--- /dev/null
+#!/usr/bin/perl -w
+
+#
+#
+# Wrap a kernel module (.ko) so that all undefined functions
+# are resolved at compile time to wrapper that have the template
+# as given here
+#
+# TODO: parameterize hypercall numbers
+# TODO: remove printk special case
+#
+
+use Getopt::Long;
+use File::Basename;
+
+$user=0;
+$kern=0;
+
+$V3_BORDER_OUT_CALL_NR = 0x6003;
+$V3_BORDER_IN_RET_NR = 0x6004;
+
+&GetOptions("user"=>\$user, "kern"=>\$kern);
+
+$#ARGV==0 or die "christo.pl [--user|--kern] <object-file>\n";
+
+$of=shift; chomp($of);
+($ofstem) = split(/\./,fileparse($of));
+
+if ($user) {
+
+ print "Wrapping $of to produce $ofstem-wrapped\n";
+
+ # First, find all undefined symbols that are text
+ @funcs = ExtractUndefinedFunctions($of);
+
+ print "Wrapping the following functions\n";
+ print join("\n", @funcs),"\n";
+
+ print "Generating wrapper $ofstem\_wrapper.c\n";
+
+ open(WRAPPER, ">$ofstem\_wrapper.c");
+ GenerateUserWrapper(WRAPPER, @funcs);
+ close(WRAPPER);
+
+ print "Compiling wrapper\n";
+
+ CompileUserWrapper($ofstem);
+
+
+ print "Linking with your supplied file $of to form $ofstem\_wrapped\n";
+
+ LinkUserWrapped($of,"$ofstem\_wrapper.o","$ofstem\_wrapped",@funcs);
+
+ print "Done.\n"
+
+} else {
+
+ print "Wrapping $of to produce $ofstem-wrapped\n";
+
+ @funcs = KernUndefFuncs($of);
+
+
+ print "Wrapping the following functions\n";
+ print join("\n", @funcs), "\n";
+
+ print "Generating wrapper $ofstem\_wrapper.S\n";
+
+ open(WRAPPER,">$ofstem\_wrapper.S");
+ GenerateKernWrapper($ofstem, WRAPPER, @funcs);
+ close(WRAPPER);
+
+}
+
+sub CompileUserWrapper {
+ my $stem=shift;
+
+ return system("gcc -c -fPIC $stem.c -o $stem.o");
+}
+
+
+sub LinkUserWrapped {
+ my ($of,$wrapper,$wrapped,@funcs) = @_;
+
+ $cmd = "gcc ".join(" ",
+ join(" ",
+ map {" -Xlinker --wrap=$_ "} @funcs
+ ),
+ $of, $wrapper)." -o $wrapped";
+
+ print $cmd;
+ return system $cmd;
+
+}
+
+sub KernUndefFuncs {
+ my $of = shift;
+ my $line;
+ my @funcs;
+ my @lines;
+ my @final_funcs;
+ my %sysmap;
+
+ print STDERR "Acquiring all undefined symbols from file\n";
+
+ open(OBJDUMP, "objdump -t $of |") or die "Cannot open file $of\n";
+
+ while ($line=<OBJDUMP>) {
+ if ($line =~ /.*\*UND\*\s+\S+\s+(\S+)$/) {
+ push @funcs, $1;
+ }
+ }
+
+ close(OBJDUMP);
+
+ print STDERR "Finding all functions listed in System.map\n";
+
+ open(MAP,"System.map") or die "Cannot open System.map\n";
+
+ while ($line=<MAP>) {
+ chomp($line);
+ my ($addr,$type,$name) = split(/\s+/,$line);
+ if (($type eq "t") or ($type eq "T")) {
+ $sysmap{$name}=1;
+ }
+ }
+
+ close(MAP);
+
+ foreach $func (@funcs) {
+ if (defined($sysmap{$func}) and ($func ne "printk") and ($func ne "mcount")
+ and ($func ne "__cyg_profile_func_enter") and ($func ne "__cyg_profile_func_exit")) {
+ print STDERR "ACCEPT $func\n";
+ push @final_funcs, $func;
+ } else {
+ print STDERR "DISCARD $func\n";
+ }
+ }
+
+ return @final_funcs;
+}
+
+sub ExtractUndefinedFunctions {
