kernel/tools/lib, branch linux-6.13.y

libbpf: Fix accessing BTF.ext core_relo header

2025-04-10T12:41:44Z

[ Upstream commit 0a7c2a84359612e54328aa52030eb202093da6e2 ] Update btf_ext_parse_info() to ensure the core_relo header is present before reading its fields. This avoids a potential buffer read overflow reported by the OSS Fuzz project. Fixes: cf579164e9ea ("libbpf: Support BTF.ext loading and output in either endianness") Signed-off-by: Tony Ambardar Signed-off-by: Andrii Nakryiko Link: https://issues.oss-fuzz.com/issues/388905046 Link: https://lore.kernel.org/bpf/20250125065236.2603346-1-itugrok@yahoo.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: Add namespace for errstr making it libbpf_errstr

2025-04-10T12:41:43Z

[ Upstream commit 307ef667e94530c2f2f77797bfe9ea85c22bec7d ] When statically linking symbols can be replaced with those from other statically linked libraries depending on the link order and the hoped for "multiple definition" error may not appear. To avoid conflicts it is good practice to namespace symbols, this change renames errstr to libbpf_errstr. To avoid churn a #define is used to turn use of errstr(err) to libbpf_errstr(err). Fixes: 1633a83bf993 ("libbpf: Introduce errstr() for stringifying errno") Signed-off-by: Ian Rogers Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250320222439.1350187-1-irogers@google.com Signed-off-by: Sasha Levin

libbpf: Fix hypothetical STT_SECTION extern NULL deref case

2025-04-10T12:41:40Z

[ Upstream commit e0525cd72b5979d8089fe524a071ea93fd011dc9 ] Fix theoretical NULL dereference in linker when resolving *extern* STT_SECTION symbol against not-yet-existing ELF section. Not sure if it's possible in practice for valid ELF object files (this would require embedded assembly manipulations, at which point BTF will be missing), but fix the s/dst_sym/dst_sec/ typo guarding this condition anyways. Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs") Fixes: a46349227cd8 ("libbpf: Add linker extern resolution support for functions and global variables") Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20250220002821.834400-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: Fix incorrect traversal end type ID when marking BTF_IS_EMBEDDED

2025-02-08T09:01:39Z

[ Upstream commit 5ca681a86ef93369685cb63f71994f4cf7303e7c ] When redirecting the split BTF to the vmlinux base BTF, we need to mark the distilled base struct/union members of split BTF structs/unions in id_map with BTF_IS_EMBEDDED. This indicates that these types must match both name and size later. Therefore, we need to traverse the entire split BTF, which involves traversing type IDs from nr_dist_base_types to nr_types. However, the current implementation uses an incorrect traversal end type ID, so let's correct it. Fixes: 19e00c897d50 ("libbpf: Split BTF relocation") Signed-off-by: Pu Lehui Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250115100241.4171581-3-pulehui@huaweicloud.com Signed-off-by: Sasha Levin

libbpf: Fix return zero when elf_begin failed

2025-02-08T09:01:39Z

[ Upstream commit 5436a54332c19df0acbef2b87cbf9f7cba56f2dd ] The error number of elf_begin is omitted when encapsulating the btf_find_elf_sections function. Fixes: c86f180ffc99 ("libbpf: Make btf_parse_elf process .BTF.base transparently") Signed-off-by: Pu Lehui Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250115100241.4171581-2-pulehui@huaweicloud.com Signed-off-by: Sasha Levin

