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git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next
Pull perf tool updates from Arnaldo Carvalho de Melo:
- Support instruction tracking on arm64 for data type profiling,
resolving stack, global, per-CPU and 'current' variable accesses, so
that 'perf annotate --data-type' resolves types on arm64 the way it
does on x86.
- Port the Python scripts to the perf module and standalone execution,
and improve the module: lazy sample callchains and event copies, GIL
handling, better session/thread lookup, new treport, flamegraph and
sqlite/postgres exporters.
- Reenable and fix the attribute expectation test suite: per-PMU bit
masks, other core PMUs' events, dummy tracking events, group checks
and spelled out skip reasons.
- perf trace: filter the target's tasks in BPF, open the BPF output
event on every CPU, add an option to disable syscall augmentation and
raise TRACE_AUG_MAX_BUF.
- perf jitdump: harden record parsing, validating unwinding sizes and
symbol names, byte-swapping debug entries via safe accessors and
fixing frees on error paths.
- perf annotate-data fixes: bound the member nesting recursion, resolve
type DIEs in the debug file they came from, adjust the offset for
flex-arrays and show the sample count in the data-type browser.
- perf symbol and debug info: try linked debug files for DSOs, avoid
repeated failing searches, set binary/symtab types for split
kallsyms, JIT maps and the build-id cache, fix libbfd symbol loading.
- perf config: serialize config file access with a mutex, add the
DEFINE_MUTEX() and DO_ONCE() primitives and a robust process shared
mutex, add the core.hybrid-merge option.
- perf report: add --progress and --no-progress options.
- perf mem: add a false sharing workload to 'perf test', request
PERF_SAMPLE_CPU by default, use the IBS swfilt filter when available
and decode L0 in the memory level.
- perf test: take turns using the perf mlock budget in the mmaping
tests, add the 'needs_mlock' suite flag, scope the probe based tests
to their PID and make more tests non-exclusive.
- perf vendor events intel: update events and metrics to TMA 5.2,
refresh the event tables and fix umask encodings.
- perf build: run shellcheck, mypy and pylint in parallel, make pylint
opt-out with NO_PYLINT=1, fix clean and install dependencies.
- Add a script and a 'make sync-headers' target to sync the tools/
copies of kernel headers with the kernel sources, plus the resulting
syncs of the cpufeatures, KVM, fs, mount, fcntl, socket, rtnetlink,
if_addr and sound headers.
- Fix cs-etm HW_ID mapping synthesis for raw trace, queue teardown
leaks and duplicate v0 global mappings.
- Add a 'perf bench atomic' benchmark for atomic operations.
- Filter events before creating lock_stat in 'perf lock contention'.
- Add a 'perf test' case for events re-armed with
PERF_EVENT_IOC_REFRESH.
- Fix memory leaks on 'perf c2c' output fields and add function view
stdio coverage to its test.
- Fix a NULL dereference resolving callchains in 'perf machine'.
- Optimize the libdw fallback when DWARF is missing and try the symbol
file first when checking for debuginfo.
- Don't call eprintf() in pr_debugN() when not verbose.
- Don't delete cumulative caller entries before the stat_acc decays in
'perf report'.
- Fix ring buffer cursor handling: keep the consumed cursor in forward
mode and use the head selected by read_init.
- Fix 'perf test mmap-basic' user rdpmc detection and only test
userspace reading on supported platforms.
- Build fixes: include sys/types.h for ssize_t, errno.h before kernel
headers and fix jevents.py type annotations for mypy 2.x.
* tag 'perf-tools-for-v7.4-1-2026-10-30' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next: (425 commits)
perf machine: Fix NULL deref in thread__resolve_callchain_sample()
perf pmu-events: Fix jevents.py type annotations for mypy 2.x
perf parse-events: Include errno.h before kernel headers
perf print_insn: Include sys/types.h for ssize_t
perf tests mmap-basic: Fix user rdpmc detection logic
perf tests mmap-basic: Only test userspace reading on supported platforms
perf mmap: Preserve the consumed cursor in forward mode
perf mmap: Use the head selected by read_init
perf hist: Do not delete cumulative caller entries before stat_acc decays
perf debug: Avoid calling eprintf() in pr_debugN() when verbose < n
perf libdw: Optimize fallback logic for missing DWARF
tools headers: Sync KVM headers with the kernel sources
tools headers: Sync UAPI sound/asound.h with the kernel sources
tools headers: Sync UAPI linux/mount.h with the kernel sources
tools headers: Sync UAPI linux/fs.h with the kernel sources
tools headers: Sync UAPI linux/fcntl.h with the kernel sources
tools headers: Sync linux/socket.h with the kernel sources
tools arch x86: Sync the cpufeatures.h copy with the kernel sources
tools headers UAPI: Sync linux/rtnetlink.h with the kernel sources
tools headers UAPI: Sync linux/if_addr.h with the kernel sources
...
