From: Peter Dinda <pdinda@northwestern.edu>
Date: Fri, 13 Apr 2012 21:31:57 +0000 (-0500)
Subject: Gears - compilation for user injection
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=commitdiff_plain;h=0593c588b97054f631d1a729d045c97c9abd3e3b

Gears - compilation for user injection
---

diff --git a/gears/service_setup/compile-for-static-user-level-injection.pl b/gears/service_setup/compile-for-static-user-level-injection.pl
new file mode 100755
index 0000000..9d422dc
--- /dev/null
+++ b/gears/service_setup/compile-for-static-user-level-injection.pl
@@ -0,0 +1,83 @@
+#!/usr/bin/perl -w
+
+use Getopt::Long;
+
+&GetOptions(32=>\$m32, 64=>\$m64, "output=s"=>\$mod);
+
+$#ARGV >= 0 or die "usage: compile-for-static-user-level-injection.pl [-32|-64] [--output=module_name] source.c+ [lib.a]*\n";
+
+if (!$m32 && !$m64) {
+  print "Assuming 32 bit.  Use -64 to override\n";
+  $m32=1;
+}
+
+if (!$mod) { 
+  print "No module name given, assuming a.tooth\n";
+  $mod = "a.tooth";
+}
+
+if ($m32) { 
+  $gopt = "-m32";
+  $lopt = "-melf_i386 --oformat elf32-i386";
+} 
+
+if ($m64) { 
+  $gopt = "-m64";
+  $lopt = "-melf_x86_64 --oformat elf64-x86-64";
+}
+
+
+$linkerscript = <<END;
+SECTIONS
+{
+/* Must be on a page boundary */
+/* Should link like ld -z max-page-size=4096 -T ld.script ... */
+/* If object file is -fPIC, then it shouldn't matter where we load it */
+  . = 0x1000;   
+/* Text, data, and bss squished together */
+  .text : { *(.text) }
+  .data : { *(.data) }
+  .bss : { *(.bss) }
+/* Result will be one load group marked RWX */
+}
+END
+
+
+
+@stems=grep(/.*\.c$/,@ARGV);
+@libs=grep(/.*\.a$/,@ARGV);
+
+map { $_ =~ s/\.c$//g} @stems;
+
+print "Compiling...\n";
+foreach $s (@stems) { 
+  system("gcc $gopt -fPIE -Wa,-R -c $s.c -nostartfiles -nodefaultlibs -nostdlib -static -o $s.o") == 0 
+   or die "Compilation of $s.c failed\n";
+  system("gcc $gopt -fPIE -Wa,-R -S $s.c -nostartfiles -nodefaultlibs -nostdlib -static -o $s.s") == 0 
+   or die "Compilation of $s.c failed\n";
+}
+print "Compilation done.\n";
+
+open(W,">.linker_script");
+print W $linkerscript;
+close(W);
+
+print "Linking...\n";
+
+$rc=system("ld $lopt -z max-page-size=4096 -T .linker_script ".join(" ",map { "$_.o" } @stems)." ".join(" ",@libs)." -o $mod\n");
+
+unlink ".linker_script";
+
+$rc==0 or die "Linking of $mod failed\n";
+
+print "Linking of $mod completed.  Done.\n";
+
+open(E,"readelf -h $mod |");
+while (<E>) { 
+  if (/^\s*Entry point address:\s+(\S+)$/) {
+    print "Entry point relative to beginning of file: $1\n";
+    last;
+  }
+}
+close(E);
+