<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/linux/pgtable.h, branch v7.2-rc1</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2026-06-17T08:18:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-17T08:18:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9c87e61e3c5797277407ba5eae4eac8a52be3fa3'/>
<id>9c87e61e3c5797277407ba5eae4eac8a52be3fa3</id>
<content type='text'>
Pull bpf updates from Alexei Starovoitov:
 "Major changes:

   - Recover from BPF arena page faults using a scratch page and add
     ptep_try_set() for lockless empty-slot installs on x86 and arm64.

     This allows BPF kfuncs to access arena pointers directly.

     The 'arena_direct_access' stable branch was created for this work
     and was pulled into sched-ext and bpf-next trees (Tejun Heo, Kumar
     Kartikeya Dwivedi)

   - Lift old restriction and support 6+ arguments in BPF programs and
     kfuncs on x86 and arm64 (Yonghong Song, Puranjay Mohan)

  Other features and fixes:

   - Add 24-bit BTF vlen and reclaim unused bits in the BTF UAPI to ease
     addition of new BTF kinds (Alan Maguire)

   - Raise the maximum BPF call chain depth from 8 to 16 frames (Alexei
     Starovoitov)

   - Refactor object relationship tracking in the verifier and fix a
     dynptr use-after-free bug (Amery Hung)

   - Harden the signed program loader and reject exclusive maps as inner
     maps (Daniel Borkmann)

   - Replace the verifier min/max bounds fields with a circular number
     (cnum) representation and improve 32-&gt;64 bit range refinements
     (Eduard Zingerman)

   - Introduce the arena library and runtime (libarena) with a buddy
     allocator, rbtree and SPMC queue data structures, ASAN support and
     a parallel test harness. Allow subprograms to return arena pointers
     and switch to a BTF type-tag based __arena annotation (Emil
     Tsalapatis)

   - Cache build IDs in the sleepable stackmap path and avoid faultable
     build ID reads under mm locks (Ihor Solodrai)

   - Introduce the tracing_multi link to attach a single BPF program to
     many kernel functions at once. Allow specifying the uprobe_multi
     target via FD (Jiri Olsa)

   - Extend the bpf_list family of kfuncs with bpf_list_add/del(), and
     bpf_list_is_first/is_last/empty() (Kaitao Cheng)

   - Extend the BPF syscall with common attributes support for
     prog_load, btf_load and map_create (Leon Hwang)

   - Wrap rhashtable as BPF map (Mykyta Yatsenko, Herbert Xu)

   - Add sleepable support for tracepoint programs and fix deadlocks in
     LRU map due to NMI reentry (Mykyta Yatsenko)

   - Fix OOB access in bpf_flow_keys, fix nullness analysis of inner
     arrays, enforce write checks for global subprograms (Nuoqi Gui)

   - Report the maximum combined stack depth and print a breakdown of
     instructions processed per subprogram (Paul Chaignon)

   - Add an XDP load-balancer benchmark and arm64 JIT support for stack
     arguments (Puranjay Mohan)

   - Add kfuncs to traverse over wakeup_sources (Samuel Wu)

   - Allow sleepable BPF programs to use LPM trie maps directly (Vlad
     Poenaru)

   - Many more fixes and cleanups across the verifier, BTF, sockmap,
     devmap, bpffs, security hooks, s390/riscv/loongarch JITs,
     rqspinlock, libbpf, bpftool, selftests"

* tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (336 commits)
  selftests/bpf: Work around llvm stack overflow in crypto progs
  selftests/bpf: add test for bpf_msg_pop_data() overflow
  bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check
  sockmap: Fix use-after-free in udp_bpf_recvmsg()
  bpf, sockmap: keep sk_msg copy state in sync
  bpf, sockmap: Fix wrong rsge offset in bpf_msg_push_data()
  bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data()
  selftsets/bpf: Retry map update on helper_fill_hashmap()
  selftests/bpf: Add test for sleepable lsm_cgroup rejection
  selftests/bpf: Add test to verify the fix for bpf_setsockopt() helper
  bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket
  selftests/bpf: Avoid static LLVM linking for cross builds
  selftests/bpf: Use common CFLAGS for urandom_read
  selftests/bpf: Initialize operation name before use
  tools/bpf: build: Append extra cflags
  libbpf: Initialize CFLAGS before including Makefile.include
  bpftool: Append extra host flags
  bpftool: Avoid adding EXTRA_CFLAGS to HOST_CFLAGS
  bpftool: Pass host flags to bootstrap libbpf
  selftests/bpf: correct CONFIG_PPC64 macro name in comment
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bpf updates from Alexei Starovoitov:
 "Major changes:

   - Recover from BPF arena page faults using a scratch page and add
     ptep_try_set() for lockless empty-slot installs on x86 and arm64.

