Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933761AbaGVW2W (ORCPT ); Tue, 22 Jul 2014 18:28:22 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:45002 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933737AbaGVW15 (ORCPT ); Tue, 22 Jul 2014 18:27:57 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Hugh Dickins , Peter Zijlstra , Andrew Morton , Linus Torvalds , Kamal Mostafa Subject: [PATCH 3.8 053/116] mm: fix sleeping function warning from __put_anon_vma Date: Tue, 22 Jul 2014 15:21:04 -0700 Message-Id: <1406067727-19683-54-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1406067727-19683-1-git-send-email-kamal@canonical.com> References: <1406067727-19683-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.27 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Hugh Dickins commit 7f39dda9d86fb4f4f17af0de170decf125726f8c upstream. Trinity reports BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:47 in_atomic(): 0, irqs_disabled(): 0, pid: 5787, name: trinity-c27 __might_sleep < down_write < __put_anon_vma < page_get_anon_vma < migrate_pages < compact_zone < compact_zone_order < try_to_compact_pages .. Right, since conversion to mutex then rwsem, we should not put_anon_vma() from inside an rcu_read_lock()ed section: fix the two places that did so. And add might_sleep() to anon_vma_free(), as suggested by Peter Zijlstra. Fixes: 88c22088bf23 ("mm: optimize page_lock_anon_vma() fast-path") Reported-by: Dave Jones Signed-off-by: Hugh Dickins Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Kamal Mostafa --- mm/rmap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index 770320b..f350f9f 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -103,6 +103,7 @@ static inline void anon_vma_free(struct anon_vma *anon_vma) * LOCK should suffice since the actual taking of the lock must * happen _before_ what follows. */ + might_sleep(); if (rwsem_is_locked(&anon_vma->root->rwsem)) { anon_vma_lock_write(anon_vma); anon_vma_unlock_write(anon_vma); @@ -426,8 +427,9 @@ struct anon_vma *page_get_anon_vma(struct page *page) * above cannot corrupt). */ if (!page_mapped(page)) { + rcu_read_unlock(); put_anon_vma(anon_vma); - anon_vma = NULL; + return NULL; } out: rcu_read_unlock(); @@ -477,9 +479,9 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page) } if (!page_mapped(page)) { + rcu_read_unlock(); put_anon_vma(anon_vma); - anon_vma = NULL; - goto out; + return NULL; } /* we pinned the anon_vma, its safe to sleep */ -- 1.9.1 -- 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/