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/*
* This file is part of the libpayload project.
*
* Copyright 2013 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' 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 AUTHOR 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.
*/
#include <arch/exception.h>
#include <exception.h>
#include <libpayload.h>
#include <stdint.h>
#include <arch/apic.h>
#define IF_FLAG (1 << 9)
/*
* Local and I/O APICs support 240 vectors (in the range of 16 to 255) as valid
* interrupts. The Intel 64 and IA-32 architectures reserve vectors 16
* through 31 for predefined interrupts, exceptions, and Intel-reserved
* encodings.
*/
#define FIRST_USER_DEFINED_VECTOR 32
u32 exception_stack[0x400] __attribute__((aligned(8)));
static exception_hook hook;
static interrupt_handler handlers[256];
static const char *names[EXC_COUNT] = {
[EXC_DE] = "Divide by Zero",
[EXC_DB] = "Debug",
[EXC_NMI] = "Non-Maskable-Interrupt",
[EXC_BP] = "Breakpoint",
[EXC_OF] = "Overflow",
[EXC_BR] = "Bound Range",
[EXC_UD] = "Invalid Opcode",
[EXC_NM] = "Device Not Available",
[EXC_DF] = "Double Fault",
[EXC_TS] = "Invalid TSS",
[EXC_NP] = "Segment Not Present",
[EXC_SS] = "Stack Fault",
[EXC_GP] = "General Protection Fault",
[EXC_PF] = "Page Fault",
[EXC_MF] = "x87 Floating Point",
[EXC_AC] = "Alignment Check",
[EXC_MC] = "Machine Check",
[EXC_XF] = "SIMD Floating Point",
[EXC_SX] = "Security",
};
static void print_segment_error_code(u32 code)
{
printf("%#x - descriptor %#x in the ", code, (code >> 3) & 0x1FFF);
if (code & (0x1 << 1)) {
printf("IDT");
} else {
if (code & 0x04)
printf("LDT");
else
printf("GDT");
}
if (code & (0x1 << 0))
printf(", external to the CPU");
else
printf(", internal to the CPU");
}
static void print_page_fault_error_code(u32 code)
{
printf("%#x -", code);
if (code & (0x1 << 0))
printf(" page protection");
else
printf(" page not present");
if (code & (0x1 << 1))
printf(", write");
else
printf(", read");
if (code & (0x1 << 2))
printf(", user");
else
printf(", supervisor");
if (code & (0x1 << 3))
printf(", reserved bits set");
if (code & (0x1 << 4))
printf(", instruction fetch");
}
static void print_raw_error_code(u32 code)
{
printf("%#x", code);
}
static void dump_stack(uintptr_t addr, size_t bytes)
{
int i, j;
const int line = 8;
uint32_t *ptr = (uint32_t *)(addr & ~(line * sizeof(*ptr) - 1));
printf("Dumping stack:\n");
for (i = bytes / sizeof(*ptr); i >= 0; i -= line) {
printf("%p: ", ptr + i);
for (j = i; j < i + line; j++)
printf("%08x ", *(ptr + j));
printf("\n");
}
}
static void dump_exception_state(void)
{
printf("%s Exception\n", names[exception_state->vector]);
printf("Error code: ");
switch (exception_state->vector) {
case EXC_PF:
print_page_fault_error_code(exception_state->error_code);
break;
case EXC_TS:
case EXC_NP:
case EXC_SS:
case EXC_GP:
print_segment_error_code(exception_state->error_code);
break;
case EXC_DF:
case EXC_AC:
case EXC_SX:
print_raw_error_code(exception_state->error_code);
break;
default:
printf("n/a");
break;
}
printf("\n");
printf("EIP: 0x%08x\n", exception_state->regs.eip);
printf("CS: 0x%04x\n", exception_state->regs.cs);
printf("EFLAGS: 0x%08x\n", exception_state->regs.eflags);
printf("EAX: 0x%08x\n", exception_state->regs.eax);
printf("ECX: 0x%08x\n", exception_state->regs.ecx);
printf("EDX: 0x%08x\n", exception_state->regs.edx);
printf("EBX: 0x%08x\n", exception_state->regs.ebx);
printf("ESP: 0x%08x\n", exception_state->regs.esp);
printf("EBP: 0x%08x\n", exception_state->regs.ebp);
printf("ESI: 0x%08x\n", exception_state->regs.esi);
printf("EDI: 0x%08x\n", exception_state->regs.edi);
printf("DS: 0x%04x\n", exception_state->regs.ds);
printf("ES: 0x%04x\n", exception_state->regs.es);
printf("SS: 0x%04x\n", exception_state->regs.ss);
printf("FS: 0x%04x\n", exception_state->regs.fs);
printf("GS: 0x%04x\n", exception_state->regs.gs);
}
void exception_dispatch(void)
{
u32 vec = exception_state->vector;
die_if(vec >= ARRAY_SIZE(handlers), "Invalid vector %u\n", vec);
if (handlers[vec]) {
handlers[vec](vec);
if (IS_ENABLED(CONFIG_LP_ENABLE_APIC)
&& vec >= FIRST_USER_DEFINED_VECTOR)
apic_eoi();
return;
}
die_if(vec >= EXC_COUNT || !names[vec], "Bad exception vector %u\n",
vec);
if (hook && hook(vec))
return;
dump_exception_state();
dump_stack(exception_state->regs.esp, 512);
halt();
}
void exception_init(void)
{
exception_stack_end = exception_stack + ARRAY_SIZE(exception_stack);
exception_init_asm();
}
void exception_install_hook(exception_hook h)
{
die_if(hook, "Implement support for a list of hooks if you need it.");
hook = h;
}
void set_interrupt_handler(u8 vector, interrupt_handler handler)
{
handlers[vector] = handler;
}
static uint32_t eflags(void)
{
uint32_t eflags;
asm volatile(
"pushf\n\t"
"pop %0\n\t"
: "=rm" (eflags));
return eflags;
}
void enable_interrupts(void)
{
asm volatile (
"sti\n"
: : : "cc"
);
}
void disable_interrupts(void)
{
asm volatile (
"cli\n"
: : : "cc"
);
}
int interrupts_enabled(void)
{
return !!(eflags() & IF_FLAG);
}
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