kernel/linux.git/tools/perf, branch v4.4.243

perf intel-pt: Fix "context_switch event has no tid" error

2020-10-29T08:03:06+00:00

[ Upstream commit 7d537a8d2e76bc4fc71e34545ceaa463ac2cd928 ] A context_switch event can have no tid because pids can be detached from a task while the task is still running (in do_exit()). Note this won't happen with per-task contexts because then tracing stops at perf_event_exit_task() If a task with no tid gets preempted, or a dying task gets preempted and its parent releases it, when it subsequently gets switched back in, Intel PT will not be able to determine what task is running and prints an error "context_switch event has no tid". However, it is not really an error because the task is in kernel space and the decoder can continue to decode successfully. Fix by changing the error to be only a logged message, and make allowance for tid == -1. Example: Using 5.9-rc4 with Preemptible Kernel (Low-Latency Desktop) e.g. $ uname -r 5.9.0-rc4 $ grep PREEMPT .config # CONFIG_PREEMPT_NONE is not set # CONFIG_PREEMPT_VOLUNTARY is not set CONFIG_PREEMPT=y CONFIG_PREEMPT_COUNT=y CONFIG_PREEMPTION=y CONFIG_PREEMPT_RCU=y CONFIG_PREEMPT_NOTIFIERS=y CONFIG_DRM_I915_PREEMPT_TIMEOUT=640 CONFIG_DEBUG_PREEMPT=y # CONFIG_PREEMPT_TRACER is not set # CONFIG_PREEMPTIRQ_DELAY_TEST is not set Before: $ cat forkit.c #include #include #include int main() { pid_t child; int status = 0; child = fork(); if (child == 0) return 123; wait(&status); return 0; } $ gcc -o forkit forkit.c $ sudo ~/bin/perf record --kcore -a -m,64M -e intel_pt/cyc/k & [1] 11016 $ taskset 2 ./forkit $ sudo pkill perf $ [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 17.262 MB perf.data ] [1]+ Terminated sudo ~/bin/perf record --kcore -a -m,64M -e intel_pt/cyc/k $ sudo ~/bin/perf script --show-task-events --show-switch-events --itrace=iqqe-o -C 1 --ns | grep -C 2 forkit context_switch event has no tid taskset 11019 [001] 66663.270045029: 1 instructions:k: ffffffffb1d9f844 strnlen_user+0xb4 ([kernel.kallsyms]) taskset 11019 [001] 66663.270201816: 1 instructions:k: ffffffffb1a83121 unmap_page_range+0x561 ([kernel.kallsyms]) forkit 11019 [001] 66663.270327553: PERF_RECORD_COMM exec: forkit:11019/11019 forkit 11019 [001] 66663.270420028: 1 instructions:k: ffffffffb1db9537 __clear_user+0x27 ([kernel.kallsyms]) forkit 11019 [001] 66663.270648704: 1 instructions:k: ffffffffb18829e6 do_user_addr_fault+0xf6 ([kernel.kallsyms]) forkit 11019 [001] 66663.270833163: 1 instructions:k: ffffffffb230a825 irqentry_exit_to_user_mode+0x15 ([kernel.kallsyms]) forkit 11019 [001] 66663.271092359: 1 instructions:k: ffffffffb1aea3d9 lock_page_memcg+0x9 ([kernel.kallsyms]) forkit 11019 [001] 66663.271207092: PERF_RECORD_FORK(11020:11020):(11019:11019) forkit 11019 [001] 66663.271234775: PERF_RECORD_SWITCH_CPU_WIDE OUT next pid/tid: 11020/11020 forkit 11020 [001] 66663.271238407: PERF_RECORD_SWITCH_CPU_WIDE