libbpf: Fix segfault due to libelf functions not setting errno

2025-02-08T09:01:31Z

[ Upstream commit e10500b69c3f3378f3dcfc8c2fe4cdb74fc844f5 ] Libelf functions do not set errno on failure. Instead, it relies on its internal _elf_errno value, that can be retrieved via elf_errno (or the corresponding message via elf_errmsg()). From "man libelf": If a libelf function encounters an error it will set an internal error code that can be retrieved with elf_errno. Each thread maintains its own separate error code. The meaning of each error code can be determined with elf_errmsg, which returns a string describing the error. As a consequence, libbpf should not return -errno when a function from libelf fails, because an empty value will not be interpreted as an error and won't prevent the program to stop. This is visible in bpf_linker__add_file(), for example, where we call a succession of functions that rely on libelf: err = err ?: linker_load_obj_file(linker, filename, opts, &obj); err = err ?: linker_append_sec_data(linker, &obj); err = err ?: linker_append_elf_syms(linker, &obj); err = err ?: linker_append_elf_relos(linker, &obj); err = err ?: linker_append_btf(linker, &obj); err = err ?: linker_append_btf_ext(linker, &obj); If the object file that we try to process is not, in fact, a correct object file, linker_load_obj_file() may fail with errno not being set, and return 0. In this case we attempt to run linker_append_elf_sysms() and may segfault. This can happen (and was discovered) with bpftool: $ bpftool gen object output.o sample_ret0.bpf.c libbpf: failed to get ELF header for sample_ret0.bpf.c: invalid `Elf' handle zsh: segmentation fault (core dumped) bpftool gen object output.o sample_ret0.bpf.c Fix the issue by returning a non-null error code (-EINVAL) when libelf functions fail. Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20241205135942.65262-1-qmo@kernel.org Signed-off-by: Sasha Levin

libbpf: don't adjust USDT semaphore address if .stapsdt.base addr is missing

2025-02-08T09:01:30Z

[ Upstream commit 98ebe5ef6f5c4517ba92fb3e56f95827ebea83fd ] USDT ELF note optionally can record an offset of .stapsdt.base, which is used to make adjustments to USDT target attach address. Currently, libbpf will do this address adjustment unconditionally if it finds .stapsdt.base ELF section in target binary. But there is a corner case where .stapsdt.base ELF section is present, but specific USDT note doesn't reference it. In such case, libbpf will basically just add base address and end up with absolutely incorrect USDT target address. This adjustment has to be done only if both .stapsdt.sema section is present and USDT note is recording a reference to it. Fixes: 74cc6311cec9 ("libbpf: Add USDT notes parsing and resolution logic") Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20241121224558.796110-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libperf: evlist: Fix --cpu argument on hybrid platform

2024-12-11T17:19:44Z

Since the linked fixes: commit, specifying a CPU on hybrid platforms results in an error because Perf tries to open an extended type event on "any" CPU which isn't valid. Extended type events can only be opened on CPUs that match the type. Before (working): $ perf record --cpu 1 -- true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.385 MB perf.data (7 samples) ] After (not working): $ perf record -C 1 -- true WARNING: A requested CPU in '1' is not supported by PMU 'cpu_atom' (CPUs 16-27) for event 'cycles:P' Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cpu_atom/cycles:P/). /bin/dmesg | grep -i perf may provide additional information. (Ignore the warning message, that's expected and not particularly relevant to this issue). This is because perf_cpu_map__intersect() of the user specified CPU (1) and one of the PMU's CPUs (16-27) correctly results in an empty (NULL) CPU map. However for the purposes of opening an event, libperf converts empty CPU maps into an any CPU (-1) which the kernel rejects. Fix it by deleting evsels with empty CPU maps in the specific case where user requested CPU maps are evaluated. Fixes: 251aa040244a ("perf parse-events: Wildcard most "numeric" events") Reviewed-by: Ian Rogers Tested-by: Thomas Falcon Signed-off-by: James Clark Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20241114160450.295844-2-james.clark@linaro.org Signed-off-by: Namhyung Kim

Merge tag 'perf-tools-for-v6.13-2024-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

