<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include, branch v7.0-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2026-03-01T23:34:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-01T23:34:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=949d0a46ad1b9ab3450fb6ed69ff1e3e13c657bd'/>
<id>949d0a46ad1b9ab3450fb6ed69ff1e3e13c657bd</id>
<content type='text'>
Pull kvm fixes from Paolo Bonzini:
 "Arm:

   - Make sure we don't leak any S1POE state from guest to guest when
     the feature is supported on the HW, but not enabled on the host

   - Propagate the ID registers from the host into non-protected VMs
     managed by pKVM, ensuring that the guest sees the intended feature
     set

   - Drop double kern_hyp_va() from unpin_host_sve_state(), which could
     bite us if we were to change kern_hyp_va() to not being idempotent

   - Don't leak stage-2 mappings in protected mode

   - Correctly align the faulting address when dealing with single page
     stage-2 mappings for PAGE_SIZE &gt; 4kB

   - Fix detection of virtualisation-capable GICv5 IRS, due to the
     maintainer being obviously fat fingered... [his words, not mine]

   - Remove duplication of code retrieving the ASID for the purpose of
     S1 PT handling

   - Fix slightly abusive const-ification in vgic_set_kvm_info()

  Generic:

   - Remove internal Kconfigs that are now set on all architectures

   - Remove per-architecture code to enable KVM_CAP_SYNC_MMU, all
     architectures finally enable it in Linux 7.0"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: always define KVM_CAP_SYNC_MMU
  KVM: remove CONFIG_KVM_GENERIC_MMU_NOTIFIER
  KVM: arm64: Deduplicate ASID retrieval code
  irqchip/gic-v5: Fix inversion of IRS_IDR0.virt flag
  KVM: arm64: Revert accidental drop of kvm_uninit_stage2_mmu() for non-NV VMs
  KVM: arm64: Fix protected mode handling of pages larger than 4kB
  KVM: arm64: vgic: Handle const qualifier from gic_kvm_info allocation type
  KVM: arm64: Remove redundant kern_hyp_va() in unpin_host_sve_state()
  KVM: arm64: Fix ID register initialization for non-protected pKVM guests
  KVM: arm64: Optimise away S1POE handling when not supported by host
  KVM: arm64: Hide S1POE from guests when not supported by the host
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull kvm fixes from Paolo Bonzini:
 "Arm:

   - Make sure we don't leak any S1POE state from guest to guest when
     the feature is supported on the HW, but not enabled on the host

   - Propagate the ID registers from the host into non-protected VMs
     managed by pKVM, ensuring that the guest sees the intended feature
     set

   - Drop double kern_hyp_va() from unpin_host_sve_state(), which could
     bite us if we were to change kern_hyp_va() to not being idempotent

   - Don't leak stage-2 mappings in protected mode

   - Correctly align the faulting address when dealing with single page
     stage-2 mappings for PAGE_SIZE &gt; 4kB

   - Fix detection of virtualisation-capable GICv5 IRS, due to the
     maintainer being obviously fat fingered... [his words, not mine]

   - Remove duplication of code retrieving the ASID for the purpose of
     S1 PT handling

   - Fix slightly abusive const-ification in vgic_set_kvm_info()

  Generic:

   - Remove internal Kconfigs that are now set on all architectures

   - Remove per-architecture code to enable KVM_CAP_SYNC_MMU, all
     architectures finally enable it in Linux 7.0"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: always define KVM_CAP_SYNC_MMU
  KVM: remove CONFIG_KVM_GENERIC_MMU_NOTIFIER
  KVM: arm64: Deduplicate ASID retrieval code
  irqchip/gic-v5: Fix inversion of IRS_IDR0.virt flag
  KVM: arm64: Revert accidental drop of kvm_uninit_stage2_mmu() for non-NV VMs
  KVM: arm64: Fix protected mode handling of pages larger than 4kB
  KVM: arm64: vgic: Handle const qualifier from gic_kvm_info allocation type
  KVM: arm64: Remove redundant kern_hyp_va() in unpin_host_sve_state()
  KVM: arm64: Fix ID register initialization for non-protected pKVM guests
  KVM: arm64: Optimise away S1POE handling when not supported by host
  KVM: arm64: Hide S1POE from guests when not supported by the host
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'timers-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-03-01T20:15:58+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-01T20:15:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f6542af92298d8a44ab5588144086fa2d0edf391'/>
<id>f6542af92298d8a44ab5588144086fa2d0edf391</id>
<content type='text'>
Pull timer fix from Ingo Molnar:
 "Improve the inlining of jiffies_to_msecs() and jiffies_to_usecs(), for
  the common HZ=100, 250 or 1000 cases. Only use a function call for odd
  HZ values like HZ=300 that generate more code.

