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The driver defines the I2C packet layout using C bitfields in struct
mms114_touch. This is not portable as the layout of bitfields within a
byte is compiler-dependent and varies with endianness. On Big Endian
systems, the fields will be parsed incorrectly.
Fix this by redefining struct mms114_touch with plain u8 fields and
introducing bitwise macros to extract the values portably.
Reported-by: sashiko-bot@kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Link: https://patch.msgid.link/20260704060115.353049-2-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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Sync up with mainline to pull in stable fixes to avoid merge conflicts.
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is_created is written under config_lock. Every concurrent reader is
serialised against that write: pkvm_create_hyp_vm() under config_lock,
and the memslot path (kvm_arch_prepare_memory_region) via slots_lock,
which the creation writer also holds. The teardown-path accesses have no
concurrent writer. The read is therefore serialised, and the READ_ONCE()
is unnecessary.
Reviewed-by: Keir Fraser <keirf@google.com>
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260706103129.706974-4-fuad.tabba@linux.dev
Signed-off-by: Oliver Upton <oupton@kernel.org>
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pkvm_init_host_vm() runs once from kvm_arch_init_vm(), while the VM is
still being allocated and is not yet reachable by another thread. Both
early checks therefore test impossible state: is_created is still false
(it is only set on first vCPU run) and the handle is still zero (this
function is what reserves it). Neither branch can be taken.
Remove them.
Reviewed-by: Keir Fraser <keirf@google.com>
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260706103129.706974-3-fuad.tabba@linux.dev
Signed-off-by: Oliver Upton <oupton@kernel.org>
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init_pkvm_hyp_vm() sets is_created on the EL2-private VM struct, but the
hypervisor never reads it: pkvm_hyp_vm_is_created() and every other
consumer operate on the host's struct kvm, a distinct allocation from
the EL2-private copy. The field is write-only at EL2.
Remove the store; host-side is_created tracking is unaffected.
Reviewed-by: Keir Fraser <keirf@google.com>
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260706103129.706974-2-fuad.tabba@linux.dev
Signed-off-by: Oliver Upton <oupton@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
- A cpuset that never set its memory nodes could divide by zero when a
task's mempolicy rebinds on CPU hotplug. Rebind against the effective
nodes, which are always populated
- Documentation fixes for memory.stat, io.stat, and the misc and v1
RDMA controllers
* tag 'cgroup-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
Docs/admin-guide/cgroup-v2: note blkcg_debug_stats gates io.latency stats
Docs/admin-guide/cgroup-v1: document rdma.peak, rdma.events and rdma.events.local
Docs/admin-guide/cgroup-v2: drop stale misc interface file count
cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed
Docs/admin-guide/cgroup-v2: fix memory.stat doc details
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Now that the revocation Completion is in place, also address the
symmetric case. When Devres::drop() wins the is_available swap and the
devres callback loses, the callback returns to devres_release_all()
without waiting. This means device unbinding can complete while
Devres::drop() is still executing drop_in_place() on another CPU, which
is a problem if T's destructor accesses device state.
Make the synchronization bidirectional. Whichever side performs
drop_in_place() signals the Completion, and the other side waits.
This does not reintroduce the nested Devres deadlock fixed by commit
ba268514ea14 ("rust: devres: fix race condition due to nesting"),
because that deadlock was caused by drop waiting for the release
callback to return (the old 'devm' Completion). Here, both sides only
wait for drop_in_place() to finish, which completes within the current
call chain. The Arc<Inner<T>> keeps the Inner allocation alive
independently.
Cc: stable@vger.kernel.org
Fixes: ba268514ea14 ("rust: devres: fix race condition due to nesting")
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260628200304.2365598-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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There is a potential race condition when two paths try to revoke a
Devres concurrently.
The driver core's devres_release_all() calls Revocable::revoke() via the
release callback, while Devres::drop() calls revoke_nosync() on another
CPU.
The revoker that does not claim the is_available swap returns
immediately, but the revoker that did may still be executing
drop_in_place() on the inner data. This can cause a use-after-free when
the other revoker's caller proceeds to drop adjacent resources that
drop_in_place() still references (e.g., Devres<DmaMappedSgt> racing with
SGTable freeing the backing sg_table and pages).
Fix this by adding a Completion. The release callback signals the
Completion after revoke() finishes, and Devres::drop() waits for it when
it loses the is_available swap. This ensures the wrapped object is fully
torn down before Devres::drop() returns.
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/dri-devel/20260612202841.2577C1F000E9@smtp.kernel.org/
Fixes: 05aa6fb1c21d ("rust: scatterlist: Add abstraction for sg_table")
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260628174451.2275679-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext
Pull sched_ext fixes from Tejun Heo:
- Lifecycle fixes for the new sub-scheduler support: two
use-after-frees and an enable-failure path that left a
half-initialized sub-scheduler linked.
- Two dispatch-path locking bugs: a spurious scheduler abort from a
migration race, and a lockdep splat from stale runqueue-lock
tracking.
- Callback and task-state fixes: stale scheduler-owned state on a task
leaving SCX, a weight callback running after disable, and a bogus
warning on core-scheduling forced idle.
- On nohz_full, finite-slice tasks could miss the tick that expires
their slice. Enable it when such a task is picked, with a selftest.