     This allows BPF kfuncs to access arena pointers directly.

     The 'arena_direct_access' stable branch was created for this work
     and was pulled into sched-ext and bpf-next trees (Tejun Heo, Kumar
     Kartikeya Dwivedi)

   - Lift old restriction and support 6+ arguments in BPF programs and
     kfuncs on x86 and arm64 (Yonghong Song, Puranjay Mohan)

  Other features and fixes:

   - Add 24-bit BTF vlen and reclaim unused bits in the BTF UAPI to ease
     addition of new BTF kinds (Alan Maguire)

   - Raise the maximum BPF call chain depth from 8 to 16 frames (Alexei
     Starovoitov)

   - Refactor object relationship tracking in the verifier and fix a
     dynptr use-after-free bug (Amery Hung)

   - Harden the signed program loader and reject exclusive maps as inner
     maps (Daniel Borkmann)

   - Replace the verifier min/max bounds fields with a circular number
     (cnum) representation and improve 32-&gt;64 bit range refinements
     (Eduard Zingerman)

   - Introduce the arena library and runtime (libarena) with a buddy
     allocator, rbtree and SPMC queue data structures, ASAN support and
     a parallel test harness. Allow subprograms to return arena pointers
     and switch to a BTF type-tag based __arena annotation (Emil
     Tsalapatis)

   - Cache build IDs in the sleepable stackmap path and avoid faultable
     build ID reads under mm locks (Ihor Solodrai)

   - Introduce the tracing_multi link to attach a single BPF program to
     many kernel functions at once. Allow specifying the uprobe_multi
     target via FD (Jiri Olsa)

   - Extend the bpf_list family of kfuncs with bpf_list_add/del(), and
     bpf_list_is_first/is_last/empty() (Kaitao Cheng)

   - Extend the BPF syscall with common attributes support for
     prog_load, btf_load and map_create (Leon Hwang)

   - Wrap rhashtable as BPF map (Mykyta Yatsenko, Herbert Xu)

   - Add sleepable support for tracepoint programs and fix deadlocks in
     LRU map due to NMI reentry (Mykyta Yatsenko)

   - Fix OOB access in bpf_flow_keys, fix nullness analysis of inner
     arrays, enforce write checks for global subprograms (Nuoqi Gui)

   - Report the maximum combined stack depth and print a breakdown of
     instructions processed per subprogram (Paul Chaignon)

   - Add an XDP load-balancer benchmark and arm64 JIT support for stack
     arguments (Puranjay Mohan)

   - Add kfuncs to traverse over wakeup_sources (Samuel Wu)

   - Allow sleepable BPF programs to use LPM trie maps directly (Vlad
     Poenaru)

   - Many more fixes and cleanups across the verifier, BTF, sockmap,
     devmap, bpffs, security hooks, s390/riscv/loongarch JITs,
     rqspinlock, libbpf, bpftool, selftests"

