mirror of
https://github.com/RGBCube/serenity
synced 2025-05-23 18:55:08 +00:00
46ff281695
This leaves interrupts enabled while we're in the kernel, which is precisely what we want. This uncovered a horrendous problem with kernel tasks silently overflowing their stacks. For now I've simply increased the stack size but I need a more MMU-y solution for this eventually.
360 lines
9.5 KiB
C++
360 lines
9.5 KiB
C++
#include "types.h"
|
|
#include "kmalloc.h"
|
|
#include "VGA.h"
|
|
#include "i386.h"
|
|
#include "Assertions.h"
|
|
#include "Task.h"
|
|
#include "MemoryManager.h"
|
|
|
|
struct DescriptorTablePointer {
|
|
WORD size;
|
|
void* address;
|
|
} PACKED;
|
|
|
|
static DescriptorTablePointer s_idtr;
|
|
static DescriptorTablePointer s_gdtr;
|
|
static Descriptor* s_idt;
|
|
static Descriptor* s_gdt;
|
|
|
|
static WORD s_gdtLength;
|
|
|
|
WORD allocateGDTEntry()
|
|
{
|
|
// FIXME: This should not grow indefinitely.
|
|
ASSERT(s_gdtLength < 256);
|
|
WORD newGDTEntry = s_gdtLength * 8;
|
|
s_gdtLength++;
|
|
return newGDTEntry;
|
|
}
|
|
|
|
extern volatile dword exception_state_dump;
|
|
extern volatile word exception_code;
|
|
asm(
|
|
".globl exception_state_dump\n"
|
|
"exception_state_dump:\n"
|
|
".long 0\n"
|
|
".globl exception_code\n"
|
|
"exception_code:\n"
|
|
".short 0\n"
|
|
);
|
|
|
|
#define EH_ENTRY(ec) \
|
|
extern "C" void exception_ ## ec ## _handler(); \
|
|
extern "C" void exception_ ## ec ## _entry(); \
|
|
asm( \
|
|
".globl exception_" # ec "_entry\n" \
|
|
"exception_" # ec "_entry: \n" \
|
|
" pop exception_code\n" \
|
|
" pusha\n" \
|
|
" pushw %ds\n" \
|
|
" pushw %es\n" \
|
|
" pushw %fs\n" \
|
|
" pushw %gs\n" \
|
|
" pushw %ss\n" \
|
|
" pushw %ss\n" \
|
|
" pushw %ss\n" \
|
|
" pushw %ss\n" \
|
|
" popw %ds\n" \
|
|
" popw %es\n" \
|
|
" popw %fs\n" \
|
|
" popw %gs\n" \
|
|
" mov %esp, exception_state_dump\n" \
|
|
" call exception_" # ec "_handler\n" \
|
|
" popw %gs\n" \
|
|
" popw %fs\n" \
|
|
" popw %es\n" \
|
|
" popw %ds\n" \
|
|
" popa\n" \
|
|
" iret\n" \
|
|
);
|
|
|
|
#define EH_ENTRY_NO_CODE(ec) \
|
|
extern "C" void exception_ ## ec ## _handler(); \
|
|
extern "C" void exception_ ## ec ## _entry(); \
|
|
asm( \
|
|
".globl exception_" # ec "_entry\n" \
|
|
"exception_" # ec "_entry: \n" \
|
|
" pusha\n" \
|
|
" pushw %ds\n" \
|
|
" pushw %es\n" \
|
|
" pushw %fs\n" \
