Jani Nikula [Mon, 9 May 2022 12:03:03 +0000 (15:03 +0300)]
drm/edid: start propagating drm_edid to lower levels
We'll need to propagate drm_edid everywhere. This is a clunky start, but
a start nonetheless. We'll eventually convert all of the EDID parsing to
struct drm_edid.
Initially, we'll just create the struct drm_edid in stack. This will be
the compat layer for legacy struct edid code. In the future, we'll have
EDID read return drm_edid objects.
Jani Nikula [Mon, 9 May 2022 12:03:02 +0000 (15:03 +0300)]
drm/edid: add struct drm_edid container
Introduce new opaque type struct drm_edid to encapsulate the EDID data
and the size allocated for it. The contents will be private to
drm_edid.c.
There are a number of reasons for adding a container around struct edid:
* struct edid is a raw blob pointer to data that usually originates
outside of the kernel. Its size is contained within the structure.
* There's no way to attach meta information (such as allocated memory
size) to struct edid.
* Validation of the EDID blob and its size become crucial, and it's
spread all over the subsystem, with varying levels of accuracy.
* HDMI Forum has introduced an HF-EEODB extension that defines an
override EDID size within an EDID extension. The size allocated for an
EDID depends on whether the allocator understands the HF-EEODB
extension. Given a struct edid *, it's impossible to know how much
memory was actually allocated for it.
There are also some reasons for making the container type struct
drm_edid opaque and private to drm_edid.c:
* Have only one place for creating and parsing the EDID, to avoid
duplicating bugs.
* Prepare for reading a pure DisplayID 2.0 from its own DDC address, and
adding it within the same struct drm_edid container, transparently,
and for all drivers.
* With the idea that the drm_edid objects are immutable during their
lifetimes, it will be possible to refcount them and reduce EDID
copying everywhere (this is left for future work).
Initially, just add the type. In follow-up, we'll start converting the
guts of drm_edid.c to use it, and finally add interfaces around it.
Zack Rusin [Fri, 18 Mar 2022 17:43:31 +0000 (13:43 -0400)]
drm/vmwgfx: Disable command buffers on svga3 without gbobjects
With very limited vram on svga3 it's difficult to handle all the surface
migrations. Without gbobjects, i.e. the ability to store surfaces in
guest mobs, there's no reason to support intermediate svga2 features,
especially because we can fall back to fb traces and svga3 will never
support those in-between features.
On svga3 we wither want to use fb traces or screen targets
(i.e. gbobjects), nothing in between. This fixes presentation on a lot
of fusion/esxi tech previews where the exposed svga3 caps haven't been
finalized yet.
Zack Rusin [Wed, 2 Mar 2022 15:24:24 +0000 (10:24 -0500)]
drm/vmwgfx: Initialize drm_mode_fb_cmd2
Transition to drm_mode_fb_cmd2 from drm_mode_fb_cmd left the structure
unitialized. drm_mode_fb_cmd2 adds a few additional members, e.g. flags
and modifiers which were never initialized. Garbage in those members
can cause random failures during the bringup of the fbcon.
Initializing the structure fixes random blank screens after bootup due
to flags/modifiers mismatches during the fbcon bring up.
Fixes: dabdcdc9822a ("drm/vmwgfx: Switch to mode_cmd2") Signed-off-by: Zack Rusin <zackr@vmware.com> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: <stable@vger.kernel.org> # v4.10+ Reviewed-by: Martin Krastev <krastevm@vmware.com> Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220302152426.885214-7-zack@kde.org
Zack Rusin [Wed, 2 Mar 2022 15:24:22 +0000 (10:24 -0500)]
drm/vmwgfx: Fix fencing on SVGAv3
Port of the vmwgfx to SVGAv3 lacked support for fencing. SVGAv3 removed
FIFO's and replaced them with command buffers and extra registers.
The initial version of SVGAv3 lacked support for most advanced features
(e.g. 3D) which made fences unnecessary. That is no longer the case,
especially as 3D support is being turned on.
Switch from FIFO commands and capabilities to command buffers and extra
registers to enable fences on SVGAv3.
zhenwei pi [Fri, 13 May 2022 03:23:10 +0000 (20:23 -0700)]
mm/hwpoison: disable hwpoison filter during removing
hwpoison filter is enabled by hwpoison-inject module, after removing this
module, hwpoison filter still works. What is worse, user can not find the
debugfs entries to know this.
