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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EDE8CC27C76 for ; Wed, 25 Jan 2023 09:02:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=LZ6ZeYc51qi0/xKTgi+b6hLWrGCwhLuOApv4JfuE0mA=; b=jtsw4blB3EqtxP 5VzwPkkY7LQqtad4Eghd0XoHab6eTKfQ++s2r+2pqM/6WVtoD3ud9h5n6F1a31QAp5Cjqr7xV/5et qS6X4Td8k8eyRJBcM1z855pubGsKahowbD0ATXQX4UNJwcpgCJuVqMWfOBAUEX0YriiDTl2UkD9N6 tmZzN1hNT23Ajv5+cwe9W/AFEUHtTRkDUAGpepLi+fL397aqWSQmiQIX6Y0rWqhpyZYDCSKEEoySb e4N2HQTFrgN+dvhzt2Eqh/fUvDYrnZVz7ka5Ts6kpPFrd6THc7x4wgTjolBX9lQbAlT+wz8Z73yXy I1Gt0EoVo89LF/i1jeEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKbg9-006WlX-4z; Wed, 25 Jan 2023 09:02:49 +0000 Received: from smtp-out2.suse.de ([195.135.220.29]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKbZy-006W0N-6X; Wed, 25 Jan 2023 08:56:27 +0000 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 0B83B1FEC6; Wed, 25 Jan 2023 08:56:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1674636983; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=HlfVezvAjFmKLztHMOaZ+yji8Nsqp9vLwu4LVliFLNo=; b=sP3k2vbL/TMjnnanRjZuUO51OPKL7NCAE7wor1COt2s99RKg6YGTByegVuny2bFzwE3+s6 UutXKdgKZ+JCm3/zcJc6jOoDAopdP55BVOpdwrjI4e178jvtCsfm11DvfUjHyJJs6l60Lo ZwU2a8676f0/M9W0HO3obY7BVSmDGjU= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id B78841339E; Wed, 25 Jan 2023 08:56:22 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id ZJ2WLLbu0GN/CQAAMHmgww (envelope-from ); Wed, 25 Jan 2023 08:56:22 +0000 Date: Wed, 25 Jan 2023 09:56:22 +0100 From: Michal Hocko To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, michel@lespinasse.org, jglisse@google.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, paulmck@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, hughlynch@google.com, leewalsh@google.com, posk@google.com, will@kernel.org, aneesh.kumar@linux.ibm.com, npiggin@gmail.com, chenhuacai@kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, qianweili@huawei.com, wangzhou1@hisilicon.com, herbert@gondor.apana.org.au, davem@davemloft.net, vkoul@kernel.org, airlied@gmail.com, daniel@ffwll.ch, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, l.stach@pengutronix.de, krzysztof.kozlowski@linaro.org, patrik.r.jakobsson@gmail.com, matthias.bgg@gmail.com, robdclark@gmail.com, quic_abhinavk@quicinc.com, dmitry.baryshkov@linaro.org, tomba@kernel.org, hjc@rock-chips.com, heiko@sntech.de, ray.huang@amd.com, kraxel@redhat.com, sre@kernel.org, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, tfiga@chromium.org, m.szyprowski@samsung.com, mchehab@kernel.org, dimitri.sivanich@hpe.com, zhangfei.gao@linaro.org, jejb@linux.ibm.com, martin.petersen@oracle.com, dgilbert@interlog.com, hdegoede@redhat.com, mst@redhat.com, jasowang@redhat.com, alex.williamson@redhat.com, deller@gmx.de, jayalk@intworks.biz, viro@zeniv.linux.org.uk, nico@fluxnic.net, xiang@kernel.org, chao@kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, miklos@szeredi.hu, mike.kravetz@oracle.com, muchun.song@linux.dev, bhe@redhat.com, andrii@kernel.org, yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org, pabeni@redhat.com, perex@perex.cz, tiwai@suse.com, haojian.zhuang@gmail.com, robert.jarzmik@free.fr, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, linux-graphics-maintainer@vmware.com, linux-ia64@vger.kernel.org, linux-arch@vger.kernel.org, loongarch@lists.linux.dev, kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-sgx@vger.kernel.org, linux-um@lists.infradead.org, linux-acpi@vger.kernel.org, linux-crypto@vger.kernel.org, nvdimm@lists.linux.dev, dmaengine@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, etnaviv@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-rockchip@lists.infradead.org, linux-tegra@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-stm32@st-md-