From: Arnaldo Carvalho de Melo <a...@redhat.com>

commit 6810158d526e483868e519befff407b91e76b3db upstream.

We were using a local buffer with an arbitrary size, that would have to
get increased to avoid truncation as warned by gcc 8:

  util/annotate.c: In function 'symbol__disassemble':
  util/annotate.c:1488:4: error: '%s' directive output may be truncated writing 
up to 4095 bytes into a region of size between 3966 and 8086 
[-Werror=format-truncation=]
      "%s %s%s --start-address=0x%016" PRIx64
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  util/annotate.c:1498:20:
      symfs_filename, symfs_filename);
                      ~~~~~~~~~~~~~~
  util/annotate.c:1490:50: note: format string is defined here
      " -l -d %s %s -C \"%s\" 2>/dev/null|grep -v \"%s:\"|expand",
                                                  ^~
  In file included from /usr/include/stdio.h:861,
                   from util/color.h:5,
                   from util/sort.h:8,
                   from util/annotate.c:14:
  /usr/include/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output 116 
or more bytes (assuming 8331) into a destination of size 8192
     return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          __bos (__s), __fmt, __va_arg_pack ());
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So switch to asprintf, that will make sure enough space is available.

Cc: Adrian Hunter <adrian.hun...@intel.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: Jin Yao <yao....@linux.intel.com>
Cc: Jiri Olsa <jo...@kernel.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Wang Nan <wangn...@huawei.com>
Link: https://lkml.kernel.org/n/tip-qagoy2dmbjpc9gdnaj0r3...@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 tools/perf/util/annotate.c |   14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1077,7 +1077,7 @@ int symbol__annotate(struct symbol *sym,
        struct dso *dso = map->dso;
        char *filename = dso__build_id_filename(dso, NULL, 0);
        bool free_filename = true;
-       char command[PATH_MAX * 2];
+       char *command;
        FILE *file;
        int err = 0;
        char symfs_filename[PATH_MAX];
@@ -1192,7 +1192,7 @@ fallback:
                strcpy(symfs_filename, tmp);
        }
 
-       snprintf(command, sizeof(command),
+       err = asprintf(&command,
                 "%s %s%s --start-address=0x%016" PRIx64
                 " --stop-address=0x%016" PRIx64
                 " -l -d %s %s -C %s 2>/dev/null|grep -v %s|expand",
@@ -1205,6 +1205,11 @@ fallback:
                 symbol_conf.annotate_src ? "-S" : "",
                 symfs_filename, filename);
 
+       if (err < 0) {
+               pr_err("Failure allocating memory for the command to run\n");
+               goto out_remove_tmp;
+       }
+
        pr_debug("Executing: %s\n", command);
 
        file = popen(command, "r");
@@ -1214,7 +1219,7 @@ fallback:
                 * If we were using debug info should retry with
                 * original binary.
                 */
-               goto out_remove_tmp;
+               goto out_free_command;
        }
 
        nline = 0;
@@ -1237,6 +1242,9 @@ fallback:
 
        pclose(file);
 
+out_free_command:
+       free(command);
+
 out_remove_tmp:
        if (dso__needs_decompress(dso))
                unlink(symfs_filename);


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