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smtp.kernel.org (Postfix) with ESMTPSA id 0B686C433EF; Thu, 26 Jan 2023 09:17:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674724682; bh=A3jqgSV9WUxdb3ZkujtLcqAQwnfqkoU5ybDSQdNw5cg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sky5enLFwJr3DfJ9b2ymbv/d7rE2oypuJvDM2cNeWmTa68+LJkoJeMjxMVF911xjR /p46Fe2/pbyCsXipax42/Hou3ZWrY6fA7yy3y0E4tly4hSn7A+WSEbwQZyXAjmF/fy t3crMkotzOdGBKQN+I5JbdstqSnsQJbVUv4CaD/JnI/YsWTl+N0fRV5BPO+OqFre41 7ERJV1xNKFLVanuVeJ94drHEBHBdP99mIJAbLamNbCF2r05esRYyfEqSbQFmRXAtIl xm2AXIIoDKu6q2SCf9/o5Ej3L+rCFY/nYnTN8yhQCyREfEIhRdSCFxGuw7sIOiHW7k L6KyLx8xuXeew== Date: Thu, 26 Jan 2023 11:17:09 +0200 From: Mike Rapoport To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, michel@lespinasse.org, jglisse@google.com, mhocko@suse.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, 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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-20230126_011805_858246_8740A5A6 X-CRM114-Status: GOOD ( 21.87 ) X-Mailman-Approved-At: Thu, 26 Jan 2023 08:05:31 -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, Jan 25, 2023 at 12:38:46AM -0800, 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 > --- > 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) I'd suggest to make it vm_flags_init() etc. Except that Acked-by: Mike Rapoport (IBM) > +{ > + 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 > > _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um