mailman.stormreply.com, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-accelerators@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-scsi@vger.kernel.org, linux-staging@lists.linux.dev, target-devel@vger.kernel.org, linux-usb@vger.kernel.org, netdev@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-aio@kvack.org, linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, devel@lists.orangefs.org, kexec@lists.infradead.org, linux-xfs@vger.kernel.org, bpf@vger.kernel.org, linux-perf-users@vger.kernel.org, kasan-dev@googlegroups.com, selinux@vger.kernel.org, alsa-devel@alsa-project.org, kernel-team@android.com Subject: Re: [PATCH v2 1/6] mm: introduce vma->vm_flags modifier functions Message-ID: References: <20230125083851.27759-1-surenb@google.com> <20230125083851.27759-2-surenb@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230125083851.27759-2-surenb@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230125_005626_405659_9E0C089B X-CRM114-Status: GOOD ( 19.52 ) X-Mailman-Approved-At: Wed, 25 Jan 2023 01:02:42 -0800 X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Wed 25-01-23 00:38:46, Suren Baghdasaryan wrote: > vm_flags are among VMA attributes which affect decisions like VMA merging > and splitting. Therefore all vm_flags modifications are performed after > taking exclusive mmap_lock to prevent vm_flags updates racing with such > operations. Introduce modifier functions for vm_flags to be used whenever > flags are updated. This way we can better check and control correct > locking behavior during these updates. > > Signed-off-by: Suren Baghdasaryan Acked-by: Michal Hocko > --- > include/linux/mm.h | 37 +++++++++++++++++++++++++++++++++++++ > include/linux/mm_types.h | 8 +++++++- > 2 files changed, 44 insertions(+), 1 deletion(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index c2f62bdce134..b71f2809caac 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -627,6 +627,43 @@ static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) > INIT_LIST_HEAD(&vma->anon_vma_chain); > } > > +/* Use when VMA is not part of the VMA tree and needs no locking */ > +static inline void init_vm_flags(struct vm_area_struct *vma, > + unsigned long flags) > +{ > + vma->vm_flags = flags; > +} > + > +/* Use when VMA is part of the VMA tree and modifications need coordination */ > +static inline void reset_vm_flags(struct vm_area_struct *vma, > + unsigned long flags) > +{ > + mmap_assert_write_locked(vma->vm_mm); > + init_vm_flags(vma, flags); > +} > + > +static inline void set_vm_flags(struct vm_area_struct *vma, > + unsigned long flags) > +{ > + mmap_assert_write_locked(vma->vm_mm); > + vma->vm_flags |= flags; > +} > + > +static inline void clear_vm_flags(struct vm_area_struct *vma, > + unsigned long flags) > +{ > + mmap_assert_write_locked(vma->vm_mm); > + vma->vm_flags &= ~flags; > +} > + > +static inline void mod_vm_flags(struct vm_area_struct *vma, > + unsigned long set, unsigned long clear) > +{ > + mmap_assert_write_locked(vma->vm_mm); > + vma->vm_flags |= set; > + vma->vm_flags &= ~clear; > +} > + > static inline void vma_set_anonymous(struct vm_area_struct *vma) > { > vma->vm_ops = NULL; > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 2d6d790d9bed..6c7c70bf50dd 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -491,7 +491,13 @@ struct vm_area_struct { > * See vmf_insert_mixed_prot() for discussion. > */ > pgprot_t vm_page_prot; > - unsigned long vm_flags; /* Flags, see mm.h. */ > + > + /* > + * Flags, see mm.h. > + * WARNING! Do not modify directly. > + * Use {init|reset|set|clear|mod}_vm_flags() functions instead. > + */ > + unsigned long vm_flags; > > /* > * For areas with an address space and backing store, > -- > 2.39.1 -- Michal Hocko SUSE Labs _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um