libbacktrace: treat EACCESS like ENOENT

libbacktrace/
	PR go/95061
	* posix.c (backtrace_open): Treat EACCESS like ENOENT.

libbacktrace/ChangeLog

+2020-05-13  Ian Lance Taylor  <iant@golang.org>
+
+	PR go/95061
+	* posix.c (backtrace_open): Treat EACCESS like ENOENT.
+
+2020-05-12  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* Makefile.am (AM_CFLAGS): Add $(CET_HOST_FLAGS).
 	* configure.ac: Add GCC_CET_HOST_FLAGS(CET_HOST_FLAGS) and

libbacktrace/posix.c

@@ -67,7 +67,11 @@ backtrace_open (const char *filename, backtrace_error_callback error_callback,
   descriptor = open (filename, (int) (O_RDONLY | O_BINARY | O_CLOEXEC));
   if (descriptor < 0)
     {
-      if (does_not_exist != NULL && errno == ENOENT)
+      /* If DOES_NOT_EXIST is not NULL, then don't call ERROR_CALLBACK
+	 if the file does not exist.  We treat lacking permission to
+	 open the file as the file not existing; this case arises when
+	 running the libgo syscall package tests as root.  */
+      if (does_not_exist != NULL && (errno == ENOENT || errno == EACCES))
 	*does_not_exist = 1;
       else
 	error_callback (data, filename, errno);