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Pull bpf fixes from Alexei Starovoitov:
- Remove BPF_F_ARENA_SCALAR flag and .arena.data section in libbpf that
were added for rust-bpf in this merge window. We found a cleaner
approach that does it on compiler side instead of kernel/libbpf. No
released kernel has them (Alexei Starovoitov)
- Fix bpf_send_signal_task() returning -EPERM when it is called from a
kernel thread (Aditya Sharma)
- Various fixes (Alexei Starovoitov):
- Use emit_rsb_call() to call bpf_unwind_target() in x86 JIT to fix
objtool warning during the build
- Fix scalar evolution: clear delta of a widened register, don't
widen a pointer to a buffer, don't clamp a register whose type
changed in the loop, and reset the range of a clamped packet
pointer
- Finish the insn in the state that maybe_fork_scalars() splits
off, so that pruning doesn't drop it at the head of a counted
loop
- Preserve the registers that carry stack arguments across
arch_bpf_timed_may_goto() on x86-64, arm64 and riscv64
- Don't re-sort subprog_info[] for every new subprogram
- Fix flaky map_kptr and rcu_reentry selftests
- Use memmove() in bpf_skb_load_bytes(), bpf_skb_load_bytes_relative()
and bpf_xdp_load_bytes(), since the destination can be a slice of the
same packet (Ayushman Rout)
- Fixes and follow-ups for scalar evolution: reject pointer operands in
32-bit recurrences and latches, don't intersect with the current
register range on clamp to avoid a false 'verifier bug', avoid false
infinite loop reports, and recognize a 32-bit copy of the induction
variable (Eduard Zingerman)
- Fix out-of-bounds write to btf->types[] for split BTF and propagate
btf_add_type() errors in btf_check_all_metas() (Feng Yang)
- Fix use-after-free in bpf_timer callback that fires after its inner
map was freed (Mani Tofigh)
- Fix x86 JIT stopping before jumps converge: size backward jumps by
the insns they jump over (Mykyta Yatsenko)
- Fix use-after-free of struct_ops trampoline: dissociate struct_ops
progs before the grace period of the map (Qiliang Yuan)
- Validate stack argument reads against the caller state to fix
out-of-bounds read in the verifier, and reject callbacks with stack
arguments (Weiming Shi)
- Tie borrowed iterator results and pointers loaded from trusted fields
to the lifetime of their source, so that iterator next, destroy and
reference release invalidate them (Xu Yunxiang)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (48 commits)
bpf: Don't re-sort subprog_info[] for every new subprogram
bpf: Fix out-of-bounds btf->types write for split BTF
selftests/bpf: Test stack arguments across may_goto
bpf: Keep stack arguments in arch_bpf_timed_may_goto()
selftests/bpf: Test maybe_fork_scalars() at the head of a counted loop
bpf: Finish the insn in the state that maybe_fork_scalars() splits off
selftests/bpf: Test the clamp of pointers in scalar evolution
bpf: Reset the range of a packet pointer that scalar evolution clamps
bpf: Don't clamp a register whose type changed in the loop
selftests/bpf: Test a loop that moves a pointer to a buffer
bpf: Don't widen a pointer to a buffer in scalar evolution
selftests/bpf: Avoid a page fault in rcu_reentry while the handler is armed
selftests/bpf: Wait for the last maps of map_kptr to be freed
selftests/bpf: Test that a widened register is not linked
bpf: Clear delta of a register that scalar evolution widens
bpf, x86: Remove r0_on_stack from fetching atomics in arena
bpf: Remove BPF_F_ARENA_SCALAR
selftests/bpf: Remove tests for arena access through numbers
libbpf: Keep format strings of bpf_printk() in .rodata
libbpf: Remove .arena.data
...
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git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux
Pull more documentation updates from Jonathan Corbet:
"A handful of late-arriving changes, most of which were ready ahead of
the merge window:
- More Portuguese translation updates
- Some docs-build and self-test fixes
- Bring documentation for the user-space access primitives
in include/linux/uaccess.h into the docs build.
This revealed a number of malformed kerneldoc comments,
which are fixed in a subsequent tweak to uaccess.h"
* tag 'docs-7.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux:
uaccess: fix some erroneous kerneldoc comments
docs/translations/pt_BR: admin-guide: add efi-stub.rst
docs/translations/pt_BR: admin-guide: add kernel-parameters.rst
docs/translations/pt_BR: admin-guide: add bootconfig.rst
docs/translations/pt_BR: admin-guide: add perf-security.rst
docs/translations/pt_BR: admin-guide: add LSM/index.rst
docs/translations/pt_BR: admin-guide: add hw-vuln/index.rst
docs/translations/pt_BR: admin-guide: add cputopology.rst
docs/translations/pt_BR: admin-guide: add sysctl/index.rst
docs/translations/pt_BR: admin-guide: add sysfs-rules.rst
docs/translations/pt_BR: admin-guide: add features.rst
docs: pt_BR: process: translate userspace debugging guide
docs: kerneldoc.py: preserve headings in kernel-doc output
docs: xforms_lists: Handle DECLARE_KHOSER_PTR() struct members
docs: test_doc_build: don't select urllib3 yanked version
docs: test_doc_build: address pylint warnings
docs: test_doc_build: update it to support newer Sphinx versions
docs: test_doc_build: better handle python version
docs: admin-guide: Fix typo in kernel-parameters.txt
docs: core-api: include documentation from linux/uaccess.h
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The format strings of bpf_printk() moved from .rodata to .rodata.str for
one reason. .arena.data moved .rodata into arena, and helpers cannot read
strings from arena.
.arena.data is removed. Move the strings back to .rodata. As a result, an
object that has its own .rodata has one map less.
This reverts commit 373e1223ff00
("libbpf: Keep format strings of bpf_printk() in .rodata.str"). libbpf
1.8.0 has the strings in .rodata.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20261027190314.1440199-4-alexei.starovoitov@gmail.com
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Rust has no address spaces. Thus a global variable cannot have the __arena
attribute. The .arena.data section was a workaround. It told libbpf to do
two things:
- Move .data, .bss and .rodata into arena.
- Load the progs with BPF_F_ARENA_SCALAR.
The compiler must select the location of a variable, not libbpf. libbpf
already puts the .addr_space.1 section in arena. The __arena variables of C
are in this section, and LLVM can use it for Rust too. Until LLVM does
that, the global data of Rust progs stays in array maps.
This reverts commit 8ab58ed42b08 ("libbpf: Keep global data in arena when
the object has .arena.data"). libbpf 1.8.0 does not have the section.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20261027190314.1440199-3-alexei.starovoitov@gmail.com
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perf_mmap__read_event() updates prev as it consumes forward-buffer
records. perf_mmap__read_done() then overwrites prev with a fresh
producer head, even when unread records remain.
perf_kvm__mmap_read_idx() stops after 25 records per mmap and calls
read_done(). If more records are pending, prev advances past them. The
next drain starts at that new position and skips the unread remainder.
An event arriving after the last empty read_event() and before
read_done() can also be skipped. read_done() does not itself update the
kernel's data_tail.
Only refresh prev for overwrite buffers, which need the current head as
the end of the next backward read. Leave the forward cursor at the
consumed position.
Fixes: 53172f9057e92c9b ("perf kvm: Switch to new perf_mmap__read_event() interface")
Signed-off-by: Paul Moses <p@1g4.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
"Major changes:
- Introduce scalar evolution (SCEV) analysis in the verifier.
