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	 39c1783387
			
		
	
	
		39c1783387
		
	
	
	
	
		
			
			IRQ 7 and 15 on the PIC architecture are used for spurious interrupts. IRQ 7 could also be used for LPT connection, and IRQ 15 can be used for the secondary IDE channel. Therefore, we need to allow to install a real IRQ handler and check if a real IRQ was asserted. If so, we handle them in the usual way. A note on this fix - unregistering or registering a new IRQ handler after we already registered one in the spurious interrupt handler is not supported yet.
		
			
				
	
	
		
			2314 lines
		
	
	
	
		
			86 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			2314 lines
		
	
	
	
		
			86 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
 | |
|  * modification, are permitted provided that the following conditions are met:
 | |
|  *
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|  * 1. Redistributions of source code must retain the above copyright notice, this
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|  *    list of conditions and the following disclaimer.
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|  *
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|  * 2. Redistributions in binary form must reproduce the above copyright notice,
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|  *    this list of conditions and the following disclaimer in the documentation
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|  *    and/or other materials provided with the distribution.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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|  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 | |
|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 | |
|  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 | |
|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 | |
|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 | |
|  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 | |
|  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 | |
|  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 | |
|  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 | |
|  */
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| 
 | |
| #include <AK/Assertions.h>
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| #include <AK/String.h>
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| #include <AK/StringBuilder.h>
 | |
| #include <AK/Types.h>
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| #include <Kernel/Arch/i386/CPU.h>
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| #include <Kernel/Arch/i386/ISRStubs.h>
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| #include <Kernel/Arch/i386/ProcessorInfo.h>
 | |
| #include <Kernel/IO.h>
 | |
| #include <Kernel/Interrupts/APIC.h>
 | |
| #include <Kernel/Interrupts/GenericInterruptHandler.h>
 | |
| #include <Kernel/Interrupts/IRQHandler.h>
 | |
| #include <Kernel/Interrupts/InterruptManagement.h>
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| #include <Kernel/Interrupts/SharedIRQHandler.h>
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| #include <Kernel/Interrupts/SpuriousInterruptHandler.h>
 | |
| #include <Kernel/Interrupts/UnhandledInterruptHandler.h>
 | |
| #include <Kernel/KSyms.h>
 | |
| #include <Kernel/Process.h>
 | |
| #include <Kernel/SpinLock.h>
 | |
| #include <Kernel/Thread.h>
 | |
| #include <Kernel/VM/MemoryManager.h>
 | |
| #include <Kernel/VM/PageDirectory.h>
 | |
| #include <Kernel/VM/ProcessPagingScope.h>
 | |
| #include <LibC/mallocdefs.h>
 | |
| 
 | |
| //#define PAGE_FAULT_DEBUG
 | |
| //#define CONTEXT_SWITCH_DEBUG
 | |
| //#define SMP_DEBUG
 | |
| 
 | |
| namespace Kernel {
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| 
 | |
| static DescriptorTablePointer s_idtr;
 | |
| static Descriptor s_idt[256];
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| 
 | |
| static GenericInterruptHandler* s_interrupt_handler[GENERIC_INTERRUPT_HANDLERS_COUNT];
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| 
 | |
| // The compiler can't see the calls to these functions inside assembly.
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| // Declare them, to avoid dead code warnings.
 | |
| extern "C" void enter_thread_context(Thread* from_thread, Thread* to_thread);
 | |
| extern "C" void context_first_init(Thread* from_thread, Thread* to_thread, TrapFrame* trap);
 | |
| extern "C" u32 do_init_context(Thread* thread, u32 flags);
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| extern "C" void exit_kernel_thread();
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| extern "C" void pre_init_finished();
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| extern "C" void post_init_finished();
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| extern "C" void handle_interrupt(TrapFrame*);
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| 
 | |
| #define EH_ENTRY(ec, title)                         \
 | |
|     extern "C" void title##_asm_entry();            \
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|     extern "C" void title##_handler(TrapFrame*); \
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|     asm(                                            \
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|         ".globl " #title "_asm_entry\n"             \
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|         "" #title "_asm_entry: \n"                  \
 | |
|         "    pusha\n"                               \
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|         "    pushl %ds\n"                           \
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|         "    pushl %es\n"                           \
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|         "    pushl %fs\n"                           \
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|         "    pushl %gs\n"                           \
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|         "    pushl %ss\n"                           \
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|         "    mov $" __STRINGIFY(GDT_SELECTOR_DATA0) ", %ax\n" \
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|         "    mov %ax, %ds\n"                        \
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|         "    mov %ax, %es\n"                        \
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|         "    mov $" __STRINGIFY(GDT_SELECTOR_PROC) ", %ax\n" \
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|         "    mov %ax, %fs\n"                        \
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|         "    pushl %esp \n" /* set TrapFrame::regs */ \
 | |
|         "    subl $" __STRINGIFY(TRAP_FRAME_SIZE - 4) ", %esp \n" \
 | |
|         "    pushl %esp \n"                         \
 | |
|         "    cld\n"                                 \
 | |
|         "    call enter_trap_no_irq \n"             \
 | |
|         "    call " #title "_handler\n"             \
 | |
|         "    jmp common_trap_exit \n");
 | |
| 
 | |
| #define EH_ENTRY_NO_CODE(ec, title)                 \
 | |
|     extern "C" void title##_handler(TrapFrame*); \
 | |
|     extern "C" void title##_asm_entry();            \
 | |
|     asm(                                            \
 | |
|         ".globl " #title "_asm_entry\n"             \
 | |
|         "" #title "_asm_entry: \n"                  \
 | |
|         "    pushl $0x0\n"                          \
 | |
|         "    pusha\n"                               \
 | |
|         "    pushl %ds\n"                           \
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|         "    pushl %es\n"                           \
 | |
|         "    pushl %fs\n"                           \
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|         "    pushl %gs\n"                           \
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|         "    pushl %ss\n"                           \
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|         "    mov $" __STRINGIFY(GDT_SELECTOR_DATA0) ", %ax\n" \
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|         "    mov %ax, %ds\n"                        \
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|         "    mov %ax, %es\n"                        \
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|         "    mov $" __STRINGIFY(GDT_SELECTOR_PROC) ", %ax\n" \
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|         "    mov %ax, %fs\n"                        \
 | |
|         "    pushl %esp \n" /* set TrapFrame::regs */ \
 | |
|         "    subl $" __STRINGIFY(TRAP_FRAME_SIZE - 4) ", %esp \n" \
 | |
|         "    pushl %esp \n"                         \
 | |
|         "    cld\n"                                 \
 | |
|         "    call enter_trap_no_irq \n"             \
 | |
|         "    call " #title "_handler\n"             \
 | |
|         "    jmp common_trap_exit \n");
 | |
| 
 | |
| static void dump(const RegisterState& regs)
 | |
| {
 | |
|     u16 ss;
 | |
|     u32 esp;
 | |
| 
 | |
|     if (!(regs.cs & 3)) {
 | |
|         ss = regs.ss;
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|         esp = regs.esp;
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|     } else {
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|         ss = regs.userspace_ss;
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|         esp = regs.userspace_esp;
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|     }
 | |
| 
 | |
|     klog() << "exception code: " << String::format("%04x", regs.exception_code) << " (isr: " << String::format("%04x", regs.isr_number);
 | |
|     klog() << "  pc=" << String::format("%04x", (u16)regs.cs) << ":" << String::format("%08x", regs.eip) << " flags=" << String::format("%04x", (u16)regs.eflags);
 | |
|     klog() << " stk=" << String::format("%04x", ss) << ":" << String::format("%08x", esp);
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|     klog() << "  ds=" << String::format("%04x", (u16)regs.ds) << " es=" << String::format("%04x", (u16)regs.es) << " fs=" << String::format("%04x", (u16)regs.fs) << " gs=" << String::format("%04x", (u16)regs.gs);
 | |
|     klog() << "eax=" << String::format("%08x", regs.eax) << " ebx=" << String::format("%08x", regs.ebx) << " ecx=" << String::format("%08x", regs.ecx) << " edx=" << String::format("%08x", regs.edx);
 | |
|     klog() << "ebp=" << String::format("%08x", regs.ebp) << " esp=" << String::format("%08x", regs.esp) << " esi=" << String::format("%08x", regs.esi) << " edi=" << String::format("%08x", regs.edi);
 | |
|     u32 cr0;
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|     asm("movl %%cr0, %%eax"
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|         : "=a"(cr0));
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|     u32 cr2;
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|     asm("movl %%cr2, %%eax"
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|         : "=a"(cr2));
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|     u32 cr3 = read_cr3();
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|     u32 cr4;
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|     asm("movl %%cr4, %%eax"
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|         : "=a"(cr4));
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|     klog() << "cr0=" << String::format("%08x", cr0) << " cr2=" << String::format("%08x", cr2) << " cr3=" << String::format("%08x", cr3) << " cr4=" << String::format("%08x", cr4);
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| 
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|     auto process = Process::current();
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|     u8 code[8];
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|     void* fault_at;
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|     if (process && safe_memcpy(code, (void*)regs.eip, 8, fault_at)) {
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|         SmapDisabler disabler;
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|         klog() << "code: " << String::format("%02x", code[0]) << " " << String::format("%02x", code[1]) << " " << String::format("%02x", code[2]) << " " << String::format("%02x", code[3]) << " " << String::format("%02x", code[4]) << " " << String::format("%02x", code[5]) << " " << String::format("%02x", code[6]) << " " << String::format("%02x", code[7]);
 | |
|     }
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| }
 | |
| 
 | |
| void handle_crash(RegisterState& regs, const char* description, int signal, bool out_of_memory)
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| {
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|     auto process = Process::current();
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|     if (!process) {
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|         klog() << description << " with !current";
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|         Processor::halt();
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|     }
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| 
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|     // If a process crashed while inspecting another process,
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|     // make sure we switch back to the right page tables.
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|     MM.enter_process_paging_scope(*process);
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| 