IN prev pid/tid: 11019/11019 forkit 11020 [001] 66663.271312066: 1 instructions:k: ffffffffb1a88140 handle_mm_fault+0x10 ([kernel.kallsyms]) forkit 11020 [001] 66663.271476225: PERF_RECORD_EXIT(11020:11020):(11019:11019) forkit 11020 [001] 66663.271497488: PERF_RECORD_SWITCH_CPU_WIDE OUT preempt next pid/tid: 11019/11019 forkit 11019 [001] 66663.271500523: PERF_RECORD_SWITCH_CPU_WIDE IN prev pid/tid: 11020/11020 forkit 11019 [001] 66663.271517241: 1 instructions:k: ffffffffb24012cd error_entry+0x6d ([kernel.kallsyms]) forkit 11019 [001] 66663.271664080: PERF_RECORD_EXIT(11019:11019):(1386:1386) After: $ sudo ~/bin/perf script --show-task-events --show-switch-events --itrace=iqqe-o -C 1 --ns | grep -C 2 forkit taskset 11019 [001] 66663.270045029: 1 instructions:k: ffffffffb1d9f844 strnlen_user+0xb4 ([kernel.kallsyms]) taskset 11019 [001] 66663.270201816: 1 instructions:k: ffffffffb1a83121 unmap_page_range+0x561 ([kernel.kallsyms]) forkit 11019 [001] 66663.270327553: PERF_RECORD_COMM exec: forkit:11019/11019 forkit 11019 [001] 66663.270420028: 1 instructions:k: ffffffffb1db9537 __clear_user+0x27 ([kernel.kallsyms]) forkit 11019 [001] 66663.270648704: 1 instructions:k: ffffffffb18829e6 do_user_addr_fault+0xf6 ([kernel.kallsyms]) forkit 11019 [001] 66663.270833163: 1 instructions:k: ffffffffb230a825 irqentry_exit_to_user_mode+0x15 ([kernel.kallsyms]) forkit 11019 [001] 66663.271092359: 1 instructions:k: ffffffffb1aea3d9 lock_page_memcg+0x9 ([kernel.kallsyms]) forkit 11019 [001] 66663.271207092: PERF_RECORD_FORK(11020:11020):(11019:11019) forkit 11019 [001] 66663.271234775: PERF_RECORD_SWITCH_CPU_WIDE OUT next pid/tid: 11020/11020 forkit 11020 [001] 66663.271238407: PERF_RECORD_SWITCH_CPU_WIDE IN prev pid/tid: 11019/11019 forkit 11020 [001] 66663.271312066: 1 instructions:k: ffffffffb1a88140 handle_mm_fault+0x10 ([kernel.kallsyms]) forkit 11020 [001] 66663.271476225: PERF_RECORD_EXIT(11020:11020):(11019:11019) forkit 11020 [001] 66663.271497488: PERF_RECORD_SWITCH_CPU_WIDE OUT preempt next pid/tid: 11019/11019 forkit 11019 [001] 66663.271500523: PERF_RECORD_SWITCH_CPU_WIDE IN prev pid/tid: 11020/11020 forkit 11019 [001] 66663.271517241: 1 instructions:k: ffffffffb24012cd error_entry+0x6d ([kernel.kallsyms]) forkit 11019 [001] 66663.271664080: PERF_RECORD_EXIT(11019:11019):(1386:1386) forkit 11019 [001] 66663.271688752: PERF_RECORD_SWITCH_CPU_WIDE OUT next pid/tid: -1/-1 :-1 -1 [001] 66663.271692086: PERF_RECORD_SWITCH_CPU_WIDE IN prev pid/tid: 11019/11019 :-1 -1 [001] 66663.271707466: 1 instructions:k: ffffffffb18eb096 update_load_avg+0x306 ([kernel.kallsyms]) Fixes: 86c2786994bd7c ("perf intel-pt: Add support for PERF_RECORD_SWITCH") Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: Yu-cheng Yu Link: http://lore.kernel.org/lkml/20200909084923.9096-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf top: Fix stdio interface input handling with glibc 2.28+