It infers how registers and stack slots change in a loop and lets
the verifier check bounded loops with induction variables as ranges
instead of walking every iteration. The number of processed insns
drops ten fold in programs with loops (Eduard Zingerman)
- Add 'callx' instruction: indirect call of a static BPF subprogram.
The address is taken with ld_imm64 or loaded from read-only data.
Supported by x86-64, arm64 and riscv64 JITs (Alexei Starovoitov, Pu
Lehui)
- Add unwind_goto and unwind_exit instructions, so that Rust panic or
C++ exception can run destructors of every frame it passes through.
The normal path is free of unwind code. Supported by x86-64 and
arm64 JITs (Alexei Starovoitov)
- Support programs compiled by rust-bpf: treat load and store through
a number as arena access with BPF_F_ARENA_SCALAR, accept rust names
in BTF (Alexei Starovoitov)
- Raise BPF program stack size from 512 bytes to 2 KiB on x86-64 and
arm64 (Kumar Kartikeya Dwivedi)
- Support struct, union and __int128 up to 16 bytes passed and
returned by value in BPF subprograms and kfuncs, and fix x86-64 and
arm64 trampolines for such arguments (Yonghong Song)
- Introduce a common way to attach struct_ops to a cgroup via
bpf_link. bpf_tcp_ops is the first user and mirrors TCP sock_ops
callbacks (Martin KaFai Lau, Amery Hung)
- Describe inlined functions in BTF. New kinds tell where the inline
sites are and how to fetch the arguments there.
CONFIG_DEBUG_INFO_BTF_INLINE keeps it apart from the main BTF in
.BTF.inline section or in btf_vmlinux_inline.ko (Alan Maguire)
- Fix many memory safety, lifetime and locking bugs in BPF core,
verifier, iterators, local storage, dynptr, devmap, cpumap and
seg6local (Josef Bacik, Alexei Starovoitov)
- Diff stat is dominated by selftests and by removal of
lib/test_bpf.c. Its 16k lines of instruction tests were converted
to BPF selftests that BPF CI runs on every architecture it covers
(Daniel Borkmann)
Other features and fixes:
- Add KASAN checks to memory accesses of JITed programs on x86-64
(Alexis Lothoré)
- Complete unification of helper, kfunc and subprog argument checks
in the verifier (Amery Hung)
- Add bpf_copy_from_user_mm[_str]() kfuncs (Anastasios Papagiannis)
- Various features and fixes (Daniel Borkmann):
- Add .bpf keyring for program signature verification, modelled
after dm-verity keyring, and support ML-DSA in signing tools
- Emit shorter and faster code in x86-64 JIT for patterns that
LLVM generates
- Fix various issues in gotox handling
- Let BPF LSM set xattrs at inode creation with bpf_inode_init_xattr()
(David Windsor, Daniel Borkmann)
- Use sleepable page allocation in sleepable arena paths. Fix races
between arena free, allocation and user page fault (Emil Tsalapatis)
- Switch BPF crypto from lskcipher to AES-CBC and AES-ECB libraries
(Eric Biggers)
- Add bpf_proactive_reclaim() kfunc (Hui Zhu)
- Render decl_tags in libbpf btf_dump and add tests for bpftool C
dump (Ihor Solodrai)
- Speed up tracing_multi attach on x86 (Jiri Olsa)
- Various features and fixes (Kumar Kartikeya Dwivedi):
- Add BPF_PROG_STREAM_OPEN command to read BPF streams through a
file descriptor with poll support
- Let kernel structs publish arena pointers with __arena type tag
- Fix __uninit kfunc output buffers and fastcall rewrite with
indirect stack accesses
- Refuse CO-RE relocations for signed programs
- Add enqueue_rcvq and dequeue_rcvq hooks to bpf_tcp_ops to adjust
sk_rcvlowat and avoid unnecessary wakeups (Kuniyuki Iwashima)
- Add bpf_ksock_sendto() kfunc and allow ksock connect and send from
bpf_wq (Mahe Tardy)
- Fix racy plt target update in arm64 bpf_arch_text_poke()
(Matthew Wood)
- Restructure BPF selftests Makefile as a layered build
(Mykola Lysenko)
- Speed up hash map lookups for u32 and u64 keys (Mykyta Yatsenko)
- Add signed div/mod, movsx, bswap and gotol to MIPS JITs, signed
div/mod to parisc JITs (Nicholas Dudar, Johan Almbladh)
- Fix stack overflow in build ID parser on 32-bit (Nickolai
Zeldovich)
- Add stack arguments, signed arena loads and gotox to riscv64 JIT.
Pu Lehui is now co-maintainer of riscv BPF JITs (Pu Lehui, Chen
Pei, Feng Jiang)
- Add bpf_call_rcu() and bpf_call_rcu_tasks_trace() kfuncs. Support
fetching and/or/xor atomics in arena on x86-64 (Puranjay Mohan)
- Fix flaky selftests, selftests with clang 23 and bpf-gcc
(Qiliang Yuan, KaFai Wan, Vineet Gupta)
- Fix builds broken by fatal resolve_btfids warnings, BTF generation
on ARC, and define arch_cmpxchg_local() on arc, hexagon and
openrisc (Sasha Levin)
- Reduce memory use of hash maps by up to 50% per element
(T.J. Mercier)
- Mark pointer fields of sched_ext ops arguments as trusted (Tejun
Heo)
- Remove legacy bpf_asm, bpf_dbg and bpf_jit_disasm tools (Xia Yan)
- Fix index overflow in queue and stack maps, arena range tree after
allocation failure, tail call loop after freplace detach, lost
signal in bpf_send_signal() (Yuan Chen)
- Many more fixes and cleanups"
* tag 'bpf-next-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (660 commits)
selftests/bpf: Time tc_edt from its first packet with data
selftests/bpf: Test unwind_exit of an exception callback
selftests/bpf: Tests for 32-bit scalar evolution bounds computation
bpf: Reject unwind_goto and unwind_exit in offloaded progs
bpf: Support 32-bit linear scalar evolution
bpf: Make unwind_exit of an exception callback exit in JITs
selftests/bpf: Test forbidden bpf_ksock_sendto() LSM attach
selftests/bpf: Test ksock sendto()
bpf: Add bpf_ksock_sendto() kfunc
selftests/bpf: Test unwinding from R0: R2 subprog
selftests/bpf: Add a C++ prog with exceptions
selftests/bpf: Add tests for unwind_goto and unwind_exit
bpf, arm64: Support unwind_goto and unwind_exit
bpf, x86: Support unwind_goto and unwind_exit
bpf: Add unwind_goto and unwind_exit insns
tools/bpf: Remove legacy BPF tools
bpf: Annotate data races on bpf_lru_node type
selftests/bpf: Add arena allocation race tests
bpf: Fix arena race between page free and alloc leading to incoherency
bpf: Revalidate faulted arena pages before installing user mappings
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "selftests/mm: improve khugepaged coverage" (Kiryl Shutsemau):
Give khugepaged a proper workout. Extend the tests to all supported
mTHP orders, check exactly which windows collapsed, and make scan
completion deterministic. Race collapse against faults, pinning, fork
and remap; verify that the contents survive.