  The function call overhead showed up in performance tests of the TCP
  code"

* tag 'timers-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time/jiffies: Inline jiffies_to_msecs() and jiffies_to_usecs()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull timer fix from Ingo Molnar:
 "Improve the inlining of jiffies_to_msecs() and jiffies_to_usecs(), for
  the common HZ=100, 250 or 1000 cases. Only use a function call for odd
  HZ values like HZ=300 that generate more code.

  The function call overhead showed up in performance tests of the TCP
  code"

* tag 'timers-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time/jiffies: Inline jiffies_to_msecs() and jiffies_to_usecs()
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'sched-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-03-01T19:09:24+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-01T19:09:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=61706251492eff650e91c58507bc77e1a12c7fbb'/>
<id>61706251492eff650e91c58507bc77e1a12c7fbb</id>
<content type='text'>
Pull scheduler fixes from Ingo Molnar:

 - Fix zero_vruntime tracking when there's a single task running

 - Fix slice protection logic

 - Fix the -&gt;vprot logic for reniced tasks

 - Fix lag clamping in mixed slice workloads

 - Fix objtool uaccess warning (and bug) in the
   !CONFIG_RSEQ_SLICE_EXTENSION case caused by unexpected un-inlining,
   which triggers with older compilers

 - Fix a comment in the rseq registration rseq_size bound check code

 - Fix a legacy RSEQ ABI quirk that handled 32-byte area sizes
   differently, which special size we now reached naturally and want to
   avoid. The visible ugliness of the new reserved field will be avoided
   the next time the RSEQ area is extended.

* tag 'sched-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq: slice ext: Ensure rseq feature size differs from original rseq size
  rseq: Clarify rseq registration rseq_size bound check comment
  sched/core: Fix wakeup_preempt's next_class tracking
  rseq: Mark rseq_arm_slice_extension_timer() __always_inline
  sched/fair: Fix lag clamp
  sched/eevdf: Update se-&gt;vprot in reweight_entity()
  sched/fair: Only set slice protection at pick time
  sched/fair: Fix zero_vruntime tracking
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull scheduler fixes from Ingo Molnar:

 - Fix zero_vruntime tracking when there's a single task running

 - Fix slice protection logic

 - Fix the -&gt;vprot logic for reniced tasks

 - Fix lag clamping in mixed slice workloads

 - Fix objtool uaccess warning (and bug) in the
   !CONFIG_RSEQ_SLICE_EXTENSION case caused by unexpected un-inlining,
   which triggers with older compilers

 - Fix a comment in the rseq registration rseq_size bound check code

 - Fix a legacy RSEQ ABI quirk that handled 32-byte area sizes
   differently, which special size we now reached naturally and want to
   avoid. The visible ugliness of the new reserved field will be avoided
   the next time the RSEQ area is extended.

* tag 'sched-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq: slice ext: Ensure rseq feature size differs from original rseq size
  rseq: Clarify rseq registration rseq_size bound check comment
  sched/core: Fix wakeup_preempt's next_class tracking
  rseq: Mark rseq_arm_slice_extension_timer() __always_inline
  sched/fair: Fix lag clamp
  sched/eevdf: Update se-&gt;vprot in reweight_entity()
  sched/fair: Only set slice protection at pick time
  sched/fair: Fix zero_vruntime tracking
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'irq-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2026-03-01T18:58:16+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-01T18:58:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=afa844360bc527d2a7e9e2542b5bd59b361cfb7c'/>
<id>afa844360bc527d2a7e9e2542b5bd59b361cfb7c</id>
<content type='text'>
Pull irqchip driver fixes from Ingo Molnar:

