Bpftool sync 2026-04-10#254
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qmonnet merged 7 commits intolibbpf:mainfrom Apr 10, 2026
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The LLVM disassembler needs ISA extension features enabled to correctly decode instructions from those extensions. On aarch64, without these features, instructions like LSE atomics (e.g. ldaddal) are silently decoded as incorrect instructions and disassembly is truncated. Use LLVMCreateDisasmCPUFeatures() with "+all" features for aarch64 targets so that the disassembler can handle any instruction the kernel JIT might emit. Before: int bench_trigger_uprobe(void * ctx): bpf_prog_538c6a43d1c6b84c_bench_trigger_uprobe: ; int cpu = bpf_get_smp_processor_id(); 0: mov x9, x30 4: nop 8: stp x29, x30, [sp, #-16]! c: mov x29, sp 10: stp xzr, x26, [sp, #-16]! 14: mov x26, sp 18: mrs x10, SP_EL0 1c: ldr w7, [x10, libbpf#16] ; __sync_add_and_fetch(&hits[cpu & CPU_MASK].value, 1); 20: and w7, w7, #0xff ; __sync_add_and_fetch(&hits[cpu & CPU_MASK].value, 1); 24: lsl x7, x7, libbpf#7 28: mov x0, #-281474976710656 2c: movk x0, #32768, lsl libbpf#32 30: movk x0, #35407, lsl libbpf#16 34: add x0, x0, x7 38: mov x1, #1 ; __sync_add_and_fetch(&hits[cpu & CPU_MASK].value, 1); 3c: mov x1, #1 After: int bench_trigger_uprobe(void * ctx): bpf_prog_538c6a43d1c6b84c_bench_trigger_uprobe: ; int cpu = bpf_get_smp_processor_id(); 0: mov x9, x30 4: nop 8: stp x29, x30, [sp, #-16]! c: mov x29, sp 10: stp xzr, x26, [sp, #-16]! 14: mov x26, sp 18: mrs x10, SP_EL0 1c: ldr w7, [x10, libbpf#16] ; __sync_add_and_fetch(&hits[cpu & CPU_MASK].value, 1); 20: and w7, w7, #0xff ; __sync_add_and_fetch(&hits[cpu & CPU_MASK].value, 1); 24: lsl x7, x7, libbpf#7 28: mov x0, #-281474976710656 2c: movk x0, #32768, lsl libbpf#32 30: movk x0, #35407, lsl libbpf#16 34: add x0, x0, x7 38: mov x1, #1 ; __sync_add_and_fetch(&hits[cpu & CPU_MASK].value, 1); 3c: ldaddal x1, x1, [x0] ; return 0; 40: mov w7, #0 44: ldp xzr, x26, [sp], libbpf#16 48: ldp x29, x30, [sp], libbpf#16 4c: mov x0, x7 50: ret 54: nop 58: ldr x10, libbpf#8 5c: br x10 Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Acked-by: Leon Hwang <leon.hwang@linux.dev> Acked-by: Quentin Monnet <qmo@kernel.org> Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> Link: https://lore.kernel.org/r/20260318172259.2882792-1-puranjay@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BTF kind layouts provide information to parse BTF kinds. By separating parsing BTF from using all the information it provides, we allow BTF to encode new features even if they cannot be used by readers. This will be helpful in particular for cases where older tools are used to parse newer BTF with kinds the older tools do not recognize; the BTF can still be parsed in such cases using kind layout. The intent is to support encoding of kind layouts optionally so that tools like pahole can add this information. For each kind, we record - length of singular element following struct btf_type - length of each of the btf_vlen() elements following - a (currently unused) flags field The ideas here were discussed at [1], [2]; hence Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260326145444.2076244-2-alan.maguire@oracle.com [1] https://lore.kernel.org/bpf/CAEf4BzYjWHRdNNw4B=eOXOs_ONrDwrgX4bn=Nuc1g8JPFC34MA@mail.gmail.com/ [2] https://lore.kernel.org/bpf/20230531201936.1992188-1-alan.maguire@oracle.com/
Clarify bpf_ringbuf_discard() documentation for BPF_RB_NO_WAKEUP. Discarded ring buffer records are still left in the ring buffer and are only skipped when user space consumes them. This can matter when BPF_RB_NO_WAKEUP is used: a later submit relying on adaptive wakeup might not wake the consumer, because the discarded record still needs to be consumed first. Scenario: epoll_wait(rb_fd); // blocks rec = bpf_ringbuf_reserve(&rb, ...); bpf_ringbuf_discard(rec, BPF_RB_NO_WAKEUP); rec = bpf_ringbuf_reserve(&rb, ...); bpf_ringbuf_submit(rec, 0); // valid record, but no wakeup Document this in bpf_ringbuf_discard() to make the interaction between discarded records, user-space consumption, and adaptive wakeups explicit. Reported-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Signed-off-by: Eyal Birger <eyal.birger@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260331130612.3762433-1-eyal.birger@gmail.com ---- v2: adapt wording per feedback from Andrii.