Add coverage for whole-page-table zaps and memory pressure too.
- "selftests/mm: separate GUP microbenchmarking from functional testing"
(Sarthak Sharma):
Untangle GUP benchmarking from correctness testing. Move the
benchmark into tools/mm, add a standalone harness-based GUP selftest,
and move shared helpers into tools/lib/mm. Give each tool one job
instead of mixing timing measurements with correctness checks.
Cover the mapping, pinning and batch-size combinations explicitly.
- "mm: Switch device DAX to section-based vmemmap optimization" (Muchun
Song):
Apply section-based vmemmap optimization to device DAX. Rework the
backing metadata layout to save memory while preserving the handling
of device memory hotplug and its different alignment and lifetime
requirements.
- "mm: Introduce section-based vmemmap optimization for HugeTLB"
(Muchun Song):
Cut the memory consumed by HugeTLB's struct page array with
section-based vmemmap optimization. Arrange the metadata so large
huge pages need fewer backing pages, while keeping initialization,
teardown and the various hugepage configurations straight.
- "mm/huge_memory: clean up and decouple the anon and file split
helpers" (Kairui Song):
Separate anonymous and file-backed folio splitting, which have rather
different locking and bookkeeping requirements. Move the work into
separate helpers, drop dead checks and tidy swap-cache handling. Fix
error paths, including one that could leave a folio frozen.
Keep the swap cache cases separate from file-cache splitting.
- "mm: Unconditional per-VMA locks and cleanups" (Dave Hansen):
Make per-VMA locking unconditional and clean up the old conditional
code around it. This removes configuration-dependent plumbing and
lets callers depend on one locking model rather than carrying both
cases along.
- "memcg: remove the v1 soft limit" (Shakeel Butt):
Remove the old cgroup v1 memory soft-limit machinery. This has long
since been superseded by the newer memory-control interfaces; hauling
around a separate reclaim scheme for it no longer buys us much.
- "read proc/pid/smaps_rollup under per-vma lock" (Suren Baghdasaryan):
Read /proc/PID/smaps_rollup using per-VMA locks where possible,
rather than holding mmap_lock across the entire walk. Retain the
contention fallback and add tearing tests. This considerably reduces
latency when another thread is busy changing its mappings.
- "mm/damon: introduce data access-as-a-data attribute" (SJ Park):
Teach DAMON to expose memory access observations as data attributes,
making them available to the probe and filtering machinery. Extend
the interfaces, documentation and tests so the new information can be
used rather than merely collected.
- "Remove PG_private by using page/folio->private checks instead" (Zi
Yan):
Get rid of PG_private and use the folio's private pointer to say
whether private data is attached. Convert the filesystem users,
including erofs, f2fs and md, and clean up the old accessors and
flags. There are a few special cases, notably swapcache and hugetlb,
which need explicit care.
- "mm: make userland page table freeing RCU-safe" (Lorenzo Stoakes):
Make freeing userspace page tables safe against RCU readers. Sort out
the page-table lifetime and locking rules so walkers cannot stumble
over freed tables while mappings are being torn down.
- "make unused huge shrinker memcg aware" (Qi Zheng):
Make shmem's unused-huge-folio shrinker aware of memory cgroups, so
reclaim can find those folios under the right memcg. Wire up the
per-memcg tracking and its lifetime rules, and give the shrinklist
its own lockdep class to avoid spurious dependency reports.
- "mm: Drop pxd_ERROR()" (Anshuman Khandual):
Remove the old pxd_ERROR() page-table checks and their
architecture-specific baggage. Simplify the common page-table
interfaces and callers now that these checks no longer serve a
useful purpose.
- "memcg: group struct fields by access pattern" (Shakeel Butt):
Rearrange memcg's hot and cold fields according to how they're
actually accessed. Keep frequently updated counters and their
neighboring state from fighting over cachelines and reduce needless
cacheline traffic.
- "mm/damon/core: fix the size charged for a filter-trimmed region"
(Donggeun Yoo):
Fix DAMOS quota accounting when a filter trims a monitoring region.
Charge only the part left after filtering, not the original region,
and add KUnit coverage. Previously the excluded memory could eat into
the quota and make schemes run more slowly than requested.
- "mm/damon: add kunit and selftests for probes and probe weights" (SJ
Park):
Add more tests for DAMON probes and their weights, including
validation and the results reported to userspace. This is mostly
about catching regressions in the newer probe infrastructure before
they become harder to diagnose.
- "mm: memcontrol: constify the read side of the read side of the memcg
API" (Tal Zussman):
Mark the read-only parts of the memcg interface const, from folio and
lruvec accessors to counters and swap helpers. Most of this is
mechanical, but it makes the contracts clearer and lets the compiler
catch accidental writes.
- "mm/damon/vaddr: support {prep,apply}_probes" (SJ Park):
Support the new prepare/apply probe operations in DAMON's
virtual-address backend. This brings vaddr monitoring into line with
the probe infrastructure and makes the added probe types useful there
too.
- "mm/mglru: clean up folio counters and flag usage" (Kairui Song):
Simplify MGLRU's folio counters and flag handling. Remove redundant
accounting paths and make the state transitions easier to follow
without changing the intended reclaim policy.
