X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/cd1ed48ddbbb487a40bbf2ecc55ca1d8377c1819..d267aea2424783f5eefb6e733a6806ffd3323fa0:/src/unexmacosx.c

diff --git a/src/unexmacosx.c b/src/unexmacosx.c
index 89971bb8a7..bdacc8b540 100644
--- a/src/unexmacosx.c
+++ b/src/unexmacosx.c
@@ -1,12 +1,12 @@
 /* Dump Emacs in Mach-O format for use on Mac OS X.
-   Copyright (C) 2001-2014 Free Software Foundation, Inc.
+   Copyright (C) 2001-2016 Free Software Foundation, Inc.
 
 This file is part of GNU Emacs.
 
 GNU Emacs is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
 
 GNU Emacs is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -99,12 +99,15 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "unexec.h"
 #include "lisp.h"
 
+#include <errno.h>
 #include <stdio.h>
 #include <fcntl.h>
 #include <stdarg.h>
+#include <stdint.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <mach/mach.h>
+#include <mach/vm_map.h>
 #include <mach-o/loader.h>
 #include <mach-o/reloc.h>
 #ifdef HAVE_MALLOC_MALLOC_H
@@ -216,10 +219,27 @@ unexec_read (void *dest, size_t n)
 static int
 unexec_write (off_t dest, const void *src, size_t count)
 {
+  task_t task = mach_task_self();
+  if (task == MACH_PORT_NULL || task == MACH_PORT_DEAD)
+    return false;
+
   if (lseek (outfd, dest, SEEK_SET) != dest)
     return 0;
 
-  return write (outfd, src, count) == count;
+  /* We use the Mach virtual memory API to read our process memory
+     because using src directly would be undefined behavior and fails
+     under Address Sanitizer.  */
+  bool success = false;
+  vm_offset_t data;
+  mach_msg_type_number_t data_count;
+  if (vm_read (task, (uintptr_t) src, count, &data, &data_count)
+      == KERN_SUCCESS)
+    {
+      success =
+        write (outfd, (const void *) (uintptr_t) data, data_count) == count;
+      vm_deallocate (task, data, data_count);
+    }
+  return success;
 }
 
 /* Write COUNT bytes of zeros to outfd starting at offset DEST.
@@ -1264,14 +1284,14 @@ unexec (const char *outfile, const char *infile)
   infd = emacs_open (infile, O_RDONLY, 0);
   if (infd < 0)
     {
-      unexec_error ("cannot open input file `%s'", infile);
+      unexec_error ("%s: %s", infile, strerror (errno));
     }
 
   outfd = emacs_open (outfile, O_WRONLY | O_TRUNC | O_CREAT, 0777);
   if (outfd < 0)
     {
       emacs_close (infd);
-      unexec_error ("cannot open output file `%s'", outfile);
+      unexec_error ("%s: %s", outfile, strerror (errno));
     }
 
   build_region_list ();