Al Viro [Wed, 27 Aug 2025 16:33:11 +0000 (12:33 -0400)]
preparations to taking MNT_WRITE_HOLD out of ->mnt_flags
We have an unpleasant wart in accessibility rules for struct mount. There
are per-superblock lists of mounts, used by sb_prepare_remount_readonly()
to check if any of those is currently claimed for write access and to
block further attempts to get write access on those until we are done.
As soon as it is attached to a filesystem, mount becomes reachable
via that list. Only sb_prepare_remount_readonly() traverses it and
it only accesses a few members of struct mount. Unfortunately,
->mnt_flags is one of those and it is modified - MNT_WRITE_HOLD set
and then cleared. It is done under mount_lock, so from the locking
rules POV everything's fine.
However, it has easily overlooked implications - once mount has been
attached to a filesystem, it has to be treated as globally visible.
In particular, initializing ->mnt_flags *must* be done either prior
to that point or under mount_lock. All other members are still
private at that point.
Life gets simpler if we move that bit (and that's *all* that can get
touched by access via this list) out of ->mnt_flags. It's not even
hard to do - currently the list is implemented as list_head one,
anchored in super_block->s_mounts and linked via mount->mnt_instance.
As the first step, switch it to hlist-like open-coded structure -
address of the first mount in the set is stored in ->s_mounts
and ->mnt_instance replaced with ->mnt_next_for_sb and ->mnt_pprev_for_sb -
the former either NULL or pointing to the next mount in set, the
latter - address of either ->s_mounts or ->mnt_next_for_sb in the
previous element of the set.
In the next commit we'll steal the LSB of ->mnt_pprev_for_sb as
replacement for MNT_WRITE_HOLD.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Sat, 5 Jul 2025 04:38:09 +0000 (00:38 -0400)]
setup_mnt(): primitive for connecting a mount to filesystem
Take the identical logics in vfs_create_mount() and clone_mnt() into
a new helper that takes an empty struct mount and attaches it to
given dentry (sub)tree.
Should be called once in the lifetime of every mount, prior to making
it visible in any data structures.
After that point ->mnt_root and ->mnt_sb never change; ->mnt_root
is a counting reference to dentry and ->mnt_sb - an active reference
to superblock.
Mount remains associated with that dentry tree all the way until
the call of cleanup_mnt(), when the refcount eventually drops
to zero.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 27 Aug 2025 17:46:33 +0000 (13:46 -0400)]
simplify the callers of mnt_unhold_writers()
The logics in cleanup on failure in mount_setattr_prepare() is simplified
by having the mnt_hold_writers() failure followed by advancing m to the
next node in the tree before leaving the loop.
And since all calls are preceded by the same check that flag has been set
and the function is inlined, let's just shift the check into it.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Tue, 26 Aug 2025 21:04:44 +0000 (17:04 -0400)]
copy_mnt_ns(): use the regular mechanism for freeing empty mnt_ns on failure
Now that free_mnt_ns() works prior to mnt_ns_tree_add(), there's no need for
an open-coded analogue free_mnt_ns() there - yes, we do avoid one call_rcu()
use per failing call of clone() or unshare(), if they fail due to OOM in that
particular spot, but it's not really worth bothering.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Tue, 26 Aug 2025 20:35:55 +0000 (16:35 -0400)]
mnt_ns_tree_remove(): DTRT if mnt_ns had never been added to mnt_ns_list
Actual removal is done under the lock, but for checking if need to bother
the lockless RB_EMPTY_NODE() is safe - either that namespace had never
been added to mnt_ns_tree, in which case the the node will stay empty, or
whoever had allocated it has called mnt_ns_tree_add() and it has already
run to completion. After that point RB_EMPTY_NODE() will become false and
will remain false, no matter what we do with other nodes in the tree.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Tue, 26 Aug 2025 20:53:42 +0000 (16:53 -0400)]
open_detached_copy(): don't bother with mount_lock_hash()
we are holding namespace_sem and a reference to root of tree;
iterating through that tree does not need mount_lock. Neither
does the insertion into the rbtree of new namespace or incrementing
the mount count of that namespace.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Fri, 25 Jul 2025 02:45:09 +0000 (22:45 -0400)]
ecryptfs: get rid of pointless mount references in ecryptfs dentries
->lower_path.mnt has the same value for all dentries on given ecryptfs
instance and if somebody goes for mountpoint-crossing variant where that
would not be true, we can deal with that when it happens (and _not_
with duplicating these reference into each dentry).
As it is, we are better off just sticking a reference into ecryptfs-private
part of superblock and keeping it pinned until ->kill_sb().
That way we can stick a reference to underlying dentry right into ->d_fsdata
of ecryptfs one, getting rid of indirection through struct ecryptfs_dentry_info,
along with the entire struct ecryptfs_dentry_info machinery.
[kudos to Dan Carpenter for spotting a bug in ecryptfs_get_tree() part]
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Tue, 19 Aug 2025 16:22:03 +0000 (12:22 -0400)]
umount_tree(): take all victims out of propagation graph at once
For each removed mount we need to calculate where the slaves will end up.
