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=-14.6 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, UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 1111CC2D0EE for ; Fri, 27 Mar 2020 02:11:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D6FB52074D for ; Fri, 27 Mar 2020 02:11:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vff5HijL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727849AbgC0CLV (ORCPT ); Thu, 26 Mar 2020 22:11:21 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:47043 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727708AbgC0CLT (ORCPT ); Thu, 26 Mar 2020 22:11:19 -0400 Received: by mail-pg1-f202.google.com with SMTP id s18so6631988pgd.13 for ; Thu, 26 Mar 2020 19:11:16 -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=oxDWeBm7sOHjpiApO9NbnvZLKdMBOgGtnj1GVCKM9PM=; b=vff5HijLm3rVFWQg1Q6tILibVb0/t3dACKm0UD0fwBJMKC9ohGcRlug/Kuglwu1XyW 7ahlsaaY+O/P+CM86RifHiol654wkqYYPFnbzAP1Epq+gRAvZ8G6houEHhq9Dd4FOGA8 LFas61baJo5B8lNp/Ro7RhBxKogZEauq+zhA+7v9tTtNPw9GWfaO2z2+5nNh1/GYfhgQ JLUzwzAqNmpmCdF5H1M3vldBSYZkhtjyMvWBzestCGLa956M1XKtKaSRByaM5ib8N0Bg kAJlN3LxNobDGIKEQANlS/2PS9VRCrhMzqttI0gyG3zqH5bD2HO1F03dC4GtKGIYb3f4 pfcg== 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=oxDWeBm7sOHjpiApO9NbnvZLKdMBOgGtnj1GVCKM9PM=; b=QF8Cy6vcFVTbgVEvG8P0RHitLTXlEavQ0ixF0hBtRQbRndiXd1IbZpBimQQCR6k+K9 OLL1gSaI24S2sg00wBA/O0ZOLYtI0AzasldMWiw584xoc1KKSmbZjokq4XEoj8ejz5zm 4K/FxMMVPXnlhjgtYBySZVyoNSCNhR0//NLKGf34QQ8C2gMOJKYdlyRW6Bsv/G5coBhB /0SBwvLsgVhmEcwHUC544uNBcNXZu63wcGEkqpFuimXaLuaqNnFuNwGE+YeAOjol+gFY q27mv3CulgY9/Et+C7CzS16s7qT3Hn1VbsYSsqz/cXbhogr87NK7U3CcUGzhQyJgGyuf 6odQ== X-Gm-Message-State: ANhLgQ17RHdK2V5ZZIpZynixETXGuTZm2sYK1/5NGaMAfjrcKj2Fesm7 W5DXkye8Q1a6cZFL2x03HZyDCY/OI5I= X-Google-Smtp-Source: ADFU+vuh3Psmnwb5B2KXKfiPZ7gW9ScpNWqCS0cyKYTi8+z/ypo7VtLCrBAXmFLp6QjG5Evl+DPNu+S2aKw= X-Received: by 2002:a17:90a:d78b:: with SMTP id z11mr2409659pju.34.1585275076325; Thu, 26 Mar 2020 19:11:16 -0700 (PDT) Date: Thu, 26 Mar 2020 19:10:54 -0700 In-Reply-To: <20200327021058.221911-1-walken@google.com> Message-Id: <20200327021058.221911-7-walken@google.com> Mime-Version: 1.0 References: <20200327021058.221911-1-walken@google.com> X-Mailer: git-send-email 2.26.0.rc2.310.g2932bb562d-goog Subject: [PATCH v2 06/10] 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 , Markus Elfring , Michel Lespinasse Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add API for nested write locks and convert the few call sites doing that. Signed-off-by: Michel Lespinasse --- arch/um/include/asm/mmu_context.h | 5 +++-- include/linux/mmap_lock.h | 11 +++++++++++ kernel/fork.c | 4 ++-- 3 files changed, 16 insertions(+), 4 deletions(-) diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h index 62262c5c7785..cc15173f7518 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 @@ -47,9 +48,9 @@ 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, 1); uml_setup_stubs(new); - mmap_write_unlock(new); + mmap_write_unlock_nested(new); } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index cffd25afe92b..40a972a26857 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); @@ -26,6 +31,12 @@ static inline void mmap_write_unlock(struct mm_struct *mm) up_write(&mm->mmap_sem); } +/* Pairs with mmap_write_lock_nested() */ +static inline void mmap_write_unlock_nested(struct mm_struct *mm) +{ + up_write(&mm->mmap_sem); +} + static inline void mmap_downgrade_write_lock(struct mm_struct *mm) { downgrade_write(&mm->mmap_sem); diff --git a/kernel/fork.c b/kernel/fork.c index c321910d46e8..3460308b2213 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -497,7 +497,7 @@ 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)); @@ -612,7 +612,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, /* a new mm has just been created */ retval = arch_dup_mmap(oldmm, mm); out: - mmap_write_unlock(mm); + mmap_write_unlock_nested(mm); flush_tlb_mm(oldmm); mmap_write_unlock(oldmm); dup_userfaultfd_complete(&uf); -- 2.26.0.rc2.310.g2932bb562d-goog 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=-14.6 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, UNWANTED_LANGUAGE_BODY,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 29915C43331 for ; Fri, 27 Mar 2020 02:11:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D2FB32074D for ; 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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 --- arch/um/include/asm/mmu_context.h | 5 +++-- include/linux/mmap_lock.h | 11 +++++++++++ kernel/fork.c | 4 ++-- 3 files changed, 16 insertions(+), 4 deletions(-) diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h index 62262c5c7785..cc15173f7518 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 @@ -47,9 +48,9 @@ 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, 1); uml_setup_stubs(new); - mmap_write_unlock(new); + mmap_write_unlock_nested(new); } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index cffd25afe92b..40a972a26857 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); @@ -26,6 +31,12 @@ static inline void mmap_write_unlock(struct mm_struct *mm) up_write(&mm->mmap_sem); } +/* Pairs with mmap_write_lock_nested() */ +static inline void mmap_write_unlock_nested(struct mm_struct *mm) +{ + up_write(&mm->mmap_sem); +} + static inline void mmap_downgrade_write_lock(struct mm_struct *mm) { downgrade_write(&mm->mmap_sem); diff --git a/kernel/fork.c b/kernel/fork.c index c321910d46e8..3460308b2213 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -497,7 +497,7 @@ 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)); @@ -612,7 +612,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, /* a new mm has just been created */ retval = arch_dup_mmap(oldmm, mm); out: - mmap_write_unlock(mm); + mmap_write_unlock_nested(mm); flush_tlb_mm(oldmm); mmap_write_unlock(oldmm); dup_userfaultfd_complete(&uf); -- 2.26.0.rc2.310.g2932bb562d-goog