- Smaller fixes: userspace CPU-mask helpers, ratelimited deprecation
warnings, docs and a sparse annotation.
* tag 'sched_ext-for-7.2-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Skip ops.set_weight() for disabled tasks
tools/sched_ext: scx - Fix cmask_subset(), cmask_equal() and cmask_weight()
sched_ext: Fix premature ops->priv publication in scx_alloc_and_add_sched()
sched_ext: Record an error on errno-only sub-enable failure
selftests/sched_ext: Verify nohz_full tick behavior
sched_ext: Enable tick for finite slices on nohz_full
sched_ext: Preserve rq tracking across local DSQ dispatch
sched_ext: Documentation: Fix ops table header reference
sched_ext: Don't warn on core-sched forced idle in put_prev_task_scx()
sched_ext: Pin parent scx_sched across a child sub-scheduler's lifetime
sched_ext: Annotate ksyncs with __rcu in alloc/free_kick_syncs()
sched_ext: Check remote rq eligibility under task's rq lock
sched_ext: Reset dsq_vtime and slice when a task leaves SCX
sched_ext: Avoid flooding the log with deprecation warnings
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Convert xen_mm_unpin_all() to ptdescs in preparation for the eventual
splitting of ptdescs from struct page. Continue checking PagePinned
through the underlying page as we do not have a per-memdesc api yet.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-10-vishal.moola@gmail.com
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Convert xen_mm_pin_all() to ptdescs in preparation for the eventual
splitting of ptdescs from struct page. Continue checking PagePinned
through the underlying page as we do not have a per-memdesc api for
page flags yet.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-9-vishal.moola@gmail.com
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Convert pgd_page_get_mm() to ptdescs. Define struct ptdesc in our
pgtable_types so that our declarations recognize ptdesc as an
appropriate page table type.
Now that all callers are using ptdescs, we can pass in that
ptdesc to get the underlying mm_struct.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-8-vishal.moola@gmail.com
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Convert sync_global_pgds_l4() to ptdescs in preparation for the
eventual splitting of ptdescs from struct page.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-7-vishal.moola@gmail.com
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Convert sync_global_pgds_l5() to ptdescs in preparation for the
eventual splitting of ptdescs from struct page.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-6-vishal.moola@gmail.com
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Convert arch_sync_kernel_mappings() to ptdescs in preparation for
the eventual splitting of ptdescs from struct page.
Following this patch, we can successfully boot a 32-bit x86 kernel with
separately allocated ptdescs.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-5-vishal.moola@gmail.com
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Convert collapse_pmd_page() to ptdescs in preparation for the
eventual splitting of ptdescs from struct page.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-4-vishal.moola@gmail.com
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Convert __set_pmd_pte() to ptdescs in preparation for the eventual
splitting of ptdescs from struct page.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-3-vishal.moola@gmail.com
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Use IS_ENABLED() to check if we are on 32 bit. This standardizes this
check with the other 32 bit check in the file. No functional changes.
Signed-off-by: Vishal Moola <vishal.moola@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@linux.dev>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260629185742.126987-2-vishal.moola@gmail.com
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When the hypervisor tracing (CONFIG_NVHE_EL2_TRACING) is disabled, it
defines a static inline stub for trace_clock().
However, trace_clock() is already declared as an extern function in
linux/trace_clock.h which is pulled in EL2 compilation.
If the file <nvhe/clock.h> is included when CONFIG_NVHE_EL2_TRACING
is disabled (by including it manually in setup.c) it will cause:
In file included from arch/arm64/kvm/hyp/nvhe/setup.c:22:
./arch/arm64/kvm/hyp/include/nvhe/clock.h:14:19: error: static declaration of ‘trace_clock’ follows non-static declaration
14 | static inline u64 trace_clock(void) { return 0; }
| ^~~~~~~~~~~
on GCC and a linker error on LLVM (it seems to change the linkage to
global)
Although that is not a problem at the moment, as no other files
include <nvhe/clock.h>. That does not seem to be the intent of
this code and that will cause issues with more users as the SMMUv3
driver.
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Tested-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260713141320.4065600-1-smostafa@google.com
Signed-off-by: Oliver Upton <oupton@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull RTLA fixes from Steven Rostedt:
- Fix missing unistd include
A missing #include <unistd.h> broke build on uclibc systems.
Add the include to fix it.
- Fix missing tools/lib/ctype.c dependency
RTLA links tools/lib/string.c as a dependency of libsubcmd, some of
its functions require _ctype. Link tools/lib/ctype.c as well, to fix
build without GCC LTO.
* tag 'trace-tools-v7.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rtla: Also link in ctype.c
rtla: Fix missing unistd include
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Commit 16df4cc63c58 ("drm/i915/display: Use ceiling division for NV12
UV surface offset calculation") computes the UV (chroma) surface
start/size as ceiling(half of Y plane start/size) directly from the
U16.16 fixed-point source rectangle:
x = fp_16_16_to_int_ceil(fp_16_16_div2(src.x1));
For a single pipe the source coordinates are integers, so this is
correct.
(UV start = ceiling(half of Y plane start)).
