queue-4.19/perf-data-fix-strncat-may-truncate-build-failure-wit.patch

   1 From ad9dc0e3d1796e1337486a8859ee737a08c8a764 Mon Sep 17 00:00:00 2001
   2 From: Shawn Landden <shawn@git.icu>
   3 Date: Sat, 18 May 2019 15:32:38 -0300
   4 Subject: perf data: Fix 'strncat may truncate' build failure with recent gcc
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 [ Upstream commit 97acec7df172cd1e450f81f5e293c0aa145a2797 ]
  10
  11 This strncat() is safe because the buffer was allocated with zalloc(),
  12 however gcc doesn't know that. Since the string always has 4 non-null
  13 bytes, just use memcpy() here.
  14
  15     CC       /home/shawn/linux/tools/perf/util/data-convert-bt.o
  16   In file included from /usr/include/string.h:494,
  17                    from /home/shawn/linux/tools/lib/traceevent/event-parse.h:27,
  18                    from util/data-convert-bt.c:22:
  19   In function ‘strncat’,
  20       inlined from ‘string_set_value’ at util/data-convert-bt.c:274:4:
  21   /usr/include/powerpc64le-linux-gnu/bits/string_fortified.h:136:10: error: ‘__builtin_strncat’ output may be truncated copying 4 bytes from a string of length 4 [-Werror=stringop-truncation]
  22     136 |   return __builtin___strncat_chk (__dest, __src, __len, __bos (__dest));
  23         |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24
  25 Signed-off-by: Shawn Landden <shawn@git.icu>
  26 Cc: Adrian Hunter <adrian.hunter@intel.com>
  27 Cc: Jiri Olsa <jolsa@redhat.com>
  28 Cc: Namhyung Kim <namhyung@kernel.org>
  29 Cc: Wang Nan <wangnan0@huawei.com>
  30 LPU-Reference: 20190518183238.10954-1-shawn@git.icu
  31 Link: https://lkml.kernel.org/n/tip-289f1jice17ta7tr3tstm9jm@git.kernel.org
  32 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
  33 Signed-off-by: Sasha Levin <sashal@kernel.org>
  34 ---
  35  tools/perf/util/data-convert-bt.c | 2 +-
  36  1 file changed, 1 insertion(+), 1 deletion(-)
  37
  38 diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c
  39 index abd38abf1d91..24f2a87cf91d 100644
  40 --- a/tools/perf/util/data-convert-bt.c
  41 +++ b/tools/perf/util/data-convert-bt.c
  42 @@ -271,7 +271,7 @@ static int string_set_value(struct bt_ctf_field *field, const char *string)
  43                                 if (i > 0)
  44                                         strncpy(buffer, string, i);
  45                         }
  46 -                       strncat(buffer + p, numstr, 4);
  47 +                       memcpy(buffer + p, numstr, 4);
  48                         p += 3;
  49                 }
  50         }
  51 --
  52 2.20.1
  53