Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761129AbYBLNNZ (ORCPT ); Tue, 12 Feb 2008 08:13:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755989AbYBLNNN (ORCPT ); Tue, 12 Feb 2008 08:13:13 -0500 Received: from mx1.redhat.com ([66.187.233.31]:48371 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755924AbYBLNNN (ORCPT ); Tue, 12 Feb 2008 08:13:13 -0500 Date: Tue, 12 Feb 2008 21:10:30 +0800 From: Eugene Teo To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org, corbet@lwn.net Subject: Re: [PATCH 2/2 resend] mm: various cleanups in get_user_pages() Message-ID: <20080212131030.GA3332@kernel.sg> Reply-To: Eugene Teo References: <20080212112919.GB3481@kernel.sg> <20080212114024.GA4440@kernel.sg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080212114024.GA4440@kernel.sg> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2941 Lines: 93 Sorry for the repeated emails. Kindly ignore the previous resend. Please review this instead. Thanks. I have tested this. [PATCH 2/2] mm: various cleanups in get_user_pages() This patch contains various cleanups, including making sure vma is valid, and the return value of follow_hugetlb_page() is validated. Signed-off-by: Eugene Teo --- mm/memory.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 54f951b..c7e0610 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1003,7 +1003,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned int foll_flags; vma = find_extend_vma(mm, start); - if (!vma && in_gate_area(tsk, start)) { + if (!vma) + goto finish_or_fault; + if (in_gate_area(tsk, start)) { unsigned long pg = start & PAGE_MASK; struct vm_area_struct *gate_vma = get_gate_vma(tsk); pgd_t *pgd; @@ -1011,7 +1013,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, pmd_t *pmd; pte_t *pte; if (write) /* user gate pages are read-only */ - return i ? : -EFAULT; + goto finish_or_fault; if (pg > TASK_SIZE) pgd = pgd_offset_k(pg); else @@ -1021,11 +1023,11 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, BUG_ON(pud_none(*pud)); pmd = pmd_offset(pud, pg); if (pmd_none(*pmd)) - return i ? : -EFAULT; + goto finish_or_fault; pte = pte_offset_map(pmd, pg); if (pte_none(*pte)) { pte_unmap(pte); - return i ? : -EFAULT; + goto finish_or_fault; } if (pages) { struct page *page = vm_normal_page(gate_vma, start, *pte); @@ -1041,9 +1043,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, continue; } - if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP)) + if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) || !(vm_flags & vma->vm_flags)) - return i ? : -EFAULT; + goto finish_or_fault; if (is_vm_hugetlb_page(vma)) { i = follow_hugetlb_page(mm, vma, pages, vmas, @@ -1080,9 +1082,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, foll_flags & FOLL_WRITE); if (ret & VM_FAULT_ERROR) { if (ret & VM_FAULT_OOM) - return i ? i : -ENOMEM; + goto finish_or_oom; else if (ret & VM_FAULT_SIGBUS) - return i ? i : -EFAULT; + goto finish_or_fault; BUG(); } if (ret & VM_FAULT_MAJOR) @@ -1115,6 +1117,12 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, } } return i; + +finish_or_oom: + return i ? : -ENOMEM; + +finish_or_fault: + return i ? : -EFAULT; } EXPORT_SYMBOL(get_user_pages); -- 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/