With bigjoiner + a plane scaler the picture changes. The pipe boundary
is a fixed integer destination pixel, but the plane's position and the
scaler ratio are arbitrary, so drm_rect_clip_scaled() maps the seam back
to a *fractional* per-pipe source. For a 1280->2407 upscaled NV12 plane
crossing the seam:
master src: width = 1204 * 1280/2407 = 640.265899, x1 = 0
joiner src: width = 1203 * 1280/2407 = 639.734115, x1 = 640.265884
The luma path floors this to an integer (src.x1 >> 16 = 640), but the
UV path takes ceiling(640.265884 / 2) = ceil(320.13) = 321. The Y plane
then starts at column 640 while the UV plane starts at 321*2 = 642,
pushing the chroma read one column past the 640-wide chroma surface on
the joiner secondary:
[CRTC:382:pipe C] PLANE ATS fault
[CRTC:382:pipe C][PLANE:267:plane 1C] fault (CTL=0x81009400, ...)
The spec "Y plane start" is the integer pixel the luma surface actually
programs (640), not the pre-floor fixed-point value (640.27). Convert
the Y plane start/size to integer first - matching skl_check_main_surface()
- and then apply the ceiling. This is a no-op for the integer (non-joiner)
case and yields the correct, in-bounds chroma offset for the fractional
joiner seam:
before fix after fix
master 1B: x=0 w=321 x=0 w=320 -> [0, 320)
slave 1C: x=321 w=320 x=320 w=320 -> [320, 640)
The two halves now tile the 640-wide chroma plane exactly and the ATS
fault is gone.
Assisted-by: GitHub-Copilot:Claude-Opus-4.8
Fixes: 16df4cc63c58 ("drm/i915/display: Use ceiling division for NV12 UV surface offset calculation")
Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patch.msgid.link/20260618181837.687302-1-vidya.srinivas@intel.com
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In preparation for removing the deprecated strlcat() API[1], replace the
strscpy()/strlcat() chain in selinux_ima_collect_state() with a struct
seq_buf, which tracks the write position and remaining space internally.
Each field is written with seq_buf_printf() using a "=%d;" format, which
removes the open-coded "=1;"/"=0;" constants. The seven per-append
WARN_ON(rc >= buf_len) truncation checks are replaced by a single
seq_buf_has_overflowed() check after the string is built.
Link: https://github.com/KSPP/linux/issues/370 [1]
Signed-off-by: Ian Bridges <icb@fastmail.org>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core into drm-rust-next
I/O type generalization and projection
This series presents a major rework of I/O types, as a summary:
- Make I/O regions typed. The existing untyped region still exists
with a dynamically sized `Region` type.
- Create I/O view types to represent subregion of a full I/O region mapped.
A projection macro is added to allow safely create such subviews.
- Split I/O traits, make I/O views play a central role, avoid
duplicate monomorphization and less `unsafe` code.
- Add a `SysMem` backend, and make `Coherent` implement `Io`.
- Add copying methods (memcpy_{from,to}io and friends).
This series generalize `Mmio` type from just an untyped region to typed
representations (so `MmioRaw<T>` is `__iomem *T`). This allows us to remove
the `IoKnownSize` trait; the information is sourced from just the pointer
from the `KnownSize` trait instead.
Building on top of that, `Mmio` and `ConfigSpace` have been converted to
typed views of I/O regions rather than just a big chunk of untyped I/O
memory. These changes made it possible to implement `Io` trait for
`Coherent<T>`.
Shared system memory, `SysMem` is also added to the series, given it
similarity in implementation compared to `Coherent`. In fact, the series
use `SysMem` to implement `Coherent`'s I/O methods.
Built on these generalization, this series add `io_project!()`.
`io_project!()` performs a safe way to project a bigger view to a small
subviews, and some Nova code has been converted in this series to
demonstrate cleanups possible with this addition.
New `io_read!()`, `io_write!()` has been added that supersedes
`dma_read!()`, `dma_write!()` macro. Although, they work for primitives
only (to be exact, types that the backend is `IoCapable` of).
One feature that was lost from the old `dma_read!()` and `dma_write!()`
series was the ability to read/write a large structs. However, the
semantics was unclear to begin with, as there was no guarantee about their
atomicity even for structs that were small enough to fit in u32.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Generic.20I.2FO.20backends/near/571198078
This is a stable tag for other trees to merge.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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Gary Guo <gary@garyguo.net> says:
This series presents a major rework of I/O types, as a summary:
- Make I/O regions typed. The existing untyped region still exists
with a dynamically sized `Region` type.
- Create I/O view types to represent subregion of a full I/O region mapped.
A projection macro is added to allow safely create such subviews.
- Split I/O traits, make I/O views play a central role, avoid
duplicate monomorphization and less `unsafe` code.
- Add a `SysMem` backend, and make `Coherent` implement `Io`.
- Add copying methods (memcpy_{from,to}io and friends).
This series generalize `Mmio` type from just an untyped region to typed
representations (so `MmioRaw<T>` is `__iomem *T`). This allows us to remove
the `IoKnownSize` trait; the information is sourced from just the pointer
from the `KnownSize` trait instead.
Building on top of that, `Mmio` and `ConfigSpace` have been converted to
typed views of I/O regions rather than just a big chunk of untyped I/O
memory. These changes made it possible to implement `Io` trait for
`Coherent<T>`.
