blob: ed3f99ae9bfef8202e499b192f67509804f4a012 [file] [log] [blame] [edit]
#include "libcflat.h"
#include "desc.h"
#include "apic-defs.h"
#include "apic.h"
#include "processor.h"
#include "vm.h"
#include "vmalloc.h"
#include "alloc_page.h"
#include "delay.h"
#define MAIN_TSS_SEL (FIRST_SPARE_SEL + 0)
#define VM86_TSS_SEL (FIRST_SPARE_SEL + 8)
#define CONFORM_CS_SEL (FIRST_SPARE_SEL + 16)
static volatile int test_count;
static volatile unsigned int test_divider;
static char *fault_addr;
static ulong fault_phys;
void do_pf_tss(ulong *error_code);
static void nmi_tss(void)
{
start:
printf("NMI task is running\n");
print_current_tss_info();
test_count++;
asm volatile ("iret");
goto start;
}
static void de_tss(void)
{
start:
printf("DE task is running\n");
print_current_tss_info();
test_divider = 10;
test_count++;
asm volatile ("iret");
goto start;
}
static void of_tss(void)
{
start:
printf("OF task is running\n");
print_current_tss_info();
test_count++;
asm volatile ("iret");
goto start;
}
static void bp_tss(void)
{
start:
printf("BP task is running\n");
print_current_tss_info();
test_count++;
asm volatile ("iret");
goto start;
}
void do_pf_tss(ulong *error_code)
{
printf("PF task is running %p %lx\n", error_code, *error_code);
print_current_tss_info();
if (*error_code == 0x2) /* write access, not present */
test_count++;
install_pte(phys_to_virt(read_cr3()), 1, fault_addr,
fault_phys | PT_PRESENT_MASK | PT_WRITABLE_MASK, 0);
}
extern void pf_tss(void);
asm (
"pf_tss: \n\t"
"push %esp \n\t"
"call do_pf_tss \n\t"
"add $4, %esp \n\t"
"iret\n\t"
"jmp pf_tss\n\t"
);
static void jmp_tss(void)
{
start:
printf("JMP to task succeeded\n");
print_current_tss_info();
test_count++;
asm volatile ("ljmp $" xstr(TSS_MAIN) ", $0");
goto start;
}
static void irq_tss(void)
{
start:
printf("IRQ task is running\n");
print_current_tss_info();
test_count++;
asm volatile ("iret");
test_count++;
printf("IRQ task restarts after iret.\n");
goto start;
}
static void user_tss(void)
{
start:
printf("Conforming task is running\n");
print_current_tss_info();
test_count++;
asm volatile ("iret");
goto start;
}
static void test_kernel_mode_int(void)
{
unsigned int res;
/* test that int $2 triggers task gate */
test_count = 0;
set_intr_task_gate(2, nmi_tss);
printf("Triggering nmi 2\n");
asm volatile ("int $2");
printf("Return from nmi %d\n", test_count);
report(test_count == 1, "NMI int $2");
/* test that external NMI triggers task gate */
test_count = 0;
set_intr_task_gate(2, nmi_tss);
printf("Triggering nmi through APIC\n");
apic_icr_write(APIC_DEST_PHYSICAL | APIC_DM_NMI | APIC_INT_ASSERT, 0);
io_delay();
printf("Return from APIC nmi\n");
report(test_count == 1, "NMI external");
/* test that external interrupt triggesr task gate */
test_count = 0;
printf("Trigger IRQ from APIC\n");
set_intr_task_gate(0xf0, irq_tss);
irq_enable();
apic_icr_write(APIC_DEST_SELF | APIC_DEST_PHYSICAL | APIC_DM_FIXED | APIC_INT_ASSERT | 0xf0, 0);
io_delay();
irq_disable();
printf("Return from APIC IRQ\n");
report(test_count == 1, "IRQ external");
/* test that HW exception triggesr task gate */
set_intr_task_gate(0, de_tss);
printf("Try to devide by 0\n");
asm volatile ("divl %3": "=a"(res)
: "d"(0), "a"(1500), "m"(test_divider));
printf("Result is %d\n", res);
report(res == 150, "DE exeption");
/* test if call HW exeption DE by int $0 triggers task gate */
test_count = 0;