* tag 'bpf-next-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (336 commits)
  selftests/bpf: Work around llvm stack overflow in crypto progs
  selftests/bpf: add test for bpf_msg_pop_data() overflow
  bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check
  sockmap: Fix use-after-free in udp_bpf_recvmsg()
  bpf, sockmap: keep sk_msg copy state in sync
  bpf, sockmap: Fix wrong rsge offset in bpf_msg_push_data()
  bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data()
  selftsets/bpf: Retry map update on helper_fill_hashmap()
  selftests/bpf: Add test for sleepable lsm_cgroup rejection
  selftests/bpf: Add test to verify the fix for bpf_setsockopt() helper
  bpf: Fix bpf_get/setsockopt to tos for ipv4-mapped ipv6 socket
  selftests/bpf: Avoid static LLVM linking for cross builds
  selftests/bpf: Use common CFLAGS for urandom_read
  selftests/bpf: Initialize operation name before use
  tools/bpf: build: Append extra cflags
  libbpf: Initialize CFLAGS before including Makefile.include
  bpftool: Append extra host flags
  bpftool: Avoid adding EXTRA_CFLAGS to HOST_CFLAGS
  bpftool: Pass host flags to bootstrap libbpf
  selftests/bpf: correct CONFIG_PPC64 macro name in comment
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'arm64-upstream' of gitolite.kernel.org:pub/scm/linux/kernel/git/arm64/linux</title>
<updated>2026-06-15T23:48:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-06-15T23:48:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=80476f22b8b7e193b26f285a7c9f9e4b63abca16'/>
<id>80476f22b8b7e193b26f285a7c9f9e4b63abca16</id>
<content type='text'>
Pull arm64 updates from Will Deacon:
 "It feels like the new world of AI tooling has slowed us down a little
  on the feature side when compared to the fixes side. The extra rounds
  of Sashiko review have also pushed a few things out until next time.

  Still, there's some good foundational stuff here for the fpsimd code
  and hardening work towards removing the predictable linear alias of
  the kernel image.

  CPU errata handling:
   - Extend CnP disabling workaround to HiSilicon HIP09 hardware.
   - Work around eternally broken broadcast TLB invalidation on more
     CPUs.
   - Documentation and code cleanups.

  CPU features:
   - Add new hwcaps for the 2025 dpISA extensions.

  Floating point / SVE / SME:
   - Significant cleanup to the low-level state management code in the
     core architecture code and KVM.
   - Use correct register widths during SVE/SME save/restore assembly.
   - Expose SVE/SME save/restore memory accesses to sanitisers.

  Memory management:
   - Preparatory work for unmapping the kernel data and bss sections
     from the linear map.

  Miscellaneous:
   - Inline DAIF manipulation helpers so they can be used safely from
     non-instrumentable code.
   - Fix handling of the 'nosmp' cmdline option to avoid marking
     secondary cores as "possible".

  MPAM:
   - Add support for v0.1 of the MPAM architecture.

  Perf:
   - Update HiSilicon PMU MAINTAINERS entry.
   - Fix event encodings for the DVM node in the CMN driver.

  Selftests:
   - Extend sigframe tests to cover POE context.
   - Add coverage for the newly added 2025 dpISA hwcaps.

  System registers:
   - Add new registers and ESR encodings for the HDBSS feature.

  Plus minor fixes and cleanups across the board"

* tag 'arm64-upstream' of gitolite.kernel.org:pub/scm/linux/kernel/git/arm64/linux: (73 commits)
  arm64: errata: Mitigate TLBI errata on Microsoft Azure Cobalt 100 CPU
  arm64: errata: Mitigate TLBI errata on NVIDIA Olympus CPU
  arm64: errata: Mitigate TLBI errata on various Arm CPUs
  arm64: cputype: Add C1-Premium definitions
  arm64: cputype: Add C1-Ultra definitions
  Revert "arm64: mm: Unmap kernel data/bss entirely from the linear map"
  Revert "arm64: mm: Defer remap of linear alias of data/bss"
  arm64: arch_timer: reuse arch_timer_read_cnt{p,v}ct_el0() helpers
  arm64/mm: Rename ptdesc_t
  arm64: mm: Defer remap of linear alias of data/bss
  KVM: arm64: Omit tag sync on stage-2 mappings of the zero page
  arm64: Avoid double evaluation of __ptep_get()
  kasan: Move generic KASAN page tables out of BSS too
  arm64: Rename page table BSS section to .bss..pgtbl
  arm64: patching: replace min_t with min in __text_poke
  perf/arm-cmn: Fix DVM node events
  arm64: fpsimd: Remove &lt;asm/fpsimdmacros.h&gt;
  arm64: fpsimd: Move SME save/restore inline
  arm64: fpsimd: Move sve_flush_live() inline
  arm64: fpsimd: Move SVE save/restore inline
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull arm64 updates from Will Deacon:
 "It feels like the new world of AI tooling has slowed us down a little
  on the feature side when compared to the fixes side. The extra rounds
  of Sashiko review have also pushed a few things out until next time.