2020-10-14T07:46:22+00:00

commit 29b4f5f188571c112713c35cc87eefb46efee612 upstream. Since glibc 2.28 when running 'perf top --stdio', input handling no longer works, but hitting any key always just prints the "Mapped keys" help text. To fix it, call clearerr() in the display_thread() loop to clear any EOF sticky errors, as instructed in the glibc NEWS file (https://sourceware.org/git/?p=glibc.git;a=blob;f=NEWS): * All stdio functions now treat end-of-file as a sticky condition. If you read from a file until EOF, and then the file is enlarged by another process, you must call clearerr or another function with the same effect (e.g. fseek, rewind) before you can read the additional data. This corrects a longstanding C99 conformance bug. It is most likely to affect programs that use stdio to read interactive input from a terminal. (Bug #1190.) Signed-off-by: Tommi Rantala Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20200305083714.9381-2-tommi.t.rantala@nokia.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf kcore_copy: Fix module map when there are no modules loaded

2020-10-01T09:11:56+00:00

[ Upstream commit 61f82e3fb697a8e85f22fdec786528af73dc36d1 ] In the absence of any modules, no "modules" map is created, but there are other executable pages to map, due to eBPF JIT, kprobe or ftrace. Map them by recognizing that the first "module" symbol is not necessarily from a module, and adjust the map accordingly. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Mathieu Poirier Cc: Peter Zijlstra Cc: Steven Rostedt (VMware) Cc: x86@kernel.org Link: http://lore.kernel.org/lkml/20200512121922.8997-10-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf test: Free formats for perf pmu parse test

2020-09-23T06:44:27+00:00

[ Upstream commit d26383dcb2b4b8629fde05270b4e3633be9e3d4b ] The following leaks were detected by ASAN: Indirect leak of 360 byte(s) in 9 object(s) allocated from: #0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e) #1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333 #2 0x560578f752fc in perf_pmu_parse util/pmu.y:59 #3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73 #4 0x560578e07045 in test__pmu tests/pmu.c:155 #5 0x560578de109b in run_test tests/builtin-test.c:410 #6 0x560578de109b in test_and_print tests/builtin-test.c:440 #7 0x560578de401a in __cmd_test tests/builtin-test.c:661 #8 0x560578de401a in cmd_test tests/builtin-test.c:807 #9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312 #10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364 #11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408 #12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538 #13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308 Fixes: cff7f956ec4a1 ("perf tests: Move pmu tests into separate object") Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Ian Rogers Cc: Mark Rutland Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200915031819.386559-12-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf record/stat: Explicitly call out event modifiers in the documentation

2020-09-12T09:45:26+00:00

commit e48a73a312ebf19cc3d72aa74985db25c30757c1 upstream. Event modifiers are not mentioned in the perf record or perf stat manpages. Add them to orient new users more effectively by pointing them to the perf list manpage for details. Fixes: 2055fdaf8703 ("perf list: Document precise event sampling for AMD IBS") Signed-off-by: Kim Phillips Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Ian Rogers Cc: Jin Yao Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Tony Jones Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/20200901215853.276234-1-kim.phillips@amd.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf probe: Fix memory leakage when the probe point is not found

2020-08-26T08:27:06+00:00

[ Upstream commit 12d572e785b15bc764e956caaa8a4c846fd15694 ] Fix the memory leakage in debuginfo__find_trace_events() when the probe point is not found in the debuginfo. If there is no probe point found in the debuginfo, debuginfo__find_probes() will NOT return -ENOENT, but 0. Thus the caller of debuginfo__find_probes() must check the tf.ntevs and release the allocated memory for the array of struct probe_trace_event. The current code releases the memory only if the debuginfo__find_probes() hits an error but not checks tf.ntevs. In the result, the memory allocated on *tevs are not released if tf.ntevs == 0. This fixes the memory leakage by checking tf.ntevs == 0 in addition to ret < 0. Fixes: ff741783506c ("perf probe: Introduce debuginfo to encapsulate dwarf information") Signed-off-by: Masami Hiramatsu Reviewed-by: Srikar Dronamraju Cc: Andi Kleen Cc: Oleg Nesterov Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/159438668346.62703.10887420400718492503.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin

perf probe: Fix to check blacklist address correctly

2020-07-31T14:43:17+00:00

commit 80526491c2ca6abc028c0f0dbb0707a1f35fb18a upstream. Fix to check kprobe blacklist address correctly with relocated address by adjusting debuginfo address. Since the address in the debuginfo is same as objdump, it is different from relocated kernel address with KASLR. Thus, 'perf probe' always misses to catch the blacklisted addresses. Without this patch, 'perf probe' can not detect the blacklist addresses on a KASLR enabled kernel. # perf probe kprobe_dispatcher Failed to write event: Invalid argument Error: Failed to add events. # With this patch, it correctly shows the error message. # perf probe kprobe_dispatcher kprobe_dispatcher is blacklisted function, skip it. Probe point 'kprobe_dispatcher' not found. Error: Failed to add events. # Fixes: 9aaf5a5f479b ("perf probe: Check kprobes blacklist when adding new events") Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/158763966411.30755.5882376357738273695.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf annotate: Use asprintf when formatting objdump command line

2020-07-31T14:43:17+00:00

commit 6810158d526e483868e519befff407b91e76b3db upstream. We were using a local buffer with an arbitrary size, that would have to get increased to avoid truncation as warned by gcc 8: util/annotate.c: In function 'symbol__disassemble': util/annotate.c:1488:4: error: '%s' directive output may be truncated writing up to 4095 bytes into a region of size between 3966 and 8086 [-Werror=format-truncation=] "%s %s%s --start-address=0x%016" PRIx64 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ util/annotate.c:1498:20: symfs_filename, symfs_filename); ~~~~~~~~~~~~~~ util/annotate.c:1490:50: note: format string is defined here " -l -d %s %s -C \"%s\" 2>/dev/null|grep -v \"%s:\"|expand", ^~ In file included from /usr/include/stdio.h:861, from util/color.h:5, from util/sort.h:8, from util/annotate.c:14: /usr/include/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output 116 or more bytes (assuming 8331) into a destination of size 8192 return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ __bos (__s), __fmt, __va_arg_pack ()); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ So switch to asprintf, that will make sure enough space is available. Cc: Adrian Hunter Cc: David Ahern Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-qagoy2dmbjpc9gdnaj0r3mml@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf tools: Fix snprint warnings for gcc 8

2020-07-31T14:43:17+00:00

commit 77f18153c080855e1c3fb520ca31a4e61530121d upstream. [Add an additional sprintf replacement in tools/perf/builtin-script.c] With gcc 8 we get new set of snprintf() warnings that breaks the compilation, one example: tests/mem.c: In function ‘check’: tests/mem.c:19:48: error: ‘%s’ directive output may be truncated writing \ up to 99 bytes into a region of size 89 [-Werror=format-truncation=] snprintf(failure, sizeof failure, "unexpected %s", out); The gcc docs says: To avoid the warning either use a bigger buffer or handle the function's return value which indicates whether or not its output has been truncated. Given that all these warnings are harmless, because the code either properly fails due to uncomplete file path or we don't care for truncated output at all, I'm changing all those snprintf() calls to scnprintf(), which actually 'checks' for the snprint return value so the gcc stays silent. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: David Ahern Cc: Josh Poimboeuf Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sergey Senozhatsky Link: http://lkml.kernel.org/r/20180319082902.4518-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

perf: Make perf able to build with latest libbfd

2020-07-31T14:43:17+00:00

commit 0ada120c883d4f1f6aafd01cf0fbb10d8bbba015 upstream. libbfd has changed the bfd_section_* macros to inline functions bfd_section_ since 2019-09-18. See below two commits: o http://www.sourceware.org/ml/gdb-cvs/2019-09/msg00064.html o https://www.sourceware.org/ml/gdb-cvs/2019-09/msg00072.html This fix make perf able to build with both old and new libbfd. Signed-off-by: Changbin Du Acked-by: Jiri Olsa Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20200128152938.31413-1-changbin.du@gmail.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman