Commit graph

1,412,004 commits

Author SHA1 Message Date
Marc Zyngier
dd598fc113 KVM: arm64: Compute vgic state irrespective of the number of interrupts
As we are going to rely on the [G]ICH_HCR{,_EL2} register to be
programmed with MI information at all times, slightly de-optimise
the flush/sync code to always be called. This is rather lightweight
when no interrupts are in flight.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-20-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
0660bc4a2b KVM: arm64: GICv2: Extract LR computing primitive
Split vgic_v2_populate_lr() into two helpers, so that we have another
primitive that computes the LR from a vgic_irq, but doesn't update
anything in the shadow structure.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-19-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
3aa9a50c20 KVM: arm64: GICv2: Extract LR folding primitive
As we are going to need to handle deactivation for interrupts that
are not in the LRs, split vgic_v2_fold_lr_state() into a helper
that deals with a single interrupt, and the function that loops
over the used LRs.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-18-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
a00c88ac1f KVM: arm64: GICv2: Decouple GICH_HCR programming from LRs being loaded
Not programming GICH_HCR while no LRs are populated is a bit
of an issue, as we otherwise don't see any maintenance interrupt
when the guest interacts with the LRs.

Decouple the two and always program the control register, even when
we don't have to touch the LRs.

This is very similar to what we are already doing for GICv3.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-17-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
5ceb3dac80 KVM: arm64: GICv2: Preserve EOIcount on exit
EOIcount is how the virtual CPU interface signals that the guest
is deactivating interrupts outside of the LRs when EOImode==0.

We therefore need to preserve that information so that we can find
out what actually needs deactivating, just like we already do on
GICv3.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-16-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
1ae0448ca7 KVM: arm64: GICv3: Extract LR computing primitive
Split vgic_v3_populate_lr() into two, so that we have another
primitive that computes the LR from a vgic_irq, but doesn't
update anything in the shadow structure.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-15-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
438e47b697 KVM: arm64: GICv3: Extract LR folding primitive
As we are going to need to handle deactivation for interrupts that
are not in the LRs, split vgic_v3_fold_lr_state() into a helper
that deals with a single interrupt, and the function that loops
over the used LRs.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-14-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
00c6d0d4a8 KVM: arm64: GICv3: Decouple ICH_HCR_EL2 programming from LRs
Not programming ICH_HCR_EL2 while no LRs are populated is a bit
of an issue, as we otherwise don't see any maintenance interrupt
when the guest interacts with the LRs.

Decouple the two and always program the control register, even when
we don't have to touch the LRs.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-13-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
f4ded7b084 KVM: arm64: GICv3: Preserve EOIcount on exit
EOIcount is how the virtual CPU interface signals that the guest
is deactivating interrupts outside of the LRs when EOImode==0.

We therefore need to preserve that information so that we can find
out what actually needs deactivating.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-12-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
73c9726975 KVM: arm64: GICv3: Drop LPI active state when folding LRs
Despite LPIs not having an active state, *virtual* LPIs do have
one, which gets cleared on EOI. So far, so good.

However, this leads to a small problem: when an active LPI is not
in the LRs, that EOImode==0 and that the guest EOIs it, EOIcount
doesn't get bumped up. Which means that in these condition, the
LPI would stay active forever.

Clearly, we can't have that. So if we spot an active LPI, we drop
that state. It's pretty pointless anyway, and only serves as a way
to trip SW over.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-11-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
0dc433e79a KVM: arm64: Add LR overflow handling documentation
Add a bit of documentation describing how we are dealing with LR
overflow. This is mostly a braindump of how things are expected
to work. For now anyway.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-10-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
879a7fd4fd KVM: arm64: Add tracking of vgic_irq being present in a LR
We currently cannot identify whether an interrupt is queued into
a LR. It wasn't needed until now, but that's about to change.