  Still, there's some good foundational stuff here for the fpsimd code
  and hardening work towards removing the predictable linear alias of
  the kernel image.

  CPU errata handling:
   - Extend CnP disabling workaround to HiSilicon HIP09 hardware.
   - Work around eternally broken broadcast TLB invalidation on more
     CPUs.
   - Documentation and code cleanups.

  CPU features:
   - Add new hwcaps for the 2025 dpISA extensions.

  Floating point / SVE / SME:
   - Significant cleanup to the low-level state management code in the
     core architecture code and KVM.
   - Use correct register widths during SVE/SME save/restore assembly.
   - Expose SVE/SME save/restore memory accesses to sanitisers.

  Memory management:
   - Preparatory work for unmapping the kernel data and bss sections
     from the linear map.

  Miscellaneous:
   - Inline DAIF manipulation helpers so they can be used safely from
     non-instrumentable code.
   - Fix handling of the 'nosmp' cmdline option to avoid marking
     secondary cores as "possible".

  MPAM:
   - Add support for v0.1 of the MPAM architecture.

  Perf:
   - Update HiSilicon PMU MAINTAINERS entry.
   - Fix event encodings for the DVM node in the CMN driver.

  Selftests:
   - Extend sigframe tests to cover POE context.
   - Add coverage for the newly added 2025 dpISA hwcaps.

  System registers:
   - Add new registers and ESR encodings for the HDBSS feature.

  Plus minor fixes and cleanups across the board"

* tag 'arm64-upstream' of gitolite.kernel.org:pub/scm/linux/kernel/git/arm64/linux: (73 commits)
  arm64: errata: Mitigate TLBI errata on Microsoft Azure Cobalt 100 CPU
  arm64: errata: Mitigate TLBI errata on NVIDIA Olympus CPU
  arm64: errata: Mitigate TLBI errata on various Arm CPUs
  arm64: cputype: Add C1-Premium definitions
  arm64: cputype: Add C1-Ultra definitions
  Revert "arm64: mm: Unmap kernel data/bss entirely from the linear map"
  Revert "arm64: mm: Defer remap of linear alias of data/bss"
  arm64: arch_timer: reuse arch_timer_read_cnt{p,v}ct_el0() helpers
  arm64/mm: Rename ptdesc_t
  arm64: mm: Defer remap of linear alias of data/bss
  KVM: arm64: Omit tag sync on stage-2 mappings of the zero page
  arm64: Avoid double evaluation of __ptep_get()
  kasan: Move generic KASAN page tables out of BSS too
  arm64: Rename page table BSS section to .bss..pgtbl
  arm64: patching: replace min_t with min in __text_poke
  perf/arm-cmn: Fix DVM node events
  arm64: fpsimd: Remove &lt;asm/fpsimdmacros.h&gt;
  arm64: fpsimd: Move SME save/restore inline
  arm64: fpsimd: Move sve_flush_live() inline
  arm64: fpsimd: Move SVE save/restore inline
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: Refactor lazy_mmu_mode_pause() and lazy_mmu_mode_resume()</title>
<updated>2026-06-08T07:21:06+00:00</updated>
<author>
<name>Juergen Gross</name>
<email>jgross@suse.com</email>
</author>
<published>2026-05-26T15:05:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=811f0d8caa407b7acd8d1ff9e2dd69835a7b3d9a'/>
<id>811f0d8caa407b7acd8d1ff9e2dd69835a7b3d9a</id>
<content type='text'>
In order to allow pausing and resuming MMU lazy mode for other tasks
than current, refactor lazy_mmu_mode_pause() and
lazy_mmu_mode_resume().

This will be needed when dropping the Xen PV private lazy MMU
bookkeeping.

Acked-by: "David Hildenbrand (Arm)" &lt;david@kernel.org&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Message-ID: &lt;20260526150514.129330-4-jgross@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In order to allow pausing and resuming MMU lazy mode for other tasks
than current, refactor lazy_mmu_mode_pause() and
lazy_mmu_mode_resume().

This will be needed when dropping the Xen PV private lazy MMU
bookkeeping.