To avoid duplicating that work, do it for all mounts to be removed
at once, taking the mounts themselves out of propagation graph as
we go, then do all transfers; the duplicate work on finding destinations
is avoided since if we run into a mount that already had destination found,
we don't need to trace the rest of the way. That's guaranteed
O(removed mounts) for finding destinations and removing from propagation
graph and O(surviving mounts that have master removed) for transfers.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Fri, 22 Aug 2025 21:41:55 +0000 (17:41 -0400)]
do_lock_mount(): don't modify path.
Currently do_lock_mount() has the target path switched to whatever
might be overmounting it. We _do_ want to have the parent
mount/mountpoint chosen on top of the overmounting pile; however,
the way it's done has unpleasant races - if umount propagation
removes the overmount while we'd been trying to set the environment
up, we might end up failing if our target path strays into that overmount
just before the overmount gets kicked out.
Users of do_lock_mount() do not need the target path changed - they
have all information in res->{parent,mp}; only one place (in
do_move_mount()) currently uses the resulting path->mnt, and that value
is trivial to reconstruct by the original value of path->mnt + chosen
parent mount.
Let's keep the target path unchanged; it avoids a bunch of subtle races
and it's not hard to do:
do
as mount_locked_reader
find the prospective parent mount/mountpoint dentry
grab references if it's not the original target
lock the prospective mountpoint dentry
take namespace_sem exclusive
if prospective parent/mountpoint would be different now
err = -EAGAIN
else if location has been unmounted
err = -ENOENT
else if mountpoint dentry is not allowed to be mounted on
err = -ENOENT
else if beneath and the top of the pile was the absolute root
err = -EINVAL
else
try to get struct mountpoint (by dentry), set
err to 0 on success and -ENO{MEM,ENT} on failure
if err != 0
res->parent = ERR_PTR(err)
drop locks
else
res->parent = prospective parent
drop temporary references
while err == -EAGAIN
A somewhat subtle part is that dropping temporary references is allowed.
Neither mounts nor dentries should be evicted by a thread that holds
namespace_sem. On success we are dropping those references under
namespace_sem, so we need to be sure that these are not the last
references remaining. However, on success we'd already verified (under
namespace_sem) that original target is still mounted and that mount
and dentry we are about to drop are still reachable from it via the
mount tree. That guarantees that we are not about to drop the last
remaining references.
Al Viro [Wed, 20 Aug 2025 07:23:12 +0000 (03:23 -0400)]
new helper: topmost_overmount()
Returns the final (topmost) mount in the chain of overmounts
starting at given mount. Same locking rules as for any mount
tree traversal - either the spinlock side of mount_lock, or
rcu + sample the seqcount side of mount_lock before the call
and recheck afterwards.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 20 Aug 2025 01:21:24 +0000 (21:21 -0400)]
do_add_mount(): switch to passing pinned_mountpoint instead of mountpoint + path
Both callers pass it a mountpoint reference picked from pinned_mountpoint
and path it corresponds to.
First of all, path->dentry is equal to mp.mp->m_dentry. Furthermore, path->mnt
is &mp.parent->mnt, making struct path contents redundant.
Pass it the address of that pinned_mountpoint instead; what's more, if we
teach it to treat ERR_PTR(error) in ->parent as "bail out with that error"
we can simplify the callers even more - do_add_mount() will do the right
thing even when called after lock_mount() failure.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 20 Aug 2025 17:47:43 +0000 (13:47 -0400)]
do_move_mount(): use the parent mount returned by do_lock_mount()
After successful do_lock_mount() call, mp.parent is set to either
real_mount(path->mnt) (for !beneath case) or to ->mnt_parent of that
(for beneath). p is set to real_mount(path->mnt) and after
several uses it's made equal to mp.parent. All uses prior to that
care only about p->mnt_ns and since p->mnt_ns == parent->mnt_ns,
we might as well use mp.parent all along.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 20 Aug 2025 17:42:24 +0000 (13:42 -0400)]
change calling conventions for lock_mount() et.al.
1) pinned_mountpoint gets a new member - struct mount *parent.
Set only if we locked the sucker; ERR_PTR() - on failed attempt.
2) do_lock_mount() et.al. return void and set ->parent to
* on success with !beneath - mount corresponding to path->mnt
* on success with beneath - the parent of mount corresponding
to path->mnt
* in case of error - ERR_PTR(-E...).
IOW, we get the mount we will be actually mounting upon or ERR_PTR().
3) we can't use CLASS, since the pinned_mountpoint is placed on
hlist during initialization, so we define local macros:
LOCK_MOUNT(mp, path)
LOCK_MOUNT_MAYBE_BENEATH(mp, path, beneath)
LOCK_MOUNT_EXACT(mp, path)
All of them declare and initialize struct pinned_mountpoint mp,
with unlock_mount done via __cleanup().
Users converted.
