORCPT ); Mon, 24 Sep 2012 14:16:31 -0400 In-Reply-To: <20120924174256.GD24172@moon> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Cyrill Gorcunov Cc: Andrew Morton , Russell King , Geert Uytterhoeven , Kees Cook , linux-kernel@vger.kernel.org, Linux-Arch , Heiko Carstens , "H. Peter Anvin" , "Eric W. Biederman" , Pavel Emelyanov On Mon, 2012-09-24 at 21:42 +0400, Cyrill Gorcunov wrote: > On Mon, Sep 24, 2012 at 08:49:42PM +0400, Cyrill Gorcunov wrote: > > > I got past that with: > > > > > > diff --git a/include/linux/security.h b/include/linux/security.h > > > index 01ef030..14e394d 100644 > > > --- a/include/linux/security.h > > > +++ b/include/linux/security.h > > > @@ -118,6 +118,7 @@ void reset_security_ops(void); > > > extern unsigned long mmap_min_addr; > > > extern unsigned long dac_mmap_min_addr; > > > #else > > > +#define mmap_min_addr 0UL > > > #define dac_mmap_min_addr 0UL > > > #endif > > > > > I think better to add CONFIG_MMU test here. Well, my patch was just something quick to get the kernel to build, but thinking about it a bit, I still prefer it. The CONFIG_MMU check is in security.h already so I think it is less clutter and better for future code which may use mmap_min_addr. In any case, the compiler will drop any test for "x < 0UL" so the end result is the same. > --- > From: Cyrill Gorcunov > Subject: prctl: prctl_set_mm -- Don't test for mmap_min_addr on non-MMU config > > In case if CONFIG_MMU is not set the @mmap_min_addr > is undefined leading to build error. Thus test for > it iif CONFIG_MMU is present. > > Note this code snippet depends on CONFIG_CHECKPOINT_RESTORE=y. > > Reported-by: Mark Salter > Signed-off-by: Cyrill Gorcunov > --- > kernel/sys.c | 4 ++++ > 1 file changed, 4 insertions(+) > > Index: linux-2.6.git/kernel/sys.c > =================================================================== > --- linux-2.6.git.orig/kernel/sys.c > +++ linux-2.6.git/kernel/sys.c > @@ -1865,7 +1865,11 @@ static int prctl_set_mm(int opt, unsigne > if (opt == PR_SET_MM_EXE_FILE) > return prctl_set_mm_exe_file(mm, (unsigned int)addr); > > +#ifdef CONFIG_MMU > if (addr >= TASK_SIZE || addr < mmap_min_addr) > +#else > + if (addr >= TASK_SIZE) > +#endif > return -EINVAL; > > error = -EINVAL;