linux-rng/tools/perf, branch master

Merge tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-12-02T04:18:59Z

Pull objtool updates from Ingo Molnar: - klp-build livepatch module generation (Josh Poimboeuf) Introduce new objtool features and a klp-build script to generate livepatch modules using a source .patch as input. This builds on concepts from the longstanding out-of-tree kpatch project which began in 2012 and has been used for many years to generate livepatch modules for production kernels. However, this is a complete rewrite which incorporates hard-earned lessons from 12+ years of maintaining kpatch. Key improvements compared to kpatch-build: - Integrated with objtool: Leverages objtool's existing control-flow graph analysis to help detect changed functions. - Works on vmlinux.o: Supports late-linked objects, making it compatible with LTO, IBT, and similar. - Simplified code base: ~3k fewer lines of code. - Upstream: No more out-of-tree #ifdef hacks, far less cruft. - Cleaner internals: Vastly simplified logic for symbol/section/reloc inclusion and special section extraction. - Robust __LINE__ macro handling: Avoids false positive binary diffs caused by the __LINE__ macro by introducing a fix-patch-lines script which injects #line directives into the source .patch to preserve the original line numbers at compile time. - Disassemble code with libopcodes instead of running objdump (Alexandre Chartre) - Disassemble support (-d option to objtool) by Alexandre Chartre, which supports the decoding of various Linux kernel code generation specials such as alternatives: 17ef: sched_balance_find_dst_group+0x62f mov 0x34(%r9),%edx 17f3: sched_balance_find_dst_group+0x633 | | X86_FEATURE_POPCNT 17f3: sched_balance_find_dst_group+0x633 | call 0x17f8 <__sw_hweight64> | popcnt %rdi,%rax 17f8: sched_balance_find_dst_group+0x638 cmp %eax,%edx ... jump table alternatives: 1895: sched_use_asym_prio+0x5 test $0x8,%ch 1898: sched_use_asym_prio+0x8 je 0x18a9 189a: sched_use_asym_prio+0xa | | JUMP 189a: sched_use_asym_prio+0xa | jmp 0x18ae | nop2 189c: sched_use_asym_prio+0xc mov $0x1,%eax 18a1: sched_use_asym_prio+0x11 and $0x80,%ecx ... exception table alternatives: native_read_msr: 5b80: native_read_msr+0x0 mov %edi,%ecx 5b82: native_read_msr+0x2 | | EXCEPTION 5b82: native_read_msr+0x2 | rdmsr | resume at 0x5b84 5b84: native_read_msr+0x4 shl $0x20,%rdx .... x86 feature flag decoding (also see the X86_FEATURE_POPCNT example in sched_balance_find_dst_group() above): 2faaf: start_thread_common.constprop.0+0x1f jne 0x2fba4 2fab5: start_thread_common.constprop.0+0x25 | | X86_FEATURE_ALWAYS | X86_BUG_NULL_SEG 2fab5: start_thread_common.constprop.0+0x25 | jmp 0x2faba <.altinstr_aux+0x2f4> | jmp 0x4b0 | nop5 2faba: start_thread_common.constprop.0+0x2a mov $0x2b,%eax ... NOP sequence shortening: 1048e2: snapshot_write_finalize+0xc2 je 0x104917 1048e4: snapshot_write_finalize+0xc4 nop6 1048ea: snapshot_write_finalize+0xca nop11 1048f5: snapshot_write_finalize+0xd5 nop11 104900: snapshot_write_finalize+0xe0 mov %rax,%rcx 104903: snapshot_write_finalize+0xe3 mov 0x10(%rdx),%rax ... and much more. - Function validation tracing support (Alexandre Chartre) - Various -ffunction-sections fixes (Josh Poimboeuf) - Clang AutoFDO (Automated Feedback-Directed Optimizations) support (Josh Poimboeuf) - Misc fixes and cleanups (Borislav Petkov, Chen Ni, Dylan Hatch, Ingo Molnar, John Wang, Josh Poimboeuf, Pankaj Raghav, Peter Zijlstra, Thorsten Blum) * tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits) objtool: Fix segfault on unknown alternatives objtool: Build with disassembly can fail when including bdf.h objtool: Trim trailing NOPs in alternative objtool: Add wide output for disassembly objtool: Compact output for alternatives with one instruction objtool: Improve naming of group alternatives objtool: Add Function to get the name of a CPU feature objtool: Provide access to feature and flags of group alternatives objtool: Fix address references in alternatives objtool: Disassemble jump table alternatives objtool: Disassemble exception table alternatives objtool: Print addresses with alternative instructions objtool: Disassemble group alternatives objtool: Print headers for alternatives objtool: Preserve alternatives order objtool: Add the --disas= action objtool: Do not validate IBT for .return_sites and .call_sites objtool: Improve tracing of alternative instructions objtool: Add functions to better name alternatives objtool: Identify the different types of alternatives ...