- "arch, mm/execmem: resolve confusion about set_direct_map_valid_noflush()"
(Mike Rapoport (Microsoft)):
Clarify and straighten out the set_direct_map_valid_noflush()
interface across architectures and execmem. Make the requested
mapping changes and the callers' expectations agree, rather than
relying on subtly different architecture behavior.
- "mm: zswap: free cold writeback folios promptly" (Alexandre Ghiti):
Free zswap writeback folios as soon as their disk write completes.
They are cold temporary buffers, so putting them on the LRU only
makes reclaim rediscover them later. Extend swap-cache dropbehind and
let zswap keep these folios off the LRU altogether.
- "mm: gup: cleanup gup_fast call chain" (Aristeu Rozanski):
Clean up the GUP-fast call chain and simplify how the fast-path
helpers pass their arguments and results around. Keep the page-pin
behavior the same while making the call sequence easier to maintain.
- "mm: optimize zone-device memmap initialization" (Li Zhe):
Speed up initialization of zone-device struct pages. Avoid redundant
work when setting up large device-memory ranges, where touching every
descriptor can get expensive.
- "mm/zswap: shrink zswap_entry via a pool id" (Jianyue Wu):
Reduce the size of zswap_entry by storing a compact pool identifier
instead of a full pointer. Keep the pool lookup and lifetime handling
correct while saving per-entry metadata.
- "mm/damon: support access monitoring of hugetlb-backed memory"
(Krishna Iyer):
Let DAMON monitor hugetlb-backed memory too. Extend the relevant
access checks and add coverage so those mappings no longer fall
through a hole in the monitoring machinery.
- "mm/execmem: fixes and cleanups for the ROX cache" (Mike Rapoport):
Tidy execmem's read-only-executable cache and fix its handling of the
awkward allocation and release cases. The aim is to make the cache's
ownership and permission transitions more predictable.
- "zsmallc: remove old object read API" (Sergey Senozhatsky):
Drop zsmalloc's old object-read API and move its remaining users to
the supported access mechanism. This removes a duplicate interface
which we no longer need.
- "mm/mempolicy: stop copying state in the interleave paths" (Gregory
Price):
Stop copying mempolicy state in the interleave paths when a reference
to the existing policy will do. This avoids extra work and makes the
ownership rules less obscure.
- "mm/mglru: speed up inc_min_seq() and fix cold/hot inversions" (Barry
Song):
Make MGLRU's generation advancement cheaper and fix cases where cold
and hot folios end up in the wrong order. Adjust the counter and list
handling so reclaim doesn't keep passing over the better eviction
candidates.
- "mm: Fix MF_DELAYED handling on memory failure" (Lisa Wang):
Treat MF_DELAYED as a partially completed memory-failure operation,
not an outright failure. Propagate that result correctly through
shmem and the generic handler, fix the extra-reference accounting,
and add tests for the resulting SIGBUS behavior.
- "tools/mm/page_owner_sort: fix --sort, add module filter, improve
usage" (Ye Liu):
Fix page_owner_sort's --sort handling, add module-based filtering and
make the usage output more helpful. This makes the tool less
frustrating when tracking down who is holding on to pages.
- "mm/damon: move damos filter range arguments validation to core" (SJ
Park):
Move DAMOS filter range validation into the core, where all callers
can share it. Also close the sysfs read-twice races which could pass
inconsistent ranges, and add tests for invalid input.
- "mm/damon: misc cleanups" (Zenghui Yu):
Clean up a collection of small DAMON rough edges in the core,
interfaces and tests. No large behavior change here, just simpler
code and fewer opportunities for confusion.
- "mm/damon: cleanup code, add test cases, and update guidances in
docs" (SJ Park):
Clean up DAMON's core and interfaces, add missing test cases and
bring the documentation into line with the code. These changes should
make the newer facilities easier to understand and maintain.
- "mm/damon: introduce hugepage_size probe filter" (SJ Park):
Add a DAMON probe filter for hugepage size. Let users select a range
of folio sizes through sysfs, validate the range and document the new
interface, so monitoring can concentrate on memory backed by the
desired hugepage sizes.
- "selftests/mm: pagemap_ioctl test fixes and cleanups" (Zenghui Yu):
Fix some pagemap ioctl test assumptions and clean up their setup and
reporting. Make failures point to the operation that went wrong
rather than to test harness bookkeeping.
- "mm: avoid large folio splits when swap is unavailable" (Johannes
Weiner):
Avoid splitting large folios merely to attempt swap when no swap
space is available. There is little point paying for an expensive
split when reclaim cannot actually swap the resulting pages out.
- "mm: workingset: fix the shadow node budget under MGLRU" (Hui Zhu):
Fix the workingset shadow-node budget with MGLRU enabled. Keep the
shadow entries within the intended limits so refault tracking does
not quietly consume more metadata than it should.
- "selftests/mm: TAP output and global-state fixes" (Song Hu):
Fix selftests which produce misleading TAP output or fail to restore
global settings after a run. A test ought to leave the system as it
found it, particularly when a whole suite follows behind.
- "mm: remove page_swap_entry()" (Tal Zussman):
Remove page_swap_entry() and convert its remaining users to the folio
and swap-entry helpers. Lose an old page-level interface and make the
swap paths a little more consistent.
- "mm: refactor zonelist constructors and iterators" (Gregory Price):
Refactor the zonelist construction and walk helpers to reduce
duplicated logic. Keep the allocation ordering rules intact while
making it clearer how zones are selected.
- "mm: kmemleak: batch the struct page scan" (Breno Leitao):
Scan adjacent struct pages in batches instead of taking kmemleak_lock
once for every single page. This preserves scan coverage and the
lock-hold bound, while cutting overhead substantially on debug
kernels.
- "mm/damon: misc improvements in tests and documents" (Zenghui Yu):
Fix some DAMON selftests which leave kdamond running or fail under
Python safe-path mode, and improve the KUnit coverage and
documentation. Nothing especially glamorous, but these are worth
doing.
- "mm/damon: introduce probe_hits_wsum DAMOS core filter" (SJ Park):
Add a DAMOS core filter using weighted probe-hit counts. This gives
schemes another way to select regions based on what the monitoring
probes observed.
