perf top: Fix global-buffer-overflow issue

perf top: Fix global-buffer-overflow issue

[ Upstream commit 1e5b0cf8672e622257df024074e6e09bfbcb7750 ]

The array str[] should have six elements.

  =================================================================
  ==4322==ERROR: AddressSanitizer: global-buffer-overflow on address 0x56463844e300 at pc 0x564637e7ad0d bp 0x7f30c8c89d10 sp 0x7f30c8c89d00
  READ of size 8 at 0x56463844e300 thread T9
      #0 0x564637e7ad0c in __ordered_events__flush util/ordered-events.c:316
      #1 0x564637e7b0e4 in ordered_events__flush util/ordered-events.c:338
      #2 0x564637c6a57d in process_thread /home/changbin/work/linux/tools/perf/builtin-top.c:1073
      #3 0x7f30d173a163 in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x8163)
      #4 0x7f30cfffbdee in __clone (/lib/x86_64-linux-gnu/libc.so.6+0x11adee)

  0x56463844e300 is located 32 bytes to the left of global variable 'flags' defined in 'util/trace-event-parse.c:229:26' (0x56463844e320) of size 192
  0x56463844e300 is located 0 bytes to the right of global variable 'str' defined in 'util/ordered-events.c:268:28' (0x56463844e2e0) of size 32
  SUMMARY: AddressSanitizer: global-buffer-overflow util/ordered-events.c:316 in __ordered_events__flush
  Shadow bytes around the buggy address:
    0x0ac947081c10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c40: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c50: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00
  =>0x0ac947081c60:[f9]f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c70: 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 f9 f9
    0x0ac947081c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081c90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081ca0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x0ac947081cb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Heap left redzone:       fa
    Freed heap region:       fd
    Stack left redzone:      f1
    Stack mid redzone:       f2
    Stack right redzone:     f3
    Stack after return:      f5
    Stack use after scope:   f8
    Global redzone:          f9
    Global init order:       f6
    Poisoned by user:        f7
    Container overflow:      fc
    Array cookie:            ac
    Intra object redzone:    bb
    ASan internal:           fe
    Left alloca redzone:     ca
    Right alloca redzone:    cb
  Thread T9 created by T0 here:
      #0 0x7f30d179de5f in __interceptor_pthread_create (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x4ae5f)
      #1 0x564637c6b954 in __cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1253
      #2 0x564637c7173c in cmd_top /home/changbin/work/linux/tools/perf/builtin-top.c:1642
      #3 0x564637d85038 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #4 0x564637d85577 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #5 0x564637d8597b in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #6 0x564637d860e9 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #7 0x7f30cff0509a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Fixes: 16c66bc167cc ("perf top: Add processing thread")
Fixes: 68ca5d07de20 ("perf ordered_events: Add ordered_events__flush_time interface")
Link: http://lkml.kernel.org/r/20190316080556.3075-13-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>