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|     klog() << "CRASH: CPU #" << Processor::current().id() << " " << description << ". Ring " << (regs.cs & 3) << ".";
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|     dump(regs);
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| 
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|     if (!(regs.cs & 3)) {
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|         klog() << "Crash in ring 0 :(";
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|         dump_backtrace();
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|         Processor::halt();
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|     }
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| 
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|     cli();
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|     process->crash(signal, regs.eip, out_of_memory);
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| }
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| 
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| EH_ENTRY_NO_CODE(6, illegal_instruction);
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| void illegal_instruction_handler(TrapFrame* trap)
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| {
 | |
|     clac();
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|     handle_crash(*trap->regs, "Illegal instruction", SIGILL);
 | |
| }
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| 
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| EH_ENTRY_NO_CODE(0, divide_error);
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| void divide_error_handler(TrapFrame* trap)
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| {
 | |
|     clac();
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|     handle_crash(*trap->regs, "Divide error", SIGFPE);
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| }
 | |
| 
 | |
| EH_ENTRY(13, general_protection_fault);
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| void general_protection_fault_handler(TrapFrame* trap)
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| {
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|     clac();
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|     handle_crash(*trap->regs, "General protection fault", SIGSEGV);
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| }
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| 
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| // 7: FPU not available exception
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| EH_ENTRY_NO_CODE(7, fpu_exception);
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| void fpu_exception_handler(TrapFrame*)
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| {
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|     // Just clear the TS flag. We've already restored the FPU state eagerly.
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|     // FIXME: It would be nice if we didn't have to do this at all.
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|     asm volatile("clts");
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| }
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| 
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| extern "C" u8* safe_memcpy_ins_1;
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| extern "C" u8* safe_memcpy_1_faulted;
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| extern "C" u8* safe_memcpy_ins_2;
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| extern "C" u8* safe_memcpy_2_faulted;
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| extern "C" u8* safe_strnlen_ins;
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| extern "C" u8* safe_strnlen_faulted;
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| extern "C" u8* safe_memset_ins_1;
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| extern "C" u8* safe_memset_1_faulted;
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| extern "C" u8* safe_memset_ins_2;
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| extern "C" u8* safe_memset_2_faulted;
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| 
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| bool safe_memcpy(void* dest_ptr, const void* src_ptr, size_t n, void*& fault_at)
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| {
 | |
|     fault_at = nullptr;
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|     size_t dest = (size_t)dest_ptr;
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|     size_t src = (size_t)src_ptr;
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|     size_t remainder;
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|     // FIXME: Support starting at an unaligned address.
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|     if (!(dest & 0x3) && !(src & 0x3) && n >= 12) {
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|         size_t size_ts = n / sizeof(size_t);
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|         asm volatile(
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|             ".global safe_memcpy_ins_1 \n"
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|             "safe_memcpy_ins_1: \n"
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|             "rep movsl \n"
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|             ".global safe_memcpy_1_faulted \n"
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|             "safe_memcpy_1_faulted: \n" // handle_safe_access_fault() set edx to the fault address!
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|             : "=S" (src),
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|               "=D" (dest),
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|               "=c" (remainder),
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|               [fault_at] "=d" (fault_at)
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|             : "S" (src),
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|               "D" (dest),
 | |
|               "c" (size_ts)
 | |
|             : "memory");
 | |
|         if (remainder != 0)
 | |
|             return false; // fault_at is already set!
 | |
|         n -= size_ts * sizeof(size_t);
 | |
|         if (n == 0) {
 | |
|             fault_at = nullptr;
 | |
|             return true;
 | |
|         }
 | |
|     }
 | |
|     asm volatile(
 | |
|         ".global safe_memcpy_ins_2 \n"
 | |
|         "safe_memcpy_ins_2: \n"
 | |
|         "rep movsb \n"
 | |
|         ".global safe_memcpy_2_faulted \n"
 | |
|         "safe_memcpy_2_faulted: \n" // handle_safe_access_fault() set edx to the fault address!
 | |
|         : "=c" (remainder),
 | |
|           [fault_at] "=d" (fault_at)
 | |
|         : "S" (src),
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|           "D" (dest),
 | |
|           "c" (n)
 | |
|         : "memory");
 | |
|     if (remainder != 0)
 | |
|         return false; // fault_at is already set!
 | |
|     fault_at = nullptr;
 | |
|     return true;
 | |
| }
 | |
| 
 | |
| ssize_t safe_strnlen(const char* str, size_t max_n, void*& fault_at)
 | |
| {
 | |
|     ssize_t count = 0;
 | |
|     fault_at = nullptr;
 | |
|     asm volatile(
 | |
|         "1: \n"
 | |
|         "test %[max_n], %[max_n] \n"
 | |
|         "je 2f \n"
 | |
|         "dec %[max_n] \n"
 | |
|         ".global safe_strnlen_ins \n"
 | |
|         "safe_strnlen_ins: \n"
 | |
|         "cmpb $0,(%[str], %[count], 1) \n"
 | |
|         "je 2f \n"
 | |
|         "inc %[count] \n"
 | |
|         "jmp 1b \n"
 | |
|         ".global safe_strnlen_faulted \n"
 | |
|         "safe_strnlen_faulted: \n" // handle_safe_access_fault() set edx to the fault address!
 | |
|         "xor %[count_on_error], %[count_on_error] \n"
 | |
|         "dec %[count_on_error] \n" // return -1 on fault
 | |
|         "2:"
 | |
|         : [count_on_error] "=c" (count),
 | |
|           [fault_at] "=d" (fault_at)
 | |
|         : [str] "b" (str),
 | |
|           [count] "c" (count),
 | |
|           [max_n] "d" (max_n)
 | |
|     );
 | |
|     if (count >= 0)
 | |
|         fault_at = nullptr;
 | |
|     return count;
 | |
| }
 | |
| 
 | |
| bool safe_memset(void* dest_ptr, int c, size_t n, void*& fault_at)
 | |
| {
 | |
|     fault_at = nullptr;
 | |
|     size_t dest = (size_t)dest_ptr;
 | |
|     size_t remainder;
 | |
|     // FIXME: Support starting at an unaligned address.
 | |
|     if (!(dest & 0x3) && n >= 12) {
 | |
|         size_t size_ts = n / sizeof(size_t);
 | |
|         size_t expanded_c = (u8)c;
 | |
|         expanded_c |= expanded_c << 8;
 | |
|         expanded_c |= expanded_c << 16;
 | |
|         asm volatile(
 | |
|             ".global safe_memset_ins_1 \n"
 | |
|             "safe_memset_ins_1: \n"
 | |
|             "rep stosl \n"
 | |
|             ".global safe_memset_1_faulted \n"
 | |
|             "safe_memset_1_faulted: \n" // handle_safe_access_fault() set edx to the fault address!
 | |
|             : "=D" (dest),
 | |
|               "=c" (remainder),
 | |
|               [fault_at] "=d" (fault_at)
 | |
|             : "D" (dest),
 | |
|               "a" (expanded_c),
 | |
|               "c" (size_ts)
 | |
|             : "memory");
 | |
|         if (remainder != 0)
 | |
|             return false; // fault_at is already set!
 | |
|         n -= size_ts * sizeof(size_t);
 | |
|         if (remainder == 0) {
 | |
|             fault_at = nullptr;
 | |
|             return true;
 | |
|         }
 | |
|     }
 | |
|     asm volatile(
 | |
|         ".global safe_memset_ins_2 \n"
 | |
|         "safe_memset_ins_2: \n"
 | |
|         "rep stosb \n"
 | |
|         ".global safe_memset_2_faulted \n"
 | |
|         "safe_memset_2_faulted: \n" // handle_safe_access_fault() set edx to the fault address!
 | |
|         : "=D" (dest),
 | |
|           "=c" (remainder),
 | |
|           [fault_at] "=d" (fault_at)
 | |
|         : "D" (dest),
 | |
|           "c" (n),
 | |
|           "a" (c)
 | |
|         : "memory");
 | |
|     if (remainder != 0)
 | |
|         return false; // fault_at is already set!
 | |
|     fault_at = nullptr;
 | |
|     return true;
 | |
| }
 | |
| 
 | |
| static bool handle_safe_access_fault(RegisterState& regs, u32 fault_address)
 | |
| {
 | |
|     // If we detect that the fault happened in safe_memcpy() safe_strnlen(),
 | |
|     // or safe_memset() then resume at the appropriate _faulted label
 | |
|     if (regs.eip == (FlatPtr)&safe_memcpy_ins_1)
 | |
|         regs.eip = (FlatPtr)&safe_memcpy_1_faulted;
 | |
|     else if (regs.eip == (FlatPtr)&safe_memcpy_ins_2)
 | |
|         regs.eip = (FlatPtr)&safe_memcpy_2_faulted;
 | |
|     else if (regs.eip == (FlatPtr)&safe_strnlen_ins)
 | |
|         regs.eip = (FlatPtr)&safe_strnlen_faulted;
 | |
|     else if (regs.eip == (FlatPtr)&safe_memset_ins_1)
 | |
|         regs.eip = (FlatPtr)&safe_memset_1_faulted;
 | |
|     else if (regs.eip == (FlatPtr)&safe_memset_ins_2)
 | |
|         regs.eip = (FlatPtr)&safe_memset_2_faulted;
 | |
|     else
 | |
|         return false;
 | |
| 
 | |
|     regs.edx = fault_address;
 | |
|     return true;
 | |
| }
 | |
| 
 | |
| // 14: Page Fault
 | |
| EH_ENTRY(14, page_fault);
 | |
| void page_fault_handler(TrapFrame* trap)
 | |
| {
 | |
|     clac();
 | |
| 
 | |
|     auto& regs = *trap->regs;
 | |
|     u32 fault_address;
 | |
|     asm("movl %%cr2, %%eax"
 | |
|         : "=a"(fault_address));
 | |
| 
 | |
| #ifdef PAGE_FAULT_DEBUG
 | |
|     u32 fault_page_directory = read_cr3();
 | |
|     dbg() << "CPU #" << (Processor::is_initialized() ? Processor::current().id() : 0) << " ring " << (regs.cs & 3)
 | |
|           << " " << (regs.exception_code & 1 ? "PV" : "NP")
 | |
|           << " page fault in PD=" << String::format("%x", fault_page_directory) << ", "
 | |
|           << (regs.exception_code & 8 ? "reserved-bit " : "")
 | |
|           << (regs.exception_code & 2 ? "write" : "read")
 | |
|           << " " << VirtualAddress(fault_address);
 | |
| #endif
 | |
| 
 | |
| #ifdef PAGE_FAULT_DEBUG
 | |
|     dump(regs);
 | |
| #endif
 | |
| 
 | |
|     bool faulted_in_kernel = !(regs.cs & 3);
 | |
| 
 | |
|     if (faulted_in_kernel && Processor::current().in_irq()) {
 | |
|         // If we're faulting in an IRQ handler, first check if we failed
 | |
|         // due to safe_memcpy, safe_strnlen, or safe_memset. If we did,
 | |
|         // gracefully continue immediately. Because we're in an IRQ handler
 | |
|         // we can't really try to resolve the page fault in a meaningful
 | |
|         // way, so we need to do this before calling into
 | |
|         // MemoryManager::handle_page_fault, which would just bail and
 | |
|         // request a crash
 | |
|         if (handle_safe_access_fault(regs, fault_address))
 | |
|             return;
 | |
|     }
 | |
| 
 | |
|     auto current_thread = Thread::current();
 | |
|     if (!faulted_in_kernel && !MM.validate_user_stack(current_thread->process(), VirtualAddress(regs.userspace_esp))) {
 | |
|         dbg() << "Invalid stack pointer: " << VirtualAddress(regs.userspace_esp);
 | |
|         handle_crash(regs, "Bad stack on page fault", SIGSTKFLT);
 | |
|         ASSERT_NOT_REACHED();
 | |
|     }
 | |
| 
 | |
|     auto response = MM.handle_page_fault(PageFault(regs.exception_code, VirtualAddress(fault_address)));
 | |
| 
 | |
|     if (response == PageFaultResponse::ShouldCrash || response == PageFaultResponse::OutOfMemory) {
 | |
|         if (faulted_in_kernel && handle_safe_access_fault(regs, fault_address)) {
 | |
|             // If this would be a ring0 (kernel) fault and the fault was triggered by
 | |
|             // safe_memcpy, safe_strnlen, or safe_memset then we resume execution at
 | |
