[Sanitizers] Fix SanitizerCommon-Unit :: ./Sanitizer-*-Test/MemoryMappingLayout.DumpListOfModules on Solaris

[ro]

Summary

The MemoryMappingLayout.DumpListOfModules currently FAILs on Solaris:

[ RUN      ] MemoryMappingLayout.DumpListOfModules
/vol/llvm/src/compiler-rt/local/lib/sanitizer_common/tests/sanitizer_procmaps_test.cc:52: Failure
Value of: found
  Actual: false
Expected: true
[  FAILED  ] MemoryMappingLayout.DumpListOfModules (22 ms)

The problem is that the test expects the executable name from modules[i].full_name(),
however the pr_mapname field of struct prmap is just the entry in /proc/<pid>/object,
which is "a.out" instead of "Sanitizer-i386-Test ". Fortunately, the real name can
be determined by looking in proc/<pid>/path where "a.out" is a symlink to the
real path.

Tested on x86_64-pc-solaris2.11. Ok for trunk?

[eugenis]

LGTM

lib/sanitizer_common/sanitizer_procmaps_solaris.cc

bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
   if ((xmapentry->pr_mflags & MA_READ) != 0)
     segment->protection |= kProtectionRead;
   if ((xmapentry->pr_mflags & MA_WRITE) != 0)
     segment->protection |= kProtectionWrite;
   if ((xmapentry->pr_mflags & MA_EXEC) != 0)
     segment->protection |= kProtectionExecute;
 
   if (segment->filename != NULL && segment->filename_size > 0) {
-    internal_snprintf(segment->filename,
-                      Min(segment->filename_size, (uptr)PATH_MAX), "%s",
+    char proc_path[PATH_MAX + 1];
+
+    internal_snprintf(proc_path, sizeof(proc_path), "/proc/self/path/%s",
                       xmapentry->pr_mapname);
+    internal_readlink(proc_path, segment->filename, segment->filename_size);
   }
 
   data_.current += sizeof(prxmap_t);
 
   return true;
 }
 
 }  // namespace __sanitizer
 
 #endif  // SANITIZER_SOLARIS