From: Chao Peng <chao.p.peng@linux.intel.com> To: Vlastimil Babka <vbabka@suse.cz> Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>, Jonathan Corbet <corbet@lwn.net>, Sean Christopherson <seanjc@google.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, Wanpeng Li <wanpengli@tencent.com>, Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>, Hugh Dickins <hughd@google.com>, Jeff Layton <jlayton@kernel.org>, "J . Bruce Fields" <bfields@fieldses.org>, Andrew Morton <akpm@linux-foundation.org>, Yu Zhang <yu.c.zhang@linux.intel.com>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>, luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com Subject: Re: [PATCH v4 01/12] mm/shmem: Introduce F_SEAL_INACCESSIBLE Date: Thu, 17 Feb 2022 20:56:57 +0800 [thread overview] Message-ID: <20220217125656.GA32679@chaop.bj.intel.com> (raw) In-Reply-To: <64407833-1387-0c46-c569-8b6a3db8e88c@suse.cz> On Mon, Feb 07, 2022 at 01:24:42PM +0100, Vlastimil Babka wrote: > On 1/18/22 14:21, Chao Peng wrote: > > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > > > /* > > diff --git a/mm/shmem.c b/mm/shmem.c > > index 18f93c2d68f1..72185630e7c4 100644 > > --- a/mm/shmem.c > > +++ b/mm/shmem.c > > @@ -1098,6 +1098,13 @@ static int shmem_setattr(struct user_namespace *mnt_userns, > > (newsize > oldsize && (info->seals & F_SEAL_GROW))) > > return -EPERM; > > > > + if (info->seals & F_SEAL_INACCESSIBLE) { > > + if(i_size_read(inode)) > > Is this needed? The rest of the function seems to trust oldsize obtained by > plain reading inode->i_size well enough, so why be suddenly paranoid here? oldsize sounds enough here, unless kirill has different mind. > > > + return -EPERM; > > + if (newsize & ~PAGE_MASK) > > + return -EINVAL; > > + } > > + > > if (newsize != oldsize) { > > error = shmem_reacct_size(SHMEM_I(inode)->flags, > > + if ((info->seals & F_SEAL_INACCESSIBLE) && > > + (offset & ~PAGE_MASK || len & ~PAGE_MASK)) { > > Could we use PAGE_ALIGNED()? Yes, definitely, thanks. Chao > > > + error = -EINVAL; > > + goto out; > > + } > > + > > shmem_falloc.waitq = &shmem_falloc_waitq; > > shmem_falloc.start = (u64)unmap_start >> PAGE_SHIFT; > > shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT;
WARNING: multiple messages have this Message-ID (diff)
From: Chao Peng <chao.p.peng@linux.intel.com> To: Vlastimil Babka <vbabka@suse.cz> Cc: Wanpeng Li <wanpengli@tencent.com>, jun.nakajima@intel.com, kvm@vger.kernel.org, david@redhat.com, qemu-devel@nongnu.org, "J . Bruce Fields" <bfields@fieldses.org>, linux-mm@kvack.org, "H . Peter Anvin" <hpa@zytor.com>, ak@linux.intel.com, Jonathan Corbet <corbet@lwn.net>, Joerg Roedel <joro@8bytes.org>, x86@kernel.org, Hugh Dickins <hughd@google.com>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, luto@kernel.org, Thomas Gleixner <tglx@linutronix.de>, Vitaly Kuznetsov <vkuznets@redhat.com>, Jim Mattson <jmattson@google.com>, dave.hansen@intel.com, Sean Christopherson <seanjc@google.com>, Jeff Layton <jlayton@kernel.org>, linux-kernel@vger.kernel.org, Yu Zhang <yu.c.zhang@linux.intel.com>, linux-fsdevel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Subject: Re: [PATCH v4 01/12] mm/shmem: Introduce F_SEAL_INACCESSIBLE Date: Thu, 17 Feb 2022 20:56:57 +0800 [thread overview] Message-ID: <20220217125656.GA32679@chaop.bj.intel.com> (raw) In-Reply-To: <64407833-1387-0c46-c569-8b6a3db8e88c@suse.cz> On Mon, Feb 07, 2022 at 01:24:42PM +0100, Vlastimil Babka wrote: > On 1/18/22 14:21, Chao Peng wrote: > > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > > > /* > > diff --git a/mm/shmem.c b/mm/shmem.c > > index 18f93c2d68f1..72185630e7c4 100644 > > --- a/mm/shmem.c > > +++ b/mm/shmem.c > > @@ -1098,6 +1098,13 @@ static int shmem_setattr(struct user_namespace *mnt_userns, > > (newsize > oldsize && (info->seals & F_SEAL_GROW))) > > return -EPERM; > > > > + if (info->seals & F_SEAL_INACCESSIBLE) { > > + if(i_size_read(inode)) > > Is this needed? The rest of the function seems to trust oldsize obtained by > plain reading inode->i_size well enough, so why be suddenly paranoid here? oldsize sounds enough here, unless kirill has different mind. > > > + return -EPERM; > > + if (newsize & ~PAGE_MASK) > > + return -EINVAL; > > + } > > + > > if (newsize != oldsize) { > > error = shmem_reacct_size(SHMEM_I(inode)->flags, > > + if ((info->seals & F_SEAL_INACCESSIBLE) && > > + (offset & ~PAGE_MASK || len & ~PAGE_MASK)) { > > Could we use PAGE_ALIGNED()? Yes, definitely, thanks. Chao > > > + error = -EINVAL; > > + goto out; > > + } > > + > > shmem_falloc.waitq = &shmem_falloc_waitq; > > shmem_falloc.start = (u64)unmap_start >> PAGE_SHIFT; > > shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT;