|
|
" pushw %gs\n" \
|
|
" pushw %ss\n" \
|
|
" pushw %ss\n" \
|
|
" pushw %ss\n" \
|
|
" pushw %ss\n" \
|
|
" popw %ds\n" \
|
|
" popw %es\n" \
|
|
" popw %fs\n" \
|
|
" popw %gs\n" \
|
|
" mov %esp, exception_state_dump\n" \
|
|
" call exception_" # ec "_handler\n" \
|
|
" popw %gs\n" \
|
|
" popw %fs\n" \
|
|
" popw %es\n" \
|
|
" popw %ds\n" \
|
|
" popa\n" \
|
|
" iret\n" \
|
|
);
|
|
|
|
// 6: Invalid Opcode
|
|
EH_ENTRY_NO_CODE(6);
|
|
void exception_6_handler()
|
|
{
|
|
auto& regs = *reinterpret_cast<RegisterDump*>(exception_state_dump);
|
|
kprintf("%s invalid opcode: %u(%s)\n", current->isRing0() ? "Kernel" : "Process", current->pid(), current->name().characters());
|
|
|
|
word ss;
|
|
dword esp;
|
|
if (current->isRing0()) {
|
|
ss = regs.ds;
|
|
esp = regs.esp;
|
|
} else {
|
|
ss = regs.ss_if_crossRing;
|
|
esp = regs.esp_if_crossRing;
|
|
}
|
|
|
|
kprintf("exception code: %w\n", exception_code);
|
|
kprintf("pc=%w:%x ds=%w es=%w fs=%w gs=%w\n", regs.cs, regs.eip, regs.ds, regs.es, regs.fs, regs.gs);
|
|
kprintf("eax=%x ebx=%x ecx=%x edx=%x\n", regs.eax, regs.ebx, regs.ecx, regs.edx);
|
|
kprintf("ebp=%x esp=%x esi=%x edi=%x\n", regs.ebp, esp, regs.esi, regs.edi);
|
|
|
|
if (current->isRing0()) {
|
|
kprintf("Oh shit, we've crashed in ring 0 :(\n");
|
|
HANG;
|
|
}
|
|
HANG;
|
|
|
|
// NOTE: This will schedule a new task.
|
|
Task::taskDidCrash(current);
|
|
}
|
|
|
|
// 13: General Protection Fault
|
|
EH_ENTRY(13);
|
|
void exception_13_handler()
|
|
{
|
|
auto& regs = *reinterpret_cast<RegisterDump*>(exception_state_dump);
|
|
kprintf("%s crash: %u(%s)\n", current->isRing0() ? "Kernel" : "Process", current->pid(), current->name().characters());
|
|
|
|
word ss;
|
|
dword esp;
|
|
if (current->isRing0()) {
|
|
ss = regs.ds;
|
|
esp = regs.esp;
|
|
} else {
|
|
ss = regs.ss_if_crossRing;
|
|
esp = regs.esp_if_crossRing;
|
|
}
|
|
|
|
kprintf("exception code: %w\n", exception_code);
|
|
kprintf("pc=%w:%x ds=%w es=%w fs=%w gs=%w\n", regs.cs, regs.eip, regs.ds, regs.es, regs.fs, regs.gs);
|
|
kprintf("eax=%x ebx=%x ecx=%x edx=%x\n", regs.eax, regs.ebx, regs.ecx, regs.edx);
|
|
kprintf("ebp=%x esp=%x esi=%x edi=%x\n", regs.ebp, esp, regs.esi, regs.edi);
|
|
|
|
if (current->isRing0()) {
|
|
kprintf("Oh shit, we've crashed in ring 0 :(\n");
|
|
HANG;
|
|
}
|
|
|
|
// NOTE: This will schedule a new task.