Disable the hwpoison filter during removing hwpoison-inject module.
zhenwei pi [Fri, 13 May 2022 03:23:10 +0000 (20:23 -0700)]
mm/memory-failure.c: add hwpoison_filter for soft offline
hwpoison_filter is missing in the soft offline path, this leads an issue:
after enabling the corrupt filter, the user process still has a chance to
inject hwpoison fault by madvise(addr, len, MADV_SOFT_OFFLINE) at PFN
which is expected to reject.
Also do a minor change in comment of memory_failure().
zhenwei pi [Fri, 13 May 2022 03:23:09 +0000 (20:23 -0700)]
mm/memory-failure.c: move clear_hwpoisoned_pages
Patch series "memory-failure: fix hwpoison_filter", v2.
As well known, the memory failure mechanism handles memory corrupted
event, and try to send SIGBUS to the user process which uses this
corrupted page.
For the virtualization case, QEMU catches SIGBUS and tries to inject MCE
into the guest, and the guest handles memory failure again. Thus the
guest gets the minimal effect from hardware memory corruption.
The further step I'm working on:
1, try to modify code to decrease poisoned pages in a single place
(mm/memofy-failure.c: simplify num_poisoned_pages_dec in this series).
2, try to use page_handle_poison() to handle SetPageHWPoison() and
num_poisoned_pages_inc() together. It would be best to call
num_poisoned_pages_inc() in a single place too.
3, introduce memory failure notifier list in memory-failure.c: notify
the corrupted PFN to someone who registers this list. If I can
complete [1] and [2] part, [3] will be quite easy(just call notifier
list after increasing poisoned page).
4, introduce memory recover VQ for memory balloon device, and registers
memory failure notifier list. During the guest kernel handles memory
failure, balloon device gets notified by memory failure notifier list,
and tells the host to recover the corrupted PFN(GPA) by the new VQ.
5, host side remaps the corrupted page(HVA), and tells the guest side
to unpoison the PFN(GPA). Then the guest fixes the corrupted page(GPA)
dynamically.
This patch (of 5):
clear_hwpoisoned_pages() clears HWPoison flag and decreases the number of
poisoned pages, this actually works as part of memory failure.
Move this function from sparse.c to memory-failure.c, finally there is no
CONFIG_MEMORY_FAILURE in sparse.c.
Andrey Konovalov [Fri, 13 May 2022 03:23:09 +0000 (20:23 -0700)]
kasan: update documentation
Do assorted clean-ups and improvements to KASAN documentation, including:
- Describe each mode in a dedicated paragraph.
- Split out a Support section that describes in details which compilers,
architectures and memory types each mode requires/supports.
- Capitalize the first letter in the names of each KASAN mode.
mm/vmalloc: use raw_cpu_ptr() for vmap_block_queue access
The per-CPU resource vmap_block_queue is accessed via get_cpu_var(). That
macro disables preemption and then loads the pointer from the current CPU.
This doesn't work on PREEMPT_RT because a spinlock_t is later accessed
within the preempt-disable section.
There is no need to disable preemption while accessing the per-CPU struct
vmap_block_queue because the list is protected with a spinlock_t. The
per-CPU struct is also accessed cross-CPU in purge_fragmented_blocks().
It is possible that by using raw_cpu_ptr() the code migrates to another
CPU and uses struct from another CPU. This is fine because the list is
locked and the locked section is very short.
Use raw_cpu_ptr() to access vmap_block_queue.
Link: https://lkml.kernel.org/r/YnKx3duAB53P7ojN@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexey Romanov [Fri, 13 May 2022 03:23:07 +0000 (20:23 -0700)]
zram: remove double compression logic
The 2nd trial allocation under per-cpu presumption has been used to
prevent regression of allocation failure. However, it makes trouble for
maintenance without significant benefit. The slowpath branch is executed
extremely rarely: getting there is problematic. Therefore, we delete this
branch.
Since b09ab054b69b ("zram: support BDI_CAP_STABLE_WRITES"), zram has used
QUEUE_FLAG_STABLE_WRITES to prevent buffer change between 1st and 2nd
memory allocations. Since we remove second trial memory allocation logic,
we could remove the STABLE_WRITES flag because there is no change buffer
to be modified under us.