[
lock_mount() is unused now; removed. Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
]
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Fri, 22 Aug 2025 02:43:32 +0000 (22:43 -0400)]
do_new_mount_fc(): use __free() to deal with dropping mnt on failure
do_add_mount() consumes vfsmount on success; just follow it with
conditional retain_and_null_ptr() on success and we can switch
to __free() for mnt and be done with that - unlock_mount() is
in the very end.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Fri, 22 Aug 2025 16:59:10 +0000 (12:59 -0400)]
finish_automount(): take the lock_mount() analogue into a helper
finish_automount() can't use lock_mount() - it treats finding something
already mounted as "quitely drop our mount and return 0", not as
"mount on top of whatever mounted there". It's been open-coded;
let's take it into a helper similar to lock_mount(). "something's
already mounted" => -EBUSY, finish_automount() needs to distinguish
it from the normal case and it can't happen in other failure cases.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 20 Aug 2025 03:54:39 +0000 (23:54 -0400)]
move_mount(2): take sanity checks in 'beneath' case into do_lock_mount()
We want to mount beneath the given location. For that operation to
make sense, location must be the root of some mount that has something
under it. Currently we let it proceed if those requirements are not met,
with rather meaningless results, and have that bogosity caught further
down the road; let's fail early instead - do_lock_mount() doesn't make
sense unless those conditions hold, and checking them there makes
things simpler.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 20 Aug 2025 18:50:09 +0000 (14:50 -0400)]
do_move_mount(): deal with the checks on old_path early
1) checking that location we want to move does point to root of some mount
can be done before anything else; that property is not going to change
and having it already verified simplifies the analysis.
2) checking the type agreement between what we are trying to move and what
we are trying to move it onto also belongs in the very beginning -
do_lock_mount() might end up switching new_path to something that overmounts
the original location, but... the same type agreement applies to overmounts,
so we could just as well check against the original location.
3) since we know that old_path->dentry is the root of old_path->mnt, there's
no point bothering with path_is_overmounted() in can_move_mount_beneath();
it's simply a check for the mount we are trying to move having non-NULL
->overmount. And with that, we can switch can_move_mount_beneath() to
taking old instead of old_path, leaving no uses of old_path past the original
checks.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Tue, 26 Aug 2025 17:57:42 +0000 (13:57 -0400)]
switch do_new_mount_fc() to fc_mount()
Prior to the call of do_new_mount_fc() the caller has just done successful
vfs_get_tree(). Then do_new_mount_fc() does several checks on resulting
superblock, and either does fc_drop_locked() and returns an error or
proceeds to unlock the superblock and call vfs_create_mount().
The thing is, there's no reason to delay that unlock + vfs_create_mount() -
the tests do not rely upon the state of ->s_umount and
fc_drop_locked()
put_fs_context()
is equivalent to
unlock ->s_umount
put_fs_context()
Doing vfs_create_mount() before the checks allows us to move vfs_get_tree()
from caller to do_new_mount_fc() and collapse it with vfs_create_mount()
into an fc_mount() call.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Fri, 22 Aug 2025 00:48:38 +0000 (20:48 -0400)]
path_is_under(): use guards
... and document that locking requirements for is_path_reachable().
There is one questionable caller in do_listmount() where we are not
holding mount_lock *and* might not have the first argument mounted.
However, in that case it will immediately return true without having
to look at the ancestors. Might be cleaner to move the check into
non-LSTM_ROOT case which it really belongs in - there the check is
not always true and is_mounted() is guaranteed.
Document the locking environments for is_path_reachable() callers:
get_peer_under_root()
get_dominating_id()
do_statmount()
do_listmount()
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Thu, 21 Aug 2025 00:28:35 +0000 (20:28 -0400)]
check_for_nsfs_mounts(): no need to take locks
Currently we are taking mount_writer; what that function needs is
either mount_locked_reader (we are not changing anything, we just
want to iterate through the subtree) or namespace_shared and
a reference held by caller on the root of subtree - that's also
enough to stabilize the topology.
The thing is, all callers are already holding at least namespace_shared
as well as a reference to the root of subtree.
Let's make the callers provide locking warranties - don't mess with
mount_lock in check_for_nsfs_mounts() itself and document the locking
requirements.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 20 Aug 2025 23:54:45 +0000 (19:54 -0400)]
introduced guards for mount_lock
mount_writer: write_seqlock; that's an equivalent of {un,}lock_mount_hash()
mount_locked_reader: read_seqlock_excl; these tend to be open-coded.
No bulk conversions, please - if nothing else, quite a few places take
use mount_writer form when mount_locked_reader is sufficent. It needs
to be dealt with carefully.
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro [Wed, 20 Aug 2025 23:05:21 +0000 (19:05 -0400)]
fs/namespace.c: fix the namespace_sem guard mess
If anything, namespace_lock should be DEFINE_LOCK_GUARD_0, not DEFINE_GUARD.
That way we
* do not need to feed it a bogus argument
* do not get gcc trying to compare an address of static in
file variable with -4097 - and, if we are unlucky, trying to keep
it in a register, with spills and all such.
The same problems apply to grabbing namespace_sem shared.
