From 1b9caa10b31dda0866f4028e4bfb923fb6e4072f Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 3 Oct 2018 09:20:46 +0200 Subject: Revert "perf tools: Fix PMU term format max value calculation" This reverts commit ac0e2cd555373ae6f8f3a3ad3fbbf5b6d1e7aaaa. Michael reported an issue with oversized terms values assignment and I noticed there was actually a misunderstanding of the max value check in the past. The above commit's changelog says: If bit 21 is set, there is parsing issues as below. $ perf stat -a -e uncore_qpi_0/event=0x200002,umask=0x8/ event syntax error: '..pi_0/event=0x200002,umask=0x8/' \___ value too big for format, maximum is 511 But there's no issue there, because the event value is distributed along the value defined by the format. Even if the format defines separated bit, the value is treated as a continual number, which should follow the format definition. In above case it's 9-bit value with last bit separated: $ cat uncore_qpi_0/format/event config:0-7,21 Hence the value 0x200002 is correctly reported as format violation, because it exceeds 9 bits. It should have been 0x102 instead, which sets the 9th bit - the bit 21 of the format. $ perf stat -vv -a -e uncore_qpi_0/event=0x102,umask=0x8/ Using CPUID GenuineIntel-6-2D ... ------------------------------------------------------------ perf_event_attr: type 10 size 112 config 0x200802 sample_type IDENTIFIER ... Reported-by: Michael Petlan Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Kan Liang Cc: Namhyung Kim Cc: Peter Zijlstra Fixes: ac0e2cd55537 ("perf tools: Fix PMU term format max value calculation") Link: http://lkml.kernel.org/r/20181003072046.29276-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/pmu.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'tools/perf/util') diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index afd68524ffa9..7799788f662f 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -930,13 +930,14 @@ static void pmu_format_value(unsigned long *format, __u64 value, __u64 *v, static __u64 pmu_format_max_value(const unsigned long *format) { - __u64 w = 0; - int fbit; - - for_each_set_bit(fbit, format, PERF_PMU_FORMAT_BITS) - w |= (1ULL << fbit); + int w; - return w; + w = bitmap_weight(format, PERF_PMU_FORMAT_BITS); + if (!w) + return 0; + if (w < 64) + return (1ULL << w) - 1; + return -1; } /* -- cgit v1.2.3-70-g09d2 From 4ab8455f8bd83298bf7f67ab9357e3b1cc765c7d Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 3 Oct 2018 23:20:52 +0200 Subject: perf evsel: Store ids for events with their own cpus perf_event__synthesize_event_update_cpus John reported crash when recording on an event under PMU with cpumask defined: root@localhost:~# ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1 perf: Segmentation fault Obtained 9 stack frames. ./perf_debug_() [0x4c5ef8] [0xffff82ba267c] ./perf_debug_() [0x4bc5a8] ./perf_debug_() [0x419550] ./perf_debug_() [0x41a928] ./perf_debug_() [0x472f58] ./perf_debug_() [0x473210] ./perf_debug_() [0x4070f4] /lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe0) [0xffff8294c8a0] Segmentation fault (core dumped) We synthesize an update event that needs to touch the evsel id array, which is not defined at that time. Fixing this by forcing the id allocation for events with their own cpus. Reported-by: John Garry Signed-off-by: Jiri Olsa Tested-by: John Garry Cc: Alexander Shishkin Cc: Andi Kleen Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linuxarm@huawei.com Fixes: bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update") Link: http://lkml.kernel.org/r/20181003212052.GA32371@krava Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-report.c | 1 + tools/perf/util/evsel.c | 3 +++ 2 files changed, 4 insertions(+) (limited to 'tools/perf/util') diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index 76e12bcd1765..b2188e623e22 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -981,6 +981,7 @@ int cmd_report(int argc, const char **argv) .id_index = perf_event__process_id_index, .auxtrace_info = perf_event__process_auxtrace_info, .auxtrace = perf_event__process_auxtrace, + .event_update = perf_event__process_event_update, .feature = process_feature_event, .ordered_events = true, .ordering_requires_timestamps = true, diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 1a61628a1c12..e596ae358c4d 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1089,6 +1089,9 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts, attr->exclude_user = 1; } + if (evsel->own_cpus) + evsel->attr.read_format |= PERF_FORMAT_ID; + /* * Apply event specific term settings, * it overloads any global configuration. -- cgit v1.2.3-70-g09d2 From 0ed149cf5239cc6e7e65bf00f769e8f1e91076c0 