- "mm/mglru: fix ineffective memory protection for non-kswapd reclaim"
(Ridong Chen):
Fix MGLRU's memory protection handling for reclaim outside kswapd.
The protection settings weren't having the intended effect in these
paths, leaving protected memory more exposed than requested.
- "mm/damon: improve readability, clarity and test coverage" (SJ Park):
Simplify a handful of DAMON core helpers, clarify their behavior and
expand test coverage. There are no intended userspace-visible changes
in this batch.
- "mm: replace PF_KCOMPACTD/PF_KSWAPD with kthread_func()" (Kefeng
Wang):
Stop identifying reclaim and compaction workers through the PF_KSWAPD
and PF_KCOMPACTD task flags. Use their kthread functions instead and
remove the redundant flag plumbing.
- "mm/hugetlb: fix surplus accounting and availability checks during
demotion" (Longlong Xia):
Fix HugeTLB surplus accounting and availability checks when demoting
huge pages. Keep the counters and reservation decisions consistent as
one huge page turns into several smaller ones.
- "mm/damon: add kunit tests for probe_hits handling and probe params
validation" (Jason Angelov):
Add KUnit tests for DAMON probe-hit handling and invalid probe
parameters. These cover edge cases that were too easy to miss in
ordinary monitoring tests.
- "mm/damon: fix misc bugs in kunit, quota goals and sysfs refresh_ms"
(SJ Park):
Fix a few DAMON bugs in KUnit tests, quota-goal handling and the
sysfs refresh interval. Small fixes, but the incorrect results and
control behavior were real.
- "mm: zswap: optimize zswap invalidate and store" (Kefeng Wang):
Simplify zswap's invalidate and store paths to avoid avoidable
lookups and work. Keep the entry lifetime rules intact while making
those frequent operations cheaper.
- "mm: replace custom ratelimiting logic" (Pedro Falcato):
Replace hand-rolled MM rate limiting with the common kernel helpers.
There is no need to maintain another local version of the same
mechanism.
- "mm/vmalloc: minor cleanups" (Ye Liu):
Tidy some vmalloc initialization and reporting code, and pull
duplicated vmap-area insertion work into a helper. No functional
changes are intended.
- "mm/mglru: clean up isolate_folios for readability and clarity"
(Ridong Chen):
Clean up MGLRU's isolate_folios() so the decisions are easier to read
and verify. Keep reclaim behavior unchanged while removing
unnecessary twists in the control flow.
- "Catch automatic storage in IDA and Maple Tree definitions" (Yury
Norov):
Catch IDA and maple-tree definitions placed in automatic storage
where the lifetime rules are wrong or easy to get wrong. Add checks
so such mistakes are harder to slip through unnoticed.
- "mm, swap: some random fixes and cleanups" (Kemeng Shi):
Fix and simplify a few unrelated swap paths, removing redundant work
and tidying up error handling. A small collection of things which
were better fixed than left lying around.
- "mm/page_io: folio conversion cleanups" (Tal Zussman):
Finish some page-to-folio conversions in swap I/O, removing obsolete
wrappers and using folio operations consistently. The I/O behavior is
intended to remain the same.
- "mm/swap: skip empty clusters in the swapoff scan" (Youngjun Park):
Skip empty swap clusters during swapoff instead of walking slots
which have nothing to release. This avoids pointless work on sparsely
used swap devices.
- "mm: trace: decode architecture-specific VMA flags" (Meijing Zhao):
Teach the VMA trace output to decode architecture-specific flags,
rather than leaving them as unexplained bits. That should make
tracing a good deal more useful when debugging unusual mappings.
- "mm, swap: don't spin on a bad swap entry" (Breno Leitao):
Stop repeatedly retrying a swap entry which is already known to be
bad. Make the error path terminate cleanly instead of wasting CPU
chasing an entry that cannot be used.
- "mm/page_isolation: fix UBSAN shift-out-of-bounds in
isolate_single_pageblock" (Qi Xi):
Fix an out-of-range shift in isolate_single_pageblock() and tighten
its associated boundary handling. UBSAN found the issue; the result
should be more robust pageblock isolation.
- "mm: khugepaged: fix tracepoint UAF" (Vernon Yang):
Fix a use-after-free in khugepaged tracepoint handling. Make sure the
information recorded by tracing stays valid for as long as the trace
event needs it.
- "mm/damon: fix DAMOS bugs in core, paddr and vaddr" (SJ Park):
Fix several DAMOS problems across the core and physical- and
virtual-address backends. The changes close error cases and bring the
implementations back into agreement.
- "mm/hugetlb_cgroup: move the per-node usage along with the folio"
(Hongfu Li):
Move HugeTLB per-node usage accounting when folios migrate between
nodes or are reparented to another cgroup. Otherwise numa_stat can
retain stale charges and even underflow when the folio is freed.
- "docs/core-api: memory-allocation: add k[mz]alloc_obj() and clarify
kmalloc" (Mike Rapoport):
Document the typed k[mz]alloc_obj() allocation helpers and clear up
some kmalloc guidance. Make it easier for callers to choose the right
interface.
- "selftests/mm: Validate selections and scope memfd_secret setup"
(Tianyi Chen):
Check selftest selections before running and confine memfd_secret
setup to the cases that actually need it. Avoid confusing failures
caused by the test harness itself.
- "mm/damon: move zero damos quota target_value handling to the core
layer" (SJ Park):
Handle a zero DAMOS quota goal target in the core rather than making
each user of the interface invent its own rule. Keep quota decisions
consistent across callers.
- "mm/damon: Introduce a huge page collapsing mechanism using auto
tuning" (Asier Gutierrez):
Add an auto-tuned DAMON mechanism for collapsing huge pages. Use
monitoring feedback to decide when collapse is worthwhile rather than
forcing one fixed policy onto every workload.
- "kmemleak: fix stale documentation and raise the verbose default"
(Breno Leitao):
Bring the kmemleak documentation up to date and require a third
confirming scan before verbose kernels print a suspected leak. The
extra scan helps suppress transient false positives in noisy debug
builds.
- "mm/memory: improve insert_pages() error handling" (Avi Weiss):
Tighten insert_pages() error handling so partial failures are
reported and cleaned up consistently. The caller should not have to
guess how far the operation got.