|             // the appropriate _fault label rather than crashing
 | |
|             return;
 | |
|         }
 | |
| 
 | |
|         if (response != PageFaultResponse::OutOfMemory) {
 | |
|             if (current_thread->has_signal_handler(SIGSEGV)) {
 | |
|                 current_thread->send_urgent_signal_to_self(SIGSEGV);
 | |
|                 return;
 | |
|             }
 | |
|         }
 | |
| 
 | |
|         dbg() << "Unrecoverable page fault, "
 | |
|               << (regs.exception_code & PageFaultFlags::ReservedBitViolation ? "reserved bit violation / " : "")
 | |
|               << (regs.exception_code & PageFaultFlags::InstructionFetch ? "instruction fetch / " : "")
 | |
|               << (regs.exception_code & PageFaultFlags::Write ? "write to" : "read from")
 | |
|               << " address " << VirtualAddress(fault_address);
 | |
|         u32 malloc_scrub_pattern = explode_byte(MALLOC_SCRUB_BYTE);
 | |
|         u32 free_scrub_pattern = explode_byte(FREE_SCRUB_BYTE);
 | |
|         u32 kmalloc_scrub_pattern = explode_byte(KMALLOC_SCRUB_BYTE);
 | |
|         u32 kfree_scrub_pattern = explode_byte(KFREE_SCRUB_BYTE);
 | |
|         u32 slab_alloc_scrub_pattern = explode_byte(SLAB_ALLOC_SCRUB_BYTE);
 | |
|         u32 slab_dealloc_scrub_pattern = explode_byte(SLAB_DEALLOC_SCRUB_BYTE);
 | |
|         if ((fault_address & 0xffff0000) == (malloc_scrub_pattern & 0xffff0000)) {
 | |
|             dbg() << "Note: Address " << VirtualAddress(fault_address) << " looks like it may be uninitialized malloc() memory";
 | |
|         } else if ((fault_address & 0xffff0000) == (free_scrub_pattern & 0xffff0000)) {
 | |
|             dbg() << "Note: Address " << VirtualAddress(fault_address) << " looks like it may be recently free()'d memory";
 | |
|         } else if ((fault_address & 0xffff0000) == (kmalloc_scrub_pattern & 0xffff0000)) {
 | |
|             dbg() << "Note: Address " << VirtualAddress(fault_address) << " looks like it may be uninitialized kmalloc() memory";
 | |
|         } else if ((fault_address & 0xffff0000) == (kfree_scrub_pattern & 0xffff0000)) {
 | |
|             dbg() << "Note: Address " << VirtualAddress(fault_address) << " looks like it may be recently kfree()'d memory";
 | |
|         } else if ((fault_address & 0xffff0000) == (slab_alloc_scrub_pattern & 0xffff0000)) {
 | |
|             dbg() << "Note: Address " << VirtualAddress(fault_address) << " looks like it may be uninitialized slab_alloc() memory";
 | |
|         } else if ((fault_address & 0xffff0000) == (slab_dealloc_scrub_pattern & 0xffff0000)) {
 | |
|             dbg() << "Note: Address " << VirtualAddress(fault_address) << " looks like it may be recently slab_dealloc()'d memory";
 | |
|         } else if (fault_address < 4096) {
 | |
|             dbg() << "Note: Address " << VirtualAddress(fault_address) << " looks like a possible nullptr dereference";
 | |
|         }
 | |
| 
 | |
|         handle_crash(regs, "Page Fault", SIGSEGV, response == PageFaultResponse::OutOfMemory);
 | |
|     } else if (response == PageFaultResponse::Continue) {
 | |
| #ifdef PAGE_FAULT_DEBUG
 | |
|         dbg() << "Continuing after resolved page fault";
 | |
| #endif
 | |
|     } else {
 | |
|         ASSERT_NOT_REACHED();
 | |
|     }
 | |
| }
 | |
| 
 | |
| EH_ENTRY_NO_CODE(1, debug);
 | |
| void debug_handler(TrapFrame* trap)
 | |
| {
 | |
|     clac();
 | |
|     auto& regs = *trap->regs;
 | |
|     auto current_thread = Thread::current();
 | |
|     auto& process = current_thread->process();
 | |
|     if ((regs.cs & 3) == 0) {
 | |
|         klog() << "Debug Exception in Ring0";
 | |
|         Processor::halt();
 | |
|         return;
 | |
|     }
 | |
|     constexpr u8 REASON_SINGLESTEP = 14;
 | |
|     bool is_reason_singlestep = (read_dr6() & (1 << REASON_SINGLESTEP));
 | |
|     if (!is_reason_singlestep)
 | |
|         return;
 | |
| 
 | |
|     if (auto tracer = process.tracer()) {
 | |
|         tracer->set_regs(regs);
 | |
|     }
 | |
|     current_thread->send_urgent_signal_to_self(SIGTRAP);
 | |
| }
 | |
| 
 | |
| EH_ENTRY_NO_CODE(3, breakpoint);
 | |
| void breakpoint_handler(TrapFrame* trap)
 | |
| {
 | |
|     clac();
 | |
|     auto& regs = *trap->regs;
 | |
|     auto current_thread = Thread::current();
 | |
|     auto& process = current_thread->process();
 | |
|     if ((regs.cs & 3) == 0) {
 | |
|         klog() << "Breakpoint Trap in Ring0";
 | |
|         Processor::halt();
 | |
|         return;
 | |
|     }
 | |
|     if (auto tracer = process.tracer()) {
 | |
|         tracer->set_regs(regs);
 | |
|     }
 | |
|     current_thread->send_urgent_signal_to_self(SIGTRAP);
 | |
| }
 | |
| 
 | |
| #define EH(i, msg)                                                                                                                                                             \
 | |
|     static void _exception##i()                                                                                                                                                \
 | |
|     {                                                                                                                                                                          \
 | |
|         klog() << msg;                                                                                                                                                         \
 | |
|         u32 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));                                                                                                                                                      \
 | |
|         klog() << "CR0=" << String::format("%x", cr0) << " CR2=" << String::format("%x", cr2) << " CR3=" << String::format("%x", cr3) << " CR4=" << String::format("%x", cr4); \
 | |
|         Processor::halt();                                                                                                                                                     \
 | |
|     }
 | |
| 
 | |
| EH(2, "Unknown error")
 | |
| EH(4, "Overflow")
 | |
| EH(5, "Bounds check")
 | |
| EH(8, "Double fault")
 | |
| EH(9, "Coprocessor segment overrun")
 | |
| EH(10, "Invalid TSS")
 | |
| EH(11, "Segment not present")
 | |
| EH(12, "Stack exception")
 | |
| EH(15, "Unknown error")
 | |
| EH(16, "Coprocessor error")
 | |
| 
 | |
| const DescriptorTablePointer& get_idtr()
 | |
| {
 | |
|     return s_idtr;
 | |
| }
 | |
| 
 | |
| static void unimp_trap()
 | |
| {
 | |
|     klog() << "Unhandled IRQ.";
 | |
|     Processor::Processor::halt();
 | |
| }
 | |
| 
 | |
| GenericInterruptHandler& get_interrupt_handler(u8 interrupt_number)
 | |
| {
 | |
|     ASSERT(s_interrupt_handler[interrupt_number] != nullptr);
 | |
|     return *s_interrupt_handler[interrupt_number];
 | |
| }
 | |
| 
 | |
| static void revert_to_unused_handler(u8 interrupt_number)
 | |
| {
 | |
|     new UnhandledInterruptHandler(interrupt_number);
 | |
| }
 | |
| 
 | |
| void register_generic_interrupt_handler(u8 interrupt_number, GenericInterruptHandler& handler)
 | |
| {
 | |
|     ASSERT(interrupt_number < GENERIC_INTERRUPT_HANDLERS_COUNT);
 | |
|     if (s_interrupt_handler[interrupt_number] != nullptr) {
 | |
|         if (s_interrupt_handler[interrupt_number]->type() == HandlerType::UnhandledInterruptHandler) {
 | |
|             s_interrupt_handler[interrupt_number] = &handler;
 | |
|             return;
 | |
|         }
 | |
|         if (s_interrupt_handler[interrupt_number]->is_shared_handler() && !s_interrupt_handler[interrupt_number]->is_sharing_with_others()) {
 | |
|             ASSERT(s_interrupt_handler[interrupt_number]->type() == HandlerType::SharedIRQHandler);
 | |
|             static_cast<SharedIRQHandler*>(s_interrupt_handler[interrupt_number])->register_handler(handler);
 | |
|             return;
 | |
|         }
 | |
|         if (!s_interrupt_handler[interrupt_number]->is_shared_handler()) {
 | |
|             if (s_interrupt_handler[interrupt_number]->type() == HandlerType::SpuriousInterruptHandler) {
 | |
|                 static_cast<SpuriousInterruptHandler*>(s_interrupt_handler[interrupt_number])->register_handler(handler);
 | |
|                 return;
 | |
|             }
 | |
|             ASSERT(s_interrupt_handler[interrupt_number]->type() == HandlerType::IRQHandler);
 | |
|             auto& previous_handler = *s_interrupt_handler[interrupt_number];
 | |
|             s_interrupt_handler[interrupt_number] = nullptr;
 | |
|             SharedIRQHandler::initialize(interrupt_number);
 | |
|             static_cast<SharedIRQHandler*>(s_interrupt_handler[interrupt_number])->register_handler(previous_handler);
 | |
|             static_cast<SharedIRQHandler*>(s_interrupt_handler[interrupt_number])->register_handler(handler);
 | |
|             return;
 | |
|         }
 | |
|         ASSERT_NOT_REACHED();
 | |
|     } else {
 | |
|         s_interrupt_handler[interrupt_number] = &handler;
 | |
|     }
 | |
| }
 | |
| 
 | |
| void unregister_generic_interrupt_handler(u8 interrupt_number, GenericInterruptHandler& handler)
 | |
| {
 | |
|     ASSERT(s_interrupt_handler[interrupt_number] != nullptr);
 | |
|     if (s_interrupt_handler[interrupt_number]->type() == HandlerType::UnhandledInterruptHandler) {
 | |
|         dbg() << "Trying to unregister unused handler (?)";
 | |
|         return;
 | |
|     }
 | |
|     if (s_interrupt_handler[interrupt_number]->is_shared_handler() && !s_interrupt_handler[interrupt_number]->is_sharing_with_others()) {
 | |
|         ASSERT(s_interrupt_handler[interrupt_number]->type() == HandlerType::SharedIRQHandler);
 | |
|         static_cast<SharedIRQHandler*>(s_interrupt_handler[interrupt_number])->unregister_handler(handler);
 | |
|         if (!static_cast<SharedIRQHandler*>(s_interrupt_handler[interrupt_number])->sharing_devices_count()) {
 | |
|             revert_to_unused_handler(interrupt_number);
 | |
|         }
 | |
|         return;
 | |
|     }
 | |
|     if (!s_interrupt_handler[interrupt_number]->is_shared_handler()) {
 | |
|         ASSERT(s_interrupt_handler[interrupt_number]->type() == HandlerType::IRQHandler);
 | |
|         revert_to_unused_handler(interrupt_number);
 | |
|         return;
 | |
|     }
 | |
|     ASSERT_NOT_REACHED();
 | |
| }
 | |
| 
 | |
| void register_interrupt_handler(u8 index, void (*f)())
 | |
| {
 | |
|     s_idt[index].low = 0x00080000 | LSW((f));
 | |
|     s_idt[index].high = ((u32)(f)&0xffff0000) | 0x8e00;
 | |
| }
 | |
| 
 | |
| void register_user_callable_interrupt_handler(u8 index, void (*f)())
 | |
| {
 | |
|     s_idt[index].low = 0x00080000 | LSW((f));
 | |
|     s_idt[index].high = ((u32)(f)&0xffff0000) | 0xef00;
 | |
| }
 | |
| 
 | |
| void flush_idt()
 | |
| {
 | |
|     asm("lidt %0" ::"m"(s_idtr));
 | |
| }
 | |
| 
 | |
| static void idt_init()
 | |
| {
 | |
|     s_idtr.address = s_idt;
 | |
|     s_idtr.limit = 256 * 8 - 1;
 | |
| 
 | |
|     register_interrupt_handler(0x00, divide_error_asm_entry);
 | |
|     register_user_callable_interrupt_handler(0x01, debug_asm_entry);
 | |
|     register_interrupt_handler(0x02, _exception2);
 | |
|     register_user_callable_interrupt_handler(0x03, breakpoint_asm_entry);
 | |
|     register_interrupt_handler(0x04, _exception4);
 | |
|     register_interrupt_handler(0x05, _exception5);
 | |
|     register_interrupt_handler(0x06, illegal_instruction_asm_entry);
 | |
|     register_interrupt_handler(0x07, fpu_exception_asm_entry);
 | |
|     register_interrupt_handler(0x08, _exception8);
 | |
|     register_interrupt_handler(0x09, _exception9);
 | |
|     register_interrupt_handler(0x0a, _exception10);
 | |
|     register_interrupt_handler(0x0b, _exception11);
 | |
|     register_interrupt_handler(0x0c, _exception12);
 | |
|     register_interrupt_handler(0x0d, general_protection_fault_asm_entry);
 | |
|     register_interrupt_handler(0x0e, page_fault_asm_entry);
 | |
|     register_interrupt_handler(0x0f, _exception15);
 | |
|     register_interrupt_handler(0x10, _exception16);
 | |
| 
 | |
|     for (u8 i = 0x11; i < 0x50; i++)
 | |
|         register_interrupt_handler(i, unimp_trap);
 | |
| 
 | |
|     register_interrupt_handler(0x50, interrupt_80_asm_entry);
 | |
|     register_interrupt_handler(0x51, interrupt_81_asm_entry);
 | |
|     register_interrupt_handler(0x52, interrupt_82_asm_entry);
 | |
|     register_interrupt_handler(0x53, interrupt_83_asm_entry);
 | |
|     register_interrupt_handler(0x54, interrupt_84_asm_entry);
 | |
|     register_interrupt_handler(0x55, interrupt_85_asm_entry);
 | |
|     register_interrupt_handler(0x56, interrupt_86_asm_entry);
 | |
|     register_interrupt_handler(0x57, interrupt_87_asm_entry);
 | |
|     register_interrupt_handler(0x58, interrupt_88_asm_entry);
 | |
|     register_interrupt_handler(0x59, interrupt_89_asm_entry);
 | |
|     register_interrupt_handler(0x5a, interrupt_90_asm_entry);
 | |
|     register_interrupt_handler(0x5b, interrupt_91_asm_entry);
 | |
|     register_interrupt_handler(0x5c, interrupt_92_asm_entry);
 | |
|     register_interrupt_handler(0x5d, interrupt_93_asm_entry);
 | |
|     register_interrupt_handler(0x5e, interrupt_94_asm_entry);
 | |
|     register_interrupt_handler(0x5f, interrupt_95_asm_entry);
 | |
|     register_interrupt_handler(0x60, interrupt_96_asm_entry);
 | |
|     register_interrupt_handler(0x61, interrupt_97_asm_entry);
 | |
|     register_interrupt_handler(0x62, interrupt_98_asm_entry);
 | |
|     register_interrupt_handler(0x63, interrupt_99_asm_entry);
 | |
|     register_interrupt_handler(0x64, interrupt_100_asm_entry);
 | |
|     register_interrupt_handler(0x65, interrupt_101_asm_entry);
 | |
|     register_interrupt_handler(0x66, interrupt_102_asm_entry);
 | |
|     register_interrupt_handler(0x67, interrupt_103_asm_entry);
 | |