Add yet another flag to track that state.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-9-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:12 -08:00
Marc Zyngier
a4413a7c31 KVM: arm64: Repack struct vgic_irq fields
struct vgic_irq has grown over the years, in a rather bad way.
Repack it using bitfields so that the individual flags, and move
things around a bit so that it a bit smaller.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-8-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
2a28810cbb KVM: arm64: GICv3: Detect and work around the lack of ICV_DIR_EL1 trapping
A long time ago, an unsuspecting architect forgot to add a trap
bit for ICV_DIR_EL1 in ICH_HCR_EL2. Which was unfortunate, but
what's a bit of spec between friends? Thankfully, this was fixed
in a later revision, and ARM "deprecates" the lack of trapping
ability.

Unfortuantely, a few (billion) CPUs went out with that defect,
anything ARMv8.0 from ARM, give or take. And on these CPUs,
you can't trap DIR on its own, full stop.

As the next best thing, we can trap everything in the common group,
which is a tad expensive, but hey ho, that's what you get. You can
otherwise recycle the HW in the neaby bin.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-7-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
567ebfedb5 KVM: arm64: vgic-v3: Fix GICv3 trapping in protected mode
As we are about to start trapping a bunch of extra things, augment
the pKVM trap description with all the registers trapped by ICH_HCR_EL2.TC,
making them legal instead of resulting in a UNDEF injection in the guest.

While we're at it, ensure that pKVM captures the vgic model so that it
can be checked by the emulation code.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-6-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
8d3dfab1d3 KVM: arm64: Turn vgic-v3 errata traps into a patched-in constant
The trap bits are currently only set to manage CPU errata. However,
we are about to make use of them for purposes beyond beating broken
CPUs into submission.

For this purpose, turn these errata-driven bits into a patched-in
constant that is merged with the KVM-driven value at the point of
programming the ICH_HCR_EL2 register, rather than being directly
stored with with the shadow value..

This allows the KVM code to distinguish between a trap being handled
for the purpose of an erratum workaround, or for KVM's own need.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-5-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
08f4f41c1e irqchip/apple-aic: Spit out ICH_MISR_EL2 value on spurious vGIC MI
It is all good and well to scream about spurious vGIC maintenance
interrupts. It would be even better to output the reason why, which
is already checked, but not printed out.

The unsuspecting kernel tinkerer thanks you.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-4-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
fa8f11e8e1 irqchip/gic: Expose CPU interface VA to KVM
Future changes will require KVM to be able to perform deactivations
by writing to the physical CPU interface. Add the corresponding
VA to the kvm_info structure, and let KVM stash it.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-3-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Marc Zyngier
8cb4ecec5e irqchip/gic: Add missing GICH_HCR control bits
The GICH_HCR description is missing a bunch of control bits that
control the maintenance interrupt. Add them.

Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://msgid.link/20251120172540.2267180-2-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:29:11 -08:00
Kiryl Shutsemau
7c9580f44f mm/filemap: fix logic around SIGBUS in filemap_map_pages()
Chris noticed that filemap_map_pages() calculates can_map_large only once
for the first page in the fault around range.  The value is not valid for
the following pages in the range and must be recalculated.

Instead of recalculating can_map_large on each iteration, pass down
file_end to filemap_map_folio_range() and let it make the decision on what
can be mapped.

Link: https://lkml.kernel.org/r/20251120161411.859078-1-kirill@shutemov.name
Fixes: 74207de2ba ("mm/memory: do not populate page table entries beyond i_size")h
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reported-by: Chris Mason <clm@meta.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Mason <clm@meta.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:18 -08:00
Wei Yang
cff47b9e39 mm/huge_memory: fix NULL pointer deference when splitting folio
Commit c010d47f10 ("mm: thp: split huge page to any lower order pages")
introduced an early check on the folio's order via mapping->flags before
proceeding with the split work.

This check introduced a bug: for shmem folios in the swap cache and
truncated folios, the mapping pointer can be NULL.  Accessing
mapping->flags in this state leads directly to a NULL pointer dereference.

This commit fixes the issue by moving the check for mapping != NULL before
any attempt to access mapping->flags.

