From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 4662D6B004F for ; Tue, 15 Sep 2009 20:23:34 -0400 (EDT) Date: Wed, 16 Sep 2009 08:23:29 +0800 From: Wu Fengguang Subject: Re: [PATCH] hwpoison: fix uninitialized warning Message-ID: <20090916002329.GA8476@localhost> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Hugh Dickins Cc: Andi Kleen , Andrew Morton , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" List-ID: On Wed, Sep 16, 2009 at 05:19:07AM +0800, Hugh Dickins wrote: > Fix mmotm build warning, presumably also in linux-next: > mm/memory.c: In function `do_swap_page': > mm/memory.c:2498: warning: `pte' may be used uninitialized in this function > > Signed-off-by: Hugh Dickins > --- > I've only noticed this warning on one machine, the powerpc: certainly it > needs CONFIG_MIGRATION or CONFIG_MEMORY_FAILURE to see it, but I thought > I had one of those set on other machines - just musing in case it's being > masked elsewhere by some other bug... > > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- mmotm/mm/memory.c 2009-09-14 16:34:37.000000000 +0100 > +++ linux/mm/memory.c 2009-09-15 22:00:48.000000000 +0100 > @@ -2495,7 +2495,7 @@ static int do_swap_page(struct mm_struct > } else if (is_hwpoison_entry(entry)) { > ret = VM_FAULT_HWPOISON; > } else { > - print_bad_pte(vma, address, pte, NULL); > + print_bad_pte(vma, address, orig_pte, NULL); > ret = VM_FAULT_OOM; > } The lines was introduced in this patch: entry = pte_to_swp_entry(orig_pte); - if (is_migration_entry(entry)) { - migration_entry_wait(mm, pmd, address); + if (unlikely(non_swap_entry(entry))) { + if (is_migration_entry(entry)) { + migration_entry_wait(mm, pmd, address); + } else if (is_hwpoison_entry(entry)) { + ret = VM_FAULT_HWPOISON; + } else { + print_bad_pte(vma, address, pte, NULL); + ret = VM_FAULT_OOM; + } goto out; } Given that currently there are only two types of non swap entries: migration/hwpoison, the last 'else' block is in fact dead code.. Thanks, Fengguang -- 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