Shared system memory, `SysMem` is also added to the series, given it
similarity in implementation compared to `Coherent`. In fact, the series
use `SysMem` to implement `Coherent`'s I/O methods.
Built on these generalization, this series add `io_project!()`.
`io_project!()` performs a safe way to project a bigger view to a small
subviews, and some Nova code has been converted in this series to
demonstrate cleanups possible with this addition.
New `io_read!()`, `io_write!()` has been added that supersedes
`dma_read!()`, `dma_write!()` macro. Although, they work for primitives
only (to be exact, types that the backend is `IoCapable` of).
One feature that was lost from the old `dma_read!()` and `dma_write!()`
series was the ability to read/write a large structs. However, the
semantics was unclear to begin with, as there was no guarantee about their
atomicity even for structs that were small enough to fit in u32.
Suggested-by: Danilo Krummrich <dakr@kernel.org>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/288089-General/topic/Generic.20I.2FO.20backends/near/571198078
Link: https://patch.msgid.link/20260706-io_projection-v6-0-72cd5d055d54@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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According to x86 architecture rules, 32-bit operations zero-extend the
result to 64 bits. The current implementation of handle_in() only masks
the lower 32 bits, which preserves the upper 32 bits of RAX when a
32-bit port IN instruction is emulated.
Use insn_assign_reg() to write the result back into RAX with proper
partial-register-write semantics: 1- and 2-byte forms leave the upper
bits untouched, the 4-byte form zero-extends to the full register.
Fixes: 03149948832a ("x86/tdx: Port I/O: Add runtime hypercalls")
Reported-by: Borys Tsyrulnikov <tsyrulnikov.borys@gmail.com>
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/all/CAKw_Dz96rfSQc6Rn+9QBcUFHhmkK+9zu+P=bxowfZwxrATCBRg@mail.gmail.com/
Cc:stable@vger.kernel.org
Link: https://patch.msgid.link/20260713133753.223947-4-kirill@shutemov.name
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KVM's instruction emulator has a small helper, assign_register(), that
writes a value into a register following the x86 rules for writes to
general-purpose registers: an 8- or 16-bit write leaves the rest of the
register untouched, a 32-bit write zero-extends the result to 64 bits,
and a 64-bit write replaces the whole register.
The TDX guest #VE handler needs the same logic for port I/O emulation
to get 32-bit zero-extension right. Rather than add a third copy of
the same switch, move the helper verbatim to <asm/insn-eval.h>, rename
it to insn_assign_reg(), and route KVM's callers through it.
Add <asm/insn.h> to the header's includes so it builds standalone in
callers that have not pulled it in transitively.
No functional change.
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Sean Christopherson <seanjc@google.com>
Cc:stable@vger.kernel.org
Link: https://patch.msgid.link/20260713133753.223947-3-kirill@shutemov.name
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handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use:
u64 mask = GENMASK(BITS_PER_BYTE * size, 0);
GENMASK(h, l) includes bit h. For size=1 (INB), this produces
GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8
bits). The mask is one bit too wide for all I/O sizes.
Fix the mask calculation.
Fixes: 03149948832a ("x86/tdx: Port I/O: Add runtime hypercalls")
Reported-by: Borys Tsyrulnikov <tsyrulnikov.borys@gmail.com>
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://lore.kernel.org/all/CAKw_Dz96rfSQc6Rn+9QBcUFHhmkK+9zu+P=bxowfZwxrATCBRg@mail.gmail.com/
Cc:stable@vger.kernel.org
Link: https://patch.msgid.link/20260713133753.223947-2-kirill@shutemov.name
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DevresLt"
Danilo Krummrich <dakr@kernel.org> says:
The ForLt trait currently guarantees covariance, which allows safe
lifetime shortening via cast_ref(). However, some types (e.g. those
containing Mutex<&'bound T>) are invariant over their lifetime parameter
and cannot safely use cast_ref().
This series splits ForLt into two traits:
- ForLt: base trait for all lifetime-parameterized types, providing
only the Of<'a> GAT.
- CovariantForLt: unsafe subtrait that guarantees covariance,
providing a safe cast_ref() method.
For invariant types, a closure-based API (registration_data_with()) is
added to the auxiliary subsystem. The closure's HRTB prevents the caller
from choosing a concrete lifetime, which would be unsound for invariant
types.
On top of that, this series adds DevresLt<F: ForLt>, a thin wrapper
around Devres<F::Of<'static>> that shortens the stored 'static lifetime
back to the caller's borrow scope. DevresLt provides both closure-based
access (access_with/try_access_with for ForLt types) and direct
reference access (access/try_access for CovariantForLt types).
Also implement ForLt and CovariantForLt for Bar, IoMem and
ExclusiveIoMem, and update their into_devres() methods to return
DevresLt. Provide convenience type aliases DevresBar, DevresIoMem and
DevresExclusiveIoMem.
Link: https://patch.msgid.link/20260626183630.2585057-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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When deploying linux-6.18.y stable kernel to production servers, we
observed kernel dmesg being flooded with SELinux warnings when running
`ss -l`:
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=19 \
sclass=netlink_tcpdiag_socket pid=188945 comm=ss
The root cause is that DCCP support was retired in
commit 2a63dd0edf38 ("net: Retire DCCP socket."). Consequently,
DCCPDIAG_GETSOCK was removed from nlmsg_tcpdiag_perms. This causes
nlmsg_perm() to return -EINVAL, triggering the SELinux warning for every
`ss -l` invocation [0].