Rename it to namespace_excl, add namespace_shared, convert the existing users:
Linus Torvalds [Sun, 31 Aug 2025 16:20:17 +0000 (09:20 -0700)]
Merge tag 'x86_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Convert the SSB mitigation to the attack vector controls which got
forgotten at the time
- Prevent the CPUID topology hierarchy detection on AMD from
overwriting the correct initial APIC ID
- Fix the case of a machine shipping without microcode in the BIOS, in
the AMD microcode loader
- Correct the Pentium 4 model range which has a constant TSC
* tag 'x86_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/bugs: Add attack vector controls for SSB
x86/cpu/topology: Use initial APIC ID from XTOPOLOGY leaf on AMD/HYGON
x86/microcode/AMD: Handle the case of no BIOS microcode
x86/cpu/intel: Fix the constant_tsc model check for Pentium 4
Linus Torvalds [Sun, 31 Aug 2025 16:13:00 +0000 (09:13 -0700)]
Merge tag 'sched_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Borislav Petkov:
- Fix a stall on the CPU offline path due to mis-counting a deadline
server task twice as part of the runqueue's running tasks count
- Fix a realtime tasks starvation case where failure to enqueue a timer
whose expiration time is already in the past would cause repeated
attempts to re-enqueue a deadline server task which leads to starving
the former, realtime one
- Prevent a delayed deadline server task stop from breaking the
per-runqueue bandwidth tracking
- Have a function checking whether the deadline server task has
stopped, return the correct value
* tag 'sched_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Don't count nr_running for dl_server proxy tasks
sched/deadline: Fix RT task potential starvation when expiry time passed
sched/deadline: Always stop dl-server before changing parameters
sched/deadline: Fix dl_server_stopped()
Linus Torvalds [Sun, 31 Aug 2025 16:07:37 +0000 (09:07 -0700)]
Merge tag 'irq_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Borislav Petkov:
- Remove unnecessary and noisy WARN_ONs in gic-v5's init path
- Avoid a kmemleak false positive for the gic-v5's L2 IST table entries
- Fix a retval check in mvebu-gicp's probe function
- Fix a wrong conversion to guards in atmel-aic[5] irqchip
* tag 'irq_urgent_for_v6.17_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v5: Remove undue WARN_ON()s in the IRS affinity parsing
irqchip/gic-v5: Fix kmemleak L2 IST table entries false positives
irqchip/mvebu-gicp: Fix an IS_ERR() vs NULL check in probe()
irqchip/atmel-aic[5]: Fix incorrect lock guard conversion
Linus Torvalds [Sun, 31 Aug 2025 15:56:45 +0000 (08:56 -0700)]
Merge tag 'hardening-v6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening fixes from Kees Cook:
- ARM: stacktrace: include asm/sections.h in asm/stacktrace.h (Arnd
Bergmann)
- ubsan: Fix incorrect hand-side used in handle (Junhui Pei)
- hardening: Require clang 20.1.0 for __counted_by (Nathan Chancellor)
* tag 'hardening-v6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
hardening: Require clang 20.1.0 for __counted_by
ARM: stacktrace: include asm/sections.h in asm/stacktrace.h
ubsan: Fix incorrect hand-side used in handle
Linus Torvalds [Sun, 31 Aug 2025 15:49:55 +0000 (08:49 -0700)]
Merge tag 'gpio-fixes-for-v6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
- fix an off-by-one bug in interrupt handling in gpio-timberdale
- update MAINTAINERS
* tag 'gpio-fixes-for-v6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
MAINTAINERS: Change Altera-PIO driver maintainer
gpio: timberdale: fix off-by-one in IRQ type boundary check
Linus Torvalds [Sat, 30 Aug 2025 17:43:53 +0000 (10:43 -0700)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- CFI failure due to kpti_ng_pgd_alloc() signature mismatch
- Underallocation bug in the SVE ptrace kselftest
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
kselftest/arm64: Don't open code SVE_PT_SIZE() in fp-ptrace
arm64: mm: Fix CFI failure due to kpti_ng_pgd_alloc function signature
Mark Brown [Tue, 12 Aug 2025 14:49:27 +0000 (15:49 +0100)]
kselftest/arm64: Don't open code SVE_PT_SIZE() in fp-ptrace
In fp-trace when allocating a buffer to write SVE register data we open
code the addition of the header size to the VL depeendent register data
size, which lead to an underallocation bug when we cut'n'pasted the code
for FPSIMD format writes. Use the SVE_PT_SIZE() macro that the kernel
UAPI provides for this.
Linus Torvalds [Fri, 29 Aug 2025 20:54:26 +0000 (13:54 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"ARM:
- Correctly handle 'invariant' system registers for protected VMs
- Improved handling of VNCR data aborts, including external aborts
- Fixes for handling of FEAT_RAS for NV guests, providing a sane
fault context during SEA injection and preventing the use of
RASv1p1 fault injection hardware
- Ensure that page table destruction when a VM is destroyed gives an
opportunity to reschedule
- Large fix to KVM's infrastructure for managing guest context loaded
on the CPU, addressing issues where the output of AT emulation
doesn't get reflected to the guest
- Fix AT S12 emulation to actually perform stage-2 translation when
necessary
- Avoid attempting vLPI irqbypass when GICv4 has been explicitly
disabled for a VM
- Minor KVM + selftest fixes
RISC-V:
- Fix pte settings within kvm_riscv_gstage_ioremap()
- Fix comments in kvm_riscv_check_vcpu_requests()
- Fix stack overrun when setting vlenb via ONE_REG
x86:
- Use array_index_nospec() to sanitize the target vCPU ID when
handling PV IPIs and yields as the ID is guest-controlled.
