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 2FEB1C54E94 for ; Thu, 26 Jan 2023 16:05:37 +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=8uCSod7sEl/HY6piEOnnbangEsFVIxB4stDArPgpR4Y=; b=lKuLcb2ZT3ykoH ijBVNueA5c7Bbqo0UKeWGSXmXEifYcjATCecdMbaNrUiWPBYJHL5SpGQ2izH0BX2AuC4ARFAq4ki/ wDo/twQb1NA6oIsqjKLuMWoVdaAdqMIAPbC7Kx3VSIOsW1yP4P220mKWMsgdUPZLcXgPowqu3AnKF /e/UUs9ccE4ka0U9gdNsXGTu+bBy5IdeTib4Ne+j8LYkuL2k1lAQbUo2QZRTNuVbcq7hTzt/ruUxk 8ZNU1GslDkUgkSFjmo/8kllkCNXPr895+GoBlpouzMfwjZ3a4W4dheTjQoC63trC590l4bflnEXC+ kqdNO/EdIrkK43furqYw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pL4kq-00Bf1h-82; Thu, 26 Jan 2023 16:05:36 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pKyY0-00AHtE-99; Thu, 26 Jan 2023 09:27:57 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3647A61778; Thu, 26 Jan 2023 09:27:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3921C433EF; Thu, 26 Jan 2023 09:27:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674725274; bh=SoMuUCKccvLBFFlS2yaoZNAJ6vi8hf11UD5LIFXhHPI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j//Fl5kIolRbc8e9oVCQ2yHwbpz0TuieYLSj+mDFLpa1qwKxXUhf5PJmcO75Ujh3s twG4fOSIQIUcY+3MnnJB2LFgFpgYd/SthHle/+axd8X6B40DgEguPrzEIDstErfxF8 ko0Mb6Gc7DtRkgMx2KamDNuuhnb/IfTXyWRUAI8okoWPpJCrU+5VBwHmsXg3EJf5FZ gJ2/jlRLLWN+Ab/FNlmJJeHDKv+eOxzvt50mhgYbacQHyS9BYwkvyF434NJwFVAGsI dA9tzS1LLkbpY2wsykh131+0o90nnu9297soO8LSNeHRZppCk70KOOayN+gSrVyob+ 3jVum/MlvC8IQ== Date: Thu, 26 Jan 2023 11:26:58 +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, 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 4/6] mm: replace vma->vm_flags indirect modification in ksm_madvise Message-ID: References: <20230125083851.27759-1-surenb@google.com> <20230125083851.27759-5-surenb@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230125083851.27759-5-surenb@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230126_012756_439583_E789CF51 X-CRM114-Status: GOOD ( 20.37 ) 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 12:38:49AM -0800, Suren Baghdasaryan wrote: > Replace indirect modifications to vma->vm_flags with calls to modifier > functions to be able to track flag changes and to keep vma locking > correctness. Add a BUG_ON check in ksm_madvise() to catch indirect > vm_flags modification attempts. > > Signed-off-by: Suren Baghdasaryan Acked-by: Mike Rapoport (IBM) > --- > arch/powerpc/kvm/book3s_hv_uvmem.c | 5 ++++- > arch/s390/mm/gmap.c | 5 ++++- > mm/khugepaged.c | 2 ++ > mm/ksm.c | 2 ++ > 4 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c > index 1d67baa5557a..325a7a47d348 100644 > --- a/arch/powerpc/kvm/book3s_hv_uvmem.c > +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c > @@ -393,6 +393,7 @@ static int kvmppc_memslot_page_merge(struct kvm *kvm, > { > unsigned long gfn = memslot->base_gfn; > unsigned long end, start = gfn_to_hva(kvm, gfn); > + unsigned long vm_flags; > int ret = 0; > struct vm_area_struct *vma; > int merge_flag = (merge) ? MADV_MERGEABLE : MADV_UNMERGEABLE; > @@ -409,12 +410,14 @@ static int kvmppc_memslot_page_merge(struct kvm *kvm, > ret = H_STATE; > break; > } > + vm_flags = vma->vm_flags; > ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, > - merge_flag, &vma->vm_flags); > + merge_flag, &vm_flags); > if (ret) { > ret = H_STATE; > break; > } > + reset_vm_flags(vma, vm_flags); > start = vma->vm_end; > } while (end > vma->vm_end); > > diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c > index 3a695b8a1e3c..d5eb47dcdacb 100644 > --- a/arch/s390/mm/gmap.c > +++ b/arch/s390/mm/gmap.c > @@ -2587,14 +2587,17 @@ int gmap_mark_unmergeable(void) > { > struct mm_struct *mm = current->mm; > struct vm_area_struct *vma; > + unsigned long vm_flags; > int ret; > VMA_ITERATOR(vmi, mm, 0); > > for_each_vma(vmi, vma) { > + vm_flags = vma->vm_flags; > ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, > - MADV_UNMERGEABLE, &vma->vm_flags); > + MADV_UNMERGEABLE, &vm_flags); > if (ret) > return ret; > + reset_vm_flags(vma, vm_flags); > } > mm->def_flags &= ~VM_MERGEABLE; > return 0; > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 8abc59345bf2..76b24cd0c179 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -354,6 +354,8 @@ struct attribute_group khugepaged_attr_group = { > int hugepage_madvise(struct vm_area_struct *vma, > unsigned long *vm_flags, int advice) > { > + /* vma->vm_flags can be changed only using modifier functions */ > + BUG_ON(vm_flags == &vma->vm_flags); > switch (advice) { > case MADV_HUGEPAGE: > #ifdef CONFIG_S390 > diff --git a/mm/ksm.c b/mm/ksm.c > index 04f1c8c2df11..992b2be9f5e6 100644 > --- a/mm/ksm.c > +++ b/mm/ksm.c > @@ -2573,6 +2573,8 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start, > struct mm_struct *mm = vma->vm_mm; > int err; > > + /* vma->vm_flags can be changed only using modifier functions */ > + BUG_ON(vm_flags == &vma->vm_flags); > switch (advice) { > case MADV_MERGEABLE: > /* > -- > 2.39.1 > > _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um