|     register_interrupt_handler(0x68, interrupt_104_asm_entry);
 | |
|     register_interrupt_handler(0x69, interrupt_105_asm_entry);
 | |
|     register_interrupt_handler(0x6a, interrupt_106_asm_entry);
 | |
|     register_interrupt_handler(0x6b, interrupt_107_asm_entry);
 | |
|     register_interrupt_handler(0x6c, interrupt_108_asm_entry);
 | |
|     register_interrupt_handler(0x6d, interrupt_109_asm_entry);
 | |
|     register_interrupt_handler(0x6e, interrupt_110_asm_entry);
 | |
|     register_interrupt_handler(0x6f, interrupt_111_asm_entry);
 | |
|     register_interrupt_handler(0x70, interrupt_112_asm_entry);
 | |
|     register_interrupt_handler(0x71, interrupt_113_asm_entry);
 | |
|     register_interrupt_handler(0x72, interrupt_114_asm_entry);
 | |
|     register_interrupt_handler(0x73, interrupt_115_asm_entry);
 | |
|     register_interrupt_handler(0x74, interrupt_116_asm_entry);
 | |
|     register_interrupt_handler(0x75, interrupt_117_asm_entry);
 | |
|     register_interrupt_handler(0x76, interrupt_118_asm_entry);
 | |
|     register_interrupt_handler(0x77, interrupt_119_asm_entry);
 | |
|     register_interrupt_handler(0x78, interrupt_120_asm_entry);
 | |
|     register_interrupt_handler(0x79, interrupt_121_asm_entry);
 | |
|     register_interrupt_handler(0x7a, interrupt_122_asm_entry);
 | |
|     register_interrupt_handler(0x7b, interrupt_123_asm_entry);
 | |
|     register_interrupt_handler(0x7c, interrupt_124_asm_entry);
 | |
|     register_interrupt_handler(0x7d, interrupt_125_asm_entry);
 | |
|     register_interrupt_handler(0x7e, interrupt_126_asm_entry);
 | |
|     register_interrupt_handler(0x7f, interrupt_127_asm_entry);
 | |
|     register_interrupt_handler(0x80, interrupt_128_asm_entry);
 | |
|     register_interrupt_handler(0x81, interrupt_129_asm_entry);
 | |
|     register_interrupt_handler(0x82, interrupt_130_asm_entry);
 | |
|     register_interrupt_handler(0x83, interrupt_131_asm_entry);
 | |
|     register_interrupt_handler(0x84, interrupt_132_asm_entry);
 | |
|     register_interrupt_handler(0x85, interrupt_133_asm_entry);
 | |
|     register_interrupt_handler(0x86, interrupt_134_asm_entry);
 | |
|     register_interrupt_handler(0x87, interrupt_135_asm_entry);
 | |
|     register_interrupt_handler(0x88, interrupt_136_asm_entry);
 | |
|     register_interrupt_handler(0x89, interrupt_137_asm_entry);
 | |
|     register_interrupt_handler(0x8a, interrupt_138_asm_entry);
 | |
|     register_interrupt_handler(0x8b, interrupt_139_asm_entry);
 | |
|     register_interrupt_handler(0x8c, interrupt_140_asm_entry);
 | |
|     register_interrupt_handler(0x8d, interrupt_141_asm_entry);
 | |
|     register_interrupt_handler(0x8e, interrupt_142_asm_entry);
 | |
|     register_interrupt_handler(0x8f, interrupt_143_asm_entry);
 | |
|     register_interrupt_handler(0x90, interrupt_144_asm_entry);
 | |
|     register_interrupt_handler(0x91, interrupt_145_asm_entry);
 | |
|     register_interrupt_handler(0x92, interrupt_146_asm_entry);
 | |
|     register_interrupt_handler(0x93, interrupt_147_asm_entry);
 | |
|     register_interrupt_handler(0x94, interrupt_148_asm_entry);
 | |
|     register_interrupt_handler(0x95, interrupt_149_asm_entry);
 | |
|     register_interrupt_handler(0x96, interrupt_150_asm_entry);
 | |
|     register_interrupt_handler(0x97, interrupt_151_asm_entry);
 | |
|     register_interrupt_handler(0x98, interrupt_152_asm_entry);
 | |
|     register_interrupt_handler(0x99, interrupt_153_asm_entry);
 | |
|     register_interrupt_handler(0x9a, interrupt_154_asm_entry);
 | |
|     register_interrupt_handler(0x9b, interrupt_155_asm_entry);
 | |
|     register_interrupt_handler(0x9c, interrupt_156_asm_entry);
 | |
|     register_interrupt_handler(0x9d, interrupt_157_asm_entry);
 | |
|     register_interrupt_handler(0x9e, interrupt_158_asm_entry);
 | |
|     register_interrupt_handler(0x9f, interrupt_159_asm_entry);
 | |
|     register_interrupt_handler(0xa0, interrupt_160_asm_entry);
 | |
|     register_interrupt_handler(0xa1, interrupt_161_asm_entry);
 | |
|     register_interrupt_handler(0xa2, interrupt_162_asm_entry);
 | |
|     register_interrupt_handler(0xa3, interrupt_163_asm_entry);
 | |
|     register_interrupt_handler(0xa4, interrupt_164_asm_entry);
 | |
|     register_interrupt_handler(0xa5, interrupt_165_asm_entry);
 | |
|     register_interrupt_handler(0xa6, interrupt_166_asm_entry);
 | |
|     register_interrupt_handler(0xa7, interrupt_167_asm_entry);
 | |
|     register_interrupt_handler(0xa8, interrupt_168_asm_entry);
 | |
|     register_interrupt_handler(0xa9, interrupt_169_asm_entry);
 | |
|     register_interrupt_handler(0xaa, interrupt_170_asm_entry);
 | |
|     register_interrupt_handler(0xab, interrupt_171_asm_entry);
 | |
|     register_interrupt_handler(0xac, interrupt_172_asm_entry);
 | |
|     register_interrupt_handler(0xad, interrupt_173_asm_entry);
 | |
|     register_interrupt_handler(0xae, interrupt_174_asm_entry);
 | |
|     register_interrupt_handler(0xaf, interrupt_175_asm_entry);
 | |
|     register_interrupt_handler(0xb0, interrupt_176_asm_entry);
 | |
|     register_interrupt_handler(0xb1, interrupt_177_asm_entry);
 | |
|     register_interrupt_handler(0xb2, interrupt_178_asm_entry);
 | |
|     register_interrupt_handler(0xb3, interrupt_179_asm_entry);
 | |
|     register_interrupt_handler(0xb4, interrupt_180_asm_entry);
 | |
|     register_interrupt_handler(0xb5, interrupt_181_asm_entry);
 | |
|     register_interrupt_handler(0xb6, interrupt_182_asm_entry);
 | |
|     register_interrupt_handler(0xb7, interrupt_183_asm_entry);
 | |
|     register_interrupt_handler(0xb8, interrupt_184_asm_entry);
 | |
|     register_interrupt_handler(0xb9, interrupt_185_asm_entry);
 | |
|     register_interrupt_handler(0xba, interrupt_186_asm_entry);
 | |
|     register_interrupt_handler(0xbb, interrupt_187_asm_entry);
 | |
|     register_interrupt_handler(0xbc, interrupt_188_asm_entry);
 | |
|     register_interrupt_handler(0xbd, interrupt_189_asm_entry);
 | |
|     register_interrupt_handler(0xbe, interrupt_190_asm_entry);
 | |
|     register_interrupt_handler(0xbf, interrupt_191_asm_entry);
 | |
|     register_interrupt_handler(0xc0, interrupt_192_asm_entry);
 | |
|     register_interrupt_handler(0xc1, interrupt_193_asm_entry);
 | |
|     register_interrupt_handler(0xc2, interrupt_194_asm_entry);
 | |
|     register_interrupt_handler(0xc3, interrupt_195_asm_entry);
 | |
|     register_interrupt_handler(0xc4, interrupt_196_asm_entry);
 | |
|     register_interrupt_handler(0xc5, interrupt_197_asm_entry);
 | |
|     register_interrupt_handler(0xc6, interrupt_198_asm_entry);
 | |
|     register_interrupt_handler(0xc7, interrupt_199_asm_entry);
 | |
|     register_interrupt_handler(0xc8, interrupt_200_asm_entry);
 | |
|     register_interrupt_handler(0xc9, interrupt_201_asm_entry);
 | |
|     register_interrupt_handler(0xca, interrupt_202_asm_entry);
 | |
|     register_interrupt_handler(0xcb, interrupt_203_asm_entry);
 | |
|     register_interrupt_handler(0xcc, interrupt_204_asm_entry);
 | |
|     register_interrupt_handler(0xcd, interrupt_205_asm_entry);
 | |
|     register_interrupt_handler(0xce, interrupt_206_asm_entry);
 | |
|     register_interrupt_handler(0xcf, interrupt_207_asm_entry);
 | |
|     register_interrupt_handler(0xd0, interrupt_208_asm_entry);
 | |
|     register_interrupt_handler(0xd1, interrupt_209_asm_entry);
 | |
|     register_interrupt_handler(0xd2, interrupt_210_asm_entry);
 | |
|     register_interrupt_handler(0xd3, interrupt_211_asm_entry);
 | |
|     register_interrupt_handler(0xd4, interrupt_212_asm_entry);
 | |
|     register_interrupt_handler(0xd5, interrupt_213_asm_entry);
 | |
|     register_interrupt_handler(0xd6, interrupt_214_asm_entry);
 | |
|     register_interrupt_handler(0xd7, interrupt_215_asm_entry);
 | |
|     register_interrupt_handler(0xd8, interrupt_216_asm_entry);
 | |
|     register_interrupt_handler(0xd9, interrupt_217_asm_entry);
 | |
|     register_interrupt_handler(0xda, interrupt_218_asm_entry);
 | |
|     register_interrupt_handler(0xdb, interrupt_219_asm_entry);
 | |
|     register_interrupt_handler(0xdc, interrupt_220_asm_entry);
 | |
|     register_interrupt_handler(0xdd, interrupt_221_asm_entry);
 | |
|     register_interrupt_handler(0xde, interrupt_222_asm_entry);
 | |
|     register_interrupt_handler(0xdf, interrupt_223_asm_entry);
 | |
|     register_interrupt_handler(0xe0, interrupt_224_asm_entry);
 | |
|     register_interrupt_handler(0xe1, interrupt_225_asm_entry);
 | |
|     register_interrupt_handler(0xe2, interrupt_226_asm_entry);
 | |
|     register_interrupt_handler(0xe3, interrupt_227_asm_entry);
 | |
|     register_interrupt_handler(0xe4, interrupt_228_asm_entry);
 | |
|     register_interrupt_handler(0xe5, interrupt_229_asm_entry);
 | |
|     register_interrupt_handler(0xe6, interrupt_230_asm_entry);
 | |
|     register_interrupt_handler(0xe7, interrupt_231_asm_entry);
 | |
|     register_interrupt_handler(0xe8, interrupt_232_asm_entry);
 | |
|     register_interrupt_handler(0xe9, interrupt_233_asm_entry);
 | |
|     register_interrupt_handler(0xea, interrupt_234_asm_entry);
 | |
|     register_interrupt_handler(0xeb, interrupt_235_asm_entry);
 | |
|     register_interrupt_handler(0xec, interrupt_236_asm_entry);
 | |
|     register_interrupt_handler(0xed, interrupt_237_asm_entry);
 | |
|     register_interrupt_handler(0xee, interrupt_238_asm_entry);
 | |
|     register_interrupt_handler(0xef, interrupt_239_asm_entry);
 | |
|     register_interrupt_handler(0xf0, interrupt_240_asm_entry);
 | |
|     register_interrupt_handler(0xf1, interrupt_241_asm_entry);
 | |
|     register_interrupt_handler(0xf2, interrupt_242_asm_entry);
 | |
|     register_interrupt_handler(0xf3, interrupt_243_asm_entry);
 | |
|     register_interrupt_handler(0xf4, interrupt_244_asm_entry);
 | |
|     register_interrupt_handler(0xf5, interrupt_245_asm_entry);
 | |
|     register_interrupt_handler(0xf6, interrupt_246_asm_entry);
 | |
|     register_interrupt_handler(0xf7, interrupt_247_asm_entry);
 | |
|     register_interrupt_handler(0xf8, interrupt_248_asm_entry);
 | |
|     register_interrupt_handler(0xf9, interrupt_249_asm_entry);
 | |
|     register_interrupt_handler(0xfa, interrupt_250_asm_entry);
 | |
|     register_interrupt_handler(0xfb, interrupt_251_asm_entry);
 | |
|     register_interrupt_handler(0xfc, interrupt_252_asm_entry);
 | |
|     register_interrupt_handler(0xfd, interrupt_253_asm_entry);
 | |
|     register_interrupt_handler(0xfe, interrupt_254_asm_entry);
 | |
|     register_interrupt_handler(0xff, interrupt_255_asm_entry);
 | |
| 
 | |
|     dbg() << "Installing Unhandled Handlers";
 | |
| 
 | |
|     for (u8 i = 0; i < GENERIC_INTERRUPT_HANDLERS_COUNT; ++i) {
 | |
|         new UnhandledInterruptHandler(i);
 | |
|     }
 | |
| 
 | |
|     flush_idt();
 | |
| }
 | |
| 
 | |
| void load_task_register(u16 selector)
 | |
| {
 | |
|     asm("ltr %0" ::"r"(selector));
 | |
| }
 | |
| 
 | |
| void handle_interrupt(TrapFrame* trap)
 | |
| {
 | |
|     clac();
 | |
|     auto& regs = *trap->regs;
 | |
|     ASSERT(regs.isr_number >= IRQ_VECTOR_BASE && regs.isr_number <= (IRQ_VECTOR_BASE + GENERIC_INTERRUPT_HANDLERS_COUNT));
 | |
|     u8 irq = (u8)(regs.isr_number - 0x50);
 | |
|     auto* handler = s_interrupt_handler[irq];
 | |
|     ASSERT(handler);
 | |
|     handler->increment_invoking_counter();
 | |
|     handler->handle_interrupt(regs);
 | |
|     handler->eoi();
 | |
| }
 | |
| 
 | |
| void enter_trap_no_irq(TrapFrame* trap)
 | |
| {
 | |
|     Processor::current().enter_trap(*trap, false);
 | |
| }
 | |
| 
 | |
| void enter_trap(TrapFrame* trap)
 | |
| {
 | |
|     Processor::current().enter_trap(*trap, true);
 | |
| }
 | |
| 
 | |
| void exit_trap(TrapFrame* trap)
 | |
| {
 | |
|     return Processor::current().exit_trap(*trap);
 | |
| }
 | |
| 
 | |
| static void sse_init()
 | |
| {
 | |
|     asm volatile(
 | |
|         "mov %cr0, %eax\n"
 | |
|         "andl $0xfffffffb, %eax\n"
 | |
|         "orl $0x2, %eax\n"
 | |
|         "mov %eax, %cr0\n"
 | |
|         "mov %cr4, %eax\n"
 | |
|         "orl $0x600, %eax\n"
 | |
|         "mov %eax, %cr4\n");
 | |
| }
 | |
| 
 | |
| u32 read_cr0()
 | |
| {
 | |
|     u32 cr0;
 | |
|     asm("movl %%cr0, %%eax"
 | |
|         : "=a"(cr0));
 | |
|     return cr0;
 | |
| }
 | |
| 
 | |
| u32 read_cr3()
 | |
| {
 | |
|     u32 cr3;
 | |
|     asm("movl %%cr3, %%eax"
 | |
|         : "=a"(cr3));
 | |
|     return cr3;
 | |
| }
 | |
| 
 | |
| void write_cr3(u32 cr3)
 | |
| {
 | |
|     asm volatile("movl %%eax, %%cr3" ::"a"(cr3)
 | |
|                  : "memory");
 | |
| }
 | |
| 
 | |
| u32 read_cr4()
 | |
| {
 | |
|     u32 cr4;
 | |
|     asm("movl %%cr4, %%eax"
 | |
|         : "=a"(cr4));
 | |
|     return cr4;
 | |
| }
 | |
| 
 | |
| u32 read_dr6()
 | |
| {
 | |
|     u32 dr6;
 | |
|     asm("movl %%dr6, %%eax"
 | |
|         : "=a"(dr6));
 | |
|     return dr6;
 | |
| }
 | |
| 
 | |
| FPUState Processor::s_clean_fpu_state;
 | |
| 
 | |
| static Vector<Processor*>* s_processors;
 | |
| static SpinLock s_processor_lock;
 | |
| volatile u32 Processor::g_total_processors;
 | |
| static volatile bool s_smp_enabled;
 | |
| 
 | |
| Vector<Processor*>& Processor::processors()
 | |
| {
 | |
|     ASSERT(s_processors);
 | |
|     return *s_processors;
 | |
| }
 | |
| 
 | |
| Processor& Processor::by_id(u32 cpu)
 | |
| {
 | |
|     // s_processors does not need to be protected by a lock of any kind.
 | |
|     // It is populated early in the boot process, and the BSP is waiting
 | |
|     // for all APs to finish, after which this array never gets modified
 | |
|     // again, so it's safe to not protect access to it here
 | |
|     auto& procs = processors();
 | |
|     ASSERT(procs[cpu] != nullptr);
