From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
To: "Gregory Price (Meta)" <gourry@gourry.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
"Liam R. Howlett" <liam@infradead.org>,
Vlastimil Babka <vbabka@kernel.org>,
Jann Horn <jannh@google.com>, Pedro Falcato <pfalcato@suse.de>,
David Hildenbrand <david@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 01/39] mm/vma: fix mmap_prepare file handling, remove file_doesnt_need_get
Date: Wed, 21 Oct 2026 15:37:25 +0100 [thread overview]
Message-ID: <atjAgZCWdYN77C4n@gremlin> (raw)
In-Reply-To: <179253282492.1207257.6426479952081115792.b4-reply@b4>
[ cut cc list for sanity ]
On Tue, Oct 20, 2026 at 05:47:04PM -0400, Gregory Price (Meta) wrote:
> On 2026-10-13 16:04 +0100, Lorenzo Stoakes (ARM) wrote:
> > The map->file_doesnt_need_get flag is confusing and the existing
> > implementation has holes.
> >
> > Drivers are permitted to change the owning file of a mapping. If they do
> > so, they are required to take a reference on that file.
> >
> > The mmap() operation which ultimately invokes __mmap_region() is guaranteed
> > to drop the refcount for the original file the mapping was made under, but
> > this is not true for the replaced file.
> >
> ...
> >
> > Reviewed-by: Suren Baghdasaryan <surenb@google.com>
> > Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
>
> Have a nit below, but otherwise
>
> Reviewed-by: Gregory Price (Meta) <gourry@gourry.net>
Thanks! :)
>
> > +static bool map_same_file(struct mmap_state *map)
> > +{
> > + return map->vm_file == map->file;
> > +}
> >
>
> Terrible function name :]
I think let's leave things as-is and maybe chase this separately as a
follow-up ;)
--
Cheers, Lorenzo
next prev parent reply other threads:[~2026-10-21 14:37 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-13 15:04 [PATCH v6 00/39] mm: make VMA flag semantics explicit, eliminate VM_SPECIAL Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 01/39] mm/vma: fix mmap_prepare file handling, remove file_doesnt_need_get Lorenzo Stoakes (ARM)
2026-10-20 21:47 ` Gregory Price (Meta)
2026-10-21 14:37 ` Lorenzo Stoakes (ARM) [this message]
2026-10-13 15:04 ` [PATCH v6 02/39] mm/vma: introduce and use vma_[flags_]can_merge() Lorenzo Stoakes (ARM)
2026-10-13 15:19 ` David Hildenbrand (Arm)
2026-10-13 15:04 ` [PATCH v6 03/39] mm: consistently validate VMA state after mmap[_prepare] hooks Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 04/39] mm/vma: ensure mmap_prepare doesn't set actions on a mergeable vma Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 05/39] mm: make map_kernel_pages_[prepare,complete] internal and unexported Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 06/39] mm/vma: tidy up map kernel pages enum values Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 07/39] mm: assert mmap lock held, use new flags API in vm_insert_page[s] Lorenzo Stoakes (ARM)
2026-10-13 15:20 ` David Hildenbrand (Arm)
2026-10-20 21:48 ` Gregory Price (Meta)
2026-10-13 15:04 ` [PATCH v6 08/39] mm: add mmap action for discontiguous kernel page mapping Lorenzo Stoakes (ARM)
2026-10-13 15:24 ` David Hildenbrand (Arm)
2026-10-13 15:04 ` [PATCH v6 09/39] docs: filesystems: update mmap_prepare docs for discontig kernel pgs Lorenzo Stoakes (ARM)
2026-10-13 15:25 ` David Hildenbrand (Arm)
2026-10-13 15:04 ` [PATCH v6 10/39] drivers/usb/mon: update to use mmap_prepare + map kernel pages Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 11/39] infiniband: update hfi1 to use remap_vmalloc_range() Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 12/39] selinux: reject writable opens of policy file, drop mmap shared/write check Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 13/39] ALSA: pcm: use vm_insert_page() to map PCM status page Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 14/39] bpf: arena: mark arena_map_mmap() mappings VM_MIXEDMAP Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 15/39] mm/vma: add vma[_flags]_is_mm_managed() predicates Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 16/39] mm/vma: only allow mmap to clear VMA_MAYWRITE_BIT if not mm-managed Lorenzo Stoakes (ARM)
2026-10-18 2:59 ` David Carlier
2026-10-19 10:28 ` Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 17/39] mm/vma: add and use vma_[flags]_is_fixed_mapping Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 18/39] scsi: sg: convert mmap hook to mmap_prepare and rework Lorenzo Stoakes (ARM)
2026-10-13 15:04 ` [PATCH v6 19/39] fbdev: defio: assert FBINFO_VIRTFB, drop VM_IO, add VM_MIXEDMAP Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 20/39] HSI: cmt_speech: convert mmap hook to mmap_prepare, refactor Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 21/39] mm/gup: error out early on !VMA_MAYREAD_BIT VMAs Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 22/39] uprobes: remove VM_IO, set VM_MIXEDMAP for mapped kernel pages Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 23/39] mm/mlock: clear VMA_LOCKED_MASK over mmap callback Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 24/39] mm/mlock: eliminate weird VMA_IO_BIT abuse and simplify Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 25/39] mm/vma: enforce that mm-managed mappings may not set VMA_IO_BIT Lorenzo Stoakes (ARM)
2026-10-13 15:26 ` David Hildenbrand (Arm)
2026-10-13 15:05 ` [PATCH v6 26/39] mm: remove VMA_IO_BIT check in vma[_flags]_is_mm_managed() Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 27/39] mm: remove hugetlb_inline.h Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 28/39] mm: rename is_vm_hugetlb_page() to vma_is_hugetlb() Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 29/39] mm: drop some redundant checks around hugetlb VMAs Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 30/39] mm/vma: introduce vma[_flags]_is_mm_backed() Lorenzo Stoakes (ARM)
2026-10-13 15:31 ` David Hildenbrand (Arm)
2026-10-13 15:05 ` [PATCH v6 31/39] mm/madvise: update is_valid_guard_vma() to use vma_is_mm_backed() Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 32/39] mm/uffd: use predicates for userfaultfd checks Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 33/39] mm/madvise: use predicates for madvise(..., MADV_DOFORK) Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 34/39] mm: eliminate VMA_SPECIAL_FLAGS usage when hugetlb explicitly tested Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 35/39] mm: eliminate VMA_SPECIAL_FLAGS check in lru_gen_look_around() Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 36/39] mm: avoid use of VMA_SPECIAL_FLAGS in migrate_vma_setup() Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 37/39] mm: eliminate VM_SPECIAL, VMA_SPECIAL_FLAGS Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 38/39] fuse: dax: do not set VM_MIXEDMAP Lorenzo Stoakes (ARM)
2026-10-13 15:05 ` [PATCH v6 39/39] mm/huge_memory: remove vma_is_special_huge() Lorenzo Stoakes (ARM)
2026-10-13 18:50 ` [PATCH v6 00/39] mm: make VMA flag semantics explicit, eliminate VM_SPECIAL Andrew Morton
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