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a182ea8c60
This will allow us to boot from e.g GRUB which will have a different looking GDT in effect before we start moving things around.
521 lines
13 KiB
C++
521 lines
13 KiB
C++
#include <AK/Types.h>
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#include "i386.h"
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#include "Assertions.h"
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#include "Process.h"
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#include <Kernel/VM/MemoryManager.h>
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#include "IRQHandler.h"
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#include "PIC.h"
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#include "Scheduler.h"
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#include <Kernel/KSyms.h>
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//#define PAGE_FAULT_DEBUG
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struct [[gnu::packed]] DescriptorTablePointer {
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word limit;
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void* address;
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};
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static DescriptorTablePointer s_idtr;
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static DescriptorTablePointer s_gdtr;
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static Descriptor s_idt[256];
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static Descriptor s_gdt[256];
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static IRQHandler* s_irq_handler[16];
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static Vector<word>* s_gdt_freelist;
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static word s_gdt_length;
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word gdt_alloc_entry()
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{
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ASSERT(s_gdt_freelist);
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ASSERT(!s_gdt_freelist->is_empty());
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return s_gdt_freelist->take_last();
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}
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void gdt_free_entry(word entry)
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{
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s_gdt_freelist->append(entry);
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}
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extern "C" void handle_irq();
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extern "C" void asm_irq_entry();
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asm(
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".globl asm_irq_entry\n"
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"asm_irq_entry: \n"
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" pusha\n"
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" pushw %ds\n"
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" pushw %es\n"
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" pushw %ss\n"
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" pushw %ss\n"
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" popw %ds\n"
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" popw %es\n"
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" call handle_irq\n"
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" popw %es\n"
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" popw %ds\n"
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" popa\n"
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" iret\n"
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);
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#define EH_ENTRY(ec) \
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extern "C" void exception_ ## ec ## _handler(RegisterDumpWithExceptionCode&); \
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extern "C" void exception_ ## ec ## _entry(); \
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asm( \
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".globl exception_" # ec "_entry\n" \
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"exception_" # ec "_entry: \n" \
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" pusha\n" \
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" pushw %ds\n" \
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" pushw %es\n" \
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" pushw %fs\n" \
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" pushw %gs\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" popw %ds\n" \
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" popw %es\n" \
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" popw %fs\n" \
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" popw %gs\n" \
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" mov %esp, %eax\n" \
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" call exception_" # ec "_handler\n" \
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" popw %gs\n" \
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" popw %gs\n" \
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" popw %fs\n" \
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" popw %es\n" \
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" popw %ds\n" \
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" popa\n" \
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" add $0x4, %esp\n" \
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" iret\n" \
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);
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#define EH_ENTRY_NO_CODE(ec) \
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extern "C" void exception_ ## ec ## _handler(RegisterDump&); \
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extern "C" void exception_ ## ec ## _entry(); \
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asm( \
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".globl exception_" # ec "_entry\n" \
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"exception_" # ec "_entry: \n" \
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" pusha\n" \
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" pushw %ds\n" \
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" pushw %es\n" \
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" pushw %fs\n" \
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" pushw %gs\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" pushw %ss\n" \
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" popw %ds\n" \
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" popw %es\n" \
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" popw %fs\n" \
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" popw %gs\n" \
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" mov %esp, %eax\n" \
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" call exception_" # ec "_handler\n" \
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" popw %gs\n" \
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" popw %gs\n" \
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" popw %fs\n" \
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" popw %es\n" \
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" popw %ds\n" \
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" popa\n" \
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" iret\n" \
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);
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template<typename DumpType>
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static void dump(const DumpType& regs)
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{
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word ss;
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dword esp;
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if (!current || current->process().is_ring0()) {
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ss = regs.ds;
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esp = regs.esp;
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} else {