Link: https://lkml.kernel.org/r/20251119235302.24773-1-richard.weiyang@gmail.com
Fixes: c010d47f10 ("mm: thp: split huge page to any lower order pages")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Pratyush Yadav
6c96c6bd2c MAINTAINERS: add test_kho to KHO's entry
Commit b753522bed ("kho: add test for kexec handover") introduced the
KHO test but missed adding it to KHO's MAINTAINERS entry.  Add it so the
KHO maintainers can get patches for its test.

Link: https://lkml.kernel.org/r/20251118182416.70660-1-pratyush@kernel.org
Fixes: b753522bed ("kho: add test for kexec handover")
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Sam Protsenko
52ac3f5829 mailmap: add entry for Sam Protsenko
Use 'Sam Protsenko' as my name consistently in git-shortlog.  Also map my
old GlobalLogic email address to my current email to stay reachable.

Link: https://lkml.kernel.org/r/20251118033111.23382-1-semen.protsenko@linaro.org
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Carlos Llamas
f0bb6dba3d selftests/mm: fix division-by-zero in uffd-unit-tests
Commit 4dfd4bba85 ("selftests/mm/uffd: refactor non-composite global
vars into struct") moved some of the operations previously implemented in
uffd_setup_environment() earlier in the main test loop.

The calculation of nr_pages, which involves a division by page_size, now
occurs before checking that default_huge_page_size() returns a non-zero
This leads to a division-by-zero error on systems with !CONFIG_HUGETLB.

Fix this by relocating the non-zero page_size check before the nr_pages
calculation, as it was originally implemented.

Link: https://lkml.kernel.org/r/20251113034623.3127012-1-cmllamas@google.com
Fixes: 4dfd4bba85 ("selftests/mm/uffd: refactor non-composite global vars into struct")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Ujwal Kundur <ujwal.kundur@gmail.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Liam R. Howlett
270065f514 mm/mmap_lock: reset maple state on lock_vma_under_rcu() retry
The retry in lock_vma_under_rcu() drops the rcu read lock before
reacquiring the lock and trying again.  This may cause a use-after-free if
the maple node the maple state was using was freed.

The maple state is protected by the rcu read lock.  When the lock is
dropped, the state cannot be reused as it tracks pointers to objects that
may be freed during the time where the lock was not held.

Any time the rcu read lock is dropped, the maple state must be
invalidated.  Resetting the address and state to MA_START is the safest
course of action, which will result in the next operation starting from
the top of the tree.

Prior to commit 0b16f8bed1 ("mm: change vma_start_read() to drop RCU
lock on failure"), vma_start_read() would drop rcu read lock and return
NULL, so the retry would not have happened.  However, now that
vma_start_read() drops rcu read lock on failure followed by a retry, we
may end up using a freed maple tree node cached in the maple state.

[surenb@google.com: changelog alteration]
  Link: https://lkml.kernel.org/r/CAJuCfpEWMD-Z1j=nPYHcQW4F7E2Wka09KTXzGv7VE7oW1S8hcw@mail.gmail.com
Link: https://lkml.kernel.org/r/20251111215605.1721380-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Fixes: 0b16f8bed1 ("mm: change vma_start_read() to drop RCU lock on failure")
Reported-by: syzbot+131f9eb2b5807573275c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=131f9eb2b5807573275c
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Deepanshu Kartikey
de8798965f mm/memfd: fix information leak in hugetlb folios
When allocating hugetlb folios for memfd, three initialization steps are
missing:

1. Folios are not zeroed, leading to kernel memory disclosure to userspace
2. Folios are not marked uptodate before adding to page cache
3. hugetlb_fault_mutex is not taken before hugetlb_add_to_page_cache()

The memfd allocation path bypasses the normal page fault handler
(hugetlb_no_page) which would handle all of these initialization steps. 
This is problematic especially for udmabuf use cases where folios are
pinned and directly accessed by userspace via DMA.