 | |
|     ASSERT(procs.size() > cpu);
 | |
|     return *procs[cpu];
 | |
| }
 | |
| 
 | |
| [[noreturn]] static inline void halt_this()
 | |
| {
 | |
|     for (;;) {
 | |
|         asm volatile("cli; hlt");
 | |
|     }
 | |
| }
 | |
| 
 | |
| void Processor::cpu_detect()
 | |
| {
 | |
|     // NOTE: This is called during Processor::early_initialize, we cannot
 | |
|     //       safely log at this point because we don't have kmalloc
 | |
|     //       initialized yet!
 | |
|     auto set_feature =
 | |
|         [&](CPUFeature f) {
 | |
|             m_features = static_cast<CPUFeature>(static_cast<u32>(m_features) | static_cast<u32>(f));
 | |
|         };
 | |
|     m_features = static_cast<CPUFeature>(0);
 | |
| 
 | |
|     CPUID processor_info(0x1);
 | |
|     if (processor_info.edx() & (1 << 4))
 | |
|         set_feature(CPUFeature::TSC);
 | |
|     if (processor_info.edx() & (1 << 6))
 | |
|         set_feature(CPUFeature::PAE);
 | |
|     if (processor_info.edx() & (1 << 13))
 | |
|         set_feature(CPUFeature::PGE);
 | |
|     if (processor_info.edx() & (1 << 23))
 | |
|         set_feature(CPUFeature::MMX);
 | |
|     if (processor_info.edx() & (1 << 25))
 | |
|         set_feature(CPUFeature::SSE);
 | |
|     if (processor_info.edx() & (1 << 26))
 | |
|         set_feature(CPUFeature::SSE2);
 | |
|     if (processor_info.ecx() & (1 << 0))
 | |
|         set_feature(CPUFeature::SSE3);
 | |
|     if (processor_info.ecx() & (1 << 9))
 | |
|         set_feature(CPUFeature::SSSE3);
 | |
|     if (processor_info.ecx() & (1 << 19))
 | |
|         set_feature(CPUFeature::SSE4_1);
 | |
|     if (processor_info.ecx() & (1 << 20))
 | |
|         set_feature(CPUFeature::SSE4_2);
 | |
|     if (processor_info.ecx() & (1 << 30))
 | |
|         set_feature(CPUFeature::RDRAND);
 | |
|     if (processor_info.edx() & (1 << 11)) {
 | |
|         u32 stepping = processor_info.eax() & 0xf;
 | |
|         u32 model = (processor_info.eax() >> 4) & 0xf;
 | |
|         u32 family = (processor_info.eax() >> 8) & 0xf;
 | |
|         if (!(family == 6 && model < 3 && stepping < 3))
 | |
|             set_feature(CPUFeature::SEP);
 | |
|         if ((family == 6 && model >= 3) || (family == 0xf && model >= 0xe))
 | |
|             set_feature(CPUFeature::CONSTANT_TSC);
 | |
|     }
 | |
| 
 | |
|     u32 max_extended_leaf = CPUID(0x80000000).eax();
 | |
| 
 | |
|     ASSERT(max_extended_leaf >= 0x80000001);
 | |
|     CPUID extended_processor_info(0x80000001);
 | |
|     if (extended_processor_info.edx() & (1 << 20))
 | |
|         set_feature(CPUFeature::NX);
 | |
|     if (extended_processor_info.edx() & (1 << 27))
 | |
|         set_feature(CPUFeature::RDTSCP);
 | |
|     if (extended_processor_info.edx() & (1 << 11)) {
 | |
|         // Only available in 64 bit mode
 | |
|         set_feature(CPUFeature::SYSCALL);
 | |
|     }
 | |
| 
 | |
|     if (max_extended_leaf >= 0x80000007) {
 | |
|         CPUID cpuid(0x80000007);
 | |
|         if (cpuid.edx() & (1 << 8)) {
 | |
|             set_feature(CPUFeature::CONSTANT_TSC);
 | |
|             set_feature(CPUFeature::NONSTOP_TSC);
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     CPUID extended_features(0x7);
 | |
|     if (extended_features.ebx() & (1 << 20))
 | |
|         set_feature(CPUFeature::SMAP);
 | |
|     if (extended_features.ebx() & (1 << 7))
 | |
|         set_feature(CPUFeature::SMEP);
 | |
|     if (extended_features.ecx() & (1 << 2))
 | |
|         set_feature(CPUFeature::UMIP);
 | |
|     if (extended_features.ebx() & (1 << 18))
 | |
|         set_feature(CPUFeature::RDSEED);
 | |
| }
 | |
| 
 | |
| void Processor::cpu_setup()
 | |
| {
 | |
|     // NOTE: This is called during Processor::early_initialize, we cannot
 | |
|     //       safely log at this point because we don't have kmalloc
 | |
|     //       initialized yet!
 | |
|     cpu_detect();
 | |
| 
 | |
|     if (has_feature(CPUFeature::SSE))
 | |
|         sse_init();
 | |
| 
 | |
|     asm volatile(
 | |
|         "movl %%cr0, %%eax\n"
 | |
|         "orl $0x00010000, %%eax\n"
 | |
|         "movl %%eax, %%cr0\n" ::
 | |
|             : "%eax", "memory");
 | |
| 
 | |
|     if (has_feature(CPUFeature::PGE)) {
 | |
|         // Turn on CR4.PGE so the CPU will respect the G bit in page tables.
 | |
|         asm volatile(
 | |
|             "mov %cr4, %eax\n"
 | |
|             "orl $0x80, %eax\n"
 | |
|             "mov %eax, %cr4\n");
 | |
|     }
 | |
| 
 | |
|     if (has_feature(CPUFeature::NX)) {
 | |
|         // Turn on IA32_EFER.NXE
 | |
|         asm volatile(
 | |
|             "movl $0xc0000080, %ecx\n"
 | |
|             "rdmsr\n"
 | |
|             "orl $0x800, %eax\n"
 | |
|             "wrmsr\n");
 | |
|     }
 | |
| 
 | |
|     if (has_feature(CPUFeature::SMEP)) {
 | |
|         // Turn on CR4.SMEP
 | |
|         asm volatile(
 | |
|             "mov %cr4, %eax\n"
 | |
|             "orl $0x100000, %eax\n"
 | |
|             "mov %eax, %cr4\n");
 | |
|     }
 | |
| 
 | |
|     if (has_feature(CPUFeature::SMAP)) {
 | |
|         // Turn on CR4.SMAP
 | |
|         asm volatile(
 | |
|             "mov %cr4, %eax\n"
 | |
|             "orl $0x200000, %eax\n"
 | |
|             "mov %eax, %cr4\n");
 | |
|     }
 | |
| 
 | |
|     if (has_feature(CPUFeature::UMIP)) {
 | |
|         asm volatile(
 | |
|             "mov %cr4, %eax\n"
 | |
|             "orl $0x800, %eax\n"
 | |
|             "mov %eax, %cr4\n");
 | |
|     }
 | |
| 
 | |
|     if (has_feature(CPUFeature::TSC)) {
 | |
|         asm volatile(
 | |
|             "mov %cr4, %eax\n"
 | |
|             "orl $0x4, %eax\n"
 | |
|             "mov %eax, %cr4\n");
 | |
|     }
 | |
| }
 | |
| 
 | |
| String Processor::features_string() const
 | |
| {
 | |
|     StringBuilder builder;
 | |
|     auto feature_to_str =
 | |
|         [](CPUFeature f) -> const char*
 | |
|         {
 | |
|             switch (f) {
 | |
|                 case CPUFeature::NX:
 | |
|                     return "nx";
 | |
|                 case CPUFeature::PAE:
 | |
|                     return "pae";
 | |
|                 case CPUFeature::PGE:
 | |
|                     return "pge";
 | |
|                 case CPUFeature::RDRAND:
 | |
|                     return "rdrand";
 | |
|                 case CPUFeature::RDSEED:
 | |
|                     return "rdseed";
 | |
|                 case CPUFeature::SMAP:
 | |
|                     return "smap";
 | |
|                 case CPUFeature::SMEP:
 | |
|                     return "smep";
 | |
|                 case CPUFeature::SSE:
 | |
|                     return "sse";
 | |
|                 case CPUFeature::TSC:
 | |
|                     return "tsc";
 | |
|                 case CPUFeature::RDTSCP:
 | |
|                     return "rdtscp";
 | |
|                 case CPUFeature::CONSTANT_TSC:
 | |
|                     return "constant_tsc";
 | |
|                 case CPUFeature::NONSTOP_TSC:
 | |
|                     return "nonstop_tsc";
 | |
|                 case CPUFeature::UMIP:
 | |
|                     return "umip";
 | |
|                 case CPUFeature::SEP:
 | |
|                     return "sep";
 | |
|                 case CPUFeature::SYSCALL:
 | |
|                     return "syscall";
 | |
|                 case CPUFeature::MMX:
 | |
|                     return "mmx";
 | |
|                 case CPUFeature::SSE2:
 | |
|                     return "sse2";
 | |
|                 case CPUFeature::SSE3:
 | |
|                     return "sse3";
 | |
|                 case CPUFeature::SSSE3:
 | |
|                     return "ssse3";
 | |
|                 case CPUFeature::SSE4_1:
 | |
|                     return "sse4.1";
 | |
|                 case CPUFeature::SSE4_2:
 | |
|                     return "sse4.2";
 | |
|                 // no default statement here intentionally so that we get
 | |
|                 // a warning if a new feature is forgotten to be added here
 | |
|             }
 | |
|             // Shouldn't ever happen
 | |
|             return "???";
 | |
|         };
 | |
|     bool first = true;
 | |
|     for (u32 flag = 1; flag != 0; flag <<= 1) {
 | |
|         if ((static_cast<u32>(m_features) & flag) != 0) {
 | |
|             if (first)
 | |
|                 first = false;
 | |
|             else
 | |
|                 builder.append(' ');
 | |
|             auto str = feature_to_str(static_cast<CPUFeature>(flag));
 | |
|             builder.append(str, strlen(str));
 | |
|         }
 | |
|     }
 | |
|     return builder.build();
 | |
| }
 | |
| 
 | |
| void Processor::early_initialize(u32 cpu)
 | |
| {
 | |
|     m_self = this;
 | |
| 
 | |
|     m_cpu = cpu;
 | |
|     m_in_irq = 0;
 | |
|     m_in_critical = 0;
 | |
| 
 | |
|     m_invoke_scheduler_async = false;
 | |
|     m_scheduler_initialized = false;
 | |
| 
 | |
|     m_message_queue = nullptr;
 | |
|     m_idle_thread = nullptr;
 | |
|     m_current_thread = nullptr;
 | |
|     m_scheduler_data = nullptr;
 | |
|     m_mm_data = nullptr;
 | |
|     m_info = nullptr;
 | |
| 
 | |
|     m_halt_requested = false;
 | |
|     if (cpu == 0) {
 | |
|         s_smp_enabled = false;
 | |
|         atomic_store(&g_total_processors, 1u, AK::MemoryOrder::memory_order_release);
 | |
|     } else {
 | |
|         atomic_fetch_add(&g_total_processors, 1u, AK::MemoryOrder::memory_order_acq_rel);
 | |
|     }
 | |
| 
 | |
|     deferred_call_pool_init();
 | |
| 
 | |
|     cpu_setup();
 | |
|     gdt_init();
 | |
|     ASSERT(¤t() == this); // sanity check
 | |
| }
 | |
| 
 | |
| void Processor::initialize(u32 cpu)
 | |
| {
 | |
|     ASSERT(m_self == this);
 | |
|     ASSERT(¤t() == this); // sanity check
 | |
| 
 | |
|     klog() << "CPU[" << id() << "]: Supported features: " << features_string();
 | |
|     if (!has_feature(CPUFeature::RDRAND))
 | |
|         klog() << "CPU[" << id() << "]: No RDRAND support detected, randomness will be poor";
 | |
| 
 | |
|     if (cpu == 0)
 | |
|         idt_init();
 | |
|     else
 | |
|         flush_idt();
 | |
| 
 | |
|     if (cpu == 0) {
 | |
|         ASSERT((FlatPtr(&s_clean_fpu_state) & 0xF) == 0);
 | |
|         asm volatile("fninit");
 | |
|         asm volatile("fxsave %0"
 | |
|             : "=m"(s_clean_fpu_state));
 | |
|     }
 | |
| 
 | |
|     m_info = new ProcessorInfo(*this);
 | |
| 
 | |
|     {
 | |
|         ScopedSpinLock lock(s_processor_lock);
 | |
|         // We need to prevent races between APs starting up at the same time
 | |
|         if (!s_processors)
 | |
|             s_processors = new Vector<Processor*>();
 | |
|         if (cpu >= s_processors->size())
 | |
|             s_processors->resize(cpu + 1);
 | |
|         (*s_processors)[cpu] = this;
 | |
|     }
 | |
| }
 | |
| 
 | |
| void Processor::write_raw_gdt_entry(u16 selector, u32 low, u32 high)
 | |
| {
 | |
|     u16 i = (selector & 0xfffc) >> 3;
 | |
|     u32 prev_gdt_length = m_gdt_length;
 | |
| 
 | |
|     if (i > m_gdt_length) {
 | |
|         m_gdt_length = i + 1;
 | |
|         ASSERT(m_gdt_length <= sizeof(m_gdt) / sizeof(m_gdt[0]));
 | |
|         m_gdtr.limit = (m_gdt_length + 1) * 8 - 1;
 | |
|     }
 | |
|     m_gdt[i].low = low;
 | |
|     m_gdt[i].high = high;
 | |
| 
 | |
|     // clear selectors we may have skipped
 | |
|     while (i < prev_gdt_length) {
 | |
|         m_gdt[i].low = 0;
 | |
|         m_gdt[i].high = 0;
 | |
|         i++;
 | |
|     }
 | |
| }
 | |
| 
 | |
| void Processor::write_gdt_entry(u16 selector, Descriptor& descriptor)
 | |
| {
 | |
|     write_raw_gdt_entry(selector, descriptor.low, descriptor.high);
 | |
| }
 | |
| 
 | |
| Descriptor& Processor::get_gdt_entry(u16 selector)
 | |
| {
 | |
|     u16 i = (selector & 0xfffc) >> 3;
 | |
|     return *(Descriptor*)(&m_gdt[i]);
 | |
| }
 | |
| 
 | |
| void Processor::flush_gdt()
 | |
| {
 | |
|     m_gdtr.address = m_gdt;
 | |
|     m_gdtr.limit = (m_gdt_length * 8) - 1;
 | |
|     asm volatile("lgdt %0" ::"m"(m_gdtr)
 | |
|         : "memory");
 | |
| }
 | |
| 
 | |
| const DescriptorTablePointer& Processor::get_gdtr()
 | |
| {
 | |
|     return m_gdtr;
 | |
| }
 | |
| 
 | |
| Vector<FlatPtr> Processor::capture_stack_trace(Thread& thread, size_t max_frames)
 | |
| {
 | |
|     FlatPtr frame_ptr = 0, eip = 0;
 | |
|     Vector<FlatPtr, 32> stack_trace;
 | |
| 
 | |
|     auto walk_stack = [&](FlatPtr stack_ptr)
 | |
|     {
 | |
|         stack_trace.append(eip);
 | |
|         size_t count = 1;
 | |
|         while (stack_ptr) {
 | |
|             FlatPtr retaddr;
 | |
| 
 | |
|             count++;
 | |
|             if (max_frames != 0 && count > max_frames)
 | |
|                 break;
 | |
| 
 | |
|             if (is_user_range(VirtualAddress(stack_ptr), sizeof(FlatPtr) * 2)) {
 | |
|                 if (!copy_from_user(&retaddr, &((FlatPtr*)stack_ptr)[1]) || !retaddr)
 | |
|                     break;
 | |
|                 stack_trace.append(retaddr);
 | |
|                 if (!copy_from_user(&stack_ptr, (FlatPtr*)stack_ptr))
 | |
|                     break;
 | |
|             } else {
 | |
|                 void* fault_at;
 | |
|                 if (!safe_memcpy(&retaddr, &((FlatPtr*)stack_ptr)[1], sizeof(FlatPtr), fault_at) || !retaddr)
 | |
|                     break;
 | |
|                 stack_trace.append(retaddr);
 | |
|                 if (!safe_memcpy(&stack_ptr, (FlatPtr*)stack_ptr, sizeof(FlatPtr), fault_at))
 | |
|                     break;
 | |
|             }
 | |
|         }
 | |
|     };
 | |
|     auto capture_current_thread = [&]()
 | |
|     {
 | |
|         frame_ptr = (FlatPtr)__builtin_frame_address(0);
 | |
|         eip = (FlatPtr)__builtin_return_address(0);
 | |
| 
 | |
|         walk_stack(frame_ptr);
 | |
|     };
 | |
| 
 | |