Acked-by: "David Hildenbrand (Arm)" &lt;david@kernel.org&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Message-ID: &lt;20260526150514.129330-4-jgross@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Replace scratch PTE atomically when allocating arena pages</title>
<updated>2026-06-05T15:22:36+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2026-06-01T18:37:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f64c723741c911544cca4c838d7a291b06b3ad1d'/>
<id>f64c723741c911544cca4c838d7a291b06b3ad1d</id>
<content type='text'>
apply_range_set_cb() maps the pages for a new arena allocation and returned
-EBUSY when the target PTE was already populated. Kernel-fault recovery
leaves the per-arena scratch page in unallocated arena PTEs, so a later
bpf_arena_alloc_pages() over such a page hits that -EBUSY, and every
subsequent allocation of it fails the same way. Allocation must install the
real page over scratch instead.

Overwriting the scratch PTE in place is a valid-&gt;valid change, which arm64
forbids without break-before-make. Route through an invalid entry instead:
ptep_try_set() fills only a none slot, so the PTE goes scratch-&gt;none-&gt;page.
On finding scratch, clear it and flush_tlb_before_set() before retrying. The
new flush_tlb_before_set() is a no-op except on arches like arm64 that need
the break-before-make TLB invalidate. The loop also copes with a concurrent
fault re-scratching the slot.

Arches without ptep_try_set() never install the scratch page, so keep the
must-be-empty check and set_pte_at() for them.

Fixes: dc11a4dba246 ("bpf: Recover arena kernel faults with scratch page")
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: David Hildenbrand &lt;david@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/r/20260601183728.1800490-1-tj@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
apply_range_set_cb() maps the pages for a new arena allocation and returned
-EBUSY when the target PTE was already populated. Kernel-fault recovery
leaves the per-arena scratch page in unallocated arena PTEs, so a later
bpf_arena_alloc_pages() over such a page hits that -EBUSY, and every
subsequent allocation of it fails the same way. Allocation must install the
real page over scratch instead.

Overwriting the scratch PTE in place is a valid-&gt;valid change, which arm64
forbids without break-before-make. Route through an invalid entry instead:
ptep_try_set() fills only a none slot, so the PTE goes scratch-&gt;none-&gt;page.
On finding scratch, clear it and flush_tlb_before_set() before retrying. The
new flush_tlb_before_set() is a no-op except on arches like arm64 that need
the break-before-make TLB invalidate. The loop also copes with a concurrent
fault re-scratching the slot.

Arches without ptep_try_set() never install the scratch page, so keep the
must-be-empty check and set_pte_at() for them.

Fixes: dc11a4dba246 ("bpf: Recover arena kernel faults with scratch page")
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: David Hildenbrand &lt;david@kernel.org&gt;
Acked-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/r/20260601183728.1800490-1-tj@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: Make empty_zero_page[] const</title>
<updated>2026-06-02T15:29:16+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2026-05-29T15:02:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0aae825f1ed7ce3eedfadc54684aa86bbbe188b0'/>
<id>0aae825f1ed7ce3eedfadc54684aa86bbbe188b0</id>
<content type='text'>
The empty zero page is used to back any kernel or user space mapping
that is supposed to remain cleared, and so the page itself is never
supposed to be modified.

So mark it as const, which moves it into .rodata rather than .bss: on
most architectures, this ensures that both the kernel's mapping of it
and any aliases that are accessible via the kernel direct (linear) map
are mapped read-only, and cannot be used (inadvertently or maliciously)
to corrupt the contents of the zero page.

Reviewed-by: Mike Rapoport (Microsoft) &lt;rppt@kernel.org&gt;
Reviewed-by: Kevin Brodsky &lt;kevin.brodsky@arm.com&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Reviewed-by: Jann Horn &lt;jannh@google.com&gt;
Reviewed-by: Feng Tang &lt;feng.tang@linux.alibaba.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The empty zero page is used to back any kernel or user space mapping
that is supposed to remain cleared, and so the page itself is never
supposed to be modified.

So mark it as const, which moves it into .rodata rather than .bss: on
most architectures, this ensures that both the kernel's mapping of it
and any aliases that are accessible via the kernel direct (linear) map
are mapped read-only, and cannot be used (inadvertently or maliciously)
to corrupt the contents of the zero page.

