From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 130656B006A for ; Fri, 8 Oct 2010 13:09:44 -0400 (EDT) Received: (from localhost user: 'ralf' uid#500 fake: STDIN (ralf@eddie.linux-mips.org)) by eddie.linux-mips.org id S1491201Ab0JHRJm (ORCPT ); Fri, 8 Oct 2010 19:09:42 +0200 Date: Fri, 8 Oct 2010 18:09:41 +0100 From: Ralf Baechle Subject: Re: [PATCH 2/4] HWPOISON: Copy si_addr_lsb to user Message-ID: <20101008170941.GA3025@linux-mips.org> References: <1286398141-13749-1-git-send-email-andi@firstfloor.org> <1286398141-13749-3-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1286398141-13749-3-git-send-email-andi@firstfloor.org> Sender: owner-linux-mm@kvack.org To: Andi Kleen , Linus Torvalds Cc: linux-kernel@vger.kernel.org, fengguang.wu@intel.com, linux-mm@kvack.org, Andi Kleen , Manuel Lauss , linux-mips@linux-mips.org List-ID: On Wed, Oct 06, 2010 at 10:48:59PM +0200, Andi Kleen wrote: > The original hwpoison code added a new siginfo field si_addr_lsb to > pass the granuality of the fault address to user space. Unfortunately > this field was never copied to user space. Fix this here. > > I added explicit checks for the MCEERR codes to avoid having > to patch all potential callers to initialize the field. That doesn't fly, see below. > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -2215,6 +2215,14 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) > #ifdef __ARCH_SI_TRAPNO > err |= __put_user(from->si_trapno, &to->si_trapno); > #endif > +#ifdef BUS_MCEERR_AO > + /* > + * Other callers might not initialize the si_lsb field, > + * so check explicitely for the right codes here. > + */ > + if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO) > + err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb); > +#endif include/asm-generic/siginfo.h defines BUS_MCEERR_AR unconditionally and is getting include in all so that #ifdef condition is always true. struct siginfo.si_addr_lsb is defined only for the generic struct siginfo. The architectures that define HAVE_ARCH_SIGINFO_T (MIPS and IA-64) do not define this field so the build breaks. Ralf -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org