linux.git/tools/perf, branch vm-bind

perf trace: Fix SIGSEGV when processing syscall args

2022-07-17T13:59:52+00:00

On powerpc, 'perf trace' is crashing with a SIGSEGV when trying to process a perf.data file created with 'perf trace record -p': #0 0x00000001225b8988 in syscall_arg__scnprintf_augmented_string at builtin-trace.c:1492 #1 syscall_arg__scnprintf_filename at builtin-trace.c:1492 #2 syscall_arg__scnprintf_filename at builtin-trace.c:1486 #3 0x00000001225bdd9c in syscall_arg_fmt__scnprintf_val at builtin-trace.c:1973 #4 syscall__scnprintf_args at builtin-trace.c:2041 #5 0x00000001225bff04 in trace__sys_enter at builtin-trace.c:2319 That points to the below code in tools/perf/builtin-trace.c: /* * If this is raw_syscalls.sys_enter, then it always comes with the 6 possible * arguments, even if the syscall being handled, say "openat", uses only 4 arguments * this breaks syscall__augmented_args() check for augmented args, as we calculate * syscall->args_size using each syscalls:sys_enter_NAME tracefs format file, * so when handling, say the openat syscall, we end up getting 6 args for the * raw_syscalls:sys_enter event, when we expected just 4, we end up mistakenly * thinking that the extra 2 u64 args are the augmented filename, so just check * here and avoid using augmented syscalls when the evsel is the raw_syscalls one. */ if (evsel != trace->syscalls.events.sys_enter) augmented_args = syscall__augmented_args(sc, sample, &augmented_args_size, trace->raw_augmented_syscalls_args_size); As the comment points out, we should not be trying to augment the args for raw_syscalls. However, when processing a perf.data file, we are not initializing those properly. Fix the same. Reported-by: Claudio Carvalho Signed-off-by: Naveen N. Rao Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lore.kernel.org/lkml/20220707090900.572584-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf tests: Fix Convert perf time to TSC test for hybrid

2022-07-17T13:57:07+00:00

The test does not always correctly determine the number of events for hybrids, nor allow for more than 1 evsel when parsing. Fix by iterating the events actually created and getting the correct evsel for the events processed. Fixes: d9da6f70eb235110 ("perf tests: Support 'Convert perf time to TSC' test for hybrid") Reviewed-by: Kan Liang Signed-off-by: Adrian Hunter Cc: Ian Rogers Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Cc: Thomas Richter Link: https://lore.kernel.org/r/20220713123459.24145-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tests: Stop Convert perf time to TSC test opening events twice

2022-07-17T13:56:58+00:00

Do not call evlist__open() twice. Fixes: 5bb017d4b97a0f13 ("perf test: Fix error message for test case 71 on s390, where it is not supported") Reviewed-by: Kan Liang Signed-off-by: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: Thomas Richter Link: https://lore.kernel.org/r/20220713123459.24145-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf synthetic-events: Ignore dead threads during event synthesis

2022-07-02T12:22:26+00:00

When it synthesize various task events, it scans the list of task first and then accesses later. There's a window threads can die between the two and proc entries may not be available. Instead of bailing out, we can ignore that thread and move on. Signed-off-by: Namhyung Kim Acked-by: Ian Rogers Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20220701205458.985106-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf synthetic-events: Don't sort the task scan result from /proc

2022-07-02T12:21:41+00:00

It should not sort the result as procfs already returns a proper ordering of tasks. Actually sorting the order caused problems that it doesn't guararantee to process the main thread first. Signed-off-by: Namhyung Kim Acked-by: Ian Rogers Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20220701205458.985106-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf unwind: Fix unitialized 'offset' variable on aarch64

2022-07-02T12:16:52+00:00

Commit dc2cf4ca866f5715 ("perf unwind: Fix segbase for ld.lld linked objects") uncovered the following issue on aarch64: util/unwind-libunwind-local.c: In function 'find_proc_info': util/unwind-libunwind-local.c:386:28: error: 'offset' may be used uninitialized in this function [-Werror=maybe-uninitialized] 386 | if (ofs > 0) { | ^ util/unwind-libunwind-local.c:199:22: note: 'offset' was declared here 199 | u64 address, offset; | ^~~~~~ util/unwind-libunwind-local.c:371:20: error: 'offset' may be used uninitialized in this function [-Werror=maybe-uninitialized] 371 | if (ofs <= 0) { | ^ util/unwind-libunwind-local.c:199:22: note: 'offset' was declared here 199 | u64 address, offset; | ^~~~~~ util/unwind-libunwind-local.c:363:20: error: 'offset' may be used uninitialized in this function [-Werror=maybe-uninitialized] 363 | if (ofs <= 0) { | ^ util/unwind-libunwind-local.c:199:22: note: 'offset' was declared here 199 | u64 address, offset; | ^~~~~~ In file included from util/libunwind/arm64.c:37: Fixes: dc2cf4ca866f5715 ("perf unwind: Fix segbase for ld.lld linked objects") Signed-off-by: Ivan Babrou Cc: Alexander Shishkin Cc: Fangrui Song Cc: Ian Rogers Cc: James Clark Cc: Jiri Olsa Cc: kernel-team@cloudflare.com Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20220701182046.12589-1-ivan@cloudflare.com Signed-off-by: Arnaldo Carvalho de Melo