 - Fix frozen interrupt bug in the sifive-plic driver

 - Limit per-device MSI interrupts on uncommon gic-v3-its hardware
   variants

 - Address Sparse warning by constifying a variable in the MMP driver

 - Revert broken commit and also fix an error check in the ls-extirq
   driver

* tag 'irq-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/ls-extirq: Fix devm_of_iomap() error check
  Revert "irqchip/ls-extirq: Use for_each_of_imap_item iterator"
  irqchip/mmp: Make icu_irq_chip variable static const
  irqchip/gic-v3-its: Limit number of per-device MSIs to the range the ITS supports
  irqchip/sifive-plic: Fix frozen interrupt due to affinity setting
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull irqchip driver fixes from Ingo Molnar:

 - Fix frozen interrupt bug in the sifive-plic driver

 - Limit per-device MSI interrupts on uncommon gic-v3-its hardware
   variants

 - Address Sparse warning by constifying a variable in the MMP driver

 - Revert broken commit and also fix an error check in the ls-extirq
   driver

* tag 'irq-urgent-2026-03-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/ls-extirq: Fix devm_of_iomap() error check
  Revert "irqchip/ls-extirq: Use for_each_of_imap_item iterator"
  irqchip/mmp: Make icu_irq_chip variable static const
  irqchip/gic-v3-its: Limit number of per-device MSIs to the range the ITS supports
  irqchip/sifive-plic: Fix frozen interrupt due to affinity setting
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf</title>
<updated>2026-03-01T03:54:28+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-03-01T03:54:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=eb71ab2bf72260054677e348498ba995a057c463'/>
<id>eb71ab2bf72260054677e348498ba995a057c463</id>
<content type='text'>
Pull bpf fixes from Alexei Starovoitov:

 - Fix alignment of arm64 JIT buffer to prevent atomic tearing (Fuad
   Tabba)

 - Fix invariant violation for single value tnums in the verifier
   (Harishankar Vishwanathan, Paul Chaignon)

 - Fix a bunch of issues found by ASAN in selftests/bpf (Ihor Solodrai)

 - Fix race in devmpa and cpumap on PREEMPT_RT (Jiayuan Chen)

 - Fix show_fdinfo of kprobe_multi when cookies are not present (Jiri
   Olsa)

 - Fix race in freeing special fields in BPF maps to prevent memory
   leaks (Kumar Kartikeya Dwivedi)

 - Fix OOB read in dmabuf_collector (T.J. Mercier)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (36 commits)
  selftests/bpf: Avoid simplification of crafted bounds test
  selftests/bpf: Test refinement of single-value tnum
  bpf: Improve bounds when tnum has a single possible value
  bpf: Introduce tnum_step to step through tnum's members
  bpf: Fix race in devmap on PREEMPT_RT
  bpf: Fix race in cpumap on PREEMPT_RT
  selftests/bpf: Add tests for special fields races
  bpf: Retire rcu_trace_implies_rcu_gp() from local storage
  bpf: Delay freeing fields in local storage
  bpf: Lose const-ness of map in map_check_btf()
  bpf: Register dtor for freeing special fields
  selftests/bpf: Fix OOB read in dmabuf_collector
  selftests/bpf: Fix a memory leak in xdp_flowtable test
  bpf: Fix stack-out-of-bounds write in devmap
  bpf: Fix kprobe_multi cookies access in show_fdinfo callback
  bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing
  selftests/bpf: Don't override SIGSEGV handler with ASAN
  selftests/bpf: Check BPFTOOL env var in detect_bpftool_path()
  selftests/bpf: Fix out-of-bounds array access bugs reported by ASAN
  selftests/bpf: Fix array bounds warning in jit_disasm_helpers
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bpf fixes from Alexei Starovoitov:

 - Fix alignment of arm64 JIT buffer to prevent atomic tearing (Fuad
   Tabba)

 - Fix invariant violation for single value tnums in the verifier
   (Harishankar Vishwanathan, Paul Chaignon)

 - Fix a bunch of issues found by ASAN in selftests/bpf (Ihor Solodrai)

 - Fix race in devmpa and cpumap on PREEMPT_RT (Jiayuan Chen)

 - Fix show_fdinfo of kprobe_multi when cookies are not present (Jiri
   Olsa)

