linux/tools/perf
Jiri Olsa 721f0dfc3c perf python: Fix pyrf_evlist__read_on_cpu() interface
Jaroslav reported errors from valgrind over perf python script:

  # echo 0 > /sys/devices/system/cpu/cpu4/online
  # valgrind ./test.py
  ==7524== Memcheck, a memory error detector
  ...
  ==7524== Command: ./test.py
  ==7524==
  pid 7526 exited
  ==7524== Invalid read of size 8
  ==7524==    at 0xCC2C2B3: perf_mmap__read_forward (evlist.c:780)
  ==7524==    by 0xCC2A681: pyrf_evlist__read_on_cpu (python.c:959)
  ...
  ==7524==  Address 0x65c4868 is 16 bytes after a block of size 459,36..
  ==7524==    at 0x4C2B955: calloc (vg_replace_malloc.c:711)
  ==7524==    by 0xCC2F484: zalloc (util.h:35)
  ==7524==    by 0xCC2F484: perf_evlist__alloc_mmap (evlist.c:978)
  ...

The reason for this is in the python interface, that allows a script to
pass arbitrary cpu number, which is then used to access struct
perf_evlist::mmap array. That's obviously wrong and works only when if
all cpus are available and fails if some cpu is missing, like in the
example above.

This patch makes pyrf_evlist__read_on_cpu() search the evlist's maps
array for the proper map to access.

It's linear search at the moment. Based on the way how is the
read_on_cpu used, I don't think we need to be fast in here.  But we
could add some hash in the middle to make it fast/er.

We don't allow python interface to set write_backward event attribute,
so it's safe to check only evlist's mmaps.