Mon Sep 17 00:00:00 2001 From: David Miller Date: Thu, 11 Oct 2018 22:46:55 -0700 Subject: perf cpu_map: Align cpu map synthesized events properly. The size of the resulting cpu map can be smaller than a multiple of sizeof(u64), resulting in SIGBUS on cpus like Sparc as the next event will not be aligned properly. Signed-off-by: David S. Miller Cc: Jiri Olsa Cc: Kan Liang Fixes: 6c872901af07 ("perf cpu_map: Add cpu_map event synthesize function") Link: http://lkml.kernel.org/r/20181011.224655.716771175766946817.davem@davemloft.net Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/event.c | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/perf/util') diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 0cd42150f712..0988eb3b844b 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -1081,6 +1081,7 @@ void *cpu_map_data__alloc(struct cpu_map *map, size_t *size, u16 *type, int *max } *size += sizeof(struct cpu_map_data); + *size = PERF_ALIGN(*size, sizeof(u64)); return zalloc(*size); } -- cgit v1.2.3-70-g09d2 From d4046e8e17b9f378cb861982ef71c63911b5dff3 Mon Sep 17 00:00:00 2001 From: Milian Wolff Date: Wed, 26 Sep 2018 15:52:07 +0200 Subject: perf report: Don't crash on invalid inline debug information When the function name for an inline frame is invalid, we must not try to demangle this symbol, otherwise we crash with: #0 0x0000555555895c01 in bfd_demangle () #1 0x0000555555823262 in demangle_sym (dso=0x555555d92b90, elf_name=0x0, kmodule=0) at util/symbol-elf.c:215 #2 dso__demangle_sym (dso=dso@entry=0x555555d92b90, kmodule=, kmodule@entry=0, elf_name=elf_name@entry=0x0) at util/symbol-elf.c:400 #3 0x00005555557fef4b in new_inline_sym (funcname=0x0, base_sym=0x555555d92b90, dso=0x555555d92b90) at util/srcline.c:89 #4 inline_list__append_dso_a2l (dso=dso@entry=0x555555c7bb00, node=node@entry=0x555555e31810, sym=sym@entry=0x555555d92b90) at util/srcline.c:264 #5 0x00005555557ff27f in addr2line (dso_name=dso_name@entry=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf", addr=addr@entry=2888, file=file@entry=0x0, line=line@entry=0x0, dso=dso@entry=0x555555c7bb00, unwind_inlines=unwind_inlines@entry=true, node=0x555555e31810, sym=0x555555d92b90) at util/srcline.c:313 #6 0x00005555557ffe7c in addr2inlines (sym=0x555555d92b90, dso=0x555555c7bb00, addr=2888, dso_name=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf") at util/srcline.c:358 So instead handle the case where we get invalid function names for inlined frames and use a fallback '??' function name instead. While this crash was originally reported by Hadrien for rust code, I can now also reproduce it with trivial C++ code. Indeed, it seems like libbfd fails to interpret the debug information for the inline frame symbol name: $ addr2line -e /home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf -if b48 main /usr/include/c++/8.2.1/complex:610 ?? /usr/include/c++/8.2.1/complex:618 ?? /usr/include/c++/8.2.1/complex:675 ?? /usr/include/c++/8.2.1/complex:685 main /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 I've reported this bug upstream and also attached a patch there which should fix this issue: https://sourceware.org/bugzilla/show_bug.cgi?id=23715 Reported-by: Hadrien Grasland Signed-off-by: Milian Wolff Cc: Jin Yao Cc: Jiri Olsa Cc: Namhyung Kim Fixes: a64489c56c30 ("perf report: Find the inline stack for a given address") [ The above 'Fixes:' cset is where originally the problem was introduced, i.e. using a2l->funcname without checking if it is NULL, but this current patch fixes the current codebase, i.e. multiple csets were applied after a64489c56c30 before the problem was reported by Hadrien ] Link: http://lkml.kernel.org/r/20180926135207.30263-3-milian.wolff@kdab.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/srcline.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools/perf/util') diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c index 09d6746e6ec8..e767c4a9d4d2 100644 --- a/tools/perf/util/srcline.c +++ b/tools/perf/util/srcline.c @@ -85,6 +85,9 @@ static struct symbol *new_inline_sym(struct dso *dso, struct symbol *inline_sym; char *demangled = NULL; + if (!funcname) + funcname = "??"; + if (dso) { demangled = dso__demangle_sym(dso, 0, funcname); if (demangled) -- cgit v1.2.3-70-g09d2 From edeb0c90df3581b821a764052d185df985f8b8dc Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 16 Oct 2018 17:08:29 -0300 Subject: perf tools: Stop fallbacking to kallsyms for vdso symbols lookup David reports that: Perf has this hack where it uses the kernel symbol map as a backup when a symbol can't be found in the user's symbol table(s). This causes problems because the tests driving this code path use machine__kernel_ip(), and that is completely meaningless on Sparc. On sparc64 the kernel and user live in physically separate virtual address spaces, rather than a shared one. And the kernel lives at a virtual address that overlaps common userspace addresses. So this test passes almost all the time when a user symbol lookup fails. The consequence of this is that, if the unfound user virtual address in the sample doesn't match up to a kernel symbol either, we trigger things like this code in builtin-top.c: if (al.sym == NULL && al.map != NULL) { const char *msg = "Kernel samples will not be resolved.