|     // Since the thread may be running on another processor, there
 | |
|     // is a chance a context switch may happen while we're trying
 | |
|     // to get it. It also won't be entirely accurate and merely
 | |
|     // reflect the status at the last context switch.
 | |
|     ScopedSpinLock lock(g_scheduler_lock);
 | |
|     auto& proc = Processor::current();
 | |
|     if (&thread == proc.current_thread()) {
 | |
|         ASSERT(thread.state() == Thread::Running);
 | |
|         // Leave the scheduler lock. If we trigger page faults we may
 | |
|         // need to be preempted. Since this is our own thread it won't
 | |
|         // cause any problems as the stack won't change below this frame.
 | |
|         lock.unlock();
 | |
|         capture_current_thread();
 | |
|     } else if (thread.is_active()) {
 | |
|         ASSERT(thread.cpu() != proc.id());
 | |
|         // If this is the case, the thread is currently running
 | |
|         // on another processor. We can't trust the kernel stack as
 | |
|         // it may be changing at any time. We need to probably send
 | |
|         // an IPI to that processor, have it walk the stack and wait
 | |
|         // until it returns the data back to us
 | |
|         smp_unicast(thread.cpu(),
 | |
|             [&]() {
 | |
|                 dbg() << "CPU[" << Processor::current().id() << "] getting stack for cpu #" << proc.id();
 | |
|                 ProcessPagingScope paging_scope(thread.process());
 | |
|                 auto& target_proc = Processor::current();
 | |
|                 ASSERT(&target_proc != &proc);
 | |
|                 ASSERT(&thread == target_proc.current_thread());
 | |
|                 // NOTE: Because the other processor is still holding the
 | |
|                 // scheduler lock while waiting for this callback to finish,
 | |
|                 // the current thread on the target processor cannot change
 | |
| 
 | |
|                 // TODO: What to do about page faults here? We might deadlock
 | |
|                 //       because the other processor is still holding the
 | |
|                 //       scheduler lock...
 | |
|                 capture_current_thread();
 | |
|             }, false);
 | |
|     } else {
 | |
|         switch (thread.state()) {
 | |
|         case Thread::Running:
 | |
|             ASSERT_NOT_REACHED(); // should have been handled above
 | |
|         case Thread::Runnable:
 | |
|         case Thread::Stopped:
 | |
|         case Thread::Blocked:
 | |
|         case Thread::Dying:
 | |
|         case Thread::Dead: {
 | |
|             // We need to retrieve ebp from what was last pushed to the kernel
 | |
|             // stack. Before switching out of that thread, it switch_context
 | |
|             // pushed the callee-saved registers, and the last of them happens
 | |
|             // to be ebp.
 | |
|             ProcessPagingScope paging_scope(thread.process());
 | |
|             auto& tss = thread.tss();
 | |
|             u32* stack_top = reinterpret_cast<u32*>(tss.esp);
 | |
|             if (is_user_range(VirtualAddress(stack_top), sizeof(FlatPtr))) {
 | |
|                 if (!copy_from_user(&frame_ptr, &((FlatPtr*)stack_top)[0]))
 | |
|                     frame_ptr = 0;
 | |
|             } else {
 | |
|                 void* fault_at;
 | |
|                 if (!safe_memcpy(&frame_ptr, &((FlatPtr*)stack_top)[0], sizeof(FlatPtr), fault_at))
 | |
|                     frame_ptr = 0;
 | |
|             }
 | |
|             eip = tss.eip;
 | |
|             // TODO: We need to leave the scheduler lock here, but we also
 | |
|             //       need to prevent the target thread from being run while
 | |
|             //       we walk the stack
 | |
|             lock.unlock();
 | |
|             walk_stack(frame_ptr);
 | |
|             break;
 | |
|         }
 | |
|         default:
 | |
|             dbg() << "Cannot capture stack trace for thread " << thread << " in state " << thread.state_string();
 | |
|             break;
 | |
|         }
 | |
|     }
 | |
|     return stack_trace;
 | |
| }
 | |
| 
 | |
| extern "C" void enter_thread_context(Thread* from_thread, Thread* to_thread)
 | |
| {
 | |
|     ASSERT(from_thread == to_thread || from_thread->state() != Thread::Running);
 | |
|     ASSERT(to_thread->state() == Thread::Running);
 | |
| 
 | |
|     auto& processor = Processor::current();
 | |
|     processor.set_current_thread(*to_thread);
 | |
| 
 | |
|     auto& from_tss = from_thread->tss();
 | |
|     auto& to_tss = to_thread->tss();
 | |
|     asm volatile("fxsave %0"
 | |
|         : "=m"(from_thread->fpu_state()));
 | |
| 
 | |
|     from_tss.fs = get_fs();
 | |
|     from_tss.gs = get_gs();
 | |
|     set_fs(to_tss.fs);
 | |
|     set_gs(to_tss.gs);
 | |
| 
 | |
|     auto& tls_descriptor = processor.get_gdt_entry(GDT_SELECTOR_TLS);
 | |
|     tls_descriptor.set_base(to_thread->thread_specific_data().as_ptr());
 | |
|     tls_descriptor.set_limit(to_thread->thread_specific_region_size());
 | |
| 
 | |
|     if (from_tss.cr3 != to_tss.cr3)
 | |
|         write_cr3(to_tss.cr3);
 | |
| 
 | |
|     to_thread->set_cpu(processor.id());
 | |
| 
 | |
|     asm volatile("fxrstor %0"
 | |
|         ::"m"(to_thread->fpu_state()));
 | |
| 
 | |
|     // TODO: debug registers
 | |
|     // TODO: ioperm?
 | |
| }
 | |
| 
 | |
| #define ENTER_THREAD_CONTEXT_ARGS_SIZE (2 * 4) //  to_thread, from_thread
 | |
| 
 | |
| void Processor::switch_context(Thread*& from_thread, Thread*& to_thread)
 | |
| {
 | |
|     ASSERT(!in_irq());
 | |
|     ASSERT(m_in_critical == 1);
 | |
|     ASSERT(is_kernel_mode());
 | |
| #ifdef CONTEXT_SWITCH_DEBUG
 | |
|     dbg() << "switch_context --> switching out of: " << VirtualAddress(from_thread) << " " << *from_thread;
 | |
| #endif
 | |
| 
 | |
|     // Switch to new thread context, passing from_thread and to_thread
 | |
|     // through to the new context using registers edx and eax
 | |
|     asm volatile(
 | |
|         // NOTE: changing how much we push to the stack affects
 | |
|         //       SWITCH_CONTEXT_TO_STACK_SIZE and thread_context_first_enter()!
 | |
|         "pushfl \n"
 | |
|         "pushl %%ebx \n"
 | |
|         "pushl %%esi \n"
 | |
|         "pushl %%edi \n"
 | |
|         "pushl %%ebp \n"
 | |
|         "movl %%esp, %[from_esp] \n"
 | |
|         "movl $1f, %[from_eip] \n"
 | |
|         "movl %[to_esp0], %%ebx \n"
 | |
|         "movl %%ebx, %[tss_esp0] \n"
 | |
|         "movl %[to_esp], %%esp \n"
 | |
|         "pushl %[to_thread] \n"
 | |
|         "pushl %[from_thread] \n"
 | |
|         "pushl %[to_eip] \n"
 | |
|         "cld \n"
 | |
|         "jmp enter_thread_context \n"
 | |
|         "1: \n"
 | |
|         "popl %%edx \n"
 | |
|         "popl %%eax \n"
 | |
|         "popl %%ebp \n"
 | |
|         "popl %%edi \n"
 | |
|         "popl %%esi \n"
 | |
|         "popl %%ebx \n"
 | |
|         "popfl \n"
 | |
|         : [from_esp] "=m" (from_thread->tss().esp),
 | |
|           [from_eip] "=m" (from_thread->tss().eip),
 | |
|           [tss_esp0] "=m" (m_tss.esp0),
 | |
|           "=d" (from_thread), // needed so that from_thread retains the correct value
 | |
|           "=a" (to_thread) // needed so that to_thread retains the correct value
 | |
|         : [to_esp] "g" (to_thread->tss().esp),
 | |
|           [to_esp0] "g" (to_thread->tss().esp0),
 | |
|           [to_eip] "c" (to_thread->tss().eip),
 | |
|           [from_thread] "d" (from_thread),
 | |
|           [to_thread] "a" (to_thread)
 | |
|     );
 | |
| #ifdef CONTEXT_SWITCH_DEBUG
 | |
|     dbg() << "switch_context <-- from " << VirtualAddress(from_thread) << " " << *from_thread << " to " << VirtualAddress(to_thread) << " " << *to_thread;
 | |
| #endif
 | |
| }
 | |
| 
 | |
| extern "C" void context_first_init([[maybe_unused]] Thread* from_thread, [[maybe_unused]] Thread* to_thread, [[maybe_unused]] TrapFrame* trap)
 | |
| {
 | |
|     ASSERT(!are_interrupts_enabled());
 | |
|     ASSERT(is_kernel_mode());
 | |
| 
 | |
| #ifdef CONTEXT_SWITCH_DEBUG
 | |
|     dbg() << "switch_context <-- from " << VirtualAddress(from_thread) << " " << *from_thread << " to " << VirtualAddress(to_thread) << " " << *to_thread << " (context_first_init)";
 | |
| #endif
 | |
| 
 | |
|     ASSERT(to_thread == Thread::current());
 | |
| 
 | |
|     Scheduler::enter_current(*from_thread, true);
 | |
| 
 | |
|     // Since we got here and don't have Scheduler::context_switch in the
 | |
|     // call stack (because this is the first time we switched into this
 | |
|     // context), we need to notify the scheduler so that it can release
 | |
|     // the scheduler lock.
 | |
|     Scheduler::leave_on_first_switch(trap->regs->eflags);
 | |
| }
 | |
| 
 | |
| extern "C" void thread_context_first_enter();
 | |
| asm(
 | |
| // enter_thread_context returns to here first time a thread is executing
 | |
| ".globl thread_context_first_enter \n"
 | |
| "thread_context_first_enter: \n"
 | |
| // switch_context will have pushed from_thread and to_thread to our new
 | |
| // stack prior to thread_context_first_enter() being called, and the
 | |
| // pointer to TrapFrame was the top of the stack before that
 | |
| "    movl 8(%esp), %ebx \n" // save pointer to TrapFrame
 | |
| "    cld \n"
 | |
| "    call context_first_init \n"
 | |
| "    addl $" __STRINGIFY(ENTER_THREAD_CONTEXT_ARGS_SIZE) ", %esp \n"
 | |
| "    movl %ebx, 0(%esp) \n" // push pointer to TrapFrame
 | |
| "    jmp common_trap_exit \n"
 | |
| );
 | |
| 
 | |
| void exit_kernel_thread()
 | |
| {
 | |
|     Thread::current()->exit();
 | |
| }
 | |
| 
 | |
| u32 Processor::init_context(Thread& thread, bool leave_crit)
 | |
| {
 | |
|     ASSERT(is_kernel_mode());
 | |
|     ASSERT(g_scheduler_lock.is_locked());
 | |
|     if (leave_crit) {
 | |
|         // Leave the critical section we set up in in Process::exec,
 | |
|         // but because we still have the scheduler lock we should end up with 1
 | |
|         m_in_critical--; // leave it without triggering anything or restoring flags
 | |
|         ASSERT(in_critical() == 1);
 | |
|     }
 | |
| 
 | |
|     u32 kernel_stack_top = thread.kernel_stack_top();
 | |
|     u32 stack_top = kernel_stack_top;
 | |
| 
 | |
|     // TODO: handle NT?
 | |
|     ASSERT((cpu_flags() & 0x24000) == 0); // Assume !(NT | VM)
 | |
| 
 | |
|     auto& tss = thread.tss();
 | |
|     bool return_to_user = (tss.cs & 3) != 0;
 | |
| 
 | |
|     // make room for an interrupt frame
 | |
|     if (!return_to_user) {
 | |
|         // userspace_esp and userspace_ss are not popped off by iret
 | |
|         // unless we're switching back to user mode
 | |
|         stack_top -= sizeof(RegisterState) - 2 * sizeof(u32);
 | |
| 
 | |
|         // For kernel threads we'll push the thread function argument
 | |
|         // which should be in tss.esp and exit_kernel_thread as return
 | |
|         // address.
 | |
|         stack_top -= 2 * sizeof(u32);
 | |
|         *reinterpret_cast<u32*>(kernel_stack_top - 2 * sizeof(u32)) = tss.esp;
 | |
|         *reinterpret_cast<u32*>(kernel_stack_top - 3 * sizeof(u32)) = FlatPtr(&exit_kernel_thread);
 | |
|     } else {
 | |
|         stack_top -= sizeof(RegisterState);
 | |
|     }
 | |
| 
 | |
|     // we want to end up 16-byte aligned, %esp + 4 should be aligned
 | |
|     stack_top -= sizeof(u32);
 | |
|     *reinterpret_cast<u32*>(kernel_stack_top - sizeof(u32)) = 0;
 | |
| 
 | |
|     // set up the stack so that after returning from thread_context_first_enter()
 | |
|     // we will end up either in kernel mode or user mode, depending on how the thread is set up
 | |
|     // However, the first step is to always start in kernel mode with thread_context_first_enter
 | |
|     RegisterState& iretframe = *reinterpret_cast<RegisterState*>(stack_top);
 | |
|     iretframe.ss = tss.ss;
 | |
|     iretframe.gs = tss.gs;
 | |
|     iretframe.fs = tss.fs;
 | |
|     iretframe.es = tss.es;
 | |
|     iretframe.ds = tss.ds;
 | |
|     iretframe.edi = tss.edi;
 | |
|     iretframe.esi = tss.esi;
 | |
|     iretframe.ebp = tss.ebp;
 | |
|     iretframe.esp = 0;
 | |
|     iretframe.ebx = tss.ebx;
 | |
|     iretframe.edx = tss.edx;
 | |
|     iretframe.ecx = tss.ecx;
 | |
|     iretframe.eax = tss.eax;
 | |
|     iretframe.eflags = tss.eflags;
 | |
|     iretframe.eip = tss.eip;
 | |
|     iretframe.cs = tss.cs;
 | |
|     if (return_to_user) {
 | |
|         iretframe.userspace_esp = tss.esp;
 | |
|         iretframe.userspace_ss = tss.ss;
 | |
|     }
 | |
| 
 | |
|     // make space for a trap frame
 | |
|     stack_top -= sizeof(TrapFrame);
 | |
|     TrapFrame& trap = *reinterpret_cast<TrapFrame*>(stack_top);
 | |
|     trap.regs = &iretframe;
 | |
|     trap.prev_irq_level = 0;
 | |
| 
 | |
|     stack_top -= sizeof(u32); // pointer to TrapFrame
 | |
|     *reinterpret_cast<u32*>(stack_top) = stack_top + 4;
 | |
| 
 | |
| #ifdef CONTEXT_SWITCH_DEBUG
 | |
|     if (return_to_user)
 | |
|         dbg() << "init_context " << thread << " (" << VirtualAddress(&thread) << ") set up to execute at eip: " << String::format("%02x:%08x", iretframe.cs, (u32)tss.eip) << " esp: " << VirtualAddress(tss.esp) << " stack top: " << VirtualAddress(stack_top) << " user esp: " << String::format("%02x:%08x", iretframe.userspace_ss, (u32)iretframe.userspace_esp);
 | |
|     else
 | |
|         dbg() << "init_context " << thread << " (" << VirtualAddress(&thread) << ") set up to execute at eip: " << String::format("%02x:%08x", iretframe.cs, (u32)tss.eip) << " esp: " << VirtualAddress(tss.esp) << " stack top: " << VirtualAddress(stack_top);
 | |
| #endif
 | |
| 
 | |
|     // make switch_context() always first return to thread_context_first_enter()
 | |
|     // in kernel mode, so set up these values so that we end up popping iretframe