Use pr_warn_once() for the retired DCCPDIAG_GETSOCK to prevent message
flooding.
Link: https://github.com/iproute2/iproute2/blob/main/misc/ss.c#L3901 [0]
Fixes: 2a63dd0edf38 ("net: Retire DCCP socket.")
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Kuniyuki Iwashima <kuniyu@google.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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The mbm_handle_overflow() and cqm_handle_limbo() workers read event counters
and may sleep while doing so. They are scheduled via delayed_work embedded in
struct rdt_l3_mon_domain. Architecture allocates and frees these domains from
CPU hotplug callbacks under cpus_write_lock(), and the workers acquire
cpus_read_lock() to keep the domain alive across their access.
A use-after-free can occur when a worker is blocked waiting for
cpus_read_lock() while the hotplug core holds cpus_write_lock(): the
architecture frees the rdt_l3_mon_domain that contains the worker's
work_struct. When the worker unblocks, the container_of() it performs on the
embedded work pointer dereferences freed memory.
Drop cpus_read_lock() from the workers and instead drain pending and in-flight
work synchronously before the architecture can free the domain. Since
architecture offlines the domain under cpus_write_lock() after it has been
unlinked from the RCU list and a grace period has elapsed, no new work can be
scheduled. The cancel only needs to wait out existing work. Drop
rdtgroup_mutex during CPU offline around cancel_delayed_work_sync() so that
a worker waiting on the mutex can complete before re-pinning the work on
a different CPU.
When offlining a CPU the architecture may iterate over resources in any order.
For example, the MBA control domain may be offlined before or after
a corresponding L3 monitor domain. Ensure that resctrl fs cancels the workers
no matter what order the architecture offlines the domains.
Fixes: 24247aeeabe9 ("x86/intel_rdt/cqm: Improve limbo list processing")
Closes: https://sashiko.dev/#/patchset/20260429184858.36423-1-tony.luck%40intel.com # [1]
Reported-by: Sashiko <sashiko-bot@kernel.org>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/3f0e0752deb3421606dfc4600f0ab3a4ae098cd7.1783963505.git.reinette.chatre@intel.com
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A resctrl domain consists of the domain structure self that includes
pointers to dynamically allocated filesystem as well as architecture
specific data. For example, the L3 monitoring domain structure consists
of the architecture specific struct rdt_hw_l3_mon_domain that contains
the dynamically allocated rdt_hw_l3_mon_domain::arch_mbm_states
architectural state and the embedded struct rdt_l3_mon_domain contains
the dynamically allocated rdt_l3_mon_domain::mbm_states resctrl fs state.
The domains are added to and removed from an RCU protected list while
cpus_write_lock() is held so that readers could access domains via
cpus_read_lock() or from an RCU read-side critical section. A reader
accessing a domain via the RCU list expects that the domain and all its
dynamically allocated data is accessible.
Only place the domain on the RCU list when all its dynamically allocated
data is ready, similarly unlink it from RCU list (again with cpus_write_lock()
held) before removing any of its dynamically allocated data.
Calling resctrl_online_mon_domain() before adding the domain to the RCU
list creates the kernfs files that expose the domain's monitoring data to
user space before adding the domain to the RCU list. This is safe because
rdtgroup_mondata_show() acquires cpus_read_lock() before it traverses the
RCU list and will thus block until the domain is added to the RCU list.
There are no readers accessing a domain via RCU list. Ensure safety of
access when such a reader arrives.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Chen Yu <yu.c.chen@intel.com>
Link: https://patch.msgid.link/31ae67084c983e8cb8c5ef2c65e1096de5e8f9b0.1783963505.git.reinette.chatre@intel.com
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In a multi-queue group only the group's primary queue interfaces with
GuC for scheduling; suspend/resume of secondary queues is handled
internally and is not forwarded to GuC. As a result, suspending a
secondary queue alone (e.g. on its preempt fence signalling) does not
disable the primary's GuC context, so in-flight GPU work of the group
is not actually preempted.
Make a secondary queue suspend/resume like any other queue, driven by
its own xe_guc_exec_queue.suspend_count, and additionally forward the
suspend/resume to the primary so the GPU is actually preempted. The
forward is gated on the secondary's own 0->1 / 1->0 suspend_count
transition, so each group member contributes exactly one suspend
reference to the primary: the primary keeps its GuC context disabled
until every member that suspended it has resumed, including across the
resume-all-queues-each-rebind-cycle behavior. group->suspend_lock makes
the secondary transition and the primary forward atomic, and a member
leaving while still suspended (queue teardown) drops its reference on
the primary.
v2: Add comment about suspend_wait() in drop_suspend()
v3: Do not suspend a secondary if primary is killed,
wait for primay suspend to complete before drop_suspend()
Assisted-by: Github-Copilot:Claude-opus-4.8
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260713202317.2187787-14-niranjana.vishwanathapura@intel.com
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With the lr.suspended flag a consumer already pairs its own suspend()
and resume() correctly, and no current path issues overlapping suspends
on the same queue.
Add a reference count to the exec queue suspend operations, as a small
self-contained building block for callers that can genuinely overlap.
