Support getting executable's name for sanitizers needs on FreeBSD

[kutuzov.viktor.84]

lib/sanitizer_common/sanitizer_linux.cc

672

BTW, why don't we check proc_self_exe_cache_len first?

[samsonov]

LGTM

lib/sanitizer_common/sanitizer_linux.cc

672

Weird indeed. Should be fixed by r209773.

[kutuzov.viktor.84]

Committed as rL209805.

lib/sanitizer_common/sanitizer_linux.cc

 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <unwind.h>
 
 #if SANITIZER_FREEBSD
+#include <sys/sysctl.h>
 #include <machine/atomic.h>
 extern "C" {
 // <sys/umtx.h> must be included after <errno.h> and <sys/types.h> on
 // FreeBSD 9.2 and 10.0.
 #include <sys/umtx.h>
 }
 #endif  // SANITIZER_FREEBSD
 
#else
   return sysconf(_SC_PAGESIZE);  // EXEC_PAGESIZE may not be trustworthy.
 #endif
 }
 
 static char proc_self_exe_cache_str[kMaxPathLength];
 static uptr proc_self_exe_cache_len = 0;
 
 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
+#if SANITIZER_FREEBSD
+  const int Mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
+  size_t Size = buf_len;
+  bool IsErr = (sysctl(Mib, 4, buf, &Size, NULL, 0) != 0);
+  int readlink_error = IsErr ? errno : 0;
+  uptr module_name_len = Size;
+#else
   uptr module_name_len = internal_readlink(
       "/proc/self/exe", buf, buf_len);
   int readlink_error;
-  if (internal_iserror(module_name_len, &readlink_error)) {
+  bool IsErr = internal_iserror(module_name_len, &readlink_error);
+#endif
+  if (IsErr) {
     if (proc_self_exe_cache_len) {
       // If available, use the cached module name.
       CHECK_LE(proc_self_exe_cache_len, buf_len);
       internal_strncpy(buf, proc_self_exe_cache_str, buf_len);
       module_name_len = internal_strlen(proc_self_exe_cache_str);
     } else {
       // We can't read /proc/self/exe for some reason, assume the name of the
       // binary is unknown.
       Report("WARNING: readlink(\"/proc/self/exe\") failed with errno %d, "