 - Fix race in freeing special fields in BPF maps to prevent memory
   leaks (Kumar Kartikeya Dwivedi)

 - Fix OOB read in dmabuf_collector (T.J. Mercier)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (36 commits)
  selftests/bpf: Avoid simplification of crafted bounds test
  selftests/bpf: Test refinement of single-value tnum
  bpf: Improve bounds when tnum has a single possible value
  bpf: Introduce tnum_step to step through tnum's members
  bpf: Fix race in devmap on PREEMPT_RT
  bpf: Fix race in cpumap on PREEMPT_RT
  selftests/bpf: Add tests for special fields races
  bpf: Retire rcu_trace_implies_rcu_gp() from local storage
  bpf: Delay freeing fields in local storage
  bpf: Lose const-ness of map in map_check_btf()
  bpf: Register dtor for freeing special fields
  selftests/bpf: Fix OOB read in dmabuf_collector
  selftests/bpf: Fix a memory leak in xdp_flowtable test
  bpf: Fix stack-out-of-bounds write in devmap
  bpf: Fix kprobe_multi cookies access in show_fdinfo callback
  bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing
  selftests/bpf: Don't override SIGSEGV handler with ASAN
  selftests/bpf: Check BPFTOOL env var in detect_bpftool_path()
  selftests/bpf: Fix out-of-bounds array access bugs reported by ASAN
  selftests/bpf: Fix array bounds warning in jit_disasm_helpers
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: remove CONFIG_KVM_GENERIC_MMU_NOTIFIER</title>
<updated>2026-02-28T14:31:35+00:00</updated>
<author>
<name>Paolo Bonzini</name>
<email>pbonzini@redhat.com</email>
</author>
<published>2026-02-11T18:03:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=407fd8b8d8cce03856aa67329715de48b254b529'/>
<id>407fd8b8d8cce03856aa67329715de48b254b529</id>
<content type='text'>
All architectures now use MMU notifier for KVM page table management.
Remove the Kconfig symbol and the code that is used when it is
disabled.

Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All architectures now use MMU notifier for KVM page table management.
Remove the Kconfig symbol and the code that is used when it is
disabled.

Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Introduce tnum_step to step through tnum's members</title>
<updated>2026-02-28T00:11:50+00:00</updated>
<author>
<name>Harishankar Vishwanathan</name>
<email>harishankar.vishwanathan@gmail.com</email>
</author>
<published>2026-02-27T21:32:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=76e954155b45294c502e3d3a9e15757c858ca55e'/>
<id>76e954155b45294c502e3d3a9e15757c858ca55e</id>
<content type='text'>
This commit introduces tnum_step(), a function that, when given t, and a
number z returns the smallest member of t larger than z. The number z
must be greater or equal to the smallest member of t and less than the
largest member of t.

The first step is to compute j, a number that keeps all of t's known
bits, and matches all unknown bits to z's bits. Since j is a member of
the t, it is already a candidate for result. However, we want our result
to be (minimally) greater than z.

There are only two possible cases:

(1) Case j &lt;= z. In this case, we want to increase the value of j and
make it &gt; z.
(2) Case j &gt; z. In this case, we want to decrease the value of j while
keeping it &gt; z.

(Case 1) j &lt;= z

t = xx11x0x0
z = 10111101 (189)
j = 10111000 (184)
         ^
         k

(Case 1.1) Let's first consider the case where j &lt; z. We will address j
== z later.

Since z &gt; j, there had to be a bit position that was 1 in z and a 0 in
j, beyond which all positions of higher significance are equal in j and
z. Further, this position could not have been unknown in a, because the
unknown positions of a match z. This position had to be a 1 in z and
known 0 in t.

Let k be position of the most significant 1-to-0 flip. In our example, k
= 3 (starting the count at 1 at the least significant bit).  Setting (to
1) the unknown bits of t in positions of significance smaller than
k will not produce a result &gt; z. Hence, we must set/unset the unknown
bits at positions of significance higher than k. Specifically, we look
for the next larger combination of 1s and 0s to place in those
positions, relative to the combination that exists in z. We can achieve
this by concatenating bits at unknown positions of t into an integer,
adding 1, and writing the bits of that result back into the
corresponding bit positions previously extracted from z.

