gold/

* testsuite/binary_unittest.cc (read_all): New function.
	(Sized_binary_test): Use it instead of ::read.
	* fileread.cc (do_read): Don't assume pread always reads the whole
	amount in a single call.

gold/ChangeLog

@@ -1,3 +1,10 @@
+2012-12-10  Roland McGrath  <mcgrathr@google.com>
+
+	* testsuite/binary_unittest.cc (read_all): New function.
+	(Sized_binary_test): Use it instead of ::read.
+	* fileread.cc (do_read): Don't assume pread always reads the whole
+	amount in a single call.
+
 2012-12-10  Alan Modra  <amodra@gmail.com>
 
 	* powerpc.cc (Target_selector_powerpc::Target_selector_powerpc):

gold/fileread.cc

@@ -1,6 +1,7 @@
 // fileread.cc -- read files for gold
 
-// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
+// Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
@@ -389,16 +390,26 @@ File_read::do_read(off_t start, section_size_type size, void* p)
   else
     {
       this->reopen_descriptor();
-      bytes = ::pread(this->descriptor_, p, size, start);
-      if (static_cast<section_size_type>(bytes) == size)
-	return;
 
-      if (bytes < 0)
+      char *read_ptr = static_cast<char *>(p);
+      off_t read_pos = start;
+      size_t to_read = size;
+      do
 	{
+	  bytes = ::pread(this->descriptor_, read_ptr, to_read, read_pos);
+	  if (bytes < 0)
 	    gold_fatal(_("%s: pread failed: %s"),
 		       this->filename().c_str(), strerror(errno));
+
+	  read_pos += bytes;
+	  read_ptr += bytes;
+	  to_read -= bytes;
+	  if (to_read == 0)
 	    return;
 	}
+      while (bytes > 0);
+
+      bytes = size - to_read;
     }
 
   gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),

gold/testsuite/binary_unittest.cc

@@ -38,6 +38,29 @@
 #include "test.h"
 #include "testfile.h"
 
+namespace
+{
+
+ssize_t
+read_all (int fd, unsigned char* buf, ssize_t size)
+{
+  ssize_t total_read = 0;
+  while (size > 0)
+    {
+      ssize_t nread = ::read(fd, buf, size);
+      if (nread < 0)
+	return nread;
+      if (nread == 0)
+	break;
+      buf += nread;
+      size -= nread;
+      total_read += nread;
+    }
+  return total_read;
+}
+
+} // End anonymous namespace.
+
 namespace gold_testsuite
 {
 
@@ -57,7 +80,7 @@ Sized_binary_test()
   int o = open_descriptor(-1, gold::program_name, O_RDONLY);
   CHECK(o >= 0);
   unsigned char* filedata = new unsigned char[st.st_size];
-  CHECK(::read(o, filedata, st.st_size) == st.st_size);
+  CHECK(read_all(o, filedata, st.st_size) == static_cast<ssize_t>(st.st_size));
   CHECK(::close(o) == 0);
 
   Binary_to_elf binary(static_cast<elfcpp::EM>(0xffff), size, big_endian,