Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 4 Oct 2002 19:48:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 4 Oct 2002 19:48:38 -0400 Received: from node-209-133-23-217.caravan.ru ([217.23.133.209]:11279 "EHLO mail.tv-sign.ru") by vger.kernel.org with ESMTP id ; Fri, 4 Oct 2002 19:48:37 -0400 Message-ID: <3D9E2B8A.653BEF9D@tv-sign.ru> Date: Sat, 05 Oct 2002 04:00:10 +0400 From: Oleg Nesterov X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.2.20 i686) X-Accept-Language: en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org CC: Ingo Molnar , Rohit Seth Subject: Re: [patch] futex-2.5.40-B5 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1080 Lines: 41 Hello. Ingo Molnar wrote: > the new lookup code first does a lightweight follow_page(), then if no > page is present we do the get_user_pages() thing. What if futex placed in VM_HUGETLB area? Then follow_page() return garbage. I beleive in i386 case it can be fixed something like this: --- mm/memory.c.orig Sat Oct 5 01:08:54 2002 +++ mm/memory.c Sat Oct 5 03:31:28 2002 @@ -480,6 +480,17 @@ follow_page(struct mm_struct *mm, unsign if (pmd_none(*pmd) || pmd_bad(*pmd)) goto out; +#ifdef CONFIG_HUGETLB_PAGE + if (pmd_large(pmd)) { + ptep = (pte_t *) pmd; + + if (write && !pte_write(*ptep)) + return NULL; + + return pte_page(*ptep) + ((address & ~HPAGE_MASK) >> PAGE_SHIFT); + } +#endif + ptep = pte_offset_map(pmd, address); if (!ptep) goto out; Then follow_hugetlb_page() hook can be killed. Oleg. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/