&gt;From our example, considering only positions of significance greater
than k:

t =  xx..x
z =  10..1
    +    1
     -----
     11..0

This is the exact combination 1s and 0s we need at the unknown bits of t
in positions of significance greater than k. Further, our result must
only increase the value minimally above z. Hence, unknown bits in
positions of significance smaller than k should remain 0. We finally
have,

result = 11110000 (240)

(Case 1.2) Now consider the case when j = z, for example

t = 1x1x0xxx
z = 10110100 (180)
j = 10110100 (180)

Matching the unknown bits of the t to the bits of z yielded exactly z.
To produce a number greater than z, we must set/unset the unknown bits
in t, and *all* the unknown bits of t candidates for being set/unset. We
can do this similar to Case 1.1, by adding 1 to the bits extracted from
the masked bit positions of z. Essentially, this case is equivalent to
Case 1.1, with k = 0.

t =  1x1x0xxx
z =  .0.1.100
    +       1
    ---------
     .0.1.101

This is the exact combination of bits needed in the unknown positions of
t. After recalling the known positions of t, we get

result = 10110101 (181)

(Case 2) j &gt; z

t = x00010x1
z = 10000010 (130)
j = 10001011 (139)
	^
	k

Since j &gt; z, there had to be a bit position which was 0 in z, and a 1 in
j, beyond which all positions of higher significance are equal in j and
z. This position had to be a 0 in z and known 1 in t. Let k be the
position of the most significant 0-to-1 flip. In our example, k = 4.

Because of the 0-to-1 flip at position k, a member of t can become
greater than z if the bits in positions greater than k are themselves &gt;=
to z. To make that member *minimally* greater than z, the bits in
positions greater than k must be exactly = z. Hence, we simply match all
of t's unknown bits in positions more significant than k to z's bits. In
positions less significant than k, we set all t's unknown bits to 0
to retain minimality.

In our example, in positions of greater significance than k (=4),
t=x000. These positions are matched with z (1000) to produce 1000. In
positions of lower significance than k, t=10x1. All unknown bits are set
to 0 to produce 1001. The final result is:

result = 10001001 (137)

This concludes the computation for a result &gt; z that is a member of t.

The procedure for tnum_step() in this commit implements the idea
described above. As a proof of correctness, we verified the algorithm
against a logical specification of tnum_step. The specification asserts
the following about the inputs t, z and output res that:

1. res is a member of t, and
2. res is strictly greater than z, and
3. there does not exist another value res2 such that
	3a. res2 is also a member of t, and
	3b. res2 is greater than z
	3c. res2 is smaller than res

We checked the implementation against this logical specification using
an SMT solver. The verification formula in SMTLIB format is available
at [1]. The verification returned an "unsat": indicating that no input
assignment exists for which the implementation and the specification
produce different outputs.

In addition, we also automatically generated the logical encoding of the
C implementation using Agni [2] and verified it against the same
specification. This verification also returned an "unsat", confirming
that the implementation is equivalent to the specification. The formula
for this check is also available at [3].

Link: https://pastebin.com/raw/2eRWbiit [1]
Link: https://github.com/bpfverif/agni [2]
Link: https://pastebin.com/raw/EztVbBJ2 [3]
Co-developed-by: Srinivas Narayana &lt;srinivas.narayana@rutgers.edu&gt;
Signed-off-by: Srinivas Narayana &lt;srinivas.narayana@rutgers.edu&gt;
Co-developed-by: Santosh Nagarakatte &lt;santosh.nagarakatte@rutgers.edu&gt;
Signed-off-by: Santosh Nagarakatte &lt;santosh.nagarakatte@rutgers.edu&gt;
Signed-off-by: Harishankar Vishwanathan &lt;harishankar.vishwanathan@gmail.com&gt;
Link: https://lore.kernel.org/r/93fdf71910411c0f19e282ba6d03b4c65f9c5d73.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This commit introduces tnum_step(), a function that, when given t, and a
number z returns the smallest member of t larger than z. The number z
must be greater or equal to the smallest member of t and less than the
largest member of t.

The first step is to compute j, a number that keeps all of t's known
bits, and matches all unknown bits to z's bits. Since j is a member of
the t, it is already a candidate for result. However, we want our result
to be (minimally) greater than z.