Akira Yokosawa [Fri, 13 May 2022 03:23:07 +0000 (20:23 -0700)]
docs: vm/page_owner: tweak literal block in STANDARD FORMAT SPECIFIERS
A semantic conflict between commit 5603f9bdea68 ("docs: vm/page_owner: use
literal blocks for param description") and a change queued for v5.19
authored by Jiajian Ye ("tools/vm/page_owner_sort.c: support sorting
blocks by multiple keys") results in a warning from "make htmldocs"
saying:
Tong Tiangen [Fri, 13 May 2022 03:23:06 +0000 (20:23 -0700)]
mm: remove __HAVE_ARCH_PTEP_CLEAR in pgtable.h
Currently, there is no architecture definition __HAVE_ARCH_PTEP_CLEAR,
Generic ptep_clear() is the only definition for all architecture, So drop
the "#ifndef __HAVE_ARCH_PTEP_CLEAR".
Link: https://lkml.kernel.org/r/20220507110114.4128854-5-tongtiangen@huawei.com Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> Suggested-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tong Tiangen [Fri, 13 May 2022 03:23:06 +0000 (20:23 -0700)]
mm: page_table_check: add hooks to public helpers
Move ptep_clear() to the include/linux/pgtable.h and add page table check
relate hooks to some helpers, it's prepare for support page table check
feature on new architecture.
Optimize the implementation of ptep_clear(), page table hooks added page
table check stubs, the interface control should be at stubs, there is no
rationale for doing a IS_ENABLED() check here.
For architectures that do not enable CONFIG_PAGE_TABLE_CHECK, they will
call a fallback page table check stubs[1] when getting their page table
helpers[2] in include/linux/pgtable.h.
[1] page table check stubs defined in include/linux/page_table_check.h
[2] ptep_clear() ptep_get_and_clear() pmdp_huge_get_and_clear()
pudp_huge_get_and_clear()
Link: https://lkml.kernel.org/r/20220507110114.4128854-4-tongtiangen@huawei.com Signed-off-by: Tong Tiangen <tongtiangen@huawei.com> Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tong Tiangen [Fri, 13 May 2022 03:23:06 +0000 (20:23 -0700)]
mm: page_table_check: using PxD_SIZE instead of PxD_PAGE_SIZE
Patch series "mm: page_table_check: add support on arm64 and riscv", v7.
Page table check performs extra verifications at the time when new pages
become accessible from the userspace by getting their page table entries
(PTEs PMDs etc.) added into the table. It is supported on X86[1].
This patchset made some simple changes and make it easier to support new
architecture, then we support this feature on ARM64 and RISCV.
Compared with PxD_PAGE_SIZE, which is defined and used only on X86,
PxD_SIZE is more common in each architecture. Therefore, it is more
reasonable to use PxD_SIZE instead of PxD_PAGE_SIZE in page_table_check.c.
At the same time, it is easier to support page table check in other
architectures. The substitution has no functional impact on the x86.
mm/shmem: convert shmem_getpage_gfp to use a folio
Rename shmem_alloc_and_acct_page() to shmem_alloc_and_acct_folio() and
have it return a folio, then use a folio throuughout shmem_getpage_gfp().
It continues to return a struct page.
mm/shmem: convert shmem_alloc_and_acct_page to use a folio
Convert shmem_alloc_hugepage() to return the folio that it uses and use a
folio throughout shmem_alloc_and_acct_page(). Continue to return a page
from shmem_alloc_and_acct_page() for now.
The only use of the page argument to cgroup_throttle_swaprate() is to get
the node ID, and this will be the same for all pages in the folio, so just
pass in the first page of the folio.
When calling split_huge_page() we usually have to find the precise page,
but that's not necessary here because we only need to unlock and put the
folio afterwards. Saves 231 bytes of text (20% of this function).
mm: allow can_split_folio() to be called when THP are disabled
The call to can_split_folio() in vmscan is currently guarded by a test of
PageTransHuge() so the BUILD_BUG() is eliminated if THP are disabled. The
next patch replaces that test with folio_test_large() which may be true,
even when THP are disabled. However, if THP are disabled, we cannot
split, so an unconditional return of false is appropriate.
Now that we don't interrogate the BDI for congestion, we can delay looking
up the folio's mapping until we've got further through the function,
reducing register pressure and saving a call to folio_mapping for folios
we're adding to the swap cache.
Remove a hidden call to compound_head(), and account nr_pages instead of a
single page. This matches the code in lru_lazyfree_fn() that accounts
nr_pages to PGLAZYFREE.
Due to a typo, the final argument to alloc_page_vma() didn't refer to a
real variable. This only affected CONFIG_NUMA, which was marked BROKEN in
2006 and removed from alpha in 2021. Found due to a refactoring patch.