Fix by matching the initialization pattern used in hugetlb_no_page():
- Zero the folio using folio_zero_user() which is optimized for huge pages
- Mark it uptodate with folio_mark_uptodate()
- Take hugetlb_fault_mutex before adding to page cache to prevent races

The folio_zero_user() change also fixes a potential security issue where
uninitialized kernel memory could be disclosed to userspace through read()
or mmap() operations on the memfd.

Link: https://lkml.kernel.org/r/20251112145034.2320452-1-kartikey406@gmail.com
Fixes: 89c1905d9c ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios")
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reported-by: syzbot+f64019ba229e3a5c411b@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/20251112031631.2315651-1-kartikey406@gmail.com/ [v1]
Closes: https://syzkaller.appspot.com/bug?extid=f64019ba229e3a5c411b
Suggested-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: David Hildenbrand <david@redhat.com>
Tested-by: syzbot+f64019ba229e3a5c411b@syzkaller.appspotmail.com
Acked-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com> (v2)
Cc: Christoph Hellwig <hch@lst.de> (v6)
Cc: Dave Airlie <airlied@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Youngjun Park
f5e31a196e mm: swap: remove duplicate nr_swap_pages decrement in get_swap_page_of_type()
After commit 4f78252da8, nr_swap_pages is decremented in
swap_range_alloc(). Since cluster_alloc_swap_entry() calls
swap_range_alloc() internally, the decrement in get_swap_page_of_type()
causes double-decrementing.

As a representative userspace-visible runtime example of the impact,
/proc/meminfo reports increasingly inaccurate SwapFree values.  The
discrepancy grows with each swap allocation, and during hibernation
when large amounts of memory are written to swap, the reported value
can deviate significantly from actual available swap space, misleading
users and monitoring tools.  

Remove the duplicate decrement.

Link: https://lkml.kernel.org/r/20251102082456.79807-1-youngjun.park@lge.com
Fixes: 4f78252da8 ("mm: swap: move nr_swap_pages counter decrement from folio_alloc_swap() to swap_range_alloc()")
Signed-off-by: Youngjun Park <youngjun.park@lge.com>
Acked-by: Chris Li <chrisl@kernel.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Kairui Song <kasong@tencent.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: <stable@vger.kernel.org> [6.17+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24 14:25:17 -08:00
Oliver Upton
d93febe2ed KVM: arm64: nv: Forward FEAT_XNX permissions to the shadow stage-2
Add support for FEAT_XNX to shadow stage-2 MMUs, being careful to only
evaluate XN[0] when the feature is actually exposed to the VM.
Restructure the layering of permissions in the fault handler to assume
pX and uX then restricting based on the guest's stage-2 afterwards.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-4-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:24:45 -08:00
Oliver Upton
2608563b46 KVM: arm64: Add support for FEAT_XNX stage-2 permissions
FEAT_XNX adds support for encoding separate execute permissions for EL0
and EL1 at stage-2. Add support for this to the page table library,
hiding the unintuitive encoding scheme behind generic pX and uX
permission flags.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-3-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:24:44 -08:00
Oliver Upton
dc31124379 arm64: Detect FEAT_XNX
Detect the feature in anticipation of using it in KVM.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-2-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-11-24 14:24:44 -08:00
Qu Wenruo
54df8b80cc btrfs: scrub: always update btrfs_scrub_progress::last_physical
[BUG]
When a scrub failed immediately without any byte scrubbed, the returned
btrfs_scrub_progress::last_physical will always be 0, even if there is a
non-zero @start passed into btrfs_scrub_dev() for resume cases.

This will reset the progress and make later scrub resume start from the
beginning.

[CAUSE]
The function btrfs_scrub_dev() accepts a @progress parameter to copy its
updated progress to the caller, there are cases where we either don't
touch progress::last_physical at all or copy 0 into last_physical:

- last_physical not updated at all
  If some error happened before scrubbing any super block or chunk, we
  will not copy the progress, leaving the @last_physical untouched.

  E.g. failed to allocate @sctx, scrubbing a missing device or even
  there is already a running scrub and so on.

