From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752713AbcDZM6p (ORCPT ); Tue, 26 Apr 2016 08:58:45 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35956 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752271AbcDZM4m (ORCPT ); Tue, 26 Apr 2016 08:56:42 -0400 From: Michal Hocko To: , Andrew Morton Cc: LKML , Michal Hocko , Alexander Viro , Oleg Nesterov , Vlastimil Babka Subject: [PATCH 13/18] exec: make exec path waiting for mmap_sem killable Date: Tue, 26 Apr 2016 14:56:20 +0200 Message-Id: <1461675385-5934-14-git-send-email-mhocko@kernel.org> X-Mailer: git-send-email 2.8.0.rc3 In-Reply-To: <1461675385-5934-1-git-send-email-mhocko@kernel.org> References: <1461675385-5934-1-git-send-email-mhocko@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michal Hocko setup_arg_pages requires mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. All the callers are already handling error path and the fatal signal doesn't need any additional treatment. The same applies to __bprm_mm_init. Cc: Alexander Viro Acked-by: Oleg Nesterov Acked-by: Vlastimil Babka Signed-off-by: Michal Hocko --- fs/exec.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 2f44590d88a9..d7a6ff09bb7a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -267,7 +267,10 @@ static int __bprm_mm_init(struct linux_binprm *bprm) if (!vma) return -ENOMEM; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) { + err = -EINTR; + goto err_free; + } vma->vm_mm = mm; /* @@ -294,6 +297,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm) return 0; err: up_write(&mm->mmap_sem); +err_free: bprm->vma = NULL; kmem_cache_free(vm_area_cachep, vma); return err; @@ -700,7 +704,9 @@ int setup_arg_pages(struct linux_binprm *bprm, bprm->loader -= stack_shift; bprm->exec -= stack_shift; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; + vm_flags = VM_STACK_FLAGS; /* -- 2.8.0.rc3 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id A460A6B0269 for ; Tue, 26 Apr 2016 08:56:59 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id s63so11698145wme.2 for ; Tue, 26 Apr 2016 05:56:59 -0700 (PDT) Received: from mail-wm0-f68.google.com (mail-wm0-f68.google.com. [74.125.82.68]) by mx.google.com with ESMTPS id kd3si19805132wjb.79.2016.04.26.05.56.41 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Apr 2016 05:56:41 -0700 (PDT) Received: by mail-wm0-f68.google.com with SMTP id n3so4764361wmn.1 for ; Tue, 26 Apr 2016 05:56:41 -0700 (PDT) From: Michal Hocko Subject: [PATCH 13/18] exec: make exec path waiting for mmap_sem killable Date: Tue, 26 Apr 2016 14:56:20 +0200 Message-Id: <1461675385-5934-14-git-send-email-mhocko@kernel.org> In-Reply-To: <1461675385-5934-1-git-send-email-mhocko@kernel.org> References: <1461675385-5934-1-git-send-email-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, Andrew Morton Cc: LKML , Michal Hocko , Alexander Viro , Oleg Nesterov , Vlastimil Babka From: Michal Hocko setup_arg_pages requires mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. All the callers are already handling error path and the fatal signal doesn't need any additional treatment. The same applies to __bprm_mm_init. Cc: Alexander Viro Acked-by: Oleg Nesterov Acked-by: Vlastimil Babka Signed-off-by: Michal Hocko --- fs/exec.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 2f44590d88a9..d7a6ff09bb7a 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -267,7 +267,10 @@ static int __bprm_mm_init(struct linux_binprm *bprm) if (!vma) return -ENOMEM; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) { + err = -EINTR; + goto err_free; + } vma->vm_mm = mm; /* @@ -294,6 +297,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm) return 0; err: up_write(&mm->mmap_sem); +err_free: bprm->vma = NULL; kmem_cache_free(vm_area_cachep, vma); return err; @@ -700,7 +704,9 @@ int setup_arg_pages(struct linux_binprm *bprm, bprm->loader -= stack_shift; bprm->exec -= stack_shift; - down_write(&mm->mmap_sem); + if (down_write_killable(&mm->mmap_sem)) + return -EINTR; + vm_flags = VM_STACK_FLAGS; /* -- 2.8.0.rc3 -- 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