perf libbfd: Ensure libbfd is initialized prior to use

2025-11-13T20:55:19Z

Multiple threads may be creating and destroying BFD objects in situations like `perf top`. Without appropriate initialization crashes may occur during libbfd's cache management. BFD's locks require recursive mutexes, add support for these. Committer testing: This happens only when building with 'make BUILD_NONDISTRO=1' and having the binutils-devel package (or equivalent) installed, i.e. linking with binutils devel files, an opt-in perf build. Before: root@x1:~# perf top perf: Segmentation fault -------- backtrace -------- root@x1:~# After this patch it works as before. Closes: https://lore.kernel.org/lkml/aQt66zhfxSA80xwt@gentoo.org/ Fixes: 95931d9a594dd0b5 ("perf libbfd: Move libbfd functionality to its own file") Reported-by: Guilherme Amadio Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf test: Fix lock contention test

2025-11-13T20:29:00Z

Couple of independent fixes: 1. Wire in SIGSEGV handler that terminates the test with a failure code. 2. Use "--lock-cgroup" instead of "-g"; "-g" was proposed but never merged. See commit 4d1792d0a2564caf ("perf lock contention: Add --lock-cgroup option") 3. Call cleanup() on every normal exit so trap_cleanup() doesn't mistake it for an unexpected signal and emit a false-negative "Unexpected signal in main" message. Before patch: # ./perf test -vv "lock contention" 85: kernel lock contention analysis test: --- start --- test child forked, pid 610711 Testing perf lock record and perf lock contention Testing perf lock contention --use-bpf Testing perf lock record and perf lock contention at the same time Testing perf lock contention --threads Testing perf lock contention --lock-addr Testing perf lock contention --lock-cgroup Unexpected signal in test_aggr_cgroup ---- end(0) ---- 85: kernel lock contention analysis test : Ok After patch: # ./perf test -vv "lock contention" 85: kernel lock contention analysis test: --- start --- test child forked, pid 602637 Testing perf lock record and perf lock contention Testing perf lock contention --use-bpf Testing perf lock record and perf lock contention at the same time Testing perf lock contention --threads Testing perf lock contention --lock-addr Testing perf lock contention --lock-cgroup Testing perf lock contention --type-filter (w/ spinlock) Testing perf lock contention --lock-filter (w/ tasklist_lock) Testing perf lock contention --callstack-filter (w/ unix_stream) [Skip] Could not find 'unix_stream' Testing perf lock contention --callstack-filter with task aggregation [Skip] Could not find 'unix_stream' Testing perf lock contention --cgroup-filter Testing perf lock contention CSV output ---- end(0) ---- 85: kernel lock contention analysis test : Ok Reviewed-by: Ian Rogers Signed-off-by: Ravi Bangoria Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ananth Narayan Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Cc: Santosh Shukla Cc: Tycho Andersen Signed-off-by: Arnaldo Carvalho de Melo

perf lock: Fix segfault due to missing kernel map

2025-11-13T20:17:41Z

Kernel maps are encoded in PERF_RECORD_MMAP2 samples but "perf lock report" and "perf lock contention" do not process MMAP2 samples. Because of that, machine->vmlinux_map stays NULL and any later access triggers a segmentation fault. Fix it by adding ->mmap2() callbacks. Fixes: 53b00ff358dc75b1 ("perf record: Make --buildid-mmap the default") Reported-by: Tycho Andersen (AMD) Reviewed-by: Ian Rogers Signed-off-by: Ravi Bangoria Tested-by: Tycho Andersen (AMD) Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ananth Narayan Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sandipan Das Cc: Santosh Shukla Signed-off-by: Arnaldo Carvalho de Melo

perf build: Don't fail fast path feature detection when binutils-devel is not available