- Drop a superfluous cpumask_empty() check when reclaiming SEV
memory, as the common case, by far, is that at least one CPU will
have entered the VM, and wbnoinvd_on_cpus_mask() will naturally
handle the rare case where the set of have_run_cpus is empty.
Selftests (not KVM):
- Rename the is_signed_type() macro in kselftest_harness.h to
is_signed_var() to fix a collision with linux/overflow.h. The
collision generates compiler warnings due to the two macros having
different meaning"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (29 commits)
KVM: arm64: nv: Fix ATS12 handling of single-stage translation
KVM: arm64: Remove __vcpu_{read,write}_sys_reg_{from,to}_cpu()
KVM: arm64: Fix vcpu_{read,write}_sys_reg() accessors
KVM: arm64: Simplify sysreg access on exception delivery
KVM: arm64: Check for SYSREGS_ON_CPU before accessing the 32bit state
RISC-V: KVM: fix stack overrun when loading vlenb
RISC-V: KVM: Correct kvm_riscv_check_vcpu_requests() comment
RISC-V: KVM: Fix pte settings within kvm_riscv_gstage_ioremap()
KVM: arm64: selftests: Sync ID_AA64MMFR3_EL1 in set_id_regs
KVM: arm64: Get rid of ARM64_FEATURE_MASK()
KVM: arm64: Make ID_AA64PFR1_EL1.RAS_frac writable
KVM: arm64: Make ID_AA64PFR0_EL1.RAS writable
KVM: arm64: Ignore HCR_EL2.FIEN set by L1 guest's EL2
KVM: arm64: Handle RASv1p1 registers
arm64: Add capability denoting FEAT_RASv1p1
KVM: arm64: Reschedule as needed when destroying the stage-2 page-tables
KVM: arm64: Split kvm_pgtable_stage2_destroy()
selftests: harness: Rename is_signed_type() to avoid collision with overflow.h
KVM: SEV: don't check have_run_cpus in sev_writeback_caches()
KVM: arm64: Correctly populate FAR_EL2 on nested SEA injection
...
Nathan Chancellor [Thu, 7 Aug 2025 21:36:28 +0000 (14:36 -0700)]
hardening: Require clang 20.1.0 for __counted_by
After an innocuous change in -next that modified a structure that
contains __counted_by, clang-19 start crashing when building certain
files in drivers/gpu/drm/xe. When assertions are enabled, the more
descriptive failure is:
clang: clang/lib/AST/RecordLayoutBuilder.cpp:3335: const ASTRecordLayout &clang::ASTContext::getASTRecordLayout(const RecordDecl *) const: Assertion `D && "Cannot get layout of forward declarations!"' failed.
According to a reverse bisect, a tangential change to the LLVM IR
generation phase of clang during the LLVM 20 development cycle [1]
resolves this problem. Bump the version of clang that enables
CONFIG_CC_HAS_COUNTED_BY to 20.1.0 to ensure that this issue cannot be
hit.
Paolo Bonzini [Fri, 29 Aug 2025 16:57:31 +0000 (12:57 -0400)]
Merge tag 'kvmarm-fixes-6.17-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 changes for 6.17, take #2
- Correctly handle 'invariant' system registers for protected VMs
- Improved handling of VNCR data aborts, including external aborts
- Fixes for handling of FEAT_RAS for NV guests, providing a sane
fault context during SEA injection and preventing the use of
RASv1p1 fault injection hardware
- Ensure that page table destruction when a VM is destroyed gives an
opportunity to reschedule
- Large fix to KVM's infrastructure for managing guest context loaded
on the CPU, addressing issues where the output of AT emulation
doesn't get reflected to the guest
- Fix AT S12 emulation to actually perform stage-2 translation when
necessary
- Avoid attempting vLPI irqbypass when GICv4 has been explicitly
disabled for a VM
Paolo Bonzini [Fri, 29 Aug 2025 16:57:18 +0000 (12:57 -0400)]
Merge tag 'kvm-riscv-fixes-6.17-1' of https://github.com/kvm-riscv/linux into HEAD
KVM/riscv fixes for 6.17, take #1
- Fix pte settings within kvm_riscv_gstage_ioremap()
- Fix comments in kvm_riscv_check_vcpu_requests()
- Fix stack overrun when setting vlenb via ONE_REG
Linus Torvalds [Fri, 29 Aug 2025 16:15:46 +0000 (09:15 -0700)]
Merge tag 'efi-fixes-for-v6.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI fixes from Ard Biesheuvel:
- Assorted fixes for the OP-TEE based pseudo-EFI variable store
- Fix for an OOB access when looking up the same non-existing efivarfs
entry multiple times in parallel
* tag 'efi-fixes-for-v6.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare
efi: stmm: Drop unneeded null pointer check
efi: stmm: Drop unused EFI error from setup_mm_hdr arguments
efi: stmm: Do not return EFI_OUT_OF_RESOURCES on internal errors
efi: stmm: Fix incorrect buffer allocation method
Linus Torvalds [Fri, 29 Aug 2025 15:09:34 +0000 (08:09 -0700)]
Merge tag 'xfs-fixes-6.17-rc4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Carlos Maiolino:
"The highlight I'd like to point here is related to the XFS_RT
Kconfig, which has been updated to be enabled by default now if
CONFIG_BLK_DEV_ZONED is enabled.