Link: https://lkml.kernel.org/r/20220504182857.4013401-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wei Yang [Fri, 13 May 2022 03:23:00 +0000 (20:23 -0700)]
mm/vmscan: don't use NUMA_NO_NODE as indicator of page on different node
Now we are sure there is at least one page on page_list, so it is safe to
get the nid of it. This means it is not necessary to use NUMA_NO_NODE as
an indicator for the beginning of iteration or a page on different node.
Miaohe Lin [Fri, 13 May 2022 03:23:00 +0000 (20:23 -0700)]
mm/vmscan: remove obsolete comment in kswapd_run
Since commit 6b700b5b3c59 ("mm/vmscan.c: remove cpu online notification
for now"), cpu online notification is removed. So kswapd won't move to
proper cpus if cpus are hot-added. Remove this obsolete comment.
Link: https://lkml.kernel.org/r/20220425111232.23182-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 13 May 2022 03:23:00 +0000 (20:23 -0700)]
mm/vmscan: take all base pages of THP into account when race with speculative reference
If the page has buffers, shrink_page_list will try to free the buffer
mappings associated with the page and try to free the page as well. In
the rare race with speculative reference, the page will be freed shortly
by speculative reference. But nr_reclaimed is not incremented correctly
when we come across the THP. We need to account all the base pages in
this case.
Link: https://lkml.kernel.org/r/20220425111232.23182-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 13 May 2022 03:22:59 +0000 (20:22 -0700)]
mm/vmscan: introduce helper function reclaim_page_list()
Introduce helper function reclaim_page_list() to eliminate the duplicated
code of doing shrink_page_list() and putback_lru_page. Also we can
separate node reclaim from node page list operation this way. No
functional change intended.
Link: https://lkml.kernel.org/r/20220425111232.23182-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Huang, Ying <ying.huang@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 13 May 2022 03:22:59 +0000 (20:22 -0700)]
mm/vmscan: add a comment about MADV_FREE pages check in folio_check_dirty_writeback
Patch series "A few cleanup and fixup patches for vmscan
This series contains a few patches to remove obsolete comment, introduce
helper to remove duplicated code and so no. Also we take all base pages
of THP into account in rare race condition. More details can be found in
the respective changelogs.
This patch (of 6):
The MADV_FREE pages check in folio_check_dirty_writeback is a bit hard to
follow. Add a comment to make the code clear.
Link: https://lkml.kernel.org/r/20220425111232.23182-2-linmiaohe@huawei.com Suggested-by: Huang, Ying <ying.huang@intel.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jagdish Gediya [Fri, 13 May 2022 03:22:59 +0000 (20:22 -0700)]
mm: convert sysfs input to bool using kstrtobool()
Sysfs input conversion to corrosponding bool value e.g. "false" or "0" to
false, "true" or "1" to true are currently handled through strncmp at
multiple places. Use kstrtobool() to convert sysfs input to bool value.
[akpm@linux-foundation.org: propagate kstrtobool() return value, per Andy] Link: https://lkml.kernel.org/r/20220426180203.70782-2-jvgediya@linux.ibm.com Signed-off-by: Jagdish Gediya <jvgediya@linux.ibm.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Jagdish Gediya [Fri, 13 May 2022 03:22:59 +0000 (20:22 -0700)]
lib/kstrtox.c: add "false"/"true" support to kstrtobool()
At many places in kernel, It is necessary to convert sysfs input to
corresponding bool value e.g. "false" or "0" need to be converted to bool
false, "true" or "1" need to be converted to bool true, places where such
conversion is needed currently check the input string manually,
kstrtobool() can be utilized at such places but currently it doesn't have
support to accept "false"/"true".
Add support to accept "false"/"true" as valid string in kstrtobool().
[akpm@linux-foundation.org: undo s/iff/if/, per Matthew] Link: https://lkml.kernel.org/r/20220426180203.70782-1-jvgediya@linux.ibm.com Signed-off-by: Jagdish Gediya <jvgediya@linux.ibm.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Richard Fitzgerald <rf@opensource.cirrus.com> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miaohe Lin [Fri, 13 May 2022 03:22:58 +0000 (20:22 -0700)]
mm/vmscan: take min_slab_pages into account when try to call shrink_node
Since commit 6b4f7799c6a5 ("mm: vmscan: invoke slab shrinkers from
shrink_zone()"), slab reclaim and lru page reclaim are done together in
the shrink_node. So we should take min_slab_pages into account when try
to call shrink_node.
