precise exceptions - more accurate interrupt semantics
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@193 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/linux-user/main.c b/linux-user/main.c
index a6a84e5..eeea342 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -100,24 +100,35 @@
return 0;
}
-void write_dt(void *ptr, unsigned long addr, unsigned long limit,
- int seg32_bit)
+static void write_dt(void *ptr, unsigned long addr, unsigned long limit,
+ int flags)
{
- unsigned int e1, e2, limit_in_pages;
- limit_in_pages = 0;
- if (limit > 0xffff) {
- limit = limit >> 12;
- limit_in_pages = 1;
- }
+ unsigned int e1, e2;
e1 = (addr << 16) | (limit & 0xffff);
e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
- e2 |= limit_in_pages << 23; /* byte granularity */
- e2 |= seg32_bit << 22; /* 32 bit segment */
+ e2 |= flags;
+ stl((uint8_t *)ptr, e1);
+ stl((uint8_t *)ptr + 4, e2);
+}
+
+static void set_gate(void *ptr, unsigned int type, unsigned int dpl,
+ unsigned long addr, unsigned int sel)
+{
+ unsigned int e1, e2;
+ e1 = (addr & 0xffff) | (sel << 16);
+ e2 = (addr & 0xffff0000) | 0x8000 | (dpl << 13) | (type << 8);
stl((uint8_t *)ptr, e1);
stl((uint8_t *)ptr + 4, e2);
}
uint64_t gdt_table[6];
+uint64_t idt_table[256];
+
+/* only dpl matters as we do only user space emulation */
+static void set_idt(int n, unsigned int dpl)
+{
+ set_gate(idt_table + n, 0, dpl, 0, 0);
+}
void cpu_loop(CPUX86State *env)
{
@@ -128,30 +139,34 @@
for(;;) {
trapnr = cpu_x86_exec(env);
switch(trapnr) {
+ case 0x80:
+ /* linux syscall */
+ env->regs[R_EAX] = do_syscall(env,
+ env->regs[R_EAX],
+ env->regs[R_EBX],
+ env->regs[R_ECX],
+ env->regs[R_EDX],
+ env->regs[R_ESI],
+ env->regs[R_EDI],
+ env->regs[R_EBP]);
+ break;
+ case EXCP0B_NOSEG:
+ case EXCP0C_STACK:
+ info.si_signo = SIGBUS;
+ info.si_errno = 0;
+ info.si_code = TARGET_SI_KERNEL;
+ info._sifields._sigfault._addr = 0;
+ queue_signal(info.si_signo, &info);
+ break;
case EXCP0D_GPF:
if (env->eflags & VM_MASK) {
handle_vm86_fault(env);
} else {
- pc = env->seg_cache[R_CS].base + env->eip;
- if (pc[0] == 0xcd && pc[1] == 0x80) {
- /* syscall */
- env->eip += 2;
- env->regs[R_EAX] = do_syscall(env,
- env->regs[R_EAX],
- env->regs[R_EBX],
- env->regs[R_ECX],
- env->regs[R_EDX],
- env->regs[R_ESI],
- env->regs[R_EDI],
- env->regs[R_EBP]);
- } else {
- /* XXX: more precise info */
- info.si_signo = SIGSEGV;
- info.si_errno = 0;
- info.si_code = TARGET_SI_KERNEL;
- info._sifields._sigfault._addr = 0;
- queue_signal(info.si_signo, &info);
- }
+ info.si_signo = SIGSEGV;
+ info.si_errno = 0;
+ info.si_code = TARGET_SI_KERNEL;
+ info._sifields._sigfault._addr = 0;
+ queue_signal(info.si_signo, &info);
}
break;
case EXCP0E_PAGE:
@@ -365,11 +380,40 @@
env->regs[R_ESP] = regs->esp;
env->eip = regs->eip;
+ /* linux interrupt setup */
+ env->idt.base = (void *)idt_table;
+ env->idt.limit = sizeof(idt_table) - 1;
+ set_idt(0, 0);
+ set_idt(1, 0);
+ set_idt(2, 0);
+ set_idt(3, 3);
+ set_idt(4, 3);
+ set_idt(5, 3);
+ set_idt(6, 0);
+ set_idt(7, 0);
+ set_idt(8, 0);
+ set_idt(9, 0);
+ set_idt(10, 0);
+ set_idt(11, 0);
+ set_idt(12, 0);
+ set_idt(13, 0);
+ set_idt(14, 0);
+ set_idt(15, 0);
+ set_idt(16, 0);
+ set_idt(17, 0);
+ set_idt(18, 0);
+ set_idt(19, 0);
+ set_idt(0x80, 3);
+
/* linux segment setup */
env->gdt.base = (void *)gdt_table;
env->gdt.limit = sizeof(gdt_table) - 1;
- write_dt(&gdt_table[__USER_CS >> 3], 0, 0xffffffff, 1);
- write_dt(&gdt_table[__USER_DS >> 3], 0, 0xffffffff, 1);
+ write_dt(&gdt_table[__USER_CS >> 3], 0, 0xfffff,
+ DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
+ (3 << DESC_DPL_SHIFT) | (0xa << DESC_TYPE_SHIFT));
+ write_dt(&gdt_table[__USER_DS >> 3], 0, 0xfffff,
+ DESC_G_MASK | DESC_B_MASK | DESC_P_MASK | DESC_S_MASK |
+ (3 << DESC_DPL_SHIFT) | (0x2 << DESC_TYPE_SHIFT));
cpu_x86_load_seg(env, R_CS, __USER_CS);
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
