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precise exceptions - more accurate interrupt semantics

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git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@193 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard 2003-05-27 23:28:08 +00:00
parent d731dae8e3
commit f4beb510a4
2 changed files with 250 additions and 54 deletions
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108
linux-user/main.c
View file

@ -100,24 +100,35 @@ int cpu_x86_inl(CPUX86State *env, int addr)
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 @@ void cpu_loop(CPUX86State *env)
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 @@ int main(int argc, char **argv)
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);