2024-11-26T22:54:00Z

Pull perf tools updates from Namhyung Kim: "perf record: - Enable leader sampling for inherited task events. It was supported only for system-wide events but the kernel started to support such a setup since v6.12. This is to reduce the number of PMU interrupts. The samples of the leader event will contain counts of other events and no samples will be generated for the other member events. $ perf record -e '{cycles,instructions}:S' ${MYPROG} perf report: - Fix --branch-history option to display more branch-related information like prediction, abort and cycles which is available on Intel machines. $ perf record -bg -- perf test -w brstack $ perf report --branch-history ... # # Overhead Source:Line Symbol Shared Object Predicted Abort Cycles IPC [IPC Coverage] # ........ ........................ .............. .................... ......... ..... ...... .................... # 8.17% copy_page_64.S:19 [k] copy_page [kernel.kallsyms] 50.0% 0 5 - - | ---xas_load xarray.h:171 | |--5.68%--xas_load xarray.c:245 (cycles:1) | xas_load xarray.c:242 | xas_load xarray.h:1260 (cycles:1) | xas_descend xarray.c:146 | xas_load xarray.c:244 (cycles:2) | xas_load xarray.c:245 | xas_descend xarray.c:218 (cycles:10) ... perf stat: - Add HWMON PMU support. The HWMON provides various system information like CPU/GPU temperature, fan speed and so on. Expose them as PMU events so that users can see the values using perf stat commands. $ perf stat -e temp_cpu,fan1 true Performance counter stats for 'true': 60.00 'C temp_cpu 0 rpm fan1 0.000745382 seconds time elapsed 0.000883000 seconds user 0.000000000 seconds sys - Display metric threshold in JSON output. Some metrics define thresholds to classify value ranges. It used to be in a different color but it won't work for JSON. Add "metric-threshold" field to the JSON that can be one of "good", "less good", "nearly bad" and "bad". # perf stat -a -M TopdownL1 -j true {"counter-value" : "18693525.000000", "unit" : "", "event" : "TOPDOWN.SLOTS", "event-runtime" : 5552708, "pcnt-running" : 100.00, "metric-value" : "43.226002", "metric-unit" : "% tma_backend_bound", "metric-threshold" : "bad"} {"metric-value" : "29.212267", "metric-unit" : "% tma_frontend_bound", "metric-threshold" : "bad"} {"metric-value" : "7.138972", "metric-unit" : "% tma_bad_speculation", "metric-threshold" : "good"} {"metric-value" : "20.422759", "metric-unit" : "% tma_retiring", "metric-threshold" : "good"} {"counter-value" : "3817732.000000", "unit" : "", "event" : "topdown-retiring", "event-runtime" : 5552708, "pcnt-running" : 100.00, } {"counter-value" : "5472824.000000", "unit" : "", "event" : "topdown-fe-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, } {"counter-value" : "7984780.000000", "unit" : "", "event" : "topdown-be-bound", "event-runtime" : 5552708, "pcnt-running" : 100.00, } {"counter-value" : "1418181.000000", "unit" : "", "event" : "topdown-bad-spec", "event-runtime" : 5552708, "pcnt-running" : 100.00, } ... perf sched: - Add -P/--pre-migrations option for 'timehist' sub-command to track time a task waited on a run-queue before migrating to a different CPU. $ perf sched timehist -P time cpu task name wait time sch delay run time pre-mig time [tid/pid] (msec) (msec) (msec) (msec) --------------- ------ ------------------------------ --------- --------- --------- --------- 585940.535527 [0000] perf[584885] 0.000 0.000 0.000 0.000 585940.535535 [0000] migration/0[20] 0.000 0.002 0.008 0.000 585940.535559 [0001] perf[584885] 0.000 0.000 0.000 0.000 585940.535563 [0001] migration/1[25] 0.000 0.001 0.004 0.000 585940.535678 [0002] perf[584885] 0.000 0.000 0.000 0.000 585940.535686 [0002] migration/2[31] 0.000 0.002 0.008 0.000 585940.535905 [0001] 0.000 0.000 0.342 0.000 585940.535938 [0003] perf[584885] 0.000 0.000 0.000 0.000 585940.537048 [0001] sleep[584886] 0.000 0.019 1.142 0.001 585940.537749 [0002] 0.000 0.000 2.062 0.000 ... Build: - Make libunwind opt-in (LIBUNWIND=1) rather than opt-out. The perf tools are generally built with libelf and libdw which has unwinder functionality. The libunwind support predates it and no need to have duplicate unwinders by default. - Rename NO_DWARF=1 build option to NO_LIBDW=1 in order to clarify it's using libdw for handling DWARF information. Internals: - Do not set exclude_guest bit in the perf_event_attr by default. This was causing a trouble in AMD IBS PMU as it doesn't support the bit. The bit will be set when it's needed later by the fallback logic. Also update the missing feature detection logic to make sure not clear supported bits unnecessarily. - Run perf test in parallel by default and mark flaky tests "exclusive" to run them serially at the end. Some test numbers are changed but the test can complete in less than half the time. JSON vendor events: - Add AMD Zen 5 events and metrics. - Add i.MX91 and i.MX95 DDR metrics - Fix HiSilicon HIP08 Topdown metric name. - Support compat events on PowerPC" * tag 'perf-tools-for-v6.13-2024-11-24' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (232 commits) perf tests: Fix hwmon parsing with PMU name test perf hwmon_pmu: Ensure hwmon key union is zeroed before use perf tests hwmon_pmu: Remove double evlist__delete() perf/test: fix perf ftrace test on s390 perf bpf-filter: Return -ENOMEM directly when pfi allocation fails perf test: Correct hwmon test PMU detection perf: Remove unused del_perf_probe_events() perf pmu: Move pmu_metrics_table__find and remove ARM override perf jevents: Add map_for_cpu() perf header: Pass a perf_cpu rather than a PMU to get_cpuid_str perf header: Avoid transitive PMU includes perf arm64 header: Use cpu argument in get_cpuid perf header: Refactor get_cpuid to take a CPU for ARM perf header: Move is_cpu_online to numa bench perf jevents: fix breakage when do perf stat on system metric perf test: Add missing __exit calls in tool/hwmon tests perf tests: Make leader sampling test work without branch event perf util: Remove kernel version deadcode perf test shell trace_exit_race: Use --no-comm to avoid cases where COMM isn't resolved perf test shell trace_exit_race: Show what went wrong in verbose mode ...

Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-26T00:09:48Z

Pull non-MM updates from Andrew Morton: - The series "resource: A couple of cleanups" from Andy Shevchenko performs some cleanups in the resource management code - The series "Improve the copy of task comm" from Yafang Shao addresses possible race-induced overflows in the management of task_struct.comm[] - The series "Remove unnecessary header includes from {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a small fix to the list_sort library code and to its selftest - The series "Enhance min heap API with non-inline functions and optimizations" also from Kuan-Wei Chiu optimizes and cleans up the min_heap library code - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi finishes off nilfs2's folioification - The series "add detect count for hung tasks" from Lance Yang adds more userspace visibility into the hung-task detector's activity - Apart from that, singelton patches in many places - please see the individual changelogs for details * tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits) gdb: lx-symbols: do not error out on monolithic build kernel/reboot: replace sprintf() with sysfs_emit() lib: util_macros_kunit: add kunit test for util_macros.h util_macros.h: fix/rework find_closest() macros Improve consistency of '#error' directive messages ocfs2: fix uninitialized value in ocfs2_file_read_iter() hung_task: add docs for hung_task_detect_count hung_task: add detect count for hung tasks dma-buf: use atomic64_inc_return() in dma_buf_getfile() fs/proc/kcore.c: fix coccinelle reported ERROR instances resource: avoid unnecessary resource tree walking in __region_intersects() ocfs2: remove unused errmsg function and table ocfs2: cluster: fix a typo lib/scatterlist: use sg_phys() helper checkpatch: always parse orig_commit in fixes tag nilfs2: convert metadata aops from writepage to writepages nilfs2: convert nilfs_recovery_copy_block() to take a folio nilfs2: convert nilfs_page_count_clean_buffers() to take a folio nilfs2: remove nilfs_writepage nilfs2: convert checkpoint file to be folio-based ...