set_intr_task_gate(0, de_tss);
printf("Call int 0\n");
asm volatile ("int $0");
printf("Return from int 0\n");
report(test_count == 1, "int $0");
/* test if HW exception OF triggers task gate */
test_count = 0;
set_intr_task_gate(4, of_tss);
printf("Call into\n");
asm volatile ("addb $127, %b0\ninto"::"a"(127));
printf("Return from into\n");
report(test_count, "OF exeption");
/* test if HW exception BP triggers task gate */
test_count = 0;
set_intr_task_gate(3, bp_tss);
printf("Call int 3\n");
asm volatile ("int $3");
printf("Return from int 3\n");
report(test_count == 1, "BP exeption");
/*
* test that PF triggers task gate and error code is placed on
* exception task's stack
*/
fault_addr = alloc_vpage();
fault_phys = (ulong)virt_to_phys(alloc_page());
test_count = 0;
set_intr_task_gate(14, pf_tss);
printf("Access unmapped page\n");
*fault_addr = 0;
printf("Return from pf tss\n");
report(test_count == 1, "PF exeption");
}
static void test_gdt_task_gate(void)
{
/* test that calling a task by lcall works */
test_count = 0;
tss_intr.eip = (u32)irq_tss;
printf("Calling task by lcall\n");
/* hlt opcode is 0xf4 I use destination IP 0xf4f4f4f4 to catch
incorrect instruction length calculation */
asm volatile("lcall $" xstr(TSS_INTR) ", $0xf4f4f4f4");
printf("Return from call\n");
report(test_count == 1, "lcall");
/* call the same task again and check that it restarted after iret */
test_count = 0;
asm volatile("lcall $" xstr(TSS_INTR) ", $0xf4f4f4f4");
report(test_count == 2, "lcall2");
/* test that calling a task by ljmp works */
test_count = 0;
tss_intr.eip = (u32)jmp_tss;
printf("Jumping to a task by ljmp\n");
asm volatile ("ljmp $" xstr(TSS_INTR) ", $0xf4f4f4f4");
printf("Jump back succeeded\n");
report(test_count == 1, "ljmp");
}
static void test_vm86_switch(void)
{
static tss32_t main_tss;
static tss32_t vm86_tss;
u8 *vm86_start;
/* Write a 'ud2' instruction somewhere below 1 MB */
vm86_start = (void*) 0x42000;
vm86_start[0] = 0x0f;
vm86_start[1] = 0x0b;
/* Main TSS */
set_gdt_entry(MAIN_TSS_SEL, (u32)&main_tss, sizeof(tss32_t) - 1, 0x89, 0);
ltr(MAIN_TSS_SEL);
main_tss = (tss32_t) {
.prev = VM86_TSS_SEL,
.cr3 = read_cr3(),
};
/* VM86 TSS (marked as busy, so we can iret to it) */
set_gdt_entry(VM86_TSS_SEL, (u32)&vm86_tss, sizeof(tss32_t) - 1, 0x8b, 0);
vm86_tss = (tss32_t) {
.eflags = 0x20002,
.cr3 = read_cr3(),
.eip = (u32) vm86_start & 0x0f,
.cs = (u32) vm86_start >> 4,
.ds = 0x1234,
.es = 0x2345,
};
/* Setup task gate to main TSS for #UD */
set_idt_task_gate(6, MAIN_TSS_SEL);
/* Jump into VM86 task with iret, #UD lets it come back immediately */
printf("Switch to VM86 task and back\n");
asm volatile(
"pushf\n"
"orw $0x4000, (%esp)\n"
"popf\n"
"iret\n"
);
report(1, "VM86");
}
#define IOPL_SHIFT 12
static void test_conforming_switch(void)
{
/* test lcall with conforming segment, cs.dpl != cs.rpl */
test_count = 0;
tss_intr.cs = CONFORM_CS_SEL | 3;
tss_intr.eip = (u32)user_tss;
tss_intr.ss = USER_DS;
tss_intr.ds = tss_intr.gs = tss_intr.es = tss_intr.fs = tss_intr.ss;
tss_intr.eflags |= 3 << IOPL_SHIFT;
set_gdt_entry(CONFORM_CS_SEL, 0, 0xffffffff, 0x9f, 0xc0);
asm volatile("lcall $" xstr(TSS_INTR) ", $0xf4f4f4f4");
report(test_count == 1, "lcall with cs.rpl != cs.dpl");
}
int main(void)
{
setup_vm();
setup_tss32();
test_gdt_task_gate();
test_kernel_mode_int();
test_vm86_switch();
test_conforming_switch();
return report_summary();
}