There are only two possible cases:

(1) Case j &lt;= z. In this case, we want to increase the value of j and
make it &gt; z.
(2) Case j &gt; z. In this case, we want to decrease the value of j while
keeping it &gt; z.

(Case 1) j &lt;= z

t = xx11x0x0
z = 10111101 (189)
j = 10111000 (184)
         ^
         k

(Case 1.1) Let's first consider the case where j &lt; z. We will address j
== z later.

Since z &gt; j, there had to be a bit position that was 1 in z and a 0 in
j, beyond which all positions of higher significance are equal in j and
z. Further, this position could not have been unknown in a, because the
unknown positions of a match z. This position had to be a 1 in z and
known 0 in t.

Let k be position of the most significant 1-to-0 flip. In our example, k
= 3 (starting the count at 1 at the least significant bit).  Setting (to
1) the unknown bits of t in positions of significance smaller than
k will not produce a result &gt; z. Hence, we must set/unset the unknown
bits at positions of significance higher than k. Specifically, we look
for the next larger combination of 1s and 0s to place in those
positions, relative to the combination that exists in z. We can achieve
this by concatenating bits at unknown positions of t into an integer,
adding 1, and writing the bits of that result back into the
corresponding bit positions previously extracted from z.

&gt;From our example, considering only positions of significance greater
than k:

t =  xx..x
z =  10..1
    +    1
     -----
     11..0

This is the exact combination 1s and 0s we need at the unknown bits of t
in positions of significance greater than k. Further, our result must
only increase the value minimally above z. Hence, unknown bits in
positions of significance smaller than k should remain 0. We finally
have,

result = 11110000 (240)

(Case 1.2) Now consider the case when j = z, for example

t = 1x1x0xxx
z = 10110100 (180)
j = 10110100 (180)

Matching the unknown bits of the t to the bits of z yielded exactly z.
To produce a number greater than z, we must set/unset the unknown bits
in t, and *all* the unknown bits of t candidates for being set/unset. We
can do this similar to Case 1.1, by adding 1 to the bits extracted from
the masked bit positions of z. Essentially, this case is equivalent to
Case 1.1, with k = 0.

t =  1x1x0xxx
z =  .0.1.100
    +       1
    ---------
     .0.1.101

This is the exact combination of bits needed in the unknown positions of
t. After recalling the known positions of t, we get

result = 10110101 (181)

(Case 2) j &gt; z

t = x00010x1
z = 10000010 (130)
j = 10001011 (139)
	^
	k

Since j &gt; z, there had to be a bit position which was 0 in z, and a 1 in
j, beyond which all positions of higher significance are equal in j and
z. This position had to be a 0 in z and known 1 in t. Let k be the
position of the most significant 0-to-1 flip. In our example, k = 4.

Because of the 0-to-1 flip at position k, a member of t can become
greater than z if the bits in positions greater than k are themselves &gt;=
to z. To make that member *minimally* greater than z, the bits in
positions greater than k must be exactly = z. Hence, we simply match all
of t's unknown bits in positions more significant than k to z's bits. In
positions less significant than k, we set all t's unknown bits to 0
to retain minimality.

In our example, in positions of greater significance than k (=4),
t=x000. These positions are matched with z (1000) to produce 1000. In
positions of lower significance than k, t=10x1. All unknown bits are set
to 0 to produce 1001. The final result is:

result = 10001001 (137)

This concludes the computation for a result &gt; z that is a member of t.

The procedure for tnum_step() in this commit implements the idea
described above. As a proof of correctness, we verified the algorithm
against a logical specification of tnum_step. The specification asserts
the following about the inputs t, z and output res that:

1. res is a member of t, and
2. res is strictly greater than z, and
3. there does not exist another value res2 such that
	3a. res2 is also a member of t, and
	3b. res2 is greater than z
	3c. res2 is smaller than res

We checked the implementation against this logical specification using
an SMT solver. The verification formula in SMTLIB format is available
at [1]. The verification returned an "unsat": indicating that no input
assignment exists for which the implementation and the specification
produce different outputs.

In addition, we also automatically generated the logical encoding of the
C implementation using Agni [2] and verified it against the same
specification. This verification also returned an "unsat", confirming
that the implementation is equivalent to the specification. The formula
for this check is also available at [3].