This also contains a few fixes for zoned devices support in XFS,
specially related to swapon requests in inodes belonging to the zoned
FS.
A null-ptr dereference fix in the xattr data, due to a mishandling of
medium errors generated by block devices is also included"
* tag 'xfs-fixes-6.17-rc4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: do not propagate ENODATA disk errors into xattr code
xfs: reject swapon for inodes on a zoned file system earlier
xfs: kick off inodegc when failing to reserve zoned blocks
xfs: remove xfs_last_used_zone
xfs: Default XFS_RT to Y if CONFIG_BLK_DEV_ZONED is enabled
Linus Torvalds [Fri, 29 Aug 2025 14:37:21 +0000 (07:37 -0700)]
Merge tag 'regulator-fix-v6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fix from Mark Brown:
"One simple fix for the pm8008 driver for poor error handling,
switching to use a helper which does the right thing in the
affected case"
* tag 'regulator-fix-v6.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: pm8008: fix probe failure due to negative voltage selector
Linus Torvalds [Fri, 29 Aug 2025 14:29:17 +0000 (07:29 -0700)]
Merge tag 'ata-6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux
Pull ata fixes from Damien Le Moal:
- Fix the type of return values to be signed in the ahci_xgen driver
(Qianfeng)
- Add the mask_port_ext module parameter to the ahci driver.
This is to allow a user to ignore ports that are advertized as
external (hotplug capable) in favor of lower link power management
policies instead of the default max_performance for these ports.
This is useful to allow e.g. laptops to go into low power states when
hooked up to docking station with sata slots, connected with an
external port for hotplug (me)
* tag 'ata-6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
ata: ahci_xgene: Use int type for 'rc' to store error codes
ata: ahci: Allow ignoring the external/hotplug capability of ports
Linus Torvalds [Fri, 29 Aug 2025 02:56:32 +0000 (19:56 -0700)]
Merge tag 'drm-fixes-2025-08-29' of https://gitlab.freedesktop.org/drm/kernel
Pull drm fixes from Dave Airlie:
"Weekly fixes, feels a bit big.
The major piece is msm fixes, then the usual amdgpu/xe along with some
mediatek and nouveau fixes and a tegra revert.
gpuvm:
- fix some typos
xe:
- Fix user-fence race issue
- Couple xe_vm fixes
- Don't trigger rebind on initial dma-buf validation
- Fix a build issue related to basename() posix vs gnu discrepancy
nouveau:
- fix linear modifier
- remove some dead code
msm:
- Core/GPU:
- fix comment doc warning in gpuvm
- fix build with KMS disabled
- fix pgtable setup/teardown race
- global fault counter fix
- various error path fixes
- GPU devcoredump snapshot fixes
- handle in-place VM_BIND remaps to solve turnip vm update race
- skip re-emitting IBs for unusable VMs
- Don't use %pK through printk
- moved display snapshot init earlier, fixing a crash
- DPU:
- Fixed crash in virtual plane checking code
- Fixed mode comparison in virtual plane checking code
- DSI:
- Adjusted width of resulution-related registers
- Fixed locking issue on 14nm PLLs
- UBWC (per Bjorn's ack)
- Added UBWC configuration for several missing platforms (fixing
regression)
mediatek:
- Add error handling for old state CRTC in atomic_disable
- Fix DSI host and panel bridge pre-enable order
- Fix device/node reference count leaks in mtk_drm_get_all_drm_priv
- mtk_hdmi: Fix inverted parameters in some regmap_update_bits calls
tegra:
- revert dma-buf change"
* tag 'drm-fixes-2025-08-29' of https://gitlab.freedesktop.org/drm/kernel: (56 commits)
drm/mediatek: mtk_hdmi: Fix inverted parameters in some regmap_update_bits calls
drm/amdgpu/userq: fix error handling of invalid doorbell
drm/amdgpu: update firmware version checks for user queue support
drm/amd/amdgpu: disable hwmon power1_cap* for gfx 11.0.3 on vf mode
Revert "drm/amdgpu: fix incorrect vm flags to map bo"
drm/amdgpu/gfx12: set MQD as appriopriate for queue types
drm/amdgpu/gfx11: set MQD as appriopriate for queue types
drm/xe: switch to local xbasename() helper
drm/xe: Don't trigger rebind on initial dma-buf validation
drm/xe/vm: Clear the scratch_pt pointer on error
drm/xe/vm: Don't pin the vm_resv during validation
drm/xe/xe_sync: avoid race during ufence signaling
Revert "drm/tegra: Use dma_buf from GEM object instance"
soc: qcom: use no-UBWC config for MSM8956/76
soc: qcom: add configuration for MSM8929
soc: qcom: ubwc: add more missing platforms
soc: qcom: ubwc: use no-uwbc config for MSM8917
drm/msm/dpu: Add a null ptr check for dpu_encoder_needs_modeset
dt-bindings: display/msm: qcom,mdp5: drop lut clock
drm/gpuvm: fix various typos in .c and .h gpuvm file
...