 | |
|     // off the stack right after the context switch completed, at which point
 | |
|     // control is transferred to what iretframe is pointing to.
 | |
|     tss.eip = FlatPtr(&thread_context_first_enter);
 | |
|     tss.esp0 = kernel_stack_top;
 | |
|     tss.esp = stack_top;
 | |
|     tss.cs = GDT_SELECTOR_CODE0;
 | |
|     tss.ds = GDT_SELECTOR_DATA0;
 | |
|     tss.es = GDT_SELECTOR_DATA0;
 | |
|     tss.gs = GDT_SELECTOR_DATA0;
 | |
|     tss.ss = GDT_SELECTOR_DATA0;
 | |
|     tss.fs = GDT_SELECTOR_PROC;
 | |
|     return stack_top;
 | |
| }
 | |
| 
 | |
| extern "C" u32 do_init_context(Thread* thread, u32 flags)
 | |
| {
 | |
|     ASSERT_INTERRUPTS_DISABLED();
 | |
|     thread->tss().eflags = flags;
 | |
|     return Processor::current().init_context(*thread, true);
 | |
| }
 | |
| 
 | |
| extern "C" void do_assume_context(Thread* thread, u32 flags);
 | |
| 
 | |
| asm(
 | |
| ".global do_assume_context \n"
 | |
| "do_assume_context: \n"
 | |
| "    movl 4(%esp), %ebx \n"
 | |
| "    movl 8(%esp), %esi \n"
 | |
| // We're going to call Processor::init_context, so just make sure
 | |
| // we have enough stack space so we don't stomp over it
 | |
| "    subl $(" __STRINGIFY(4 + REGISTER_STATE_SIZE + TRAP_FRAME_SIZE + 4) "), %esp \n"
 | |
| "    pushl %esi \n"
 | |
| "    pushl %ebx \n"
 | |
| "    cld \n"
 | |
| "    call do_init_context \n"
 | |
| "    addl $8, %esp \n"
 | |
| "    movl %eax, %esp \n" // move stack pointer to what Processor::init_context set up for us
 | |
| "    pushl %ebx \n" // push to_thread
 | |
| "    pushl %ebx \n" // push from_thread
 | |
| "    pushl $thread_context_first_enter \n" // should be same as tss.eip
 | |
| "    jmp enter_thread_context \n"
 | |
| );
 | |
| 
 | |
| void Processor::assume_context(Thread& thread, u32 flags)
 | |
| {
 | |
| #ifdef CONTEXT_SWITCH_DEBUG
 | |
|     dbg() << "Assume context for thread " << VirtualAddress(&thread) << " " << thread;
 | |
| #endif
 | |
|     ASSERT_INTERRUPTS_DISABLED();
 | |
|     Scheduler::prepare_after_exec();
 | |
|     // in_critical() should be 2 here. The critical section in Process::exec
 | |
|     // and then the scheduler lock
 | |
|     ASSERT(Processor::current().in_critical() == 2);
 | |
|     do_assume_context(&thread, flags);
 | |
|     ASSERT_NOT_REACHED();
 | |
| }
 | |
| 
 | |
| extern "C" void pre_init_finished()
 | |
| {
 | |
|     ASSERT(g_scheduler_lock.own_lock());
 | |
| 
 | |
|     // Because init_finished() will wait on the other APs, we need
 | |
|     // to release the scheduler lock so that the other APs can also get
 | |
|     // to this point
 | |
| 
 | |
|     // The target flags will get restored upon leaving the trap
 | |
|     u32 prev_flags = cpu_flags();
 | |
|     Scheduler::leave_on_first_switch(prev_flags);
 | |
| }
 | |
| 
 | |
| extern "C" void post_init_finished()
 | |
| {
 | |
|     // We need to re-acquire the scheduler lock before a context switch
 | |
|     // transfers control into the idle loop, which needs the lock held
 | |
|     Scheduler::prepare_for_idle_loop();
 | |
| }
 | |
| 
 | |
| void Processor::initialize_context_switching(Thread& initial_thread)
 | |
| {
 | |
|     ASSERT(initial_thread.process().is_kernel_process());
 | |
| 
 | |
|     auto& tss = initial_thread.tss();
 | |
|     m_tss = tss;
 | |
|     m_tss.esp0 = tss.esp0;
 | |
|     m_tss.ss0 = GDT_SELECTOR_DATA0;
 | |
|     // user mode needs to be able to switch to kernel mode:
 | |
|     m_tss.cs = m_tss.ds = m_tss.es = m_tss.gs = m_tss.ss = GDT_SELECTOR_CODE0 | 3;
 | |
|     m_tss.fs = GDT_SELECTOR_PROC | 3;
 | |
| 
 | |
|     m_scheduler_initialized = true;
 | |
| 
 | |
|     asm volatile(
 | |
|         "movl %[new_esp], %%esp \n" // switch to new stack
 | |
|         "pushl %[from_to_thread] \n" // to_thread
 | |
|         "pushl %[from_to_thread] \n" // from_thread
 | |
|         "pushl $" __STRINGIFY(GDT_SELECTOR_CODE0) " \n"
 | |
|         "pushl %[new_eip] \n" // save the entry eip to the stack
 | |
|         "movl %%esp, %%ebx \n"
 | |
|         "addl $20, %%ebx \n" // calculate pointer to TrapFrame
 | |
|         "pushl %%ebx \n"
 | |
|         "cld \n"
 | |
|         "pushl %[cpu] \n" // push argument for init_finished before register is clobbered
 | |
|         "call pre_init_finished \n"
 | |
|         "call init_finished \n"
 | |
|         "addl $4, %%esp \n"
 | |
|         "call post_init_finished \n"
 | |
|         "call enter_trap_no_irq \n"
 | |
|         "addl $4, %%esp \n"
 | |
|         "lret \n"
 | |
|         :: [new_esp] "g" (tss.esp),
 | |
|            [new_eip] "a" (tss.eip),
 | |
|            [from_to_thread] "b" (&initial_thread),
 | |
|            [cpu] "c" (id())
 | |
|     );
 | |
| 
 | |
|     ASSERT_NOT_REACHED();
 | |
| }
 | |
| 
 | |
| void Processor::enter_trap(TrapFrame& trap, bool raise_irq)
 | |
| {
 | |
|     InterruptDisabler disabler;
 | |
|     trap.prev_irq_level = m_in_irq;
 | |
|     if (raise_irq)
 | |
|         m_in_irq++;
 | |
| }
 | |
| 
 | |
| void Processor::exit_trap(TrapFrame& trap)
 | |
| {
 | |
|     InterruptDisabler disabler;
 | |
|     ASSERT(m_in_irq >= trap.prev_irq_level);
 | |
|     m_in_irq = trap.prev_irq_level;
 | |
| 
 | |
|     smp_process_pending_messages();
 | |
| 
 | |
|     if (!m_in_irq && !m_in_critical)
 | |
|         check_invoke_scheduler();
 | |
| }
 | |
| 
 | |
| void Processor::check_invoke_scheduler()
 | |
| {
 | |
|     ASSERT(!m_in_irq);
 | |
|     ASSERT(!m_in_critical);
 | |
|     if (m_invoke_scheduler_async && m_scheduler_initialized) {
 | |
|         m_invoke_scheduler_async = false;
 | |
|         Scheduler::invoke_async();
 | |
|     }
 | |
| }
 | |
| 
 | |
| void Processor::flush_tlb_local(VirtualAddress vaddr, size_t page_count)
 | |
| {
 | |
|     auto ptr = vaddr.as_ptr();
 | |
|     while (page_count > 0) {
 | |
|         asm volatile("invlpg %0"
 | |
|              :
 | |
|              : "m"(*ptr)
 | |
|              : "memory");
 | |
|         ptr += PAGE_SIZE;
 | |
|         page_count--;
 | |
|     }
 | |
| }
 | |
| 
 | |
| void Processor::flush_tlb(VirtualAddress vaddr, size_t page_count)
 | |
| {
 | |
|     if (s_smp_enabled)
 | |
|         smp_broadcast_flush_tlb(vaddr, page_count);
 | |
|     else
 | |
|         flush_tlb_local(vaddr, page_count);
 | |
| }
 | |
| 
 | |
| static volatile ProcessorMessage* s_message_pool;
 | |
| 
 | |
| void Processor::smp_return_to_pool(ProcessorMessage& msg)
 | |
| {
 | |
|     ProcessorMessage* next = nullptr;
 | |
|     do {
 | |
|         msg.next = next;
 | |
|     } while (!atomic_compare_exchange_strong(&s_message_pool, next, &msg, AK::MemoryOrder::memory_order_acq_rel));
 | |
| }
 | |
| 
 | |
| ProcessorMessage& Processor::smp_get_from_pool()
 | |
| {
 | |
|     ProcessorMessage* msg;
 | |
| 
 | |
|     // The assumption is that messages are never removed from the pool!
 | |
|     for (;;) {
 | |
|         msg = atomic_load(&s_message_pool, AK::MemoryOrder::memory_order_consume);
 | |
|         if (!msg) {
 | |
|             if (!Processor::current().smp_process_pending_messages()) {
 | |
|                 // TODO: pause for a bit?
 | |
|             }
 | |
|             continue;
 | |
|         }
 | |
|         // If another processor were to use this message in the meanwhile,
 | |
|         // "msg" is still valid (because it never gets freed). We'd detect
 | |
|         // this because the expected value "msg" and pool would
 | |
|         // no longer match, and the compare_exchange will fail. But accessing
 | |
|         // "msg->next" is always safe here.
 | |
|         if (atomic_compare_exchange_strong(&s_message_pool, msg, msg->next, AK::MemoryOrder::memory_order_acq_rel)) {
 | |
|             // We successfully "popped" this available message
 | |
|             break;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     ASSERT(msg != nullptr);
 | |
|     return *msg;
 | |
| }
 | |
| 
 | |
| void Processor::smp_enable()
 | |
| {
 | |
|     size_t msg_pool_size = Processor::count() * 100u;
 | |
|     size_t msg_entries_cnt = Processor::count();
 | |
| 
 | |
|     auto msgs = new ProcessorMessage[msg_pool_size];
 | |
|     auto msg_entries = new ProcessorMessageEntry[msg_pool_size * msg_entries_cnt];
 | |
|     size_t msg_entry_i = 0;
 | |
|     for (size_t i = 0; i < msg_pool_size; i++, msg_entry_i += msg_entries_cnt) {
 | |
|         auto& msg = msgs[i];
 | |
|         msg.next = i < msg_pool_size - 1 ? &msgs[i + 1] : nullptr;
 | |
|         msg.per_proc_entries = &msg_entries[msg_entry_i];
 | |
|         for (size_t k = 0; k < msg_entries_cnt; k++)
 | |
|             msg_entries[msg_entry_i + k].msg = &msg;
 | |
|     }
 | |
| 
 | |
|     atomic_store(&s_message_pool, &msgs[0], AK::MemoryOrder::memory_order_release);
 | |
| 
 | |
|     // Start sending IPI messages
 | |
|     s_smp_enabled = true;
 | |
| }
 | |
| 
 | |
| void Processor::smp_cleanup_message(ProcessorMessage& msg)
 | |
| {
 | |
|     switch (msg.type) {
 | |
|     case ProcessorMessage::CallbackWithData:
 | |
|         if (msg.callback_with_data.free)
 | |
|             msg.callback_with_data.free(msg.callback_with_data.data);
 | |
|         break;
 | |
|     default:
 | |
|         break;
 | |
|     }
 | |
| }
 | |
| 
 | |
| bool Processor::smp_process_pending_messages()
 | |
| {
 | |
|     bool did_process = false;
 | |
|     u32 prev_flags;
 | |
|     enter_critical(prev_flags);
 | |
| 
 | |
|     if (auto pending_msgs = atomic_exchange(&m_message_queue, nullptr, AK::MemoryOrder::memory_order_acq_rel)) {
 | |
|         // We pulled the stack of pending messages in LIFO order, so we need to reverse the list first
 | |
|         auto reverse_list =
 | |
|             [](ProcessorMessageEntry* list) -> ProcessorMessageEntry*
 | |
|             {
 | |
|                 ProcessorMessageEntry* rev_list = nullptr;
 | |
|                 while (list) {
 | |
|                     auto next = list->next;
 | |
|                     list->next = rev_list;
 | |
|                     rev_list = list;
 | |
|                     list = next;
 | |
|                 }
 | |
|                 return rev_list;
 | |
|             };
 | |
| 
 | |
|         pending_msgs = reverse_list(pending_msgs);
 | |
| 
 | |
|         // now process in the right order
 | |
|         ProcessorMessageEntry* next_msg;
 | |
|         for (auto cur_msg = pending_msgs; cur_msg; cur_msg = next_msg) {
 | |
|             next_msg = cur_msg->next;
 | |
|             auto msg = cur_msg->msg;
 | |
| 
 | |
| #ifdef SMP_DEBUG
 | |
|             dbg() << "SMP[" << id() << "]: Processing message " << VirtualAddress(msg);
 | |
| #endif
 | |
| 
 | |
|             switch (msg->type) {
 | |
|             case ProcessorMessage::Callback:
 | |
|                 msg->callback.handler();
 | |
|                 break;
 | |
|             case ProcessorMessage::CallbackWithData:
 | |
|                 msg->callback_with_data.handler(msg->callback_with_data.data);
 | |
|                 break;
 | |
|             case ProcessorMessage::FlushTlb:
 | |
|                 flush_tlb_local(VirtualAddress(msg->flush_tlb.ptr), msg->flush_tlb.page_count);
 | |
|                 break;
 | |
|             }
 | |
| 
 | |
|             bool is_async = msg->async; // Need to cache this value *before* dropping the ref count!
 | |
|             auto prev_refs = atomic_fetch_sub(&msg->refs, 1u, AK::MemoryOrder::memory_order_acq_rel);
 | |
|             ASSERT(prev_refs != 0);
 | |
|             if (prev_refs == 1) {
 | |
|                 // All processors handled this. If this is an async message,
 | |
|                 // we need to clean it up and return it to the pool
 | |
|                 if (is_async) {
 | |
|                     smp_cleanup_message(*msg);
 | |
|                     smp_return_to_pool(*msg);
 | |
|                 }
 | |
|             }
 | |
| 
 | |
|             if (m_halt_requested.load(AK::MemoryOrder::memory_order_relaxed))
 | |
|                 halt_this();
 | |
|         }
 | |
|         did_process = true;
 | |
|     } else if (m_halt_requested.load(AK::MemoryOrder::memory_order_relaxed)) {
 | |
|         halt_this();
 | |
|     }
 | |
| 
 | |
|     leave_critical(prev_flags);
 | |
|     return did_process;
 | |
| }
 | |
| 
 | |
| bool Processor::smp_queue_message(ProcessorMessage& msg)
 | |
| {
 | |
|     // Note that it's quite possible that the other processor may pop
 | |
|     // the queue at any given time. We rely on the fact that the messages
 | |
|     // are pooled and never get freed!
 | |
|     auto& msg_entry = msg.per_proc_entries[id()];
 | |
|     ASSERT(msg_entry.msg == &msg);
 | |
|     ProcessorMessageEntry* next = nullptr;
 | |
|     do {
 | |
|         msg_entry.next = next;
 | |
|     } while (!atomic_compare_exchange_strong(&m_message_queue, next, &msg_entry, AK::MemoryOrder::memory_order_acq_rel));
 | |
|     return next == nullptr;
 | |
| }
 | |
| 
 | |
| void Processor::smp_broadcast_message(ProcessorMessage& msg)
 | |
| {
 | |
|     auto& cur_proc = Processor::current();
 | |
| #ifdef SMP_DEBUG
 | |
|     dbg() << "SMP[" << cur_proc.id() << "]: Broadcast message " << VirtualAddress(&msg) << " to cpus: " << (count()) << " proc: " << VirtualAddress(&cur_proc);
 | |
| #endif
 | |
|     atomic_store(&msg.refs, count() - 1, AK::MemoryOrder::memory_order_release);
 | |
|     ASSERT(msg.refs > 0);
 | |
|     bool need_broadcast = false;
 | |
|     for_each(
 | |
|         [&](Processor& proc) -> IterationDecision {
 | |
|             if (&proc != &cur_proc) {
 | |
|                 if (proc.smp_queue_message(msg))
 | |
|                     need_broadcast = true;
 | |
|             }
 | |
|             return IterationDecision::Continue;
 | |
|         });
 | |
| 
 | |
