From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4510CC43381 for ; Thu, 7 Mar 2019 17:32:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13C0C2063F for ; Thu, 7 Mar 2019 17:32:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551979943; bh=aL8ZWCP1XgR7hzHwb0Lz0WUQVp5QkYzYG9ZFznNhpQ4=; h=Subject:To:Cc:From:Date:List-ID:From; b=DpDHJbYIOUXmH+kgOikt6v3fudr2LXxEQt5AI0bFngLUJm6ozjR/RRKR2Ov3opgnc 0izQppLATaCTVAno9z/S0s+x9madgLnJm4XLleBl9UZ0mVFa3H86utfWf34B66D/Ba dpc8Rqrw7TNXfCm0M3byDrgxEQBxwUaIYhxgNNWQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726241AbfCGRcW (ORCPT ); Thu, 7 Mar 2019 12:32:22 -0500 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:58647 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726172AbfCGRcW (ORCPT ); Thu, 7 Mar 2019 12:32:22 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.west.internal (Postfix) with ESMTP id 317E93755; Thu, 7 Mar 2019 12:32:21 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Thu, 07 Mar 2019 12:32:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=ZrTak+ fbjsgZigrQf8JFxn/s7xEwPRAObbblOZc2OKo=; b=PIeFOHdCrYHJ8NuVpATylx KE3sUf6IpjLG09GiMH6McRmb3eh3+xZXjSblkT3G9cSlsy5ZX94/+1bmRAn9OVxf V5yjGUgq0IxQXGOyl7oCWhD7rspER7gqp5/TUEZUSTDBpvwMCTKbuHgLHzwJT3ls /NUyQxdLsCfWhofSlVeJxKOJZx8xVKpt62RzzVmCkq+uBUT5HTeHmblhH77/VLYc SbFY73sKIt0rKHkOPRxiccZ3ddMsh4bwoy2HR6r98slmzKRknvHXbIKInwwbbSiY IMAowkIaJ1ofR945cTyIV/QKXsM3rqsDmDX2Aom/MyV0gqzEVmOl1rUQ+yNKVGKg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedutddrfeekgddutdeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucgoufhushhpvggtthffohhmrghinhculdegledmne cujfgurhepuffvhfffkfggtgfgsehtkeertddttdflnecuhfhrohhmpeeoghhrvghgkhhh sehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhgqeenucffohhmrghinheprghpphhsph hothdrtghomhenucfkphepkeefrdekiedrkeelrddutdejnecurfgrrhgrmhepmhgrihhl fhhrohhmpehgrhgvgheskhhrohgrhhdrtghomhenucevlhhushhtvghrufhiiigvpedt X-ME-Proxy: Received: from localhost (5356596b.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 05F4310344; Thu, 7 Mar 2019 12:32:19 -0500 (EST) Subject: FAILED: patch "[PATCH] staging: android: ashmem: Don't call fallocate() with" failed to apply to 4.9-stable tree To: penguin-kernel@I-love.SAKURA.ne.jp, gregkh@linuxfoundation.org, joel@joelfernandes.org, syzbot+148c2885d71194f18d28@syzkaller.appspotmail.com, syzbot+4b8b031b89e6b96c4b2e@syzkaller.appspotmail.com, syzbot+a76129f18c89f3e2ddd4@syzkaller.appspotmail.com Cc: From: Date: Thu, 07 Mar 2019 18:32:15 +0100 Message-ID: <1551979935176250@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From fb4415a12632f0b9078a0aa80c16745d48fcfc74 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Tue, 5 Feb 2019 19:28:40 +0900 Subject: [PATCH] staging: android: ashmem: Don't call fallocate() with ashmem_mutex held. syzbot is hitting lockdep warnings [1][2][3]. This patch tries to fix the warning by eliminating ashmem_shrink_scan() => {shmem|vfs}_fallocate() sequence. [1] https://syzkaller.appspot.com/bug?id=87c399f6fa6955006080b24142e2ce7680295ad4 [2] https://syzkaller.appspot.com/bug?id=7ebea492de7521048355fc84210220e1038a7908 [3] https://syzkaller.appspot.com/bug?id=e02419c12131c24e2a957ea050c2ab6dcbbc3270 Reported-by: syzbot Reported-by: syzbot Reported-by: syzbot Signed-off-by: Tetsuo Handa Cc: stable@vger.kernel.org Acked-by: Joel Fernandes (Google) Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c index 92f42cea5ae4..5d5b091b957a 100644 --- a/drivers/staging/android/ashmem.c +++ b/drivers/staging/android/ashmem.c @@ -75,6 +75,9 @@ struct ashmem_range { /* LRU list of unpinned pages, protected by ashmem_mutex */ static LIST_HEAD(ashmem_lru_list); +static atomic_t ashmem_shrink_inflight = ATOMIC_INIT(0); +static DECLARE_WAIT_QUEUE_HEAD(ashmem_shrink_wait); + /* * long lru_count - The count of pages on our LRU list. * @@ -439,7 +442,6 @@ static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) static unsigned long ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { - struct ashmem_range *range, *next; unsigned long freed = 0; /* We might recurse into filesystem code, so bail out if necessary */ @@ -449,21 +451,33 @@ ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) if (!mutex_trylock(&ashmem_mutex)) return -1; - list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) { + while (!list_empty(&ashmem_lru_list)) { + struct ashmem_range *range = + list_first_entry(&ashmem_lru_list, typeof(*range), lru); loff_t start = range->pgstart * PAGE_SIZE; loff_t end = (range->pgend + 1) * PAGE_SIZE; + struct file *f = range->asma->file; - range->asma->file->f_op->fallocate(range->asma->file, - FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, - start, end - start); + get_file(f); + atomic_inc(&ashmem_shrink_inflight); range->purged = ASHMEM_WAS_PURGED; lru_del(range); freed += range_size(range); + mutex_unlock(&ashmem_mutex); + f->f_op->fallocate(f, + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, + start, end - start); + fput(f); + if (atomic_dec_and_test(&ashmem_shrink_inflight)) + wake_up_all(&ashmem_shrink_wait); + if (!mutex_trylock(&ashmem_mutex)) + goto out; if (--sc->nr_to_scan <= 0) break; } mutex_unlock(&ashmem_mutex); +out: return freed; } @@ -714,6 +728,7 @@ static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd, return -EFAULT; mutex_lock(&ashmem_mutex); + wait_event(ashmem_shrink_wait, !atomic_read(&ashmem_shrink_inflight)); if (!asma->file) goto out_unlock;