  All those cases won't touch @progress at all, resulting the
  last_physical untouched and will be left as 0 for most cases.

- Error out before scrubbing any bytes
  In those case we allocated @sctx, and sctx->stat.last_physical is all
  zero (initialized by kvzalloc()).
  Unfortunately some critical errors happened during
  scrub_enumerate_chunks() or scrub_supers() before any stripe is really
  scrubbed.

  In that case although we will copy sctx->stat back to @progress, since
  no byte is really scrubbed, last_physical will be overwritten to 0.

[FIX]
Make sure the parameter @progress always has its @last_physical member
updated to @start parameter inside btrfs_scrub_dev().

At the very beginning of the function, set @progress->last_physical to
@start, so that even if we error out without doing progress copying,
last_physical is still at @start.

Then after we got @sctx allocated, set sctx->stat.last_physical to
@start, this will make sure even if we didn't get any byte scrubbed, at
the progress copying stage the @last_physical is not left as zero.

This should resolve the resume progress reset problem.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:26 +01:00
Filipe Manana
7a832b870b btrfs: place all boolean fields together in struct find_free_extent_ctl
Move the 'retry_uncached' and 'hint' fields close to the other boolean
fields so that we remove a hole from the structure and reduce its size
from 136 bytes down to 128 bytes. Currently this structure is only
allocated in the stack of btrfs_reserve_extent().

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:26 +01:00
Filipe Manana
e21756fc4a btrfs: use booleans for delalloc arguments and struct find_free_extent_ctl
The struct find_free_extent_ctl uses an int for the 'delalloc' field but
it's always used as a boolean, and its value is used to be passed to
several functions to signal if we are dealing with delalloc. The same goes
for the 'is_data' argument from btrfs_reserve_extent(). So change the type
from int to bool and move the field definition in the find_free_extent_ctl
structure so that it's close to other bool fields and reduces the size of
the structure from 144 down to 136 bytes (at the moment it's only declared
in the stack of btrfs_reserve_extent(), never allocated otherwise).

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:26 +01:00
Filipe Manana
d7fe41044b btrfs: use bool type for btrfs_path members used as booleans
Many fields of struct btrfs_path are used as booleans but their type is
an unsigned int (of one 1 bit width to save space). Change the type to
bool keeping the :1 suffix so that they combine with the previous u8
fields in order to save space. This makes the code more clear by using
explicit true/false and more in line with the preferred style, preserving
the size of the structure.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:25 +01:00
Filipe Manana
c2b2504ece btrfs: update check_skip variable after unlocking current node
There's no need to update the local variable 'check_skip' to false inside
the critical section delimited by the lock of the current node, so do it
after unlocking the node.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:25 +01:00
Filipe Manana
5d8222a50a btrfs: abort transaction on item count overflow in __push_leaf_left()
If we try to push an item count from the right leaf that is greater than
the number of items in the leaf, we just emit a warning. This should
never happen but if it does we get an underflow in the new number of
items in the right leaf and chaos follows from it. So replace the warning
with proper error handling, by aborting the transaction and returning
-EUCLEAN, and proper logging by using btrfs_crit() instead of WARN(),
which gives us proper formatting and information about the filesystem.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:25 +01:00
Filipe Manana
027358a090 btrfs: always use right leaf variable in __push_leaf_left()
The 'right' variable points to path->nodes[0] and path->nodes[0] is never
changed, but some places use 'right' while others refer to path->nodes[0].
Update all sites to use 'right' as not only it's shorter it's also easier
to reason since it means the right leaf and avoids any confusion with the
sibling left leaf.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:25 +01:00
Filipe Manana
29bb40ed56 btrfs: remove duplicated leaf dirty status clearing in __push_leaf_right()
We have already called btrfs_clear_buffer_dirty() against the left leaf in
the code above:

  btrfs_set_header_nritems(left, left_nritems);

  if (left_nritems)
       btrfs_mark_buffer_dirty(trans, left);
  else
       btrfs_clear_buffer_dirty(trans, left);