Pull latest libbpf from mirror. Libbpf version: 1.8.0 Libbpf commit: dd92bef7f6c7a00bb0312554119b6d9cf38e4f32 Signed-off-by: Quentin Monnet <qmo@kernel.org>
Introduce SKIP_LLVM, SKIP_LIBBFD, and SKIP_CRYPTO build flags that let users build bpftool without these optional dependencies. SKIP_LLVM=1 skips LLVM even when detected. SKIP_LIBBFD=1 prevents the libbfd JIT disassembly fallback when LLVM is absent. Together, they produce a bpftool with no disassembly support. SKIP_CRYPTO=1 excludes sign.c and removes the -lcrypto link dependency. Inline stubs in main.h return errors with a clear message if signing functions are called at runtime. Use BPFTOOL_WITHOUT_CRYPTO (not HAVE_LIBCRYPTO_SUPPORT) as the C define, following the BPFTOOL_WITHOUT_SKELETONS naming convention for bpftool-internal build config, leaving HAVE_LIBCRYPTO_SUPPORT free for proper feature detection in the future. All three flags are propagated through the selftests Makefile to bpftool sub-builds. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20260312-b4-bpftool_build-v2-1-4c9d57133644@meta.com
Update it as one comment got realigned, probably in a merge, so no
changes in perf tooling, just silences this build warning:
Warning: Kernel ABI header differences:
diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Syncing latest bpftool commits from kernel repository.
Baseline bpf-next commit: ca0f39a369c5f927c3d004e63a5a778b08a9df94
Checkpoint bpf-next commit: a0c584fc18056709c8e047a82a6045d6c209f4ce
Baseline bpf commit: e06e6b8001233241eb5b2e2791162f0585f50f4b
Checkpoint bpf commit: d8a9a4b11a137909e306e50346148fc5c3b63f9d
Alan Maguire (1):
btf: Add BTF kind layout encoding to UAPI
Arnaldo Carvalho de Melo (1):
perf beauty: Update the linux/perf_event.h copy with the kernel
sources
Eyal Birger (1):
bpf: Clarify BPF_RB_NO_WAKEUP behavior for bpf_ringbuf_discard()
Mykyta Yatsenko (1):
bpftool: Allow explicitly skip llvm, libbfd and libcrypto dependencies
Puranjay Mohan (1):
bpftool: Enable aarch64 ISA extensions for JIT disassembly
include/uapi/linux/bpf.h | 4 +++-
include/uapi/linux/btf.h | 12 ++++++++++++
include/uapi/linux/perf_event.h | 2 +-
src/Makefile | 30 ++++++++++++++++++++++++++----
src/jit_disasm.c | 11 ++++++++++-
src/main.c | 7 +++++++
src/main.h | 14 ++++++++++++++
7 files changed, 73 insertions(+), 7 deletions(-)
Signed-off-by: Quentin Monnet <qmo@kernel.org>
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Pull latest libbpf from mirror and sync bpftool repo with kernel, up to the commits used for libbpf sync. This is an automatic update performed by calling the sync script from this repo: