#define TEST_CMOV 0
#define TEST_FCOMI 0
+//#define LINUX_VM86_IOPL_FIX
#define xglue(x, y) x ## y
#define glue(x, y) xglue(x, y)
switch(VM86_TYPE(ret)) {
case VM86_INTx:
{
- int int_num, ah;
+ int int_num, ah, v;
int_num = VM86_ARG(ret);
if (int_num != 0x21)
r->eax = (r->eax & ~0xff) | '$';
}
break;
- case 0xff: /* extension: write hex number in edx */
- printf("%08x\n", (int)r->edx);
+ case 0xff: /* extension: write eflags number in edx */
+ v = (int)r->edx;
+#ifndef LINUX_VM86_IOPL_FIX
+ v &= ~0x3000;
+#endif
+ printf("%08x\n", v);
break;
default:
unknown_int:
printf("val=0x%x\n", val);
}
+/* specific precise single step test */
+void sig_trap_handler(int sig, siginfo_t *info, void *puc)
+{
+ struct ucontext *uc = puc;
+ printf("EIP=0x%08x\n", uc->uc_mcontext.gregs[REG_EIP]);
+}
+
+const uint8_t sstep_buf1[4] = { 1, 2, 3, 4};
+uint8_t sstep_buf2[4];
+
+void test_single_step(void)
+{
+ struct sigaction act;
+ volatile int val;
+ int i;
+
+ val = 0;
+ act.sa_sigaction = sig_trap_handler;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_SIGINFO;
+ sigaction(SIGTRAP, &act, NULL);
+ asm volatile ("pushf\n"
+ "orl $0x00100, (%%esp)\n"
+ "popf\n"
+ "movl $0xabcd, %0\n"
+
+ /* jmp test */
+ "movl $3, %%ecx\n"
+ "1:\n"
+ "addl $1, %0\n"
+ "decl %%ecx\n"
+ "jnz 1b\n"
+
+ /* movsb: the single step should stop at each movsb iteration */
+ "movl $sstep_buf1, %%esi\n"
+ "movl $sstep_buf2, %%edi\n"
+ "movl $0, %%ecx\n"
+ "rep movsb\n"
+ "movl $3, %%ecx\n"
+ "rep movsb\n"
+ "movl $1, %%ecx\n"
+ "rep movsb\n"
+
+ /* cmpsb: the single step should stop at each cmpsb iteration */
+ "movl $sstep_buf1, %%esi\n"
+ "movl $sstep_buf2, %%edi\n"
+ "movl $0, %%ecx\n"
+ "rep cmpsb\n"
+ "movl $4, %%ecx\n"
+ "rep cmpsb\n"
+
+ /* getpid() syscall: single step should skip one
+ instruction */
+ "movl $20, %%eax\n"
+ "int $0x80\n"
+ "movl $0, %%eax\n"
+
+ /* when modifying SS, trace is not done on the next
+ instruction */
+ "movl %%ss, %%ecx\n"
+ "movl %%ecx, %%ss\n"
+ "addl $1, %0\n"
+ "movl $1, %%eax\n"
+ "movl %%ecx, %%ss\n"
+ "jmp 1f\n"
+ "addl $1, %0\n"
+ "1:\n"
+ "movl $1, %%eax\n"
+ "pushl %%ecx\n"
+ "popl %%ss\n"
+ "addl $1, %0\n"
+ "movl $1, %%eax\n"
+
+ "pushf\n"
+ "andl $~0x00100, (%%esp)\n"
+ "popf\n"
+ : "=m" (val)
+ :
+ : "cc", "memory", "eax", "ecx", "esi", "edi");
+ printf("val=%d\n", val);
+ for(i = 0; i < 4; i++)
+ printf("sstep_buf2[%d] = %d\n", i, sstep_buf2[i]);
+}
+
/* self modifying code test */
uint8_t code[] = {
0xb8, 0x1, 0x00, 0x00, 0x00, /* movl $1, %eax */
test_vm86();
test_exceptions();
test_self_modifying_code();
+ test_single_step();
return 0;
}