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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 7B64FC433E1 for ; Wed, 20 May 2020 05:29:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 33530206C3 for ; Wed, 20 May 2020 05:29:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="QvaAR/Z1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 33530206C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C004B8005A; Wed, 20 May 2020 01:29:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B64C58002C; Wed, 20 May 2020 01:29:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A77838005A; Wed, 20 May 2020 01:29:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0186.hostedemail.com [216.40.44.186]) by kanga.kvack.org (Postfix) with ESMTP id 872148002C for ; Wed, 20 May 2020 01:29:26 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 4A9BB181AEF23 for ; Wed, 20 May 2020 05:29:26 +0000 (UTC) X-FDA: 76835969532.16.uncle16_525c15433d234 X-HE-Tag: uncle16_525c15433d234 X-Filterd-Recvd-Size: 5368 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Wed, 20 May 2020 05:29:25 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id q16so791352ybg.18 for ; Tue, 19 May 2020 22:29:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=l1uoa86T5i4IFuilenMyhOPWP4qckBe++S0EocRcQls=; b=QvaAR/Z1wFWclp2SJqNPyqR+d0jKSmW68eXhKD/5TIJ2urgqSmzVtXTqeojvszjNna zD3dHpNhkNSgq9KY5pNpqM1isqORrzmgBmmBy2t0RKNIvUDiXXVjlHDAbxxwN9kxm5yT EwlMBAvXuBJNOZAaMmCE4rw76wCn+y1ifVSQ1UFZBx0Md6wCB1QuGxrYRaUI/HQVNCfy GNvT5lMosujsnrREDE8eLE3XN6tOiSyfnKLOraUVB0d1FfvbF/Sjilw4KM/gYzHJBdvb FtJ+xmhCwLCSuAp+1RTUXcxGc7oQ1DlV5/m0u0BuNqjtQ4L0fCxtamAwhw/IzEOVLvEd C5nQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=l1uoa86T5i4IFuilenMyhOPWP4qckBe++S0EocRcQls=; b=cEaRCaZP9ES4HU4IsSnVV/LcWY4l0H8Ch1pduGXP+iSxKRt2OQszcajmy5sXEs52cr 5W/mrlFQXZy/5JUBMciY+UXZ6qt9f16JkYyR4gyKjA+anOO2VsyNouC1q3c+Ozn1vj12 BEsTnCIb9pMdYPCru63IzOaOBjpdSSQst96JAWlEyUAlKqtGy23FcLv7HL71m2UYzxSY /DgE5rkHynnXbkq71IGSdVZR9qm0Vg8+wzlYaKtBXbCFImBVbIhGHnTICBAxCpq0v1NT ckQUnmVCOIx91pBE4hzLO3HigebylQFmcARAkblCf5oNzhovBda6uFablflRGo4tbvJ9 JV5w== X-Gm-Message-State: AOAM531EtLDOaxvA3T0zBaoNUDqOEtkHNMre+GClQVIuZHsKeN5vsg4x XePjP060HKuipDzWODJTTkExUyOqTEk= X-Google-Smtp-Source: ABdhPJzr214Hi5yAoUaM72rIONWP69vka+unUZbT8FrKYJ/57UOx6B462OyViG4mcaGjpR2gxdg1NB3GA1w= X-Received: by 2002:a25:e86:: with SMTP id 128mr4998694ybo.344.1589952565280; Tue, 19 May 2020 22:29:25 -0700 (PDT) Date: Tue, 19 May 2020 22:29:02 -0700 In-Reply-To: <20200520052908.204642-1-walken@google.com> Message-Id: <20200520052908.204642-7-walken@google.com> Mime-Version: 1.0 References: <20200520052908.204642-1-walken@google.com> X-Mailer: git-send-email 2.26.2.761.g0e0b3e54be-goog Subject: [PATCH v6 06/12] mmap locking API: convert nested write lock sites From: Michel Lespinasse To: Andrew Morton , linux-mm Cc: LKML , Peter Zijlstra , Laurent Dufour , Vlastimil Babka , Matthew Wilcox , Liam Howlett , Jerome Glisse , Davidlohr Bueso , David Rientjes , Hugh Dickins , Ying Han , Jason Gunthorpe , Daniel Jordan , John Hubbard , Michel Lespinasse Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Add API for nested write locks and convert the few call sites doing that. Signed-off-by: Michel Lespinasse Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka --- arch/um/include/asm/mmu_context.h | 3 ++- include/linux/mmap_lock.h | 5 +++++ kernel/fork.c | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h index 62262c5c7785..17ddd4edf875 100644 --- a/arch/um/include/asm/mmu_context.h +++ b/arch/um/include/asm/mmu_context.h @@ -8,6 +8,7 @@ #include #include +#include #include @@ -47,7 +48,7 @@ static inline void activate_mm(struct mm_struct *old, struct mm_struct *new) * when the new ->mm is used for the first time. */ __switch_mm(&new->context.id); - down_write_nested(&new->mmap_sem, 1); + mmap_write_lock_nested(new, SINGLE_DEPTH_NESTING); uml_setup_stubs(new); mmap_write_unlock(new); } diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index 97ac53b66052..a757cb30ae77 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -11,6 +11,11 @@ static inline void mmap_write_lock(struct mm_struct *mm) down_write(&mm->mmap_sem); } +static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass) +{ + down_write_nested(&mm->mmap_sem, subclass); +} + static inline int mmap_write_lock_killable(struct mm_struct *mm) { return down_write_killable(&mm->mmap_sem); diff --git a/kernel/fork.c b/kernel/fork.c index a4db6bc952c6..e702e84897fa 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -499,7 +499,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, /* * Not linked in yet - no deadlock potential: */ - down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING); + mmap_write_lock_nested(mm, SINGLE_DEPTH_NESTING); /* No ordering required: file already has been exposed. */ RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm)); -- 2.26.2.761.g0e0b3e54be-goog