From patchwork Thu Nov 7 08:41:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Hellstr=C3=B6m_=28Intel=29?= X-Patchwork-Id: 11232257 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6720B1390 for ; Thu, 7 Nov 2019 08:41:32 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5124621D7E for ; Thu, 7 Nov 2019 08:41:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5124621D7E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shipmail.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6990A6EF08; Thu, 7 Nov 2019 08:41:31 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from pio-pvt-msa3.bahnhof.se (pio-pvt-msa3.bahnhof.se [79.136.2.42]) by gabe.freedesktop.org (Postfix) with ESMTPS id D60106EF10 for ; Thu, 7 Nov 2019 08:41:29 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by pio-pvt-msa3.bahnhof.se (Postfix) with ESMTP id 711A73F30D for ; Thu, 7 Nov 2019 09:41:28 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at bahnhof.se X-Spam-Flag: NO X-Spam-Score: -2.099 X-Spam-Level: X-Spam-Status: No, score=-2.099 tagged_above=-999 required=6.31 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Received: from pio-pvt-msa3.bahnhof.se ([127.0.0.1]) by localhost (pio-pvt-msa3.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id zewGiDr6oUf4 for ; Thu, 7 Nov 2019 09:41:25 +0100 (CET) Received: from mail1.shipmail.org (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) (Authenticated sender: mb878879) by pio-pvt-msa3.bahnhof.se (Postfix) with ESMTPA id D278C3F43B for ; Thu, 7 Nov 2019 09:41:24 +0100 (CET) Received: from localhost.localdomain.localdomain (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) by mail1.shipmail.org (Postfix) with ESMTPSA id 36BAD36014C for ; Thu, 7 Nov 2019 09:41:24 +0100 (CET) From: =?utf-8?q?Thomas_Hellstr=C3=B6m_=28VMware=29?= To: dri-devel@lists.freedesktop.org Subject: [PATCH v7 1/8] mm: Remove BUG_ON mmap_sem not held from xxx_trans_huge_lock() Date: Thu, 7 Nov 2019 09:41:09 +0100 Message-Id: <20191107084116.33032-2-thomas_os@shipmail.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191107084116.33032-1-thomas_os@shipmail.org> References: <20191107084116.33032-1-thomas_os@shipmail.org> MIME-Version: 1.0 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=shipmail.org; s=mail; t=1573116084; bh=/VtZki6GCsW+3DEzZB0xqCHXTb7savVZuIvitIAE654=; h=From:To:Subject:Date:In-Reply-To:References:From; b=oj1KMAYmLNFX3f9FtE6GGP1DMK+77HioS+MCJIpHDCu0aNBy9jGtFd7oN1wIh/l/S Xb6uVyRoZ/8kLcpoAhQxznd+RFNLtKYNOMp36VeHMPsB7WCcWjtQVeK77aSbPHl4P1 nCIAvxTCfhsyC0rPeH32Ql7dDzh9AyKxarYVKxvI= X-Mailman-Original-Authentication-Results: pio-pvt-msa3.bahnhof.se; dkim=pass (1024-bit key; unprotected) header.d=shipmail.org header.i=@shipmail.org header.b=oj1KMAYm; dkim-atps=neutral X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Thomas Hellstrom The caller needs to make sure that the vma is not torn down during the lock operation and can also use the i_mmap_rwsem for file-backed vmas. Remove the BUG_ON. We could, as an alternative, add a test that either vma->vm_mm->mmap_sem or vma->vm_file->f_mapping->i_mmap_rwsem are held. Cc: Andrew Morton Cc: Matthew Wilcox Cc: Will Deacon Cc: Peter Zijlstra Cc: Rik van Riel Cc: Minchan Kim Cc: Michal Hocko Cc: Huang Ying Cc: Jérôme Glisse Cc: Kirill A. Shutemov Signed-off-by: Thomas Hellstrom Acked-by: Kirill A. Shutemov --- include/linux/huge_mm.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 93d5cf0bc716..0b84e13e88e2 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -216,7 +216,6 @@ static inline int is_swap_pmd(pmd_t pmd) static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma) { - VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma); if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) return __pmd_trans_huge_lock(pmd, vma); else @@ -225,7 +224,6 @@ static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd, static inline spinlock_t *pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma) { - VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma); if (pud_trans_huge(*pud) || pud_devmap(*pud)) return __pud_trans_huge_lock(pud, vma); else