+ my $of=shift;
+ my $line;
+ my @funcs;
+
+ open(OBJDUMP,"objdump -t $of |") or die "Cannot open file $of\n";
+
+ while ($line=<OBJDUMP>) {
+ if ($line =~ /.*\*UND\*\s+\S+\s+(\S+)$/) {
+ push @funcs, $1;
+ }
+ }
+
+ close(OBJDUMP);
+
+ return @funcs;
+
+}
+
+sub GenerateUserWrapper {
+ my $file=shift;
+
+
+ while ($func=shift) {
+ print $file <<ENDF;
+
+int __wrap_$func(void *a1,
+ void *a2,
+ void *a3,
+ void *a4,
+ void *a5,
+ void *a6,
+ void *a7,
+ void *a8)
+{
+ asm volatile("vmmcall"
+ :"=a" (ret)
+ :"0" ($V3_GUARD_EXIT_HCALL_NR));
+ return __real_$func(a1,a2,a3,a4,a5,a6,a7,a8);
+ asm volatile("vmmcall"
+ :"=a" (ret)
+ :"0" ($V3_GUARD_ENTER_HCALL_NR));
+}
+
+ENDF
+
+ }
+}
+
+sub GenerateKernWrapper {
+ my $fname=shift;
+ my $file=shift;
+ my @funcs=@_;
+
+ open(MKFILE,">Makefile");
+ open(CFILE, ">wrap_impl.c");
+
+ print MKFILE "### THIS FILE IS AUTOMATICALLY GENERATED ###\n";
+ print MKFILE "EXTRA_LDFLAGS = ";
+
+ print $file "/* THIS FILE IS AUTOMATICALLY GENERATED */\n";
+ print $file ".text\n.align 4\n";
+ print $file map { ".globl __wrap_$_\n" } @funcs;
+ print $file map { ".globl __wrap_impl_$_\n" } @funcs;
+
+ print CFILE "/* THIS FILE IS AUTOMATICALLY GENERATED */\n";
+ print CFILE "#include <linux/kernel.h>\n\n";
+ #print CFILE "extern int wrapper_count;\n\n";
+ #print CFILE "static int border_count = 0;\n\n";
+ print CFILE map { "void __wrap_impl_$_(void);\n\n" } @funcs;
+
+ foreach $func (@funcs) {
+#__wrap_$func:
+ #nop
+ #nop
+ #nop
+ #nop
+ #nop
+ #nop
+ #nop
+ #pushq %rbp
+ #movq %rsp, %rbp
+ #pushq %rax
+ #pushq %rbx
+ #pushq %rcx
+ #pushq %rdx
+ #pushq %rdi
+ #pushq %rsi
+ #pushq %r8
+ #pushq %r9
+ #pushq %r10
+ #pushq %r11
+ #pushq %r12
+ #pushq %r13
+ #pushq %r14
+ #pushq %r15
+ #callq __wrap_impl_$func
+ #popq %r15
+ #popq %r14
+ #popq %r13
+ #popq %r12
+ #popq %r11
+ #popq %r10
+ #popq %r9
+ #popq %r8
+ #popq %rsi
+ #popq %rdi
+ #popq %rdx
+ #popq %rcx
+ #popq %rbx
+ #popq %rax
+ #popq %rbp
+ #jmp __real_$func
+ #nop
+ #nop
+ #nop
+ #nop
+ #nop
+
+ print $file <<ENDF;
+
+__wrap_$func:
+ popq %r11
+ pushq %rax
+ movq \$$V3_BORDER_OUT_CALL_NR, %rax
+ vmmcall
+ popq %rax
+ callq __real_$func
+ pushq %rax
+ movq \$$V3_BORDER_IN_RET_NR, %rax
+ vmmcall
+ popq %rax
+ pushq %r11
+ ret
+ENDF
+
+ print MKFILE "--wrap $func ";
+
+ print CFILE <<ENDF;
+void __wrap_impl_$func(void) {
+
+ //wrapper_count++;
+ //printk("exit: $func\\n");
+ //printk("wc: %d (%s)\\n", wrapper_count,__func__);
+}
+
+ENDF
+
+ }
+ print MKFILE "\n\nldflags-y := \$(EXTRA_LDFLAGS)\n";
+
+# TODO: change this to not be hardcoded!
+ my $kerndir = "/v-test/guard_modules/gm_guest/kyle_gl/";
+ print MKFILE <<ENDF;
+KERNDIR=$kerndir
+
+obj-m := $fname\_wrapped.o
+
+$fname\_wrapped-objs := $fname.ko $fname\_wrapper.o wrap_impl.o
+
+$fname\_wrapped.ko: $fname.ko $fname\_wrapper.o wrap_impl.o
+\tmake -C \$(KERNDIR) M=\$(PWD) modules
+
+clean:
+\tmake -C \$(KERNDIR) M=\$(PWD) clean
+
+ENDF
+
+ close(MKFILE);
+ close(CFILE);
+
+}