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ss = regs.ss_if_crossRing;
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esp = regs.esp_if_crossRing;
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}
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if constexpr (IsSame<DumpType, RegisterDumpWithExceptionCode>::value) {
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kprintf("exception code: %w\n", regs.exception_code);
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}
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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);
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kprintf(" stk=%w:%x\n", ss, esp);
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if (current)
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kprintf("kstk=%w:%x, base=%x, sigbase=%x\n", current->tss().ss0, current->tss().esp0, current->kernel_stack_base(), current->kernel_stack_for_signal_handler_base());
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kprintf("eax=%x ebx=%x ecx=%x edx=%x\n", regs.eax, regs.ebx, regs.ecx, regs.edx);
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kprintf("ebp=%x esp=%x esi=%x edi=%x\n", regs.ebp, esp, regs.esi, regs.edi);
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if (current && current->process().validate_read((void*)regs.eip, 8)) {
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byte* codeptr = (byte*)regs.eip;
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kprintf("code: %b %b %b %b %b %b %b %b\n",
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codeptr[0],
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codeptr[1],
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codeptr[2],
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codeptr[3],
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codeptr[4],
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codeptr[5],
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codeptr[6],
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codeptr[7]);
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}
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}
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// 6: Invalid Opcode
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EH_ENTRY_NO_CODE(6);
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void exception_6_handler(RegisterDump& regs)
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{
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if (!current) {
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kprintf("#UD with !current\n");
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hang();
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}
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kprintf("%s invalid opcode: %u(%s)\n", current->process().is_ring0() ? "Kernel" : "Process", current->pid(), current->process().name().characters());
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dump(regs);
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if (current->process().is_ring0()) {
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kprintf("Oh shit, we've crashed in ring 0 :(\n");
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hang();
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}
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hang();
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current->process().crash();
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}
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// 7: FPU not available exception
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EH_ENTRY_NO_CODE(7);
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void exception_7_handler(RegisterDump& regs)
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{
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(void)regs;
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asm volatile("clts");
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if (g_last_fpu_thread == current)
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return;
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if (g_last_fpu_thread) {
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asm volatile("fxsave %0":"=m"(g_last_fpu_thread->fpu_state()));
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} else {
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asm volatile("fnclex");
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}
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g_last_fpu_thread = current;
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if (current->has_used_fpu()) {
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asm volatile("fxrstor %0"::"m"(current->fpu_state()));
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} else {
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asm volatile("fninit");
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current->set_has_used_fpu(true);
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}
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#ifdef FPU_EXCEPTION_DEBUG
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kprintf("%s FPU not available exception: %u(%s)\n", current->process().is_ring0() ? "Kernel" : "Process", current->pid(), current->process().name().characters());
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dump(regs);
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#endif
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}
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// 0: Divide error
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EH_ENTRY_NO_CODE(0);
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void exception_0_handler(RegisterDump& regs)
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{
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kprintf("%s DIVIDE ERROR: %u(%s)\n", current->process().is_ring0() ? "Kernel" : "User", current->pid(), current->process().name().characters());
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dump(regs);
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if (current->process().is_ring0()) {
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kprintf("Oh shit, we've crashed in ring 0 :(\n");
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hang();
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}
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current->process().crash();
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}
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// 13: General Protection Fault
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EH_ENTRY(13);
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void exception_13_handler(RegisterDumpWithExceptionCode& regs)
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{
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kprintf("%s GPF: %u(%s)\n", current->process().is_ring0() ? "Kernel" : "User", current->pid(), current->process().name().characters());
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dump(regs);
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if (current->process().is_ring0()) {
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kprintf("Oh shit, we've crashed in ring 0 :(\n");
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hang();
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}
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current->process().crash();
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}
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// 14: Page Fault
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EH_ENTRY(14);
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void exception_14_handler(RegisterDumpWithExceptionCode& regs)
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{
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ASSERT(current);
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dword faultAddress;
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asm ("movl %%cr2, %%eax":"=a"(faultAddress));
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dword fault_page_directory;
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asm ("movl %%cr3, %%eax":"=a"(fault_page_directory));