next prev parent reply other threads:[~2022-02-17 12:57 UTC|newest] Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-01-18 13:21 [PATCH v4 00/12] KVM: mm: fd-based approach for supporting KVM guest private memory Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 01/12] mm/shmem: Introduce F_SEAL_INACCESSIBLE Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-02-07 12:24 ` Vlastimil Babka 2022-02-07 12:24 ` Vlastimil Babka 2022-02-17 12:56 ` Chao Peng [this message] 2022-02-17 12:56 ` Chao Peng 2022-02-11 23:33 ` Andy Lutomirski 2022-02-11 23:33 ` Andy Lutomirski 2022-02-17 13:06 ` Chao Peng 2022-02-17 13:06 ` Chao Peng 2022-02-17 19:09 ` Andy Lutomirski 2022-02-17 19:09 ` Andy Lutomirski 2022-02-23 11:49 ` Chao Peng 2022-02-23 11:49 ` Chao Peng 2022-02-23 12:05 ` Steven Price 2022-02-23 12:05 ` Steven Price 2022-03-04 19:24 ` Andy Lutomirski 2022-03-04 19:24 ` Andy Lutomirski 2022-03-07 13:26 ` Chao Peng 2022-03-07 13:26 ` Chao Peng 2022-03-08 12:17 ` Paolo Bonzini 2022-03-08 12:17 ` Paolo Bonzini 2022-01-18 13:21 ` [PATCH v4 02/12] mm/memfd: Introduce MFD_INACCESSIBLE flag Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-21 15:50 ` Steven Price 2022-01-21 15:50 ` Steven Price 2022-01-24 13:29 ` Chao Peng 2022-01-24 13:29 ` Chao Peng 2022-02-07 18:51 ` Vlastimil Babka 2022-02-07 18:51 ` Vlastimil Babka 2022-02-08 8:49 ` David Hildenbrand 2022-02-08 8:49 ` David Hildenbrand 2022-02-08 18:22 ` Mike Rapoport 2022-02-08 18:22 ` Mike Rapoport 2022-01-18 13:21 ` [PATCH v4 03/12] mm: Introduce memfile_notifier Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-03-07 15:42 ` Vlastimil Babka 2022-03-07 15:42 ` Vlastimil Babka 2022-03-08 1:45 ` Chao Peng 2022-03-08 1:45 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 04/12] mm/shmem: Support memfile_notifier Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-02-08 18:29 ` Mike Rapoport 2022-02-08 18:29 ` Mike Rapoport 2022-02-17 13:10 ` Chao Peng 2022-02-17 13:10 ` Chao Peng 2022-02-11 23:40 ` Andy Lutomirski 2022-02-11 23:40 ` Andy Lutomirski 2022-02-17 13:23 ` Chao Peng 2022-02-17 13:23 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 05/12] KVM: Extend the memslot to support fd-based private memory Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 06/12] KVM: Use kvm_userspace_memory_region_ext Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 07/12] KVM: Add KVM_EXIT_MEMORY_ERROR exit Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 08/12] KVM: Use memfile_pfn_ops to obtain pfn for private pages Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 09/12] KVM: Handle page fault for private memory Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 10/12] KVM: Register private memslot to memory backing store Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 11/12] KVM: Zap existing KVM mappings when pages changed in the private fd Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-18 13:21 ` [PATCH v4 12/12] KVM: Expose KVM_MEM_PRIVATE Chao Peng 2022-01-18 13:21 ` Chao Peng 2022-01-25 20:20 ` Maciej S. Szmigiero 2022-01-25 20:20 ` Maciej S. Szmigiero 2022-02-17 13:45 ` Chao Peng 2022-02-17 13:45 ` Chao Peng 2022-02-22 1:16 ` Maciej S. Szmigiero 2022-02-22 1:16 ` Maciej S. Szmigiero 2022-02-23 12:00 ` Chao Peng 2022-02-23 12:00 ` Chao Peng 2022-02-23 18:32 ` Maciej S. Szmigiero 2022-02-23 18:32 ` Maciej S. Szmigiero 2022-02-24 8:07 ` Chao Peng 2022-02-24 8:07 ` Chao Peng 2022-01-28 16:47 ` [PATCH v4 00/12] KVM: mm: fd-based approach for supporting KVM guest private memory Steven Price 2022-01-28 16:47 ` Steven Price 2022-02-02 2:28 ` Nakajima, Jun 2022-02-02 2:28 ` Nakajima, Jun 2022-02-02 9:23 ` Steven Price 2022-02-02 9:23 ` Steven Price 2022-02-02 20:47 ` Nakajima, Jun 2022-02-02 20:47 ` Nakajima, Jun 2022-02-08 18:33 ` Mike Rapoport 2022-02-08 18:33 ` Mike Rapoport 2022-02-17 13:47 ` Chao Peng 2022-02-17 13:47 ` Chao Peng
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