Link: https://pastebin.com/raw/2eRWbiit [1]
Link: https://github.com/bpfverif/agni [2]
Link: https://pastebin.com/raw/EztVbBJ2 [3]
Co-developed-by: Srinivas Narayana &lt;srinivas.narayana@rutgers.edu&gt;
Signed-off-by: Srinivas Narayana &lt;srinivas.narayana@rutgers.edu&gt;
Co-developed-by: Santosh Nagarakatte &lt;santosh.nagarakatte@rutgers.edu&gt;
Signed-off-by: Santosh Nagarakatte &lt;santosh.nagarakatte@rutgers.edu&gt;
Signed-off-by: Harishankar Vishwanathan &lt;harishankar.vishwanathan@gmail.com&gt;
Link: https://lore.kernel.org/r/93fdf71910411c0f19e282ba6d03b4c65f9c5d73.1772225741.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Lose const-ness of map in map_check_btf()</title>
<updated>2026-02-27T23:39:00+00:00</updated>
<author>
<name>Kumar Kartikeya Dwivedi</name>
<email>memxor@gmail.com</email>
</author>
<published>2026-02-27T22:48:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ae51772b1e94ba1d76db19085957dbccac189c1c'/>
<id>ae51772b1e94ba1d76db19085957dbccac189c1c</id>
<content type='text'>
BPF hash map may now use the map_check_btf() callback to decide whether
to set a dtor on its bpf_mem_alloc or not. Unlike C++ where members can
opt out of const-ness using mutable, we must lose the const qualifier on
the callback such that we can avoid the ugly cast. Make the change and
adjust all existing users, and lose the comment in hashtab.c.

Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/r/20260227224806.646888-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
BPF hash map may now use the map_check_btf() callback to decide whether
to set a dtor on its bpf_mem_alloc or not. Unlike C++ where members can
opt out of const-ness using mutable, we must lose the const qualifier on
the callback such that we can avoid the ugly cast. Make the change and
adjust all existing users, and lose the comment in hashtab.c.

Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/r/20260227224806.646888-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Register dtor for freeing special fields</title>
<updated>2026-02-27T23:39:00+00:00</updated>
<author>
<name>Kumar Kartikeya Dwivedi</name>
<email>memxor@gmail.com</email>
</author>
<published>2026-02-27T22:48:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1df97a7453eec80c1912c2d0360290a3970a7671'/>
<id>1df97a7453eec80c1912c2d0360290a3970a7671</id>
<content type='text'>
There is a race window where BPF hash map elements can leak special
fields if the program with access to the map value recreates these
special fields between the check_and_free_fields done on the map value
and its eventual return to the memory allocator.

Several ways were explored prior to this patch, most notably [0] tried
to use a poison value to reject attempts to recreate special fields for
map values that have been logically deleted but still accessible to BPF
programs (either while sitting in the free list or when reused). While
this approach works well for task work, timers, wq, etc., it is harder
to apply the idea to kptrs, which have a similar race and failure mode.

Instead, we change bpf_mem_alloc to allow registering destructor for
allocated elements, such that when they are returned to the allocator,
any special fields created while they were accessible to programs in the
mean time will be freed. If these values get reused, we do not free the
fields again before handing the element back. The special fields thus
may remain initialized while the map value sits in a free list.

When bpf_mem_alloc is retired in the future, a similar concept can be
introduced to kmalloc_nolock-backed kmem_cache, paired with the existing
idea of a constructor.

Note that the destructor registration happens in map_check_btf, after
the BTF record is populated and (at that point) avaiable for inspection
and duplication. Duplication is necessary since the freeing of embedded
bpf_mem_alloc can be decoupled from actual map lifetime due to logic
introduced to reduce the cost of rcu_barrier()s in mem alloc free path in
9f2c6e96c65e ("bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.").

As such, once all callbacks are done, we must also free the duplicated
record. To remove dependency on the bpf_map itself, also stash the key
size of the map to obtain value from htab_elem long after the map is
gone.