|
|
Task::taskDidCrash(current);
|
|
}
|
|
|
|
// 14: Page Fault
|
|
EH_ENTRY(14);
|
|
void exception_14_handler()
|
|
{
|
|
dword faultAddress;
|
|
asm ("movl %%cr2, %%eax":"=a"(faultAddress));
|
|
|
|
auto& regs = *reinterpret_cast<RegisterDump*>(exception_state_dump);
|
|
kprintf("%s page fault: %u(%s), %s laddr=%p\n",
|
|
current->isRing0() ? "Kernel" : "User",
|
|
current->pid(),
|
|
current->name().characters(),
|
|
exception_code & 2 ? "write" : "read",
|
|
faultAddress);
|
|
|
|
word ss;
|
|
dword esp;
|
|
if (current->isRing0()) {
|
|
ss = regs.ds;
|
|
esp = regs.esp;
|
|
} else {
|
|
ss = regs.ss_if_crossRing;
|
|
esp = regs.esp_if_crossRing;
|
|
}
|
|
|
|
kprintf("exception code: %w\n", exception_code);
|
|
kprintf("pc=%w:%x ds=%w es=%w fs=%w gs=%w\n", regs.cs, regs.eip, regs.ds, regs.es, regs.fs, regs.gs);
|
|
kprintf("eax=%x ebx=%x ecx=%x edx=%x\n", regs.eax, regs.ebx, regs.ecx, regs.edx);
|
|
kprintf("ebp=%x esp=%x esi=%x edi=%x\n", regs.ebp, esp, regs.esi, regs.edi);
|
|
|
|
if (current->isRing0())
|
|
HANG;
|
|
|
|
auto response = MemoryManager::the().handlePageFault(PageFault(exception_code, LinearAddress(faultAddress)));
|
|
|
|
if (response == PageFaultResponse::ShouldCrash) {
|
|
kprintf("Crashing after unresolved page fault\n");
|
|
// NOTE: This will schedule a new task.
|
|
Task::taskDidCrash(current);
|
|
} else if (response == PageFaultResponse::Continue) {
|
|
kprintf("Continuing after resolved page fault\n");
|
|
} else {
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
}
|
|
|
|
#define EH(i, msg) \
|
|
static void _exception ## i () \
|
|
{ \
|
|
vga_set_attr(0x0a); \
|
|
kprintf(msg"\n"); \
|
|
DWORD cr0, cr2, cr3, cr4; \
|
|
asm ("movl %%cr0, %%eax":"=a"(cr0)); \
|
|
asm ("movl %%cr2, %%eax":"=a"(cr2)); \
|
|
asm ("movl %%cr3, %%eax":"=a"(cr3)); \
|
|
asm ("movl %%cr4, %%eax":"=a"(cr4)); \
|
|
kprintf("CR0=%x CR2=%x CR3=%x CR4=%x\n", cr0, cr2, cr3, cr4); \
|
|
HANG; \
|
|
}
|
|
|
|
EH(0, "Divide error")
|
|
EH(1, "Debug exception")
|
|
EH(2, "Unknown error")
|
|
EH(3, "Breakpoint")
|
|
EH(4, "Overflow")
|
|
EH(5, "Bounds check")
|
|
EH(6, "Invalid opcode")
|
|
EH(7, "Coprocessor not available")
|
|
EH(8, "Double fault")
|
|
EH(9, "Coprocessor segment overrun")
|
|
EH(10, "Invalid TSS")
|
|
EH(11, "Segment not present")
|
|
EH(12, "Stack exception")
|
|
EH(13, "General protection fault")
|
|
EH(14, "Page fault")
|
|
EH(15, "Unknown error")
|
|
EH(16, "Coprocessor error")
|
|
|
|
static void writeRawGDTEntry(WORD selector, DWORD low, DWORD high)
|
|
{
|
|
WORD i = (selector & 0xfffc) >> 3;
|
|
s_gdt[i].low = low;
|
|
s_gdt[i].high = high;
|
|
|
|
if (i > s_gdtLength) {
|
|
s_gdtr.size = (s_gdtLength + 1) * 8;
|
|
}
|
|
}
|
|
|
|
void writeGDTEntry(WORD selector, Descriptor& descriptor)
|
|
{
|
|
writeRawGDTEntry(selector, descriptor.low, descriptor.high);
|
|
}
|
|