- "mm/damon: allow NULL or unstarted damon_ctx parameter for
damon_call()" (SJ Park):
Make damon_call() handle NULL and not-yet-started contexts safely.
Simplify the rules for callers and avoid an indefinite wait on an
invalid state.
- "mm/damon: introduce pgidle_set probe filter type" (SJ Park):
Add a pgidle_set DAMON probe filter, giving monitoring users another
way to select pages by their idle-tracking state. Wire it through the
filter interfaces and tests.
- "mm/damon/core: remove unused helper functions" (Cheng-Han Wu):
Remove DAMON core helpers which no longer have callers. Keep the API
surface smaller rather than retaining dead code just in case.
- "mm: stop calling pmd_folio() on special PMDs" (Gregory Price):
Avoid calling pmd_folio() on special PMD mappings that have no struct
page. The old assumption could fault in procfs walkers; use the
normal-folio checks and handle those mappings properly.
- "mm: remove three unused helpers from mm.h" (Tal Zussman):
Remove three unused helpers from mm.h. Fewer obsolete interfaces for
the next person to stumble over.
- "mm/damon: improvements in efficiency, error handling, documents"
(Liew Rui Yan):
Skip needless DAMOS quota work once the quota is full, propagate a
missing sysfs error and tidy a couple of comments. The ignored error
could make a monitoring-start request appear successful when it
wasn't.
- "docs/mm/damon/design: add explanation of nr_snapshots" (Liew Rui
Yan):
Explain DAMON's nr_snapshots accounting in the design documentation
and straighten out the associated terminology. Make it clearer what
users should expect from that counter.
- "selftests/cgroup: fixes for test_zswap on single core VM" (Wilson
Felipe Pereira):
Fix two test_zswap failures on single-CPU VMs. Wait for the exiting
child's cgroup to become unpopulated before reconfiguring it, and
avoid another test assumption which breaks under constrained
scheduling.
- "docs/ksm: fix advisor documentation and comment" (Jinjiang Tu):
Correct the KSM advisor documentation and a misleading code comment.
Keep the description aligned with how the advisor actually works.
- "Fix bugs in HugeTLB allocation when mem_cgroup_charge_hugetlb()
fails" (Ackerley Tng):
Fix HugeTLB allocation cleanup when the memcg charge fails. Make sure
failure exits undo what was allocated rather than leaving stale
accounting or resources behind.
- "mm, memcg: fix memory.peak reset clobbering other fds' watermark"
(Ridong Chen):
Fix memory.peak reset handling so resetting one file descriptor
doesn't overwrite the watermark kept for another. Keep those per-open
measurements independent as intended.
- "mm: reject zone device folios in more folio walkers" (Gregory
Price):
Reject zone-device folios in page walkers that cannot safely handle
them. Extend the existing checks rather than assuming every folio has
ordinary system-memory backing.
- "percpu: remove code with no effect" (Sang-Heon Jeon):
Remove a few pieces of percpu code which no longer do anything. There
is no reason to keep maintaining dead paths.
* tag 'mm-stable-2026-10-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (539 commits)
mm: shmem: assign a lock class to the unused huge shrinklist
mm: vmscan: put rotation-missed folios at the LRU tail
mm: kmemleak: scan the struct page array in MAX_SCAN_SIZE batches
mm: kmemleak: move the struct page scan into a helper
mm/damon: document that a zero sample_interval is accepted
mm/damon: fix typos in comments
mm/damon/sysfs: propagate damon_call() error in turn_damon_on
mm/damon/core: skip quota score setup when the quota is full
mm/damon/tests/core-kunit: test the size charged for a filter-trimmed region
mm/damon/core: charge only the part of a region the filter left
mm: disallow raw PFN mappings of huge/shared zeropage
selftests/mm: zap whole PTE tables in the khugepaged race harness
selftests/mm: add memory-pressure threads to the khugepaged race harness
selftests/mm: race the collapse of windows with holes
selftests/mm: add khugepaged race harness
selftests/mm: check that one khugepaged pass collapses one window
selftests/mm: run every supported collapse order by default
selftests/mm: cover a shared-source collapse write race
selftests/mm: parameterize the mixed-source collapse case by source order
selftests/mm: add order-parameterized khugepaged collapse cases
...
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KHO ABI structures declare their preservation pointers with
DECLARE_KHOSER_PTR(name, type), which expands to a union of the pointer
and its physical address. kernel-doc does not know the macro and does
not see the member: it warns that an unnamed member is not described
and that the description of the member is excess.
Translate DECLARE_KHOSER_PTR(name, type) into "type name", as is done
for DECLARE_KFIFO_PTR().
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Message-ID: <20261015020313.946940-1-pasha.tatashin@soleen.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild / Kconfig updates from Nathan Chancellor:
"Kbuild:
- Suppress compiler flags in debug info for external module builds
- Use '-fmacro-prefix-map' in more places in the build
- Merge initial set of changes from Lorenzo's speed up series, along
with some fixes found through testing:
- Avoid allocating .modinfo in vmlinux
- Speed up kallsyms by indexing symbols by token and outputting
binary data to disk directly then including in assembly via
.incbin
- Don't sort $(NM) output when unnecessary
- Only emit relocations on the final vmlinx link
- Reimplement mksysmap in C
- Move many cc-option and ld-option calls into the Kconfig stage to
cache their results
- Use pigz for gzip compression when available
- Move gen_init_cpio and gen_initramfs.sh from usr/ to scripts/
- Add a TOML configuration to scripts/container and update
documentation accordingly
- Add a generic, opt-in mechanism for checking that headers can
compile standalone
- Update machine function splitting argument for LLVM 24 rename in
AutoFDO build
- Miscellaneous minor clean ups, fixes, and hardening, mostly
found/fixed via LLMs
Kconfig:
- Turn recursive ranges into an error
- Fix savedefconfig for defaults that were adjusted for being out of
range and revert a previously applied workaround
- Improvements and hardening around integer and hexadecimal values
- Emit a warning when selecting or implying a choice symbol, which
has no effect
- Emit a warning when KCONFIG_PROBABILITY is malformed
- Introduce def_string / def_int / def_hex to mirror the existing
def_bool / def_tristate to succinctly set a value and type at the
same time.