So remove the second check for a 0 number of items in the left leaf and
calling again btrfs_clear_buffer_dirty() against the left leaf.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:25 +01:00
Filipe Manana
7447263d7d btrfs: always use left leaf variable in __push_leaf_right()
The 'left' variable points to path->nodes[0] and path->nodes[0] is never
changed, but some places use 'left' while others refer to path->nodes[0].
Update all sites to use 'left' as not only it's shorter it's also easier
to reason since it means the left leaf and avoids any confusion with the
sibling right leaf.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:25 +01:00
Filipe Manana
fad159f69e btrfs: add unlikely to critical error in btrfs_extend_item()
It's not expected to get a data size less than the leaf's free space,
which would lead to a leaf dump and BUG(), so tag the if statement's
expression as unlikely, hinting the compiler to potentially generate
better code.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:25 +01:00
Filipe Manana
86d3dc812f btrfs: remove pointless return value update in btrfs_del_items()
The call to btrfs_del_leaf() can only return an error (negative value) or
zero (success). If we didn't get an error then 'ret' is zero, so it's
pointless to set it to zero again.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:24 +01:00
Filipe Manana
e7dd1182fc btrfs: fix leaf leak in an error path in btrfs_del_items()
If the call to btrfs_del_leaf() fails we return without decrementing the
extra ref we took on the leaf, therefore leaking it. Fix this by ensuring
we drop the ref count before returning the error.

Fixes: 751a27615d ("btrfs: do not BUG_ON() on tree mod log failures at btrfs_del_ptr()")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:24 +01:00
Zhen Ni
280dd7c106 btrfs: fix incomplete parameter rename in btrfs_decompress()
Commit 2c25716dcc ("btrfs: zlib: fix and simplify the inline extent
decompression") renamed the 'start_byte' parameter to 'dest_pgoff' in
the btrfs_decompress(). The remaining 'start_byte' references are
inconsistent with the actual implementation and may cause confusion for
developers.

Ensure consistency between function declaration and implementation.

Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:24 +01:00
David Sterba
1c094e6cce btrfs: make a few more ASSERTs verbose
We have support for optional string to be printed in ASSERT() (added in
19468a623a ("btrfs: enhance ASSERT() to take optional format
string")), it's not yet everywhere it could be so add a few more files.

Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:24 +01:00
Qu Wenruo
ec20799064 btrfs: enable encoded read/write/send for bs > ps cases
Since the read verification and read repair are all supporting bs > ps
without large folios now, we can enable encoded read/write/send.

Now we can relax the alignment in assert_bbio_alignment() to
min(blocksize, PAGE_SIZE).
But also add the extra blocksize based alignment check for the logical
and length of the bbio.

There is a pitfall in btrfs_add_compress_bio_folios(), which relies on
the folios passed in to meet the minimal folio order.
But now we can pass regular page sized folios in, update it to check
each folio's size instead of using the minimal folio size.

This allows btrfs_add_compress_bio_folios() to even handle folios array
with different sizes, thankfully we don't yet need to handle such crazy
situation.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:24 +01:00
Qu Wenruo
052fd7a5ca btrfs: make read verification handle bs > ps cases without large folios
The current read verification is also relying on large folios to support
bs > ps cases, but that introduced quite some limits.

To enhance read-repair to support bs > ps without large folios:

- Make btrfs_data_csum_ok() to accept an array of paddrs
  Which can pass the paddrs[] direct into
  btrfs_calculate_block_csum_pages().

- Make repair_one_sector() to accept an array of paddrs
  So that it can submit a repair bio backed by regular pages, not only
  large folios.
  This requires us to allocate more slots at bio allocation time though.

  Also since the caller may have only partially advanced the saved_iter
  for bs > ps cases, we can not directly trust the logical bytenr from
  saved_iter (can be unaligned), thus a manual round down is necessary
  for the logical bytenr.

- Make btrfs_check_read_bio() to build an array of paddrs
  The tricky part is that we can only call btrfs_data_csum_ok() after
  all involved pages are assembled.