Linus Torvalds [Fri, 29 Aug 2025 01:51:28 +0000 (18:51 -0700)]
Merge tag 'block-6.17-20250828' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
- Fix a lockdep spotted issue on recursive locking for zoned writes, in
case of errors
- Update bcache MAINTAINERS entry address for Coly
- Fix for a ublk release issue, with selftests
- Fix for a regression introduced in this cycle, where it assumed
q->rq_qos was always set if the bio flag indicated that
- Fix for a regression introduced in this cycle, where loop retrieving
block device sizes got broken
* tag 'block-6.17-20250828' of git://git.kernel.dk/linux:
bcache: change maintainer's email address
ublk selftests: add --no_ublk_fixed_fd for not using registered ublk char device
ublk: avoid ublk_io_release() called after ublk char dev is closed
block: validate QoS before calling __rq_qos_done_bio()
blk-zoned: Fix a lockdep complaint about recursive locking
loop: fix zero sized loop for block special file
Linus Torvalds [Fri, 29 Aug 2025 01:41:53 +0000 (18:41 -0700)]
Merge tag 'io_uring-6.17-20250828' of git://git.kernel.dk/linux
Pull io_uring fixes from Jens Axboe:
- Use the proper type for min_t() in getting the min of the leftover
bytes and the buffer length.
- As good practice, use READ_ONCE() consistently for reading ring
provided buffer lengths. Additionally, stop looping for incremental
commits if a zero sized buffer is hit, as no further progress can be
made at that point.
* tag 'io_uring-6.17-20250828' of git://git.kernel.dk/linux:
io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths
io_uring/kbuf: fix signedness in this_len calculation
Linus Torvalds [Fri, 29 Aug 2025 00:35:51 +0000 (17:35 -0700)]
Merge tag 'net-6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from Bluetooth.
Current release - regressions:
- ipv4: fix regression in local-broadcast routes
- vsock: fix error-handling regression introduced in v6.17-rc1
Previous releases - regressions:
- bluetooth:
- mark connection as closed during suspend disconnect
- fix set_local_name race condition
- eth:
- ice: fix NULL pointer dereference on reset
- mlx5: fix memory leak in hws_pool_buddy_init error path
- bnxt_en: fix stats context reservation logic
- hv: fix loss of receive events from host during channel open
Previous releases - always broken:
- page_pool: fix incorrect mp_ops error handling
- sctp: initialize more fields in sctp_v6_from_sk()
- eth:
- octeontx2-vf: fix max packet length errors
- idpf: fix Tx flow scheduling to avoid Tx timeouts
- bnxt_en: fix memory corruption during ifdown
- ice: fix incorrect counter for buffer allocation failures
- mlx5: fix lockdep assertion on sync reset unload event
- fbnic: fixup rtnl_lock and devl_lock handling
- xgmac: do not enable RX FIFO overflow interrupts
- phy: mscc: fix when PTP clock is register and unregister
Misc:
- add Telit Cinterion LE910C4-WWX new compositions"
* tag 'net-6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (60 commits)
net: ipv4: fix regression in local-broadcast routes
net: macb: Disable clocks once
fbnic: Move phylink resume out of service_task and into open/close
fbnic: Fixup rtnl_lock and devl_lock handling related to mailbox code
net: rose: fix a typo in rose_clear_routes()
l2tp: do not use sock_hold() in pppol2tp_session_get_sock()
sctp: initialize more fields in sctp_v6_from_sk()
MAINTAINERS: rmnet: Update email addresses
net: rose: include node references in rose_neigh refcount
net: rose: convert 'use' field to refcount_t
net: rose: split remove and free operations in rose_remove_neigh()
net: hv_netvsc: fix loss of early receive events from host during channel open.
net: stmmac: Set CIC bit only for TX queues with COE
net: stmmac: xgmac: Correct supported speed modes
net: stmmac: xgmac: Do not enable RX FIFO Overflow interrupts
net/mlx5e: Set local Xoff after FW update
net/mlx5e: Update and set Xon/Xoff upon port speed set
net/mlx5e: Update and set Xon/Xoff upon MTU set
net/mlx5: Prevent flow steering mode changes in switchdev mode
net/mlx5: Nack sync reset when SFs are present
...
1. Add error handling for old state CRTC in atomic_disable
2. Fix DSI host and panel bridge pre-enable order
3. Fix device/node reference count leaks in mtk_drm_get_all_drm_priv
4. mtk_hdmi: Fix inverted parameters in some regmap_update_bits calls
Linus Torvalds [Thu, 28 Aug 2025 23:34:32 +0000 (16:34 -0700)]
Merge tag 'pm-6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fix from Rafael Wysocki:
"Add missing locking annotations to two recently introduced
list_for_each_entry_rcu() loops in the core device suspend/resume
code (Johannes Berg)"
* tag 'pm-6.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM: sleep: annotate RCU list iterations
Louis-Alexis Eyraud [Mon, 18 Aug 2025 14:17:52 +0000 (16:17 +0200)]
drm/mediatek: mtk_hdmi: Fix inverted parameters in some regmap_update_bits calls
In mtk_hdmi driver, a recent change replaced custom register access
function calls by regmap ones, but two replacements by regmap_update_bits
were done incorrectly, because original offset and mask parameters were
inverted, so fix them.
