WSL2-Linux-Kernel/tools
Jan Stancek 43db2843a4 perf header: Make build_cpu_topology skip offline/absent CPUs
When build_cpu_topo() encounters offline/absent CPUs, it fails to find any
sysfs entries and returns failure.

This leads to build_cpu_topology() and write_cpu_topology() failing as
well.

Because HEADER_CPU_TOPOLOGY has not been written, read leaves cpu_topology_map
NULL and we get NULL ptr deref at:

  ...
   cmd_test
    __cmd_test
     test_and_print
      run_test
       test_session_topology
        check_cpu_topology

  36: Session topology                           :
  --- start ---
  test child forked, pid 14902
  templ file: /tmp/perf-test-4CKocW
  failed to write feature HEADER_CPU_TOPOLOGY
  perf: Segmentation fault
  Obtained 9 stack frames.
  ./perf(sighandler_dump_stack+0x41) [0x5095f1]
  /lib64/libc.so.6(+0x35250) [0x7f4b7c3c9250]
  ./perf(test_session_topology+0x1db) [0x490ceb]
  ./perf() [0x475b68]
  ./perf(cmd_test+0x5b9) [0x4763c9]
  ./perf() [0x4945a3]
  ./perf(main+0x69f) [0x427e8f]
  /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f4b7c3b5b35]
  ./perf() [0x427fb9]
  test child interrupted
  ---- end ----
  Session topology: FAILED!

This patch makes build_cpu_topology() skip offline/absent CPUs, by checking
their presence against cpu_map built from online CPUs.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/a271b770175524f4961d4903af33798358a4a518.1487146877.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-02-17 12:37:04 -03:00
..
accounting
arch tools headers: Sync {tools/,}arch/powerpc/include/uapi/asm/kvm.h, {tools/,}arch/x86/include/asm/cpufeatures.h and {tools/,}arch/arm/include/uapi/asm/kvm.h 2017-01-30 16:01:20 -03:00
build tools build: Add tools tree support for 'make -s' 2017-01-26 16:29:00 -03:00
cgroup
firewire
gpio Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-12-17 16:24:13 -08:00
hv
iio
include tools include: Introduce linux/compiler-gcc.h 2017-02-13 14:29:29 -03:00
kvm/kvm_stat
laptop
leds
lguest
lib tools lib traceevent: It's preempt not prempt 2017-02-17 10:31:44 -03:00
net
nfsd
objtool objtool: Fix IRET's opcode 2017-01-19 08:39:44 +01:00
pcmcia
perf perf header: Make build_cpu_topology skip offline/absent CPUs 2017-02-17 12:37:04 -03:00
power Merge branch 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2016-12-25 14:01:28 -08:00
scripts tools: Suppress request for warning options not existent in clang 2017-02-14 10:34:35 -03:00
spi
testing Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-27 12:54:16 -08:00
thermal/tmon
time
usb
virtio tools/virtio/ringtest: tweaks for s390 2017-01-19 23:46:32 +02:00
vm
Makefile