X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Finterrupt.c;h=c6ca2bd0060339b19aa38d92655564a4869878e1;hb=f0ad7eb8b43516c7a2999fd217ec85d954dfc791;hp=7559447307db9ee59f672bf042e7e5f88a5b868c;hpb=c9c283cb3e26a5b6d918ee47dcf8efe28522b18d;p=pintos-anon diff --git a/src/threads/interrupt.c b/src/threads/interrupt.c index 7559447..c6ca2bd 100644 --- a/src/threads/interrupt.c +++ b/src/threads/interrupt.c @@ -1,14 +1,14 @@ -#include "interrupt.h" +#include "threads/interrupt.h" +#include #include #include -#include "intr-stubs.h" -#include "debug.h" -#include "gdt.h" -#include "io.h" -#include "lib.h" -#include "mmu.h" -#include "thread.h" -#include "timer.h" +#include +#include "threads/flags.h" +#include "threads/intr-stubs.h" +#include "threads/io.h" +#include "threads/mmu.h" +#include "threads/thread.h" +#include "devices/timer.h" /* Number of x86 interrupts. */ #define INTR_CNT 256 @@ -40,19 +40,21 @@ static void pic_end_of_interrupt (int irq); /* Interrupt Descriptor Table helpers. */ static uint64_t make_intr_gate (void (*) (void), int dpl); static uint64_t make_trap_gate (void (*) (void), int dpl); +static inline uint64_t make_idtr_operand (uint16_t limit, void *base); /* Interrupt handlers. */ void intr_handler (struct intr_frame *args); -static intr_handler_func panic NO_RETURN; -static intr_handler_func kill NO_RETURN; /* Returns the current interrupt status. */ enum intr_level intr_get_level (void) { uint32_t flags; - - asm ("pushfl; popl %0" : "=g" (flags)); + + /* Push the flags register on the processor stack, then pop the + value off the stack into `flags'. See [IA32-v2b] "PUSHF" + and "POP" and [IA32-v3] 5.8.1. */ + asm volatile ("pushfl; popl %0" : "=g" (flags)); return flags & FLAG_IF ? INTR_ON : INTR_OFF; } @@ -70,7 +72,12 @@ enum intr_level intr_enable (void) { enum intr_level old_level = intr_get_level (); + ASSERT (!intr_context ()); + + /* Enable interrupts by setting the interrupt flag. + See [IA32-v2b] "STI" and [IA32-v3] 5.8.1. */ asm volatile ("sti"); + return old_level; } @@ -79,7 +86,11 @@ enum intr_level intr_disable (void) { enum intr_level old_level = intr_get_level (); + + /* Disable interrupts by clearing the interrupt flag. + See [IA32-v2b] "CLI" and [IA32-v3] 5.8.1. */ asm volatile ("cli"); + return old_level; } @@ -90,40 +101,40 @@ intr_init (void) uint64_t idtr_operand; int i; + /* Initialize interrupt controller. */ pic_init (); - /* Initialize intr_names. */ + /* Initialize IDT. */ for (i = 0; i < INTR_CNT; i++) - intr_names[i] = "unknown"; + idt[i] = make_intr_gate (intr_stubs[i], 0); - /* Most exceptions require ring 0. - Exceptions 3, 4, and 5 can be caused by ring 3 directly. */ - intr_register (0, 0, INTR_ON, kill, "#DE Divide Error"); - intr_register (1, 0, INTR_ON, kill, "#DB Debug Exception"); - intr_register (2, 0, INTR_ON, panic, "NMI Interrupt"); - intr_register (3, 3, INTR_ON, kill, "#BP Breakpoint Exception"); - intr_register (4, 3, INTR_ON, kill, "#OF Overflow Exception"); - intr_register (5, 3, INTR_ON, kill, "#BR BOUND Range Exceeded Exception"); - intr_register (6, 0, INTR_ON, kill, "#UD Invalid Opcode Exception"); - intr_register (7, 0, INTR_ON, kill, "#NM Device Not Available Exception"); - intr_register (8, 0, INTR_ON, panic, "#DF Double Fault Exception"); - intr_register (9, 0, INTR_ON, panic, "Coprocessor Segment Overrun"); - intr_register (10, 0, INTR_ON, panic, "#TS Invalid TSS Exception"); - intr_register (11, 0, INTR_ON, kill, "#NP Segment Not Present"); - intr_register (12, 0, INTR_ON, kill, "#SS Stack Fault Exception"); - intr_register (13, 0, INTR_ON, kill, "#GP General Protection Exception"); - intr_register (16, 0, INTR_ON, kill, "#MF x87 FPU Floating-Point Error"); - intr_register (17, 0, INTR_ON, panic, "#AC Alignment Check Exception"); - intr_register (18, 0, INTR_ON, panic, "#MC Machine-Check Exception"); - intr_register (19, 0, INTR_ON, kill, "#XF SIMD Floating-Point Exception"); - - /* Most exceptions can be handled with interrupts turned on. - We need to disable interrupts for page faults because the - fault address is stored in CR2 and needs to be preserved. */ - intr_register (14, 0, INTR_OFF, kill, "#PF Page-Fault Exception"); - - idtr_operand = make_dtr_operand (sizeof idt - 1, idt); + /* Load IDT register. + See [IA32-v2a] "LIDT" and [IA32-v3] 5.10. */ + idtr_operand = make_idtr_operand (sizeof idt - 1, idt); asm volatile ("lidt %0" :: "m" (idtr_operand)); + + /* Initialize intr_names. */ + for (i = 0; i < INTR_CNT; i++) + intr_names[i] = "unknown"; + intr_names[0] = "#DE Divide Error"; + intr_names[1] = "#DB Debug Exception"; + intr_names[2] = "NMI Interrupt"; + intr_names[3] = "#BP Breakpoint Exception"; + intr_names[4] = "#OF Overflow Exception"; + intr_names[5] = "#BR BOUND Range Exceeded Exception"; + intr_names[6] = "#UD Invalid Opcode Exception"; + intr_names[7] = "#NM Device Not Available Exception"; + intr_names[8] = "#DF Double Fault Exception"; + intr_names[9] = "Coprocessor Segment Overrun"; + intr_names[10] = "#TS Invalid TSS Exception"; + intr_names[11] = "#NP Segment Not Present"; + intr_names[12] = "#SS Stack Fault Exception"; + intr_names[13] = "#GP General Protection Exception"; + intr_names[14] = "#PF Page-Fault Exception"; + intr_names[16] = "#MF x87 FPU Floating-Point Error"; + intr_names[17] = "#AC Alignment Check Exception"; + intr_names[18] = "#MC Machine-Check Exception"; + intr_names[19] = "#XF SIMD Floating-Point Exception"; } /* Registers interrupt VEC_NO to invoke HANDLER, which is named @@ -286,22 +297,32 @@ make_trap_gate (void (*function) (void), int dpl) { return make_gate (function, dpl, 15); } + +/* Returns a descriptor that yields the given LIMIT and BASE when + used as an operand for the LIDT instruction. */ +static inline uint64_t +make_idtr_operand (uint16_t limit, void *base) +{ + return limit | ((uint64_t) (uint32_t) base << 16); +} /* Interrupt handlers. */ -static void dump_intr_frame (struct intr_frame *); - /* Handler for all interrupts, faults, and exceptions. This function is called by the assembly language interrupt stubs in - intr-stubs.S (see intr-stubs.pl). ARGS describes the + intr-stubs.S (see intr-stubs.pl). FRAME describes the interrupt and the interrupted thread's registers. */ void -intr_handler (struct intr_frame *args) +intr_handler (struct intr_frame *frame) { bool external; intr_handler_func *handler; - external = args->vec_no >= 0x20 && args->vec_no < 0x30; + /* External interrupts are special. + We only handle one at a time (so interrupts must be off) + and they need to be acknowledged on the PIC (see below). + An external interrupt handler cannot sleep. */ + external = frame->vec_no >= 0x20 && frame->vec_no < 0x30; if (external) { ASSERT (intr_get_level () == INTR_OFF); @@ -314,10 +335,13 @@ intr_handler (struct intr_frame *args) /* Invoke the interrupt's handler. If there is no handler, invoke the unexpected interrupt handler. */ - handler = intr_handlers[args->vec_no]; + handler = intr_handlers[frame->vec_no]; if (handler == NULL) - handler = panic; - handler (args); + { + intr_dump_frame (frame); + PANIC ("Unexpected interrupt"); + } + handler (frame); /* Complete the processing of an external interrupt. */ if (external) @@ -326,78 +350,40 @@ intr_handler (struct intr_frame *args) ASSERT (intr_context ()); in_external_intr = false; - pic_end_of_interrupt (args->vec_no); + pic_end_of_interrupt (frame->vec_no); if (yield_on_return) thread_yield (); } } -/* Handler for an interrupt that should not have been invoked. */ -static void -panic (struct intr_frame *regs) -{ - dump_intr_frame (regs); - PANIC ("Panic!"); -} - -/* Handler for an exception (probably) caused by a user process. */ -static void -kill (struct intr_frame *f) -{ - /* This interrupt is one (probably) caused by a user process. - For example, the process might have tried to access unmapped - virtual memory (a page fault). For now, we simply kill the - user process. Later, we'll want to handle page faults in - the kernel. Real Unix-like operating systems pass most - exceptions back to the process via signals, but we don't - implement them. */ - - /* The interrupt frame's code segment value tells us where the - exception originated. */ - switch (f->cs) - { - case SEL_UCSEG: - /* User's code segment, so it's a user exception, as we - expected. */ - printk ("%s: dying due to interrupt %#04x (%s).\n", - thread_name (thread_current ()), - f->vec_no, intr_names[f->vec_no]); - dump_intr_frame (f); - thread_exit (); - - case SEL_KCSEG: - /* Kernel's code segment, which indicates a kernel bug. - Kernel code shouldn't throw exceptions. (Page faults - may cause kernel exceptions--but they shouldn't arrive - here.) */ - printk ("Kernel bug - unexpected interrupt in kernel\n"); - panic (f); - - default: - /* Some other code segment? Shouldn't happen. */ - printk ("Interrupt %#04x (%s) in unknown segment %04x\n", - f->vec_no, intr_names[f->vec_no], f->cs); - thread_exit (); - } -} - /* Dumps interrupt frame F to the console, for debugging. */ -static void -dump_intr_frame (struct intr_frame *f) +void +intr_dump_frame (const struct intr_frame *f) { - uint32_t cr2, ss; + uint32_t cr2; + + /* Store current value of CR2 into `cr2'. + CR2 is the linear address of the last page fault. + See [IA32-v2a] "MOV--Move to/from Control Registers" and + [IA32-v3] 5.14 "Interrupt 14--Page Fault Exception + (#PF)". */ asm ("movl %%cr2, %0" : "=r" (cr2)); - asm ("movl %%ss, %0" : "=r" (ss)); - printk ("Interrupt %#04x (%s) at eip=%p\n", + printf ("Interrupt %#04x (%s) at eip=%p\n", f->vec_no, intr_names[f->vec_no], f->eip); - printk (" cr2=%08"PRIx32" error=%08"PRIx32"\n", cr2, f->error_code); - printk (" eax=%08"PRIx32" ebx=%08"PRIx32" ecx=%08"PRIx32" edx=%08"PRIx32"\n", + printf (" cr2=%08"PRIx32" error=%08"PRIx32"\n", cr2, f->error_code); + printf (" eax=%08"PRIx32" ebx=%08"PRIx32" ecx=%08"PRIx32" edx=%08"PRIx32"\n", f->eax, f->ebx, f->ecx, f->edx); - printk (" esi=%08"PRIx32" edi=%08"PRIx32" esp=%08"PRIx32" ebp=%08"PRIx32"\n", + printf (" esi=%08"PRIx32" edi=%08"PRIx32" esp=%08"PRIx32" ebp=%08"PRIx32"\n", f->esi, f->edi, (uint32_t) f->esp, f->ebp); - printk (" cs=%04"PRIx16" ds=%04"PRIx16" es=%04"PRIx16" ss=%04"PRIx16"\n", - f->cs, f->ds, f->es, f->cs != SEL_KCSEG ? f->ss : ss); + printf (" cs=%04"PRIx16" ds=%04"PRIx16" es=%04"PRIx16" ss=%04"PRIx16"\n", + f->cs, f->ds, f->es, f->ss); } +/* Returns the name of interrupt VEC. */ +const char * +intr_name (uint8_t vec) +{ + return intr_names[vec]; +}