  This means at the call time of btrfs_check_read_bio(), our offset
  inside the bio is already at the end of the fs block.
  Thus we must re-calculate @bio_offset for btrfs_data_csum_ok() and
  repair_one_sector().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:24 +01:00
Qu Wenruo
2574e90110 btrfs: make btrfs_repair_io_failure() handle bs > ps cases without large folios
Currently btrfs_repair_io_failure() only accept a single @paddr
parameter, and for bs > ps cases it's required that @paddr is backed by
a large folio.

That assumption has quite some limitations, preventing us from utilizing
true zero-copy direct-io and encoded read/writes.

To address the problem, enhance btrfs_repair_io_failure() by:

- Accept an array of paddrs, up to 64K / PAGE_SIZE entries
  This kind of acts like a bio_vec, but with very limited entries, as the
  function is only utilized to repair one fs data block, or a tree block.

  Both have an upper size limit (BTRFS_MAX_BLOCK_SIZE, i.e. 64K), so we
  don't need the full bio_vec thing to handle it.

- Allocate a bio with multiple slots
  Previously even for bs > ps cases, we only passed in a contiguous
  physical address range, thus a single slot will be enough.

  But not anymore, so we have to allocate a bio structure, other than
  using the on-stack one.

- Use on-stack memory to allocate @paddrs array
  It's at most 16 pages (4K page size, 64K block size), will take up at
  most 128 bytes.
  I think the on-stack cost is still acceptable.

- Add one extra check to make sure the repair bio is exactly one block

- Utilize btrfs_repair_io_failure() to submit a single bio for metadata
  This should improve the read-repair performance for metadata, as now
  we submit a node sized bio then wait, other than submit each block of
  the metadata and wait for each submitted block.

- Add one extra parameter indicating the step
  This is due to the fact that metadata step can be as large as
  nodesize, instead of sectorsize.
  So we need a way to distinguish metadata and data repair.

- Reduce the width of @length parameter of btrfs_repair_io_failure()
  Since we only call btrfs_repair_io_failure() on a single data or
  metadata block, u64 is overkilled.
  Use u32 instead and add one extra ASSERT()s to make sure the length
  never exceed BTRFS_MAX_BLOCK_SIZE.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:23 +01:00
Qu Wenruo
62bcbdca0e btrfs: make btrfs_csum_one_bio() handle bs > ps without large folios
For bs > ps cases, all folios passed into btrfs_csum_one_bio() are
ensured to be backed by large folios.  But that requirement excludes
features like direct IO and encoded writes.

To support bs > ps without large folios, enhance btrfs_csum_one_bio()
by:

- Split btrfs_calculate_block_csum() into two versions
  * btrfs_calculate_block_csum_folio()
    For call sites where a fs block is always backed by a large folio.

    This will do extra checks on the folio size, build a paddrs[] array,
    and pass it into the newer btrfs_calculate_block_csum_pages()
    helper.

    For now btrfs_check_block_csum() is still using this version.

  * btrfs_calculate_block_csum_pages()
    For call sites that may hit a fs block backed by noncontiguous pages.
    The pages are represented by paddrs[] array, which includes the
    offset inside the page.

    This function will do the proper sub-block handling.

- Make btrfs_csum_one_bio() to use btrfs_calculate_block_csum_pages()
  This means we will need to build a local paddrs[] array, and after
  filling a fs block, do the checksum calculation.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:23 +01:00
Filipe Manana
fe1e50031f btrfs: move struct reserve_ticket definition to space-info.c
It's not used anywhere outside space-info.c so move it from space-info.h
into space-info.c.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:23 +01:00
David Sterba
4decf577fb btrfs: move and rename CSUM_FMT definition
Move the CSUM_FMT* definitions to fs.h where is be the BTRFS_KEY_FMT
and add the prefix for consistency.

Signed-off-by: David Sterba <dsterba@suse.com>
2025-11-24 22:42:23 +01:00