|
|
Descriptor& getGDTEntry(WORD selector)
|
|
{
|
|
WORD i = (selector & 0xfffc) >> 3;
|
|
return *(Descriptor*)(&s_gdt[i]);
|
|
}
|
|
|
|
void flushGDT()
|
|
{
|
|
s_gdtr.address = s_gdt;
|
|
s_gdtr.size = (s_gdtLength * 8) - 1;
|
|
asm("lgdt %0"::"m"(s_gdtr));
|
|
}
|
|
|
|
void gdt_init()
|
|
{
|
|
s_gdt = new Descriptor[256];
|
|
s_gdtLength = 5;
|
|
|
|
s_gdtr.address = s_gdt;
|
|
s_gdtr.size = (s_gdtLength * 8) - 1;
|
|
|
|
writeRawGDTEntry(0x0000, 0x00000000, 0x00000000);
|
|
writeRawGDTEntry(0x0008, 0x0000ffff, 0x00cf9a00);
|
|
writeRawGDTEntry(0x0010, 0x0000ffff, 0x00cf9200);
|
|
writeRawGDTEntry(0x0018, 0x0000ffff, 0x00cffa00);
|
|
writeRawGDTEntry(0x0020, 0x0000ffff, 0x00cff200);
|
|
|
|
flushGDT();
|
|
}
|
|
|
|
static void unimp_trap()
|
|
{
|
|
kprintf("Unhandled IRQ.");
|
|
HANG;
|
|
}
|
|
|
|
void registerInterruptHandler(BYTE index, void (*f)())
|
|
{
|
|
s_idt[index].low = 0x00080000 | LSW((f));
|
|
s_idt[index].high = ((DWORD)(f) & 0xffff0000) | 0x8e00;
|
|
flushIDT();
|
|
}
|
|
|
|
void registerUserCallableInterruptHandler(BYTE index, void (*f)())
|
|
{
|
|
s_idt[index].low = 0x00080000 | LSW((f));
|
|
s_idt[index].high = ((DWORD)(f) & 0xffff0000) | 0xef00;
|
|
flushIDT();
|
|
}
|
|
|
|
void flushIDT()
|
|
{
|
|
asm("lidt %0"::"m"(s_idtr));
|
|
}
|
|
|
|
/* If an 8259 gets cranky, it'll generate a spurious IRQ7.
|
|
* ATM I don't have a clear grasp on when/why this happens,
|
|
* so I ignore them and assume it makes no difference.
|
|
*/
|
|
|
|
extern "C" void irq7_handler();
|
|
asm(
|
|
".globl irq7_handler \n"
|
|
"irq7_handler: \n"
|
|
" iret\n"
|
|
);
|
|
|
|
void idt_init()
|
|
{
|
|
s_idt = new Descriptor[256];
|
|
|
|
s_idtr.address = s_idt;
|
|
s_idtr.size = 0x100 * 8;
|
|
|
|
for (BYTE i = 0xff; i > 0x10; --i)
|
|
registerInterruptHandler(i, unimp_trap);
|
|
|
|
registerInterruptHandler(0x00, _exception0);
|
|
registerInterruptHandler(0x01, _exception1);
|
|
registerInterruptHandler(0x02, _exception2);
|
|
registerInterruptHandler(0x03, _exception3);
|
|
registerInterruptHandler(0x04, _exception4);
|
|
registerInterruptHandler(0x05, _exception5);
|
|
registerInterruptHandler(0x06, exception_6_entry);
|
|
registerInterruptHandler(0x07, _exception7);
|
|
registerInterruptHandler(0x08, _exception8);
|
|
registerInterruptHandler(0x09, _exception9);
|
|
registerInterruptHandler(0x0a, _exception10);
|
|
registerInterruptHandler(0x0b, _exception11);
|
|
registerInterruptHandler(0x0c, _exception12);
|
|
registerInterruptHandler(0x0d, exception_13_entry);
|
|
registerInterruptHandler(0x0e, exception_14_entry);
|
|
registerInterruptHandler(0x0f, _exception15);
|
|
registerInterruptHandler(0x10, _exception16);
|
|
|
|
registerInterruptHandler(0x57, irq7_handler);
|
|
|
|
flushIDT();
|
|
}
|
|
|
|
void loadTaskRegister(WORD selector)
|
|
{
|
|
asm("ltr %0"::"r"(selector));
|
|
}
|