Reported-by: Jaroslav Škarvada <jskarvad@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180817114556.28000-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-08-20 08:54:59 -03:00
..
Documentation perf report: Add --percent-type option 2018-08-08 15:55:54 -03:00
arch perf arm spe: Fix uninitialized record error variable 2018-08-14 15:10:44 -03:00
bench tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy' 2018-07-30 12:36:51 -03:00
examples/bpf perf trace: Handle "bpf-output" events associated with "__augmented_syscalls__" BPF map 2018-08-08 15:55:57 -03:00
include/bpf perf bpf: Add wrappers to BPF_FUNC_probe_read(_str) functions 2018-08-08 15:55:57 -03:00
jvmti perf tools: Fix compilation errors on gcc8 2018-07-11 09:39:57 -04:00
pmu-events perf vendor events arm64: Enable JSON events for eMAG 2018-08-08 15:55:43 -03:00
python perf python: Make twatch.py work with both python2 and python3 2018-02-19 12:28:08 -03:00
scripts perf scripts python: Add Python 3 support to EventClass.py 2018-07-11 10:01:50 -03:00
tests perf tools: Remove ext from struct kmod_path 2018-08-20 08:54:59 -03:00
trace perf trace beauty: Add beautifiers for 'socket''s 'protocol' arg 2018-07-31 10:52:47 -03:00
ui perf annotate: Add support to toggle percent type 2018-08-08 15:55:52 -03:00
util perf python: Fix pyrf_evlist__read_on_cpu() interface 2018-08-20 08:54:59 -03:00
.gitignore perf tools: Add trace/beauty/generated/ into .gitignore 2018-02-05 13:58:02 -03:00
Build perf trace: Remove audit-libs dependency if syscall tables are present 2018-01-23 09:51:38 -03:00
CREDITS
MANIFEST perf tools: Get all of tools/{arch,include}/ in the MANIFEST 2017-09-25 10:39:43 -03:00
Makefile perf tools: Disable parallelism for 'make clean' 2018-08-20 08:54:58 -03:00
Makefile.config perf build: Fix installation directory for eBPF 2018-07-31 10:54:50 -03:00
Makefile.perf perf trace beauty: Add beautifiers for 'socket''s 'protocol' arg 2018-07-31 10:52:47 -03:00
builtin-annotate.c perf annotate: Add --percent-type option 2018-08-08 15:55:53 -03:00
builtin-bench.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
builtin-buildid-cache.c perf buildid-cache: Warn --purge-all failures 2018-05-15 10:32:16 -03:00
builtin-buildid-list.c Merge branch 'linus' into perf/core, to fix conflicts 2017-11-07 10:30:18 +01:00
builtin-c2c.c perf c2c report: Fix crash for empty browser 2018-07-31 10:53:20 -03:00
builtin-config.c Merge branch 'linus' into perf/core, to fix conflicts 2017-11-07 10:30:18 +01:00
builtin-data.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
builtin-diff.c perf hists: Clarify callchain disabling when available 2018-07-24 14:37:33 -03:00
builtin-evlist.c Merge branch 'linus' into perf/core, to fix conflicts 2017-11-07 10:30:18 +01:00
builtin-ftrace.c perf ftrace: Append an EOL when write tracing files 2018-02-19 09:49:12 -03:00
builtin-help.c perf tools: Rename HAVE_SYSCALL_TABLE to HAVE_SYSCALL_TABLE_SUPPORT 2018-04-12 10:33:31 -03:00
builtin-inject.c perf thread: Make thread__find_map() return the map 2018-04-26 13:47:08 -03:00
builtin-kallsyms.c perf machine: Ditch find_kernel_function variants 2018-04-30 12:20:54 -03:00
builtin-kmem.c tools lib traceevent, perf tools: Rename 'enum pevent_flag' to 'enum tep_flag' 2018-08-13 15:22:18 -03:00
builtin-kvm.c perf tools: Ditch the symbol_conf.nr_events global 2018-06-04 10:28:52 -03:00
builtin-list.c Merge branch 'linus' into perf/core, to fix conflicts 2017-11-07 10:30:18 +01:00
builtin-lock.c Merge branch 'linus' into perf/core, to fix conflicts 2017-11-07 10:30:18 +01:00
builtin-mem.c perf mem: Allow all record/report options 2018-04-18 15:35:48 -03:00
builtin-probe.c perf tools: No need to check if the argument to __get() function is NULL 2018-06-04 10:28:50 -03:00
builtin-record.c perf record: Synthesize features before events in pipe mode 2018-03-16 13:56:50 -03:00
builtin-report.c tools lib traceevent, perf tools: Rename pevent_set_* APIs 2018-08-13 15:22:10 -03:00
builtin-sched.c perf sched: Use sched->show_callchain where appropriate 2018-06-05 10:09:54 -03:00
builtin-script.c tools lib traceevent, perf tools: Rename pevent_set_* APIs 2018-08-13 15:22:10 -03:00
builtin-stat.c perf stat: Get rid of extra clock display function 2018-07-24 14:54:58 -03:00
builtin-timechart.c perf thread: Make thread__find_symbol() return the symbol searched 2018-04-26 13:47:09 -03:00
builtin-top.c perf hists: Clarify callchain disabling when available 2018-07-24 14:37:33 -03:00
builtin-trace.c perf trace: Wire up the augmented syscalls with the syscalls:sys_enter_FOO beautifier 2018-08-08 15:55:59 -03:00
builtin-version.c perf version: Print status for syscall_table 2018-04-12 10:33:34 -03:00
builtin.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
check-headers.sh perf tools: Move syscall_64.tbl check into check-headers.sh 2018-08-14 15:10:40 -03:00
command-list.txt perf tools: Missing c2c command in command-list 2017-03-13 10:59:31 -03:00
design.txt
perf-archive.sh License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
perf-completion.sh perf tools: Auto-complete for events with ':' 2017-12-27 12:16:00 -03:00
perf-read-vdso.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
perf-sys.h Drop a bunch of metag references 2018-02-23 14:29:59 +00:00
perf-with-kcore.sh
perf.c perf tools: Remove dead quote.[ch] code 2018-06-04 10:28:50 -03:00
perf.h perf tools: Allow overriding MAX_NR_CPUS at compile time 2018-08-01 12:33:24 -03:00