A queue stays suspended as long as any caller holds a suspend and only
resumes once the last caller releases it, so each caller pairs its own
suspend/resume without needing to know about the others. This is what
the upcoming multi-queue support needs, where queues in a group share
a primary and may be suspended concurrently.
Assisted-by: GitHub_Copilot:claude-sonnet-4.6
Co-authored-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260713202317.2187787-13-niranjana.vishwanathapura@intel.com
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The hw engine group fault-mode switch suspends all faulting LR queues
but ignored the suspend()/suspend_wait() return value. A suspend() can
fail (e.g. the queue is killed/banned/wedged), leaving the queue
un-suspended, so silently continuing could later resume a queue that was
never suspended.
Propagate the failure instead: in xe_hw_engine_group_add_exec_queue()
bail out if suspend() fails, and in
xe_hw_engine_group_suspend_faulting_lr_jobs() undo the partial suspend
via a new err_resume path that resumes the sibling queues already
suspended in this call. Record per-queue success with lr.suspended so
only queues that were actually suspended are waited on and resumed, and
skip the cleanup resume() when suspend_wait() failed or the queue was
reset/killed/banned/wedged (its suspend may not have completed, so
resuming would trip the !suspend_pending assert in the resume path;
teardown resolves its state instead).
Gate the group resume worker (hw_engine_group_resume_lr_jobs_func()) on
lr.suspended for the same reason, so it only resumes queues that were
actually suspended.
v2: Don't let a dying queue block the switch (Matt Brost)
Assisted-by: Github-Copilot:Claude-opus-4.8
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260713202317.2187787-12-niranjana.vishwanathapura@intel.com
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Add a suspend_wait_blocking() exec queue op: an uninterruptible variant
of suspend_wait() for callers that must complete a suspend on behalf of a
queue that may belong to a different process than the calling task (e.g.
cleanup/undo paths). An interruptible suspend_wait() returns -ERESTARTSYS
when the calling task is signalled, which would leave the other process's
queue suspended forever - a cross-process DoS.
The blocking variant waits uninterruptibly and, on a genuine GuC timeout,
bans and tears down the queue like suspend_wait() (shared via
guc_exec_queue_suspend_timeout_ban()). It deliberately does not handle VF
recovery since a blocking caller cannot retry.
Assisted-by: Github-Copilot:Claude-opus-4.8
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260713202317.2187787-11-niranjana.vishwanathapura@intel.com
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Harden guc_exec_queue_suspend_wait():
- In multi-queue mode the primary owns the group's GuC scheduling
context, so wait on the primary's suspend to complete.
- On timeout, ban the queue and trigger cleanup rather than leaving it
suspended forever. Clearing suspend_pending via __suspend_fence_signal()
lets a subsequent resume() proceed without tripping the
!suspend_pending assert. A timeout on the primary wedges the whole
group, so ban and tear down the entire group in the multi-queue case.
The ban/cleanup is factored into guc_exec_queue_suspend_timeout_ban().
Add a note that on a signal (-ERESTARTSYS) the queue is not banned and
the suspend is not confirmed complete, so callers must not resume()
without re-confirming.
Assisted-by: Github-Copilot:Claude-opus-4.8
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260713202317.2187787-10-niranjana.vishwanathapura@intel.com
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A consumer-issued suspend() can fail (e.g. the queue is killed, banned
or wedged), leaving the queue un-suspended. The consumer must then not
issue the matching resume(): resuming a queue that was never suspended
is incorrect.
Add an lr.suspended flag to struct xe_exec_queue that records whether a
consumer suspend() succeeded and a matching resume() is still owed. Set
it on a successful suspend() in the preempt-fence path, clear it on
resume(), and only resume queues that have it set.
In resume_and_reinstall_preempt_fences() also skip queues that have
since been reset/killed/banned/wedged: such a queue's suspend may not
have completed (suspend_pending can still be set, e.g. a preempt fence
signalled with -ENOENT without waiting), so resuming it would trip the
!suspend_pending assert in the backend. Leave it marked suspended and
let teardown resolve its state.
A queue is only ever suspended by a single consumer at a time
(preempt-fence mode and hw engine group fault mode are mutually
exclusive), so a single flag is sufficient.
Assisted-by: Github-Copilot:Claude-opus-4.8
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patch.msgid.link/20260713202317.2187787-9-niranjana.vishwanathapura@intel.com
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With Zstd compression enabled ('perf record -z'), a single mmap push
whose compressed output exceeds the maximum record size makes
zstd_compress_stream_to_records() emit several PERF_RECORD_COMPRESSED2
records back to back. record__pushfn() however rewrote only the first
record's header to describe the whole blob as one record:
event->data_size = compressed - sizeof(struct perf_record_compressed2);
event->header.size = PERF_ALIGN(compressed, sizeof(u64));
padding = event->header.size - compressed;
...
record__write(rec, map, &pad, padding);
perf_event_header::size is a __u16, so once the compressed blob no
longer fits in it the header.size assignment truncates and 'padding'
(size_t) underflows. write() is then handed that bogus length and fails
with EFAULT, aborting the recording:
failed to write perf data, error: Bad address
The bytes that did reach the file are mis-framed, so reading it back
cannot be decompressed.