perf bpf: 8 byte align bpil data

2022-06-28T15:05:25+00:00

bpil data is accessed assuming 64-bit alignment resulting in undefined behavior as the data is just byte aligned. With an -fsanitize=undefined build the following errors are observed: $ sudo perf record -a sleep 1 util/bpf-event.c:310:22: runtime error: load of misaligned address 0x55f61084520f for type '__u64', which requires 8 byte alignment 0x55f61084520f: note: pointer points here a8 fe ff ff 3c 51 d3 c0 ff ff ff ff 04 84 d3 c0 ff ff ff ff d8 aa d3 c0 ff ff ff ff a4 c0 d3 c0 ^ util/bpf-event.c:311:20: runtime error: load of misaligned address 0x55f61084522f for type '__u32', which requires 4 byte alignment 0x55f61084522f: note: pointer points here ff ff ff ff c7 17 00 00 f1 02 00 00 1f 04 00 00 58 04 00 00 00 00 00 00 0f 00 00 00 63 02 00 00 ^ util/bpf-event.c:198:33: runtime error: member access within misaligned address 0x55f61084523f for type 'const struct bpf_func_info', which requires 4 byte alignment 0x55f61084523f: note: pointer points here 58 04 00 00 00 00 00 00 0f 00 00 00 63 02 00 00 3b 00 00 00 ab 02 00 00 44 00 00 00 14 03 00 00 Correct this by rouding up the data sizes and aligning the pointers. Signed-off-by: Ian Rogers Acked-by: Andrii Nakryiko Cc: Alexander Shishkin Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Dave Marchevsky Cc: Ingo Molnar Cc: Jiri Olsa Cc: John Fastabend Cc: KP Singh Cc: Mark Rutland Cc: Martin KaFai Lau Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Song Liu Cc: Stephane Eranian Cc: Yonghong Song Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20220614014714.1407239-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf offcpu: Accept allowed sample types only

2022-06-28T14:45:45+00:00

As offcpu-time event is synthesized at the end, it could not get the all the sample info. Define OFFCPU_SAMPLE_TYPES for allowed ones and mask out others in evsel__config() to prevent parse errors. Because perf sample parsing assumes a specific ordering with the sample types, setting unsupported one would make it fail to read data like perf record -d/--data. Fixes: edc41a1099c2d08c ("perf record: Enable off-cpu analysis with BPF") Signed-off-by: Namhyung Kim Cc: Blake Jones Cc: Hao Luo Cc: Ian Rogers Cc: Jiri Olsa Cc: Milian Wolff Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/20220624231313.367909-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf offcpu: Fix build failure on old kernels

2022-06-28T14:41:26+00:00

Old kernels have a 'struct task_struct' which contains a "state" field and newer kernels have "__state" instead. While the get_task_state() in the BPF code handles that in some way, it assumed the current kernel has the new definition and it caused a build error on old kernels. We should not assume anything and access them carefully. Do not use 'task struct' directly access it instead using new and old definitions in a row. Fixes: edc41a1099c2d08c ("perf record: Enable off-cpu analysis with BPF") Reported-by: Ian Rogers Signed-off-by: Namhyung Kim Cc: Blake Jones Cc: Hao Luo Cc: Jiri Olsa Cc: Milian Wolff Cc: Peter Zijlstra Cc: Song Liu Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/20220624231313.367909-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Enable ignore_missing_thread

2022-06-26T15:32:55+00:00

perf already support ignore_missing_thread for -p, but not yet applied to `perf stat -p `. This patch enables ignore_missing_thread for `perf stat -p `. Committer notes: And here is a refresher about the 'ignore_missing_thread' knob, from a previous patch using it: ca8000684ec4e66f ("perf evsel: Enable ignore_missing_thread for pid option") --- While monitoring a multithread process with pid option, perf sometimes may return sys_perf_event_open failure with 3(No such process) if any of the process's threads die before we open the event. However, we want perf continue monitoring the remaining threads and do not exit with error. --- Signed-off-by: Gang Li Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20220622030037.15005-1-ligang.bdlg@bytedance.com Signed-off-by: Arnaldo Carvalho de Melo