  [0]: https://lore.kernel.org/bpf/20260216131341.1285427-1-mykyta.yatsenko5@gmail.com

Fixes: 14a324f6a67e ("bpf: Wire up freeing of referenced kptr")
Fixes: 1bfbc267ec91 ("bpf: Enable bpf_timer and bpf_wq in any context")
Reported-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/r/20260227224806.646888-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is a race window where BPF hash map elements can leak special
fields if the program with access to the map value recreates these
special fields between the check_and_free_fields done on the map value
and its eventual return to the memory allocator.

Several ways were explored prior to this patch, most notably [0] tried
to use a poison value to reject attempts to recreate special fields for
map values that have been logically deleted but still accessible to BPF
programs (either while sitting in the free list or when reused). While
this approach works well for task work, timers, wq, etc., it is harder
to apply the idea to kptrs, which have a similar race and failure mode.

Instead, we change bpf_mem_alloc to allow registering destructor for
allocated elements, such that when they are returned to the allocator,
any special fields created while they were accessible to programs in the
mean time will be freed. If these values get reused, we do not free the
fields again before handing the element back. The special fields thus
may remain initialized while the map value sits in a free list.

When bpf_mem_alloc is retired in the future, a similar concept can be
introduced to kmalloc_nolock-backed kmem_cache, paired with the existing
idea of a constructor.

Note that the destructor registration happens in map_check_btf, after
the BTF record is populated and (at that point) avaiable for inspection
and duplication. Duplication is necessary since the freeing of embedded
bpf_mem_alloc can be decoupled from actual map lifetime due to logic
introduced to reduce the cost of rcu_barrier()s in mem alloc free path in
9f2c6e96c65e ("bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.").

As such, once all callbacks are done, we must also free the duplicated
record. To remove dependency on the bpf_map itself, also stash the key
size of the map to obtain value from htab_elem long after the map is
gone.

  [0]: https://lore.kernel.org/bpf/20260216131341.1285427-1-mykyta.yatsenko5@gmail.com

Fixes: 14a324f6a67e ("bpf: Wire up freeing of referenced kptr")
Fixes: 1bfbc267ec91 ("bpf: Enable bpf_timer and bpf_wq in any context")
Reported-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: Kumar Kartikeya Dwivedi &lt;memxor@gmail.com&gt;
Link: https://lore.kernel.org/r/20260227224806.646888-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pci-v7.0-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci</title>
<updated>2026-02-27T21:32:52+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-27T21:32:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1c63df24be5f06f61b94e63cbe01aa852e463438'/>
<id>1c63df24be5f06f61b94e63cbe01aa852e463438</id>
<content type='text'>
Pull pci fixes from Bjorn Helgaas:

 - Update MAINTAINERS email address (Shawn Guo)

 - Refresh cached Endpoint driver MSI Message Address to fix a v7.0
   regression when kernel changes the address after firmware has
   configured it (Niklas Cassel)

 - Flush Endpoint MSI-X writes so they complete before the outbound ATU
   entry is unmapped (Niklas Cassel)

 - Correct the PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value, which broke VMM use
   of PCI capabilities (Bjorn Helgaas)

* tag 'pci-v7.0-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI: Correct PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value
  PCI: dwc: ep: Flush MSI-X write before unmapping its ATU entry
  PCI: dwc: ep: Refresh MSI Message Address cache on change
  MAINTAINERS: Update Shawn Guo's address for HiSilicon PCIe controller driver
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull pci fixes from Bjorn Helgaas:

 - Update MAINTAINERS email address (Shawn Guo)

 - Refresh cached Endpoint driver MSI Message Address to fix a v7.0
   regression when kernel changes the address after firmware has
   configured it (Niklas Cassel)

 - Flush Endpoint MSI-X writes so they complete before the outbound ATU
   entry is unmapped (Niklas Cassel)

 - Correct the PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value, which broke VMM use
   of PCI capabilities (Bjorn Helgaas)

* tag 'pci-v7.0-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI: Correct PCI_CAP_EXP_ENDPOINT_SIZEOF_V2 value
  PCI: dwc: ep: Flush MSI-X write before unmapping its ATU entry
  PCI: dwc: ep: Refresh MSI Message Address cache on change
  MAINTAINERS: Update Shawn Guo's address for HiSilicon PCIe controller driver
</pre>
</div>
</content>
</entry>
</feed>