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#ifdef PAGE_FAULT_DEBUG
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dbgprintf("%s(%u): ring%u %s page fault in PD=%x, %s L%x\n",
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current->process().name().characters(),
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current->pid(),
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regs.cs & 3,
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regs.exception_code & 1 ? "PV" : "NP",
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fault_page_directory,
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regs.exception_code & 2 ? "write" : "read",
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faultAddress);
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#endif
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#ifdef PAGE_FAULT_DEBUG
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dump(regs);
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#endif
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auto response = MM.handle_page_fault(PageFault(regs.exception_code, LinearAddress(faultAddress)));
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if (response == PageFaultResponse::ShouldCrash) {
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kprintf("%s(%u:%u) unrecoverable page fault, %s laddr=%p\n",
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current->process().name().characters(),
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current->pid(),
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current->tid(),
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regs.exception_code & 2 ? "write" : "read",
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faultAddress);
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dump(regs);
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current->process().crash();
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} else if (response == PageFaultResponse::Continue) {
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#ifdef PAGE_FAULT_DEBUG
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dbgprintf("Continuing after resolved page fault\n");
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#endif
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} else {
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ASSERT_NOT_REACHED();
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}
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}
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#define EH(i, msg) \
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static void _exception ## i () \
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{ \
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kprintf(msg"\n"); \
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dword cr0, cr2, cr3, cr4; \
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asm ("movl %%cr0, %%eax":"=a"(cr0)); \
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asm ("movl %%cr2, %%eax":"=a"(cr2)); \
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asm ("movl %%cr3, %%eax":"=a"(cr3)); \
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asm ("movl %%cr4, %%eax":"=a"(cr4)); \
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kprintf("CR0=%x CR2=%x CR3=%x CR4=%x\n", cr0, cr2, cr3, cr4); \
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hang(); \
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}
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EH(1, "Debug exception")
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EH(2, "Unknown error")
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EH(3, "Breakpoint")
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EH(4, "Overflow")
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EH(5, "Bounds check")
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EH(8, "Double fault")
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EH(9, "Coprocessor segment overrun")
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EH(10, "Invalid TSS")
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EH(11, "Segment not present")
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EH(12, "Stack exception")
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EH(15, "Unknown error")
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EH(16, "Coprocessor error")
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static void write_raw_gdt_entry(word selector, dword low, dword high)
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{
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word i = (selector & 0xfffc) >> 3;
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s_gdt[i].low = low;
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s_gdt[i].high = high;
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if (i > s_gdt_length)
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s_gdtr.limit = (s_gdt_length + 1) * 8 - 1;
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}
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void write_gdt_entry(word selector, Descriptor& descriptor)
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{
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write_raw_gdt_entry(selector, descriptor.low, descriptor.high);
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}
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Descriptor& get_gdt_entry(word selector)
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{
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word i = (selector & 0xfffc) >> 3;
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return *(Descriptor*)(&s_gdt[i]);
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}
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void flush_gdt()
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{
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s_gdtr.address = s_gdt;
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s_gdtr.limit = (s_gdt_length * 8) - 1;
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asm("lgdt %0"::"m"(s_gdtr):"memory");
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}
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void gdt_init()
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{
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s_gdt_length = 5;
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s_gdt_freelist = new Vector<word>();
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s_gdt_freelist->ensure_capacity(256);
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for (size_t i = s_gdt_length; i < 256; ++i)
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s_gdt_freelist->append(i * 8);
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s_gdt_length = 256;
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s_gdtr.address = s_gdt;
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s_gdtr.limit = (s_gdt_length * 8) - 1;
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write_raw_gdt_entry(0x0000, 0x00000000, 0x00000000);
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write_raw_gdt_entry(0x0008, 0x0000ffff, 0x00cf9a00);
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write_raw_gdt_entry(0x0010, 0x0000ffff, 0x00cf9200);
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write_raw_gdt_entry(0x0018, 0x0000ffff, 0x00cffa00);
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write_raw_gdt_entry(0x0020, 0x0000ffff, 0x00cff200);
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flush_gdt();
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asm volatile(
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"mov %%ax, %%ds\n"
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"mov %%ax, %%es\n"
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"mov %%ax, %%fs\n"
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"mov %%ax, %%gs\n"
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"mov %%ax, %%ss\n"
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:: "a"(0x10)
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: "memory"
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);
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// Make sure CS points to the kernel code descriptor.
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asm volatile(
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"ljmpl $0x8, $sanity\n"
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"sanity:\n"
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);
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}
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static void unimp_trap()
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{
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kprintf("Unhandled IRQ.");
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hang();
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}
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void register_irq_handler(byte irq, IRQHandler& handler)
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{
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ASSERT(!s_irq_handler[irq]);
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s_irq_handler[irq] = &handler;
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register_interrupt_handler(IRQ_VECTOR_BASE + irq, asm_irq_entry);
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}
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void unregister_irq_handler(byte irq, IRQHandler& handler)
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{
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ASSERT(s_irq_handler[irq] == &handler);
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s_irq_handler[irq] = nullptr;
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}
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void register_interrupt_handler(byte index, void (*f)())
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{
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s_idt[index].low = 0x00080000 | LSW((f));
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s_idt[index].high = ((dword)(f) & 0xffff0000) | 0x8e00;
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flush_idt();
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}
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void register_user_callable_interrupt_handler(byte index, void (*f)())
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{
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s_idt[index].low = 0x00080000 | LSW((f));
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s_idt[index].high = ((dword)(f) & 0xffff0000) | 0xef00;
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flush_idt();
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}
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void flush_idt()
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{
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asm("lidt %0"::"m"(s_idtr));
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}
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/* If an 8259 gets cranky, it'll generate a spurious IRQ7.
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* ATM I don't have a clear grasp on when/why this happens,
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* so I ignore them and assume it makes no difference.
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*/
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extern "C" void irq7_handler();
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asm(
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".globl irq7_handler \n"
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"irq7_handler: \n"
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" iret\n"
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);
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void idt_init()
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{
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s_idtr.address = s_idt;
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s_idtr.limit = 0x100 * 8 - 1;
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for (byte i = 0xff; i > 0x10; --i)
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register_interrupt_handler(i, unimp_trap);
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register_interrupt_handler(0x00, exception_0_entry);
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register_interrupt_handler(0x01, _exception1);
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register_interrupt_handler(0x02, _exception2);
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register_interrupt_handler(0x03, _exception3);
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register_interrupt_handler(0x04, _exception4);
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register_interrupt_handler(0x05, _exception5);
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register_interrupt_handler(0x06, exception_6_entry);
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register_interrupt_handler(0x07, exception_7_entry);
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register_interrupt_handler(0x08, _exception8);
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register_interrupt_handler(0x09, _exception9);
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register_interrupt_handler(0x0a, _exception10);
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register_interrupt_handler(0x0b, _exception11);
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register_interrupt_handler(0x0c, _exception12);
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register_interrupt_handler(0x0d, exception_13_entry);
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register_interrupt_handler(0x0e, exception_14_entry);
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register_interrupt_handler(0x0f, _exception15);
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register_interrupt_handler(0x10, _exception16);
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register_interrupt_handler(0x57, irq7_handler);
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for (byte i = 0; i < 16; ++i) {
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s_irq_handler[i] = nullptr;
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}
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flush_idt();
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}
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void load_task_register(word selector)
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{
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asm("ltr %0"::"r"(selector));
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}
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void handle_irq()
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{
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word isr = PIC::get_isr();
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if (!isr) {
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kprintf("Spurious IRQ\n");
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return;
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}
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byte irq = 0;
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for (byte i = 0; i < 16; ++i) {
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if (i == 2)
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continue;
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if (isr & (1 << i)) {
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irq = i;
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break;
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}
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}
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if (s_irq_handler[irq])
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s_irq_handler[irq]->handle_irq();
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PIC::eoi(irq);
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}
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#ifdef DEBUG
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void __assertion_failed(const char* msg, const char* file, unsigned line, const char* func)
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{
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asm volatile("cli");
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kprintf("ASSERTION FAILED: %s\n%s:%u in %s\n", msg, file, line, func);
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dump_backtrace();
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asm volatile("hlt");
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for (;;);
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}
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#endif
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|
|
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void sse_init()
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|
{
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asm volatile(
|
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"mov %cr0, %eax\n"
|
|
"andl $0xfffffffb, %eax\n"
|
|
"orl $0x2, %eax\n"
|
|
"mov %eax, %cr0\n"
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|
"mov %cr4, %eax\n"
|
|
"orl $0x600, %eax\n"
|
|
"mov %eax, %cr4\n"
|
|
);
|
|
}
|