Linus Torvalds [Thu, 28 Aug 2025 23:04:14 +0000 (16:04 -0700)]
Merge tag 'dma-mapping-6.17-2025-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping fixes from Marek Szyprowski:
- another small fix for arm64 systems with memory encryption (Shanker
Donthineni)
- fix for arm32 systems with non-standard CMA configuration (Oreoluwa
Babatunde)
* tag 'dma-mapping-6.17-2025-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
dma/pool: Ensure DMA_DIRECT_REMAP allocations are decrypted
of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()
Linus Torvalds [Thu, 28 Aug 2025 22:46:06 +0000 (15:46 -0700)]
Merge tag 'fixes-2025-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock fixes from Mike Rapoport:
- printk cleanups in memblock and numa_memblks
- update kernel-doc for MEMBLOCK_RSRV_NOINIT to be more accurate and
detailed
* tag 'fixes-2025-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
memblock: fix kernel-doc for MEMBLOCK_RSRV_NOINIT
mm: numa,memblock: Use SZ_1M macro to denote bytes to MB conversion
mm/numa_memblks: Use pr_debug instead of printk(KERN_DEBUG)
Dave Airlie [Thu, 28 Aug 2025 22:44:10 +0000 (08:44 +1000)]
Merge tag 'drm-misc-fixes-2025-08-28' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes
Several nouveau fixes to remove unused code, fix an error path and be
less restrictive with the formats it accepts. A fix for amdgpu to pin
vmapped dma-buf, and a revert for tegra for a regression in the dma-buf
/ GEM code.
Linus Torvalds [Thu, 28 Aug 2025 22:39:06 +0000 (15:39 -0700)]
Merge tag 'powerpc-6.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Madhavan Srinivasan:
- Merge two CONFIG_POWERPC64_CPU entries in Kconfig.cputype
- Replace extra-y to always-y in Makefile
- Cleanup to use dev_fwnode helper
- Fix misleading comment in kvmppc_prepare_to_enter()
- misc cleanup and fixes
Thanks to Amit Machhiwal, Andrew Donnellan, Christophe Leroy, Gautam
Menghani, Jiri Slaby (SUSE), Masahiro Yamada, Shrikanth Hegde, Stephen
Rothwell, Venkat Rao Bagalkote, and Xichao Zhao
* tag 'powerpc-6.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/boot/install.sh: Fix shellcheck warnings
powerpc/prom_init: Fix shellcheck warnings
powerpc/kvm: Fix ifdef to remove build warning
powerpc: unify two CONFIG_POWERPC64_CPU entries in the same choice block
powerpc: use always-y instead of extra-y in Makefiles
powerpc/64: Drop unnecessary 'rc' variable
powerpc: Use dev_fwnode()
KVM: PPC: Fix misleading interrupts comment in kvmppc_prepare_to_enter()
Marc Zyngier [Sat, 9 Aug 2025 14:48:10 +0000 (15:48 +0100)]
KVM: arm64: nv: Fix ATS12 handling of single-stage translation
Volodymyr reports that using a Xen DomU as a nested guest (where
HCR_EL2.E2H == 0), ATS12 results in a translation that stops at
the L2's S1, which isn't something you'd normally expects.
Comparing the code against the spec proves to be illuminating,
and suggests that the author of such code must have been tired,
cross-eyed, drunk, or maybe all of the above.
The gist of it is that, apart from HCR_EL2.VM or HCR_EL2.DC being
0, only the use of the EL2&0 translation regime limits the walk
to S1 only, and that we must finish the S2 walk in any other case.
Which solves the above issue, as E2H==0 indicates that ATS12 walks
the EL1&0 translation regime.
Volodymyr reports (again!) that under some circumstances (E2H==0,
walking S1 PTs), PAR_EL1 doesn't report the value of the latest
walk in the CPU register, but that instead the value is written to
the backing store.
Further investigation indicates that the root cause of this is
that a group of registers (PAR_EL1, TPIDR*_EL{0,1}, the *32_EL2 dregs)
should always be considered as "on CPU", as they are not remapped
between EL1 and EL2.
We fail to treat them accordingly, and end-up considering that
the register (PAR_EL1 in this example) should be written to memory
instead of in the register.
While it would be possible to quickly work around it, it is obvious
that the way we track these things at the moment is pretty horrible,
and could do with some improvement.
Revamp the whole thing by:
- defining a location for a register (memory, cpu), potentially
depending on the state of the vcpu
- define a transformation for this register (mapped register, potential
translation, special register needing some particular attention)
- convey this information in a structure that can be easily passed
around
As a result, the accessors themselves become much simpler, as the
state is explicit instead of being driven by hard-to-understand
conventions.
We get rid of the "pure EL2 register" notion, which wasn't very
useful, and add sanitisation of the values by applying the RESx
masks as required, something that was missing so far.
And of course, we add the missing registers to the list, with the
indication that they are always loaded.
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