This is easy to hit with a high event rate and a large buffer, e.g.:
perf record -z -F max -m 32M --per-thread -- perf test -w thloop 5 1
The single-record fixup is wrong by construction: because header.size is
16 bits a compressed record cannot exceed 64KB, so the compressor must
split a push into a chain of records, and the session reader already
consumes them as such.
Frame each record where it is produced instead: make
process_comp_header() set the per-record data_size, 8-byte-align
header.size and zero the trailing padding, and let record__pushfn()
write the resulting blob, as the AIO path already does. Reduce
max_record_size by sizeof(u64) so the per-record alignment padding
cannot push header.size past its u16 field. process_comp_header()
returns -1 when that padding would not fit the space left in 'dst', so
the compressor stops instead of overrunning the output buffer.
There is no on-disk format change; a perf.data written by the fixed tool
is still read by existing perf.
Fixes: 208c0e168344 ("perf record: Add 8-byte aligned event type PERF_RECORD_COMPRESSED2")
Reported-by: Farid Zakaria <fmzakari@meta.com>
Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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process_comp_header() is called from zstd_compress_stream_to_records()
twice per record: once with data_size == 0 to write the record header,
and once with the payload size to finalize it. It returns the increment
it was passed, and the loop separately decides whether a record still
fits by comparing the remaining 'dst_size' against the header size.
With the fit check split from the code that writes the record,
process_comp_header() cannot reject a record on its own, so any bytes it
writes into 'dst' have to be bounds-checked by the caller instead of
where they are produced.
Pass the space left in 'dst' to process_comp_header(), let it return the
number of bytes written or -1 when the header does not fit, and account
the compressed payload in the loop.
No functional change intended.
Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The recent commit caused a failure in make build-test for static builds.
Let's not pass -static the option to dlfilters which is dynamically
loaded as it's hard-coded with -shared even for static builds.
Tested-by: Leo Yan <leo.yan@arm.com>
Cc: Trevor Allison <tallison@redhat.com>
Fixes: e1065ed188cf ("perf build: Add LDFLAGS to dlfilters .so link")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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resctrl provides files under the info/ directory to expose global
configuration and capabilities to userspace. These files are instantiated
statically during filesystem mount and expose data associated with internal
schema structures via kernfs private pointers.
A potential deadlock exists between userspace readers of these info files
and the unmount filesystem teardown process. Reading an info file invokes
kernfs which acquires an active reference, after which the handler typically
attempts to acquire the rdtgroup_mutex.
Concurrently, unmounting the filesystem holds the rdtgroup_mutex and then
attempts to recursively remove the info kernfs nodes involving kernfs_drain()
which blocks until all active references are released.
Another problem exists where info files might be accessed from an outdated
mount if the filesystem is unmounted and remounted during a reader's
execution, leading to a use-after-free when reading the now-deleted private
schema data.
Introduce info_kn_lock() and info_kn_unlock() helpers to coordinate locking
across all info handlers. These helpers mirror similar logic used by resource
group handlers by deliberately breaking the kernfs active protection before
attempting to acquire the rdtgroup_mutex, preventing the deadlock.
To guard against the vulnerability from rapid mount cycling, info_kn_lock()
securely walks the parent lineage of the kernfs node under an RCU section to
confirm the node belongs to the globally active root before permitting the
operation to proceed. Convert all info file handlers to use this helper and
only de-reference the schema after it is determined safe to do so.
Make no attempt to output an error message to last_cmd_status on failure
since failure implies there is no filesystem with which to display the error
to user space.
[ bp: Massage commit message. ]
Closes: https://sashiko.dev/#/patchset/20260515193944.15114-1-tony.luck%40intel.com?part=3
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: GitHub_Copilot:gemini-3.1-pro
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://patch.msgid.link/0b5238486bd058704d908d39a75aff2815bd18aa.1783963505.git.reinette.chatre@intel.com
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A struct rdtgroup is reference counted via rdtgroup::waitcount. Callers that
need the structure to remain valid across a sleep (while waiting on acquiring
rdtgroup_mutex) take a reference with rdtgroup_kn_get() and release it with
rdtgroup_kn_put().
The release path is intended to serve as the fallback freer: if the count
drops to zero and the group has already been marked RDT_DELETED,
rdtgroup_kn_put() frees the structure.
The bulk teardown paths free_all_child_rdtgrp() and rmdir_all_sub() resulting
from a resctrl directory remove or resctrl fs unmount act as the primary
freer: they hold rdtgroup_mutex and free each rdtgroup whose waitcount is
zero, otherwise they set RDT_DELETED and leave the freeing to the last waiter.
These two freers race. rdtgroup_kn_put() commits waitcount == 0 with
atomic_dec_and_test() outside rdtgroup_mutex, then reads rdtgroup::flags.
Between those two operations a concurrent caller of free_all_child_rdtgrp()
or rmdir_all_sub() (which holds the mutex) can observe waitcount == 0 via
atomic_read(), call rdtgroup_remove(), and kfree() the structure.
The subsequent read of rdtgroup::flags in rdtgroup_kn_put() is then
a use-after-free, and the structure may even be freed twice if the freed
memory happens to satisfy the RDT_DELETED flag check.
Replace the bare atomic_dec_and_test() with atomic_dec_and_mutex_lock() so
that the decrement-to-zero takes rdtgroup_mutex before the count becomes
globally visible. The inspection of rdtgroup::flags then runs under the same
mutex held by the bulk freers, making the two paths mutually exclusive.