- Add cc-option-str and ld-option-str macros to act like Kbuild's
cc-option and ld-option, returning the string when the option is
supported, allowing many checks to be moved into Kconfig
- Minor usability improvements to Kconfig tests"
* tag 'kbuild-7.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (59 commits)
kbuild: AutoFDO: Update split machine function argument for upstream rename
kbuild: Mark the initcall ordering recipe as recursive
kbuild: Mark the gzip recipes as recursive
localmodconfig: Explicitly report boolean configs during integrity check
scripts/make_fit: Ignore schema checks when decomposing DTBs
clang-tools: Import os for broken pipe handling
kconfig: use the value argument in sym_get_near_range_bound()
kconfig: fix infinite loop in conf_choice() when no choice value is visible
kconfig: cleanup stale comment about 'keys' array
kconfig: Improve ergonomics around disabling warnings with cc-option
scripts/Kconfig.toolchain: Drop compiler symbols from dependencies
checkkconfigsymbols.py: Parse Git status output line by line
gen_init_cpio: stop parsing on lines with a missing argument list
.gitignore: drop Module.markers
.gitignore: ignore pacman package signatures
kbuild: add header check facility as a manually run static analyzer
Documentation: dev-tools: refer to user ID rather than id
Documentation: dev-tools: update container.rst with config file
scripts: add TOML config to container tool
kconfig: tests: {old,save}defconfig: Forward dynamic keyword arguments
...
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Pull documentation updates from Jonathan Corbet:
"It was a reasonably busy cycle for docs; changes include:
- Add the AGENTS.md symbolic link into the top-level directory in the
hopes that LLMs will read it and produce better work
- The removal of the Assisted-by requirement, as concluded at the
Maintainer Summit
- A new "testdocs" make target to run the documentation unit tests
- Lots of work on the Portuguese, and Chinese translations; there is
now maintenance for the traditional Chinese translations as well
...and the usual pile of minor fixes, documentation updates, etc"
* tag 'docs-7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux: (125 commits)
docs: add AGENTS.md as a symlink to README
docs: kernel-parameters: adjust reserve_mem build option
docs: kernel-parameters: don't mix cmdline options & build options
docs/ja_JP: translate submitting-patches.rst (review and report tags)
docs: remove Assisted-by references
Revert "docs: landlock: fix ENOMSG condition in create_ruleset kernel-doc"
docs: kdoc: parse context_lock_struct() as struct declaration
docs: timers: hpet: Document userspace API and ioctl commands
docs: timers: hpet: Modernize file references
Documentation: sched-preemption: Add a SPDX license identifier
docs: ABI: sysfs-driver-xdata: use literal blocks for console commands
docs: ABI: sysfs-class-firmware-attributes: use literal blocks for console commands
ABI: sysfs-bus-usb: use literal block for console commands
docs/ABI: testing: aspeed-uart-routing: use literal block for console commands
docs: kernel-parameters: fix a truncated sentence for preempt=lazy
sched/doc: add a preemption model overview
docs: ABI: TMR manager: use literal blocks for console I/O
Documentation/ABI: IFS: use literal blocks for commands
ABI: sysfs-bus-pci: use literal blocks for commands
docs: translations: pt_BR: add debugging index
...
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First merge in the window to do a first batch of header syncs and check
integration with libbpf, etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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A kernel struct member tagged __arena reaches a program built against
vmlinux.h as a pointer in the kernel address space with the tag as an
attribute, struct scx_cmask __attribute__((btf_type_tag("arena"))) *cmask,
so the program casts it to the arena address space before dereferencing
it, although the verifier already hands it an arena pointer.
The tag denotes a pointer into the BPF arena, address_space(1) to the
compiler, so render it as such: __attribute__((address_space(1)))
followed by the tag attribute as before, which keeps the dump faithful
to the BTF. A program then reads the member as an arena pointer and
hands it to anything declared with its own __arena without a cast.
Nothing else changes for consumers of the C dump. Skeletons strip the
modifiers of variable types and never carried the tag. Clang without
casts between address spaces still accepts the declaration and only a
program touching such a member would need a cast there, as it did for
every arena pointer before. GCC has no address spaces for BPF and warns,
under -Wattributes, that it ignores the attribute, which the selftests
build already silences.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20261019132203.3034698-15-memxor@gmail.com
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A program has an arena only when one of its insns refers to the arena
map. The kernel can hand a program arena pointers all the same: as
__arena struct_ops arguments, through __arena struct members and as
kfunc return values. The verifier rejects those in a program without an
arena, since it has nowhere to place them, and so a struct_ops callback
that touches nothing but its arguments fails to load until it refers to
the arena artificially, e.g. with asm volatile("" :: "r"(&arena)).
Bind the arena of an object to every program loaded from it. The kernel
binds the maps of a continuous fd_array (fd_array_cnt) like maps an insn
refers to, so pass the arena in slot 0, which is free: a kfunc insn with
offset 0 names vmlinux BTF rather than a slot. The module BTF slots that
follow stay as they are. A feature probe keeps older kernels, which
reject a non-zero fd_array_cnt, on the previous behavior.
An object has at most one arena, libbpf refuses a second one, so there
is no ambiguity about which arena a program gets. Programs that never
touch the arena see it among their maps, and pay for the arena base
setup in their JIT prologue until a later patch spares them that; the
arena now lives as long as any program of the object. With the count,
the kernel also resolves every module BTF slot of the array for every
program of the object, so each of them holds the modules the object
calls into, not only the programs that call them. Where the JIT is
disabled or the loader lacks CAP_PERFMON, every program of such an
object now fails to load, since an arena needs both, where before only
the programs using the arena did. bpf_program__clone() binds the arena
the same way, so a program loads through veristat as it does through
bpf_object__load(). An arena exclusive to another program and the
light skeleton loader are left alone.
An arena exclusive to the program itself is bound only where the kernel
checks an exclusive map against the digest of the final program. Earlier
kernels compared a map bound through the fd_array against a digest they
had not computed yet and refused the load for the very program the map
is exclusive to, so a second probe loads a program with a map exclusive
to it through fd_array_cnt; where that fails, the program keeps binding
its arena through its insns, as before.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link |