\n"; /* * As we do lazy loading of symtabs we only will know if the * specified vmlinux file is invalid when we actually have a * hit in kernel space and then try to load it. So if we get * here and there are _no_ symbols in the DSO backing the * kernel map, bail out. * * We may never get here, for instance, if we use -K/ * --hide-kernel-symbols, even if the user specifies an * invalid --vmlinux ;-) */ if (!machine->kptr_restrict_warned && !top->vmlinux_warned && __map__is_kernel(al.map) && map__has_symbols(al.map)) { if (symbol_conf.vmlinux_name) { char serr[256]; dso__strerror_load(al.map->dso, serr, sizeof(serr)); ui__warning("The %s file can't be used: %s\n%s", symbol_conf.vmlinux_name, serr, msg); } else { ui__warning("A vmlinux file was not found.\n%s", msg); } if (use_browser <= 0) sleep(5); top->vmlinux_warned = true; } } When I fire up a compilation on sparc, this triggers immediately. I'm trying to figure out what the "backup to kernel map" code is accomplishing. I see some language in the current code and in the changes that have happened in this area talking about vdso. Does that really happen? The vdso is mapped into userspace virtual addresses, not kernel ones. More history. This didn't cause problems on sparc some time ago, because the kernel IP check used to be "ip < 0" :-) Sparc kernel addresses are not negative. But now with machine__kernel_ip(), which works using the symbol table determined kernel address range, it does trigger. What it all boils down to is that on architectures like sparc, machine__kernel_ip() should always return false in this scenerio, and therefore this kind of logic: if (cpumode == PERF_RECORD_MISC_USER && machine && mg != &machine->kmaps && machine__kernel_ip(machine, al->addr)) { is basically invalid. PERF_RECORD_MISC_USER implies no kernel address can possibly match for the sample/event in question (no matter how hard you try!) :-) So, I thought something had changed and in the past we would somehow find that address in the kallsyms, but I couldn't find anything to back that up, the patch introducing this is over a decade old, lots of things changed, so I was just thinking I was missing something. I tried a gtod busy loop to generate vdso activity and added a 'perf probe' at that branch, on x86_64 to see if it ever gets hit: Made thread__find_map() noinline, as 'perf probe' in lines of inline functions seems to not be working, only at function start. (Masami?) # perf probe -x ~/bin/perf -L thread__find_map:57 57 if (cpumode == PERF_RECORD_MISC_USER && machine && 58 mg != &machine->kmaps && 59 machine__kernel_ip(machine, al->addr)) { 60 mg = &machine->kmaps; 61 load_map = true; 62 goto try_again; } } else { /* * Kernel maps might be changed when loading * symbols so loading * must be done prior to using kernel maps. */ 69 if (load_map) 70 map__load(al->map); 71 al->addr = al->map->map_ip(al->map, al->addr); # perf probe -x ~/bin/perf thread__find_map:60 Added new event: probe_perf:thread__find_map (on thread__find_map:60 in /home/acme/bin/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:thread__find_map -aR sleep 1 # Then used this to see if, system wide, those probe points were being hit: # perf trace -e *perf:thread*/max-stack=8/ ^C[root@jouet ~]# No hits when running 'perf top' and: # cat gtod.c #include int main(void) { struct timeval tv; while (1) gettimeofday(&tv, 0); return 0; } [root@jouet c]# ./gtod ^C Pressed 'P' in 'perf top' and the [vdso] samples are there: 62.84% [vdso] [.] __vdso_gettimeofday 8.13% gtod [.] main 7.51% [vdso] [.] 0x0000000000000914 5.78% [vdso] [.] 0x0000000000000917 5.43% gtod [.] _init 2.71% [vdso] [.] 0x000000000000092d 0.35% [kernel] [k] native_io_delay 0.33% libc-2.26.so [.] __memmove_avx_unaligned_erms 0.20% [vdso] [.] 0x000000000000091d 0.17% [i2c_i801] [k] i801_access 0.06% firefox [.] free 0.06% libglib-2.0.so.0.5400.3 [.] g_source_iter_next 0.05% [vdso] [.] 0x0000000000000919 0.05% libpthread-2.26.so [.] __pthread_mutex_lock 0.05% libpixman-1.so.0.34.0 [.] 