Reviewed-by: Mike Rapoport (Microsoft) &lt;rppt@kernel.org&gt;
Reviewed-by: Kevin Brodsky &lt;kevin.brodsky@arm.com&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Reviewed-by: Jann Horn &lt;jannh@google.com&gt;
Reviewed-by: Feng Tang &lt;feng.tang@linux.alibaba.com&gt;
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: Add ptep_try_set() for lockless empty-slot installs</title>
<updated>2026-05-23T08:50:32+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2026-05-22T17:22:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=258df8fce42fecc23cd04242de3d39f1fe836433'/>
<id>258df8fce42fecc23cd04242de3d39f1fe836433</id>
<content type='text'>
Add ptep_try_set(ptep, new_pte): atomically set *ptep to new_pte iff it is
currently pte_none(). Returns true on success, false if the slot was already
populated or the arch has no implementation.

The intended caller is the upcoming bpf_arena kernel-side fault recovery
path. The install runs from a page fault that can be nested under locks
held by the faulting kernel caller (e.g. a BPF program holding
raw_res_spin_lock_irqsave on its arena's spinlock), so trylock-and-retry
would A-A deadlock. Lock-free cmpxchg is the only viable option, which
constrains this helper to special kernel page tables where concurrent
writers cooperate via atomic accessors.

The generic version in &lt;linux/pgtable.h&gt; returns false. x86 and arm64
override with try_cmpxchg-based implementations on the underlying pteval.
Other architectures get the false stub - the callers there already fall
through to oops.

v2: Rename to ptep_try_set(). Tighten kerneldoc. (David, Alexei)
v3: Note that strict-zero cmpxchg is narrower than pte_none(). (Andrea)

Suggested-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Suggested-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Andrea Righi &lt;arighi@nvidia.com&gt;
Cc: David Hildenbrand &lt;david@kernel.org&gt;
Acked-by: David Hildenbrand (arm) &lt;david@kernel.org&gt;
Link: https://lore.kernel.org/r/20260522172219.1423324-2-tj@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add ptep_try_set(ptep, new_pte): atomically set *ptep to new_pte iff it is
currently pte_none(). Returns true on success, false if the slot was already
populated or the arch has no implementation.

The intended caller is the upcoming bpf_arena kernel-side fault recovery
path. The install runs from a page fault that can be nested under locks
held by the faulting kernel caller (e.g. a BPF program holding
raw_res_spin_lock_irqsave on its arena's spinlock), so trylock-and-retry
would A-A deadlock. Lock-free cmpxchg is the only viable option, which
constrains this helper to special kernel page tables where concurrent
writers cooperate via atomic accessors.

The generic version in &lt;linux/pgtable.h&gt; returns false. x86 and arm64
override with try_cmpxchg-based implementations on the underlying pteval.
Other architectures get the false stub - the callers there already fall
through to oops.

v2: Rename to ptep_try_set(). Tighten kerneldoc. (David, Alexei)
v3: Note that strict-zero cmpxchg is narrower than pte_none(). (Andrea)

Suggested-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Suggested-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Andrea Righi &lt;arighi@nvidia.com&gt;
Cc: David Hildenbrand &lt;david@kernel.org&gt;
Acked-by: David Hildenbrand (arm) &lt;david@kernel.org&gt;
Link: https://lore.kernel.org/r/20260522172219.1423324-2-tj@kernel.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: change to return bool for pmdp_clear_flush_young()</title>
<updated>2026-04-05T20:53:35+00:00</updated>
<author>
<name>Baolin Wang</name>
<email>baolin.wang@linux.alibaba.com</email>
</author>
<published>2026-03-21T06:42:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2d46a397472191a10b0df294d64da542bfd1de57'/>
<id>2d46a397472191a10b0df294d64da542bfd1de57</id>
<content type='text'>
The pmdp_clear_flush_young() is used to clear the young flag and flush the
TLB, returning whether the young flag was set for this PMD entry.  Change
the return type to bool to make the intention clearer.

Link: https://lkml.kernel.org/r/a668b9a974c0d675e7a41f6973bcbe3336e8b373.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The pmdp_clear_flush_young() is used to clear the young flag and flush the
TLB, returning whether the young flag was set for this PMD entry.  Change
the return type to bool to make the intention clearer.

Link: https://lkml.kernel.org/r/a668b9a974c0d675e7a41f6973bcbe3336e8b373.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: change to return bool for pmdp_test_and_clear_young()</title>
<updated>2026-04-05T20:53:35+00:00</updated>
<author>
<name>Baolin Wang</name>
<email>baolin.wang@linux.alibaba.com</email>
</author>
<published>2026-03-21T06:42:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=42e26354c4ef28772398b1d71b7477834037305c'/>
<id>42e26354c4ef28772398b1d71b7477834037305c</id>
<content type='text'>
Callers use pmdp_test_and_clear_young() to clear the young flag and check
whether it was set for this PMD entry.  Change the return type to bool to
make the intention clearer.

Link: https://lkml.kernel.org/r/f1d31307a13365d3d0fed5809727dcc2dd59631b.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Callers use pmdp_test_and_clear_young() to clear the young flag and check
whether it was set for this PMD entry.  Change the return type to bool to
make the intention clearer.

Link: https://lkml.kernel.org/r/f1d31307a13365d3d0fed5809727dcc2dd59631b.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: change to return bool for ptep_clear_flush_young()/clear_flush_young_ptes()</title>
<updated>2026-04-05T20:53:35+00:00</updated>
<author>
<name>Baolin Wang</name>
<email>baolin.wang@linux.alibaba.com</email>
</author>
<published>2026-03-21T06:42:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=06c4dfa3ced61635895d0e258da8dc63da539f42'/>
<id>06c4dfa3ced61635895d0e258da8dc63da539f42</id>
<content type='text'>
The ptep_clear_flush_young() and clear_flush_young_ptes() are used to
clear the young flag and flush the TLB, returning whether the young flag
was set.  Change the return type to bool to make the intention clearer.

Link: https://lkml.kernel.org/r/24af5144b96103631594501f77d4525f2475c1be.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ptep_clear_flush_young() and clear_flush_young_ptes() are used to
clear the young flag and flush the TLB, returning whether the young flag
was set.  Change the return type to bool to make the intention clearer.

Link: https://lkml.kernel.org/r/24af5144b96103631594501f77d4525f2475c1be.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: change to return bool for ptep_test_and_clear_young()</title>
<updated>2026-04-05T20:53:35+00:00</updated>
<author>
<name>Baolin Wang</name>
<email>baolin.wang@linux.alibaba.com</email>
</author>
<published>2026-03-21T06:42:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a62ca3f40feaaaf0dfc4db1f2edeca5a70f4123d'/>
<id>a62ca3f40feaaaf0dfc4db1f2edeca5a70f4123d</id>
<content type='text'>
Patch series "change young flag check functions to return bool", v2.

This is a cleanup patchset to change all young flag check functions to
return bool, as discussed with David in the previous thread[1].  Since
callers only care about whether the young flag was set, returning bool
makes the intention clearer.  No functional changes intended.


This patch (of 6):

Callers use ptep_test_and_clear_young() to clear the young flag and check
whether it was set.  Change the return type to bool to make the intention
clearer.

Link: https://lkml.kernel.org/r/cover.1774075004.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/57e70efa9703d43959aa645246ea3cbdba14fa17.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch series "change young flag check functions to return bool", v2.

This is a cleanup patchset to change all young flag check functions to
return bool, as discussed with David in the previous thread[1].  Since
callers only care about whether the young flag was set, returning bool
makes the intention clearer.  No functional changes intended.


This patch (of 6):

Callers use ptep_test_and_clear_young() to clear the young flag and check
whether it was set.  Change the return type to bool to make the intention
clearer.

Link: https://lkml.kernel.org/r/cover.1774075004.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/57e70efa9703d43959aa645246ea3cbdba14fa17.1774075004.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang &lt;baolin.wang@linux.alibaba.com&gt;
Reviewed-by: Ritesh Harjani (IBM) &lt;ritesh.list@gmail.com&gt;
Reviewed-by: Lorenzo Stoakes (Oracle) &lt;ljs@kernel.org&gt;
Acked-by: David Hildenbrand (Arm) &lt;david@kernel.org&gt;
Cc: Liam Howlett &lt;liam.howlett@oracle.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Mike Rapoport &lt;rppt@kernel.org&gt;
Cc: Suren Baghdasaryan &lt;surenb@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