The common case where the count does not reach zero remains lock-free. Defer
kernfs_unbreak_active_protection() until after the mutex is dropped since
kernfs active protections functionally wrap rdtgroup_mutex. Remove resource
group, which in turn drops its kernfs reference, after kernfs protection is
restored.
[ bp: Split the commit messsages into smaller, easier-parseable paragraphs. ]
Fixes: b8511ccc75c0 ("x86/resctrl: Fix use-after-free when deleting resource groups")
Closes: https://sashiko.dev/#/patchset/20260515193944.15114-1-tony.luck%40intel.com?part=1
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: GitHub_Copilot:gemini-3.1-pro
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://patch.msgid.link/8d028bbea582dc382a4cc166b235f75bd5901aea.1783963505.git.reinette.chatre@intel.com
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intel_engine_user.c checks CONFIG_DRM_I915_SELFTESTS before running
the engine UABI isolation check. Kconfig defines DRM_I915_SELFTEST,
without the trailing "S", and the rest of i915 uses
CONFIG_DRM_I915_SELFTEST.
Because CONFIG_DRM_I915_SELFTESTS is not backed by any Kconfig symbol,
the IS_ENABLED() test is always false. Use the existing selftest symbol
so the debug/selftest guarded path can be reached when selftests are
enabled.
This is a source-level fix. It does not claim dynamic hardware
reproduction; the evidence is the Kconfig definition and the inconsistent
guard in intel_engine_user.c.
Fixes: 750e76b4f9f6 ("drm/i915/gt: Move the [class][inst] lookup for engines onto the GT")
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Link: https://lore.kernel.org/r/20260705080225.436-1-pengpeng@iscas.ac.cn
(cherry picked from commit 14a2012a490258f3f93857bc4f1b203405964be7)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
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rdt_get_tree() acquires rdtgroup_mutex before calling kernfs_get_tree(). If
superblock setup fails inside kernfs_get_tree(), the VFS calls .kill_sb()
(rdt_kill_sb()) on the same thread before kernfs_get_tree() returns.
rdt_kill_sb() unconditionally attempts to acquire rdtgroup_mutex and
deadlock occurs.
Since mount failure resulting from kernfs_get_tree() already calls the
resctrl fs unmount handler (rdt_kill_sb()) let both call the same helper
to make it clear both paths perform the same cleanup.
Call kernfs_get_tree() outside of locks. If kernfs_get_tree() fails and
ctx->kfc.new_sb_created is set, then rdt_kill_sb() has already been called
and no further cleanup is needed.
kernfs_get_tree() may set ctx->kfc.new_sb_created and then fail to obtain
an inode for the new kn, causing the rdt_kill_sb() path to run with one fewer
reference than required for the root to remain accessible in kernfs_kill_sb().
Add an extra hold on rdtgroup_default.kn to defend against this scenario
and ensure the root can be dereferenced safely from kernfs_kill_sb().
Dropping locks before kernfs_get_tree() creates a window where CPU hotplug
callbacks can race with the mount operation. Specifically, an online event
observing resctrl_mounted == true could concurrently append directories to
the unactivated kernfs tree, allocate mon_data structures, and arm background
workers.
This concurrency is safe because the mount has not yet returned to the VFS,
meaning userspace cannot interact with these transient files. If
kernfs_get_tree() subsequently fails, the standard resctrl_unmount() teardown
safely manages the concurrent modifications: any dynamically generated kernfs
nodes are removed, and the associated memory is freed. Any background
workers spawned by the hotplug event will naturally exit without re-arming
when they acquire rdtgroup_mutex and observe resctrl_mounted == false.
Fixes: 5ff193fbde20 ("x86/intel_rdt: Add basic resctrl filesystem support")
Closes: https://sashiko.dev/#/patchset/20260429184858.36423-1-tony.luck%40intel.com [1]
Reported-by: Sashiko <sashiko-bot@kernel.org>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Chen Yu <yu.c.chen@intel.com>
Link: https://patch.msgid.link/fe701825d7f538a6bbac6732230004050300c93e.1783963505.git.reinette.chatre@intel.com
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Remove pointless declaration of "bio" and initialization using
"dm_bio_from_per_bio_data". The variable "bio" is already declared and
initialized in the upper block.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4.6
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Fix spelling: impementation -> implementation.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4.6
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The condition "remaining <= 0" can never be true. The variable remaining
has type size_t, thus it can't be negative. It can't be zero because we
made sure earlier that "remaining > sizeof(struct dm_target_spec)" and
then we added "sizeof(struct dm_target_spec)" to "outptr" (this means
that we subtraceted "sizeof(struct dm_target_spec)" from "remaining").
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4.6
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If dm_integrity_map_inline returned DM_MAPIO_KILL, the code would set
status BLK_STS_IOERR and then incorrectly fall through and submit the
bio. Luckily, dm_integrity_map_inline can't return DM_MAPIO_KILL at this
point, so the bug is just theoretical.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4.6
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Add "goto bad" to error handling. This commit doesn't fix any bug, just
cleans up the code.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4.6
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Change "reading tags" to "writing tags" because the error is reported
when writing fails.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4.6
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