0x000000000006d3a7 0.04% [kernel] [k] entry_SYSCALL_64_trampoline 0.04% libxul.so [.] style::dom_apis::query_selector_slow 0.04% [kernel] [k] module_get_kallsym 0.04% firefox [.] malloc 0.04% [vdso] [.] 0x0000000000000910 I added a 'perf probe' to thread__find_map:69, and that surely got tons of hits, i.e. for every map found, just to make sure the 'perf probe' command was really working. In the process I noticed a bug, we're only have records for '[vdso]' for pre-existing commands, i.e. ones that are running when we start 'perf top', when we will generate the PERF_RECORD_MMAP by looking at /perf/PID/maps. I.e. like this, for preexisting processes with a vdso map, again, tracing for all the system, only pre-existing processes get a [vdso] map (when having one): [root@jouet ~]# perf probe -x ~/bin/perf __machine__addnew_vdso Added new event: probe_perf:__machine__addnew_vdso (on __machine__addnew_vdso in /home/acme/bin/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:__machine__addnew_vdso -aR sleep 1 [root@jouet ~]# perf trace -e probe_perf:__machine__addnew_vdso/max-stack=8/ 0.000 probe_perf:__machine__addnew_vdso:(568eb3) __machine__addnew_vdso (/home/acme/bin/perf) map__new (/home/acme/bin/perf) machine__process_mmap2_event (/home/acme/bin/perf) machine__process_event (/home/acme/bin/perf) perf_event__process (/home/acme/bin/perf) perf_tool__process_synth_event (/home/acme/bin/perf) perf_event__synthesize_mmap_events (/home/acme/bin/perf) __event__synthesize_thread (/home/acme/bin/perf) The kernel is generating a PERF_RECORD_MMAP for vDSOs, but somehow 'perf top' is not getting those records while 'perf record' is: # perf record ~acme/c/gtod ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.076 MB perf.data (1499 samples) ] # perf report -D | grep PERF_RECORD_MMAP2 71293612401913 0x11b48 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x400000(0x1000) @ 0 fd:02 1137 541179306]: r-xp /home/acme/c/gtod 71293612419012 0x11be0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a2783000(0x227000) @ 0 fd:00 3146370 854107250]: r-xp /usr/lib64/ld-2.26.so 71293612432110 0x11c50 [0x60]: PERF_RECORD_MMAP2 25484/25484: [0x7ffcdb53a000(0x2000) @ 0 00:00 0 0]: r-xp [vdso] 71293612509944 0x11cb0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a23cd000(0x3b6000) @ 0 fd:00 3149723 262067164]: r-xp /usr/lib64/libc-2.26.so # # perf script | grep vdso | head gtod 25484 71293.612768: 2485554 cycles:ppp: 7ffcdb53a914 [unknown] ([vdso]) gtod 25484 71293.613576: 2149343 cycles:ppp: 7ffcdb53a917 [unknown] ([vdso]) gtod 25484 71293.614274: 1814652 cycles:ppp: 7ffcdb53aca8 __vdso_gettimeofday+0x98 ([vdso]) gtod 25484 71293.614862: 1669070 cycles:ppp: 7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso]) gtod 25484 71293.615404: 1451589 cycles:ppp: 7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso]) gtod 25484 71293.615999: 1269941 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso]) gtod 25484 71293.616405: 1177946 cycles:ppp: 7ffcdb53a914 [unknown] ([vdso]) gtod 25484 71293.616775: 1121290 cycles:ppp: 7ffcdb53ac47 __vdso_gettimeofday+0x37 ([vdso]) gtod 25484 71293.617150: 1037721 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso]) gtod 25484 71293.617478: 994526 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso]) # The patch is the obvious one and with it we also continue to resolve vdso symbols for pre-existing processes in 'perf top' and for all processes in 'perf record' + 'perf report/script'. Suggested-by: David Miller Acked-by: David Miller Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-cs7skq9pp0kjypiju6o7trse@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/event.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) (limited to 'tools/perf/util') diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index 0988eb3b844b..bc646185f8d9 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -1561,26 +1561,9 @@ struct map *thread__find_map(struct thread *thread, u8 cpumode, u64 addr, return NULL; } -try_again: + al->map = map_groups__find(mg, al->addr); - if (al->map == NULL) { - /* - * If this is outside of all known maps, and is a negative - * address, try to look it up in the kernel dso, as it might be - * a vsyscall or vdso (which executes in user-mode). - * - * XXX This is nasty, we should have a symbol list in the - * "[vdso]" dso, but for now lets use the old trick of looking - * in the whole kernel symbol list. - */ - if (cpumode == PERF_RECORD_MISC_USER && machine && - mg != &machine->kmaps && - machine__kernel_ip(machine, al->addr)) { - mg = &machine->kmaps; - load_map = true; - goto try_again; - } - } else { + if (al->map != NULL) { /* * Kernel maps might be changed when loading symbols so loading * must be done prior to using kernel maps. -- cgit v1.2.3-70-g09d2