|     // Now trigger an IPI on all other APs (unless all targets already had messages queued)
 | |
|     if (need_broadcast)
 | |
|         APIC::the().broadcast_ipi();
 | |
| }
 | |
| 
 | |
| void Processor::smp_broadcast_wait_sync(ProcessorMessage& msg)
 | |
| {
 | |
|     auto& cur_proc = Processor::current();
 | |
|     ASSERT(!msg.async);
 | |
|     // If synchronous then we must cleanup and return the message back
 | |
|     // to the pool. Otherwise, the last processor to complete it will return it
 | |
|     while (atomic_load(&msg.refs, AK::MemoryOrder::memory_order_consume) != 0) {
 | |
|         // TODO: pause for a bit?
 | |
| 
 | |
|         // We need to process any messages that may have been sent to
 | |
|         // us while we're waiting. This also checks if another processor
 | |
|         // may have requested us to halt.
 | |
|         cur_proc.smp_process_pending_messages();
 | |
|     }
 | |
| 
 | |
|     smp_cleanup_message(msg);
 | |
|     smp_return_to_pool(msg);
 | |
| }
 | |
| 
 | |
| void Processor::smp_broadcast(void (*callback)(void*), void* data, void (*free_data)(void*), bool async)
 | |
| {
 | |
|     auto& msg = smp_get_from_pool();
 | |
|     msg.async = async;
 | |
|     msg.type = ProcessorMessage::CallbackWithData;
 | |
|     msg.callback_with_data.handler = callback;
 | |
|     msg.callback_with_data.data = data;
 | |
|     msg.callback_with_data.free = free_data;
 | |
|     smp_broadcast_message(msg);
 | |
|     if (!async)
 | |
|         smp_broadcast_wait_sync(msg);
 | |
| }
 | |
| 
 | |
| void Processor::smp_broadcast(void (*callback)(), bool async)
 | |
| {
 | |
|     auto& msg = smp_get_from_pool();
 | |
|     msg.async = async;
 | |
|     msg.type = ProcessorMessage::CallbackWithData;
 | |
|     msg.callback.handler = callback;
 | |
|     smp_broadcast_message(msg);
 | |
|     if (!async)
 | |
|         smp_broadcast_wait_sync(msg);
 | |
| }
 | |
| 
 | |
| void Processor::smp_unicast_message(u32 cpu, ProcessorMessage& msg, bool async)
 | |
| {
 | |
|     auto& cur_proc = Processor::current();
 | |
|     ASSERT(cpu != cur_proc.id());
 | |
|     auto& target_proc = processors()[cpu];
 | |
|     msg.async = async;
 | |
| #ifdef SMP_DEBUG
 | |
|     dbg() << "SMP[" << cur_proc.id() << "]: Send message " << VirtualAddress(&msg) << " to cpu #" << cpu << " proc: " << VirtualAddress(&target_proc);
 | |
| #endif
 | |
|     atomic_store(&msg.refs, 1u, AK::MemoryOrder::memory_order_release);
 | |
|     if (target_proc->smp_queue_message(msg)) {
 | |
|         APIC::the().send_ipi(cpu);
 | |
|     }
 | |
| 
 | |
|     if (!async) {
 | |
|         // If synchronous then we must cleanup and return the message back
 | |
|         // to the pool. Otherwise, the last processor to complete it will return it
 | |
|         while (atomic_load(&msg.refs, AK::MemoryOrder::memory_order_consume) != 0) {
 | |
|             // TODO: pause for a bit?
 | |
| 
 | |
|             // We need to process any messages that may have been sent to
 | |
|             // us while we're waiting. This also checks if another processor
 | |
|             // may have requested us to halt.
 | |
|             cur_proc.smp_process_pending_messages();
 | |
|         }
 | |
| 
 | |
|         smp_cleanup_message(msg);
 | |
|         smp_return_to_pool(msg);
 | |
|     }
 | |
| }
 | |
| 
 | |
| void Processor::smp_unicast(u32 cpu, void (*callback)(void*), void* data, void (*free_data)(void*), bool async)
 | |
| {
 | |
|     auto& msg = smp_get_from_pool();
 | |
|     msg.type = ProcessorMessage::CallbackWithData;
 | |
|     msg.callback_with_data.handler = callback;
 | |
|     msg.callback_with_data.data = data;
 | |
|     msg.callback_with_data.free = free_data;
 | |
|     smp_unicast_message(cpu, msg, async);
 | |
| }
 | |
| 
 | |
| void Processor::smp_unicast(u32 cpu, void (*callback)(), bool async)
 | |
| {
 | |
|     auto& msg = smp_get_from_pool();
 | |
|     msg.type = ProcessorMessage::CallbackWithData;
 | |
|     msg.callback.handler = callback;
 | |
|     smp_unicast_message(cpu, msg, async);
 | |
| }
 | |
| 
 | |
| void Processor::smp_broadcast_flush_tlb(VirtualAddress vaddr, size_t page_count)
 | |
| {
 | |
|     auto& msg = smp_get_from_pool();
 | |
|     msg.async = false;
 | |
|     msg.type = ProcessorMessage::FlushTlb;
 | |
|     msg.flush_tlb.ptr = vaddr.as_ptr();
 | |
|     msg.flush_tlb.page_count = page_count;
 | |
|     smp_broadcast_message(msg);
 | |
|     // While the other processors handle this request, we'll flush ours
 | |
|     flush_tlb_local(vaddr, page_count);
 | |
|     // Now wait until everybody is done as well
 | |
|     smp_broadcast_wait_sync(msg);
 | |
| }
 | |
| 
 | |
| void Processor::smp_broadcast_halt()
 | |
| {
 | |
|     // We don't want to use a message, because this could have been triggered
 | |
|     // by being out of memory and we might not be able to get a message
 | |
|     for_each(
 | |
|         [&](Processor& proc) -> IterationDecision {
 | |
|             proc.m_halt_requested.store(true, AK::MemoryOrder::memory_order_release);
 | |
|             return IterationDecision::Continue;
 | |
|         });
 | |
| 
 | |
|     // Now trigger an IPI on all other APs
 | |
|     APIC::the().broadcast_ipi();
 | |
| }
 | |
| 
 | |
| void Processor::Processor::halt()
 | |
| {
 | |
|     if (s_smp_enabled)
 | |
|         smp_broadcast_halt();
 | |
| 
 | |
|     halt_this();
 | |
| }
 | |
| 
 | |
| void Processor::deferred_call_pool_init()
 | |
| {
 | |
|     size_t pool_count = sizeof(m_deferred_call_pool) / sizeof(m_deferred_call_pool[0]);
 | |
|     for (size_t i = 0; i < pool_count; i++) {
 | |
|         auto& entry = m_deferred_call_pool[i];
 | |
|         entry.next = i < pool_count - 1 ? &m_deferred_call_pool[i + 1] : nullptr;
 | |
|         entry.was_allocated = false;
 | |
|     }
 | |
|     m_pending_deferred_calls = nullptr;
 | |
|     m_free_deferred_call_pool_entry = &m_deferred_call_pool[0];
 | |
| }
 | |
| 
 | |
| void Processor::deferred_call_return_to_pool(DeferredCallEntry* entry)
 | |
| {
 | |
|     ASSERT(m_in_critical);
 | |
|     ASSERT(!entry->was_allocated);
 | |
| 
 | |
|     entry->next = m_free_deferred_call_pool_entry;
 | |
|     m_free_deferred_call_pool_entry = entry;
 | |
| }
 | |
| 
 | |
| DeferredCallEntry* Processor::deferred_call_get_free()
 | |
| {
 | |
|     ASSERT(m_in_critical);
 | |
| 
 | |
|     if (m_free_deferred_call_pool_entry) {
 | |
|         // Fast path, we have an entry in our pool
 | |
|         auto* entry = m_free_deferred_call_pool_entry;
 | |
|         m_free_deferred_call_pool_entry = entry->next;
 | |
|         ASSERT(!entry->was_allocated);
 | |
|         return entry;
 | |
|     }
 | |
| 
 | |
|     auto* entry = new DeferredCallEntry;
 | |
|     entry->was_allocated = true;
 | |
|     return entry;
 | |
| }
 | |
| 
 | |
| void Processor::deferred_call_execute_pending()
 | |
| {
 | |
|     ASSERT(m_in_critical);
 | |
| 
 | |
|     if (!m_pending_deferred_calls)
 | |
|         return;
 | |
|     auto* pending_list = m_pending_deferred_calls;
 | |
|     m_pending_deferred_calls = nullptr;
 | |
| 
 | |
|     // We pulled the stack of pending deferred calls in LIFO order, so we need to reverse the list first
 | |
|     auto reverse_list =
 | |
|         [](DeferredCallEntry* list) -> DeferredCallEntry*
 | |
|         {
 | |
|             DeferredCallEntry* rev_list = nullptr;
 | |
|             while (list) {
 | |
|                 auto next = list->next;
 | |
|                 list->next = rev_list;
 | |
|                 rev_list = list;
 | |
|                 list = next;
 | |
|             }
 | |
|             return rev_list;
 | |
|         };
 | |
|     pending_list = reverse_list(pending_list);
 | |
| 
 | |
|     do {
 | |
|         // Call the appropriate callback handler
 | |
|         if (pending_list->have_data) {
 | |
|             pending_list->callback_with_data.handler(pending_list->callback_with_data.data);
 | |
|             if (pending_list->callback_with_data.free)
 | |
|                 pending_list->callback_with_data.free(pending_list->callback_with_data.data);
 | |
|         } else {
 | |
|             pending_list->callback.handler();
 | |
|         }
 | |
| 
 | |
|         // Return the entry back to the pool, or free it
 | |
|         auto* next = pending_list->next;
 | |
|         if (pending_list->was_allocated)
 | |
|             delete pending_list;
 | |
|         else
 | |
|             deferred_call_return_to_pool(pending_list);
 | |
|         pending_list = next;
 | |
|     } while (pending_list);
 | |
| }
 | |
| 
 | |
| void Processor::deferred_call_queue_entry(DeferredCallEntry* entry)
 | |
| {
 | |
|     ASSERT(m_in_critical);
 | |
|     entry->next = m_pending_deferred_calls;
 | |
|     m_pending_deferred_calls = entry;
 | |
| }
 | |
| 
 | |
| void Processor::deferred_call_queue(void (*callback)())
 | |
| {
 | |
|     // NOTE: If we are called outside of a critical section and outside
 | |
|     // of an irq handler, the function will be executed before we return!
 | |
|     ScopedCritical critical;
 | |
|     auto& cur_proc = Processor::current();
 | |
| 
 | |
|     auto* entry = cur_proc.deferred_call_get_free();
 | |
|     entry->have_data = false;
 | |
|     entry->callback.handler = callback;
 | |
| 
 | |
|     cur_proc.deferred_call_queue_entry(entry);
 | |
| }
 | |
| 
 | |
| void Processor::deferred_call_queue(void (*callback)(void*), void* data, void (*free_data)(void*))
 | |
| {
 | |
|     // NOTE: If we are called outside of a critical section and outside
 | |
|     // of an irq handler, the function will be executed before we return!
 | |
|     ScopedCritical critical;
 | |
|     auto& cur_proc = Processor::current();
 | |
| 
 | |
|     auto* entry = cur_proc.deferred_call_get_free();
 | |
|     entry->have_data = true;
 | |
|     entry->callback_with_data.handler = callback;
 | |
|     entry->callback_with_data.data = data;
 | |
|     entry->callback_with_data.free = free_data;
 | |
| 
 | |
|     cur_proc.deferred_call_queue_entry(entry);
 | |
| }
 | |
| 
 | |
| void Processor::gdt_init()
 | |
| {
 | |
|     m_gdt_length = 0;
 | |
|     m_gdtr.address = nullptr;
 | |
|     m_gdtr.limit = 0;
 | |
| 
 | |
|     write_raw_gdt_entry(0x0000, 0x00000000, 0x00000000);
 | |
|     write_raw_gdt_entry(GDT_SELECTOR_CODE0, 0x0000ffff, 0x00cf9a00); // code0
 | |
|     write_raw_gdt_entry(GDT_SELECTOR_DATA0, 0x0000ffff, 0x00cf9200); // data0
 | |
|     write_raw_gdt_entry(GDT_SELECTOR_CODE3, 0x0000ffff, 0x00cffa00); // code3
 | |
|     write_raw_gdt_entry(GDT_SELECTOR_DATA3, 0x0000ffff, 0x00cff200); // data3
 | |
| 
 | |
|     Descriptor tls_descriptor;
 | |
|     tls_descriptor.low = tls_descriptor.high = 0;
 | |
|     tls_descriptor.dpl = 3;
 | |
|     tls_descriptor.segment_present = 1;
 | |
|     tls_descriptor.granularity = 0;
 | |
|     tls_descriptor.zero = 0;
 | |
|     tls_descriptor.operation_size = 1;
 | |
|     tls_descriptor.descriptor_type = 1;
 | |
|     tls_descriptor.type = 2;
 | |
|     write_gdt_entry(GDT_SELECTOR_TLS, tls_descriptor); // tls3
 | |
| 
 | |
|     Descriptor fs_descriptor;
 | |
|     fs_descriptor.set_base(this);
 | |
|     fs_descriptor.set_limit(sizeof(Processor));
 | |
|     fs_descriptor.dpl = 0;
 | |
|     fs_descriptor.segment_present = 1;
 | |
|     fs_descriptor.granularity = 0;
 | |
|     fs_descriptor.zero = 0;
 | |
|     fs_descriptor.operation_size = 1;
 | |
|     fs_descriptor.descriptor_type = 1;
 | |
|     fs_descriptor.type = 2;
 | |
|     write_gdt_entry(GDT_SELECTOR_PROC, fs_descriptor); // fs0
 | |
| 
 | |
|     Descriptor tss_descriptor;
 | |
|     tss_descriptor.set_base(&m_tss);
 | |
|     tss_descriptor.set_limit(sizeof(TSS32));
 | |
|     tss_descriptor.dpl = 0;
 | |
|     tss_descriptor.segment_present = 1;
 | |
|     tss_descriptor.granularity = 0;
 | |
|     tss_descriptor.zero = 0;
 | |
|     tss_descriptor.operation_size = 1;
 | |
|     tss_descriptor.descriptor_type = 0;
 | |
|     tss_descriptor.type = 9;
 | |
|     write_gdt_entry(GDT_SELECTOR_TSS, tss_descriptor); // tss
 | |
| 
 | |
|     flush_gdt();
 | |
|     load_task_register(GDT_SELECTOR_TSS);
 | |
| 
 | |
|     asm volatile(
 | |
|         "mov %%ax, %%ds\n"
 | |
|         "mov %%ax, %%es\n"
 | |
|         "mov %%ax, %%gs\n"
 | |
|         "mov %%ax, %%ss\n" ::"a"(GDT_SELECTOR_DATA0)
 | |
|         : "memory");
 | |
|     set_fs(GDT_SELECTOR_PROC);
 | |
| 
 | |
|     // Make sure CS points to the kernel code descriptor.
 | |
|     asm volatile(
 | |
|         "ljmpl $" __STRINGIFY(GDT_SELECTOR_CODE0) ", $sanity\n"
 | |
|         "sanity:\n");
 | |
| }
 | |
| 
 | |
| void Processor::set_thread_specific(u8* data, size_t len)
 | |
| {
 | |
|     auto& descriptor = get_gdt_entry(GDT_SELECTOR_TLS);
 | |
|     descriptor.set_base(data);
 | |
|     descriptor.set_limit(len);
 | |
| }
 | |
| 
 | |
| }
 | |
| 
 | |
| #ifdef DEBUG
 | |
| void __assertion_failed(const char* msg, const char* file, unsigned line, const char* func)
 | |
| {
 | |
|     asm volatile("cli");
 | |
|     klog() << "ASSERTION FAILED: " << msg << "\n"
 | |
|            << file << ":" << line << " in " << func;
 | |
| 
 | |
|     // Switch back to the current process's page tables if there are any.
 | |
|     // Otherwise stack walking will be a disaster.
 | |
|     auto process = Process::current();
 | |
|     if (process)
 | |
|         MM.enter_process_paging_scope(*process);
 | |
| 
 | |
|     Kernel::dump_backtrace();
 | |
|     Processor::halt();
 | |
| }
 | |
| #endif
 | |
| 
 | |
| NonMaskableInterruptDisabler::NonMaskableInterruptDisabler()
 | |
| {
 | |
|     IO::out8(0x70, IO::in8(0x70) | 0x80);
 | |
| }
 | |
| 
 | |
| NonMaskableInterruptDisabler::~NonMaskableInterruptDisabler()
 | |
| {
 | |
|     IO::out8(0x70, IO::in8(0x70) & 0x7F);
 | |
| }
 |