2025-11-13T20:16:34Z

This is one more remnant of the BUILD_NONDISTRO series to make building with binutils-devel opt-in due to license incompatibility. In this case just the references at link time were still in place, which make building the test-all.bin file fail, which wasn't detected before probably because the last test was done with binutils-devel available, doh. Now: $ rpm -q binutils-devel package binutils-devel is not installed $ file /tmp/build/perf-tools/feature/test-all.bin /tmp/build/perf-tools/feature/test-all.bin: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=4b5388a346b51f1b993f0b0dbd49f4570769b03c, for GNU/Linux 3.2.0, not stripped $ Fixes: 970ae86307718c34 ("perf build: The bfd features are opt-in, stop testing for them by default") Reviewed-by: Ian Rogers Cc: Adrian Hunter Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf header: Write bpf_prog (infos|btfs)_cnt to data file

2025-11-13T20:16:33Z

With commit f0d0f978f3f5830a ("perf header: Don't write empty BPF/BTF info"), the write_bpf_( prog_info() | btf() ) functions exit without writing anything if env->bpf_prog.(infos| btfs)_cnt is zero. process_bpf_( prog_info() | btf() ), however, still expect a "count" value to exist in the data file. If btf information is empty, for example, process_bpf_btf will read garbage or some other data as the number of btf nodes in the data file. As a result, the data file will not be processed correctly. Instead, write the count to the data file and exit if it is zero. Fixes: f0d0f978f3f5830a ("perf header: Don't write empty BPF/BTF info") Reviewed-by: Ian Rogers Signed-off-by: Thomas Falcon Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

Merge tag 'v6.18-rc5' into objtool/core, to pick up fixes

2025-11-13T06:58:43Z

Signed-off-by: Ingo Molnar

perf symbols: Handle '1' symbols in /proc/kallsyms

2025-11-03T17:54:31Z

I started seeing this in recent Fedora 42 kernels: root@x1:~# uname -a Linux x1 6.17.4-200.fc42.x86_64 #1 SMP PREEMPT_DYNAMIC Sun Oct 19 18:47:49 UTC 2025 x86_64 GNU/Linux root@x1:~# root@x1:~# perf test 1 1: vmlinux symtab matches kallsyms : FAILED! root@x1:~# Related to: root@x1:~# grep ' 1 ' /proc/kallsyms ffffffffb098bc00 1 __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ ffffffffb098bc10 1 _RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ root@x1:~# That is found in: root@x1:~# pahole --running_kernel_vmlinux /usr/lib/debug/lib/modules/6.17.4-200.fc42.x86_64/vmlinux root@x1:~# root@x1:~# readelf -sW /usr/lib/debug/lib/modules/6.17.4-200.fc42.x86_64/vmlinux | grep __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ 150649: ffffffff81f8bc00 16 FUNC LOCAL DEFAULT 1 __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_ root@x1:~# But was being filtered out when reading /proc/kallsyms, as the '1' symbol type was not being handled, do it, there are just two of them at this point. Cc: Alex Gaynor Cc: Alice Ryhl Cc: Andreas Hindborg Cc: Benno Lossin Cc: Björn Roy Baron Cc: Boqun Feng Cc: Danilo Krummrich Cc: Gary Guo Cc: Miguel Ojeda Cc: Trevor Gross Signed-off-by: Arnaldo Carvalho de Melo

tools headers x86: Sync table due to introducion of uprobe syscall

2025-11-01T16:04:20Z

To pick the changes in this cset: 56101b69c9190667 ("uprobes/x86: Add uprobe syscall to speed up uprobe") That add support for this new 'uprobe' syscall in tools such as 'perf trace'. Now it is possible to do a system wide 'perf trace' to look if this new syscall is being used: root@number:~# perf trace -v -e uprobe event qualifier tracepoint filter: (common_pid != 33989) && (id == 336) ^C root@number# $ grep -w uprobe tools/perf/arch/x86/entry/syscalls/syscall_64.tbl 336 common uprobe sys_uprobe $ This addresses these perf build warnings: Warning: Kernel ABI header differences: diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl Please see tools/include/uapi/README for further details. Cc: Jiri Olsa Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

tools headers: Sync uapi/linux/fcntl.h with the kernel sources

2025-11-01T16:01:13Z

To pick up the changes in this cset: e83f0b5d10dcf628 ("nsfs: support exhaustive file handles") That doesn't introduce anything of interest for tools/, just addresses these perf build warnings: Warning: Kernel ABI header differences: diff -u tools/perf/trace/beauty/include/uapi/linux/fcntl.h include/uapi/linux/fcntl.h Please see tools/include/uapi/README for further details. Cc: Christian Brauner Signed-off-by: Arnaldo Carvalho de Melo