Link: https://lkml.kernel.org/r/20220425112118.20924-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Fri, 13 May 2022 03:22:58 +0000 (20:22 -0700)]
drivers: virtio_mem: use pageblock size as the minimum virtio_mem size.
alloc_contig_range() now only needs to be aligned to pageblock_nr_pages,
drop virtio_mem size requirement that it needs to be MAX_ORDER_NR_PAGES.
Link: https://lkml.kernel.org/r/20220425143118.2850746-7-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: kernel test robot <lkp@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Fri, 13 May 2022 03:22:58 +0000 (20:22 -0700)]
mm: cma: use pageblock_order as the single alignment
Now alloc_contig_range() works at pageblock granularity. Change CMA
allocation, which uses alloc_contig_range(), to use pageblock_nr_pages
alignment.
Link: https://lkml.kernel.org/r/20220425143118.2850746-6-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: kernel test robot <lkp@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Fri, 13 May 2022 03:22:58 +0000 (20:22 -0700)]
mm: page_isolation: enable arbitrary range page isolation.
Now start_isolate_page_range() is ready to handle arbitrary range
isolation, so move the alignment check/adjustment into the function body.
Do the same for its counterpart undo_isolate_page_range().
alloc_contig_range(), its caller, can pass an arbitrary range instead of a
MAX_ORDER_NR_PAGES aligned one.
Link: https://lkml.kernel.org/r/20220425143118.2850746-5-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: kernel test robot <lkp@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Fri, 13 May 2022 03:22:58 +0000 (20:22 -0700)]
mm: make alloc_contig_range work at pageblock granularity
alloc_contig_range() worked at MAX_ORDER_NR_PAGES granularity to avoid
merging pageblocks with different migratetypes. It might unnecessarily
convert extra pageblocks at the beginning and at the end of the range.
Change alloc_contig_range() to work at pageblock granularity.
Special handling is needed for free pages and in-use pages across the
boundaries of the range specified by alloc_contig_range(). Because these=
Partially isolated pages causes free page accounting issues. The free
pages will be split and freed into separate migratetype lists; the in-use=
Pages will be migrated then the freed pages will be handled in the
aforementioned way.
[ziy@nvidia.com: fix deadlock/crash] Link: https://lkml.kernel.org/r/23A7297E-6C84-4138-A9FE-3598234004E6@nvidia.com Link: https://lkml.kernel.org/r/20220425143118.2850746-4-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: kernel test robot <lkp@intel.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Fri, 13 May 2022 03:22:58 +0000 (20:22 -0700)]
mm: page_isolation: check specified range for unmovable pages
Enable set_migratetype_isolate() to check specified range for unmovable
pages during isolation to prepare arbitrary range page isolation. The
functionality will take effect in upcoming commits by adjusting the
callers of start_isolate_page_range(), which uses
set_migratetype_isolate().
For example, alloc_contig_range(), which calls start_isolate_page_range(),
accepts unaligned ranges, but because page isolation is currently done at
MAX_ORDER_NR_PAEGS granularity, pages that are out of the specified range
but withint MAX_ORDER_NR_PAEGS alignment might be attempted for isolation
and the failure of isolating these unrelated pages fails the whole
operation undesirably.
Link: https://lkml.kernel.org/r/20220425143118.2850746-3-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: kernel test robot <lkp@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Fri, 13 May 2022 03:22:57 +0000 (20:22 -0700)]
mm: page_isolation: move has_unmovable_pages() to mm/page_isolation.c
Patch series "Use pageblock_order for cma and alloc_contig_range alignment", v11.
This patchset tries to remove the MAX_ORDER-1 alignment requirement for CMA
and alloc_contig_range(). It prepares for my upcoming changes to make
MAX_ORDER adjustable at boot time[1].
The MAX_ORDER - 1 alignment requirement comes from that
alloc_contig_range() isolates pageblocks to remove free memory from buddy
allocator but isolating only a subset of pageblocks within a page spanning
across multiple pageblocks causes free page accounting issues. Isolated
page might not be put into the right free list, since the code assumes the
migratetype of the first pageblock as the whole free page migratetype.
This is based on the discussion at [2].
To remove the requirement, this patchset:
1. isolates pages at pageblock granularity instead of
max(MAX_ORDER_NR_PAEGS, pageblock_nr_pages);
2. splits free pages across the specified range or migrates in-use pages
across the specified range then splits the freed page to avoid free page
accounting issues (it happens when multiple pageblocks within a single page
have different migratetypes);
3. only checks unmovable pages within the range instead of MAX_ORDER - 1 aligned
range during isolation to avoid alloc_contig_range() failure when pageblocks
within a MAX_ORDER - 1 aligned range are allocated separately.
4. returns pages not in the range as it did before.
One optimization might come later:
1. make MIGRATE_ISOLATE a separate bit to be able to restore the original
migratetypes when isolation fails in the middle of the range.
has_unmovable_pages() is only used in mm/page_isolation.c. Move it from
mm/page_alloc.c and make it static.
Link: https://lkml.kernel.org/r/20220425143118.2850746-2-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Minchan Kim <minchan@kernel.org> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Vernet [Fri, 13 May 2022 03:22:57 +0000 (20:22 -0700)]
cgroup: fix racy check in alloc_pagecache_max_30M() helper function
alloc_pagecache_max_30M() in the cgroup memcg tests performs a 50MB
pagecache allocation, which it expects to be capped at 30MB due to the
calling process having a memory.high setting of 30MB. After the
allocation, the function contains a check that verifies that MB(29) <
memory.current <= MB(30). This check can actually fail
non-deterministically.
The testcases that use this function are test_memcg_high() and
test_memcg_max(), which set memory.min and memory.max to 30MB respectively
for the cgroup under test. The allocation can slightly exceed this number
in both cases, and for memory.max, the process performing the allocation
will not have the OOM killer invoked as it's performing a pagecache
allocation. This patchset therefore updates the above check to instead
use the verify_close() helper function.
Link: https://lkml.kernel.org/r/20220423155619.3669555-6-void@manifault.com Signed-off-by: David Vernet <void@manifault.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Vernet [Fri, 13 May 2022 03:22:57 +0000 (20:22 -0700)]
cgroup: remove racy check in test_memcg_sock()
test_memcg_sock() in the cgroup memcg tests, verifies expected memory
accounting for sockets. The test forks a process which functions as a TCP
server, and sends large buffers back and forth between itself (as the TCP
client) and the forked TCP server. While doing so, it verifies that
memory.current and memory.stat.sock look correct.
There is currently a check in tcp_client() which asserts memory.current >=
memory.stat.sock. This check is racy, as between memory.current and
memory.stat.sock being queried, a packet could come in which causes
mem_cgroup_charge_skmem() to be invoked. This could cause
memory.stat.sock to exceed memory.current. Reversing the order of
querying doesn't address the problem either, as memory may be reclaimed
between the two calls. Instead, this patch just removes that assertion
altogether, and instead relies on the values_close() check that follows to
validate the expected accounting.
Link: https://lkml.kernel.org/r/20220423155619.3669555-5-void@manifault.com Signed-off-by: David Vernet <void@manifault.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Vernet [Fri, 13 May 2022 03:22:57 +0000 (20:22 -0700)]
cgroup: account for memory_localevents in test_memcg_oom_group_leaf_events()
The test_memcg_oom_group_leaf_events() testcase in the cgroup memcg tests
validates that processes in a group that perform allocations exceeding
memory.oom.group are killed. It also validates that the
memory.events.oom_kill events are properly propagated in this case.
Commit 06e11c907ea4 ("kselftests: memcg: update the oom group leaf events
test") fixed test_memcg_oom_group_leaf_events() to account for the fact
that the memory.events.oom_kill events in a child cgroup is propagated up
to its parent. This behavior can actually be configured by the
memory_localevents mount option, so this patch updates the testcase to
properly account for the possible presence of this mount option.
Link: https://lkml.kernel.org/r/20220423155619.3669555-4-void@manifault.com Signed-off-by: David Vernet <void@manifault.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Vernet [Fri, 13 May 2022 03:22:57 +0000 (20:22 -0700)]
cgroup: account for memory_recursiveprot in test_memcg_low()
The test_memcg_low() testcase in test_memcontrol.c verifies the expected
behavior of groups using the memory.low knob. Part of the testcase
verifies that a group with memory.low that experiences reclaim due to
memory pressure elsewhere in the system, observes memory.events.low events
as a result of that reclaim.
In commit 8a931f801340 ("mm: memcontrol: recursive memory.low
protection"), the memory controller was updated to propagate memory.low
and memory.min protection from a parent group to its children via a
configurable memory_recursiveprot mount option. This unfortunately broke
the memcg tests, which asserts that a sibling that experienced reclaim but
had a memory.low value of 0, would not observe any memory.low events.
This patch updates test_memcg_low() to account for the new behavior
introduced by memory_recursiveprot.
So as to make the test resilient to multiple configurations, the patch
also adds a new proc_mount_contains() helper that checks for a string in
/proc/mounts, and is used to toggle behavior based on whether the default
memory_recursiveprot was present.
Link: https://lkml.kernel.org/r/20220423155619.3669555-3-void@manifault.com Signed-off-by: David Vernet <void@manifault.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Vernet [Fri, 13 May 2022 03:22:56 +0000 (20:22 -0700)]
cgroups: refactor children cgroups in memcg tests
Patch series "Fix bugs in memcontroller cgroup tests", v2.
tools/testing/selftests/cgroup/test_memcontrol.c contains a set of
testcases which validate expected behavior of the cgroup memory
controller. Roman Gushchin recently sent out a patchset that fixed a few
issues in the test. This patchset continues that effort by fixing a few
more issues that were causing non-deterministic failures in the suite.
With this patchset, I'm unable to reproduce any more errors after running
the tests in a continuous loop for many iterations. Before, I was able to
reproduce at least one of the errors fixed in this patchset with just one
or two runs.
This patch (of 5):
In test_memcg_min() and test_memcg_low(), there is an array of four
sibling cgroups. All but one of these sibling groups does a 50MB
allocation, and the group that does no allocation is the third of four in
the array. This is not a problem per se, but makes it a bit tricky to do
some assertions in test_memcg_low(), as we want to make assertions on the
siblings based on whether or not they performed allocations. Having a
static index before which all groups have performed an allocation makes
this cleaner.
This patch therefore reorders the sibling groups so that the group that
performs no allocations is the last in the array. A follow-on patch will
leverage this to fix a bug in the test that incorrectly asserts that a
sibling group that had performed an allocation, but only had protection
from its parent, will not observe any memory.events.low events during
reclaim.
Peter Xu [Fri, 13 May 2022 03:22:56 +0000 (20:22 -0700)]
mm/uffd: move USERFAULTFD configs into mm/
We used to have USERFAULTFD configs stored in init/. It makes sense as a
start because that's the default place for storing syscall related
configs.
However userfaultfd evolved a bit in the past few years and some more
config options were added. They're no longer related to syscalls and
start to be not suitable to be kept in the init/ directory anymore,
because they're pure mm concepts.
But it's not ideal either to keep the userfaultfd configs separate from
each other. Hence this patch moves the userfaultfd configs under init/ to
be under mm/ so that we'll start to group all userfaultfd configs
together.
We do have quite a few examples of syscall related configs that are not
put under init/Kconfig: FTRACE_SYSCALLS, SWAP, FILE_LOCKING,
MEMFD_CREATE.. They all reside in the dir where they're more suitable for
the concept. So it seems there's no restriction to keep the role of
having syscall related CONFIG_* under init/ only.
Link: https://lkml.kernel.org/r/20220420144823.35277-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Guo Zhengkui [Fri, 13 May 2022 03:22:56 +0000 (20:22 -0700)]
userfaultfd/selftests: use swap() instead of open coding it
Address the following coccicheck warning:
tools/testing/selftests/vm/userfaultfd.c:1536:21-22: WARNING opportunity
for swap().
tools/testing/selftests/vm/userfaultfd.c:1540:33-34: WARNING opportunity
for swap().
by using swap() for the swapping of variable values and drop
`tmp_area` that is not needed any more.
`swap()` macro in userfaultfd.c is introduced in commit 681696862bc18
("selftests: vm: remove dependecy from internal kernel macros")
It has been tested with gcc (Debian 8.3.0-6) 8.3.0.
Link: https://lkml.kernel.org/r/20220407123141.4998-1-guozhengkui@vivo.com Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Fri, 13 May 2022 03:22:55 +0000 (20:22 -0700)]
mm/pagemap: recognize uffd-wp bit for shmem/hugetlbfs
This requires the pagemap code to be able to recognize the newly
introduced swap special pte for uffd-wp, meanwhile the general case for
hugetlb that we recently start to support. It should make pagemap uffd-wp
support complete.
Link: https://lkml.kernel.org/r/20220405014923.15047-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Fri, 13 May 2022 03:22:55 +0000 (20:22 -0700)]
mm/khugepaged: don't recycle vma pgtable if uffd-wp registered
When we're trying to collapse a 2M huge shmem page, don't retract pgtable
pmd page if it's registered with uffd-wp, because that pgtable could have
pte markers installed. Recycling of that pgtable means we'll lose the pte
markers. That could cause data loss for an uffd-wp enabled application on
shmem.
Instead of disabling khugepaged on these files, simply skip retracting
these special VMAs, then the page cache can still be merged into a huge
thp, and other mm/vma can still map the range of file with a huge thp when
proper.
Note that checking VM_UFFD_WP needs to be done with mmap_sem held for
write, that avoids race like:
khugepaged user thread
========== ===========
check VM_UFFD_WP, not set
UFFDIO_REGISTER with uffd-wp on shmem
wr-protect some pages (install markers)
take mmap_sem write lock
erase pmd and free pmd page
--> pte markers are dropped unnoticed!
Link: https://lkml.kernel.org/r/20220405014921.14994-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Fri, 13 May 2022 03:22:55 +0000 (20:22 -0700)]
mm/hugetlb: handle uffd-wp during fork()
Firstly, we'll need to pass in dst_vma into copy_hugetlb_page_range()
because for uffd-wp it's the dst vma that matters on deciding how we
should treat uffd-wp protected ptes.
We should recognize pte markers during fork and do the pte copy if needed.
[lkp@intel.com: vma_needs_copy can be static] Link: https://lkml.kernel.org/r/Ylb0CGeFJlc4EzLk@7ec4ff11d4ae Link: https://lkml.kernel.org/r/20220405014918.14932-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Fri, 13 May 2022 03:22:55 +0000 (20:22 -0700)]
mm/hugetlb: only drop uffd-wp special pte if required
As with shmem uffd-wp special ptes, only drop the uffd-wp special swap pte
if unmapping an entire vma or synchronized such that faults can not race
with the unmap operation. This requires passing zap_flags all the way to
the lowest level hugetlb unmap routine: __unmap_hugepage_range.
In general, unmap calls originated in hugetlbfs code will pass the
ZAP_FLAG_DROP_MARKER flag as synchronization is in place to prevent
faults. The exception is hole punch which will first unmap without any
synchronization. Later when hole punch actually removes the page from the
file, it will check to see if there was a subsequent fault and if so take
the hugetlb fault mutex while unmapping again. This second unmap will
pass in ZAP_FLAG_DROP_MARKER.
The justification of "whether to apply ZAP_FLAG_DROP_MARKER flag when
unmap a hugetlb range" is (IMHO): we should never reach a state when a
page fault could errornously fault in a page-cache page that was
wr-protected to be writable, even in an extremely short period. That
could happen if e.g. we pass ZAP_FLAG_DROP_MARKER when
hugetlbfs_punch_hole() calls hugetlb_vmdelete_list(), because if a page
faults after that call and before remove_inode_hugepages() is executed,
the page cache can be mapped writable again in the small racy window, that
can cause unexpected data overwritten.
[peterx@redhat.com: fix sparse warning] Link: https://lkml.kernel.org/r/Ylcdw8I1L5iAoWhb@xz-m1.local
[akpm@linux-foundation.org: move zap_flags_t from mm.h to mm_types.h to fix build issues] Link: https://lkml.kernel.org/r/20220405014915.14873-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Fri, 13 May 2022 03:22:55 +0000 (20:22 -0700)]
mm/hugetlb: allow uffd wr-protect none ptes
Teach hugetlbfs code to wr-protect none ptes just in case the page cache
existed for that pte. Meanwhile we also need to be able to recognize a
uffd-wp marker pte and remove it for uffd_wp_resolve.
Since at it, introduce a variable "psize" to replace all references to the
huge page size fetcher.
Link: https://lkml.kernel.org/r/20220405014912.14815-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Peter Xu [Fri, 13 May 2022 03:22:54 +0000 (20:22 -0700)]
mm/hugetlb: handle pte markers in page faults
Allow hugetlb code to handle pte markers just like none ptes. It's mostly
there, we just need to make sure we don't assume hugetlb_no_page() only
handles none pte, so when detecting pte change we should use pte_same()
rather than pte_none(). We need to pass in the old_pte to do the
comparison.
Check the original pte to see whether it's a pte marker, if it is, we
should recover uffd-wp bit on the new pte to be installed, so that the
next write will be trapped by uffd.
Link: https://lkml.kernel.org/r/20220405014909.14761-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / people / ms / linux.git / log
