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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 <exception.h>
#include <libpayload.h>
#include <stdint.h>
uint8_t exception_stack[0x1000] __attribute__((aligned(8)));
extern void *exception_stack_end;
struct exception_state
{
u32 eax;
u32 ecx;
u32 edx;
u32 ebx;
u32 esp;
u32 ebp;
u32 esi;
u32 edi;
u32 eip;
u32 eflags;
u32 cs;
u32 ss;
u32 ds;
u32 es;
u32 fs;
u32 gs;
u32 error_code;
u32 vector;
} __attribute__((packed));
struct exception_info
{
const char *name;
void (*error_code_printer)(u32 code);
};
static void print_segment_error_code(u32 code)
{
printf("%#x - descriptor %#x in the ", code, (code >> 3) & 0x1f);
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 struct exception_info exceptions[] = {
[0] = { .name = "divide by zero" },
[1] = { .name = "debug" },
[2] = { .name = "non-maskable-interrupt" },
[3] = { .name = "breakpoint" },
[4] = { .name = "overflow" },
[5] = { .name = "bound range" },
[6] = { .name = "invalid opcode" },
[7] = { .name = "device not available" },
[8] = { .name = "double fault",
.error_code_printer = &print_raw_error_code },
[10] = { .name = "invalid tss",
.error_code_printer = &print_segment_error_code },
[11] = { .name = "segment not present",
.error_code_printer = &print_segment_error_code },
[12] = { .name = "stack",
.error_code_printer = &print_segment_error_code },
[13] = { .name = "general protection",
.error_code_printer = &print_segment_error_code },
[14] = { .name = "page fault",
.error_code_printer = &print_page_fault_error_code },
[16] = { .name = "x87 floating point" },
[17] = { .name = "alignment check",
.error_code_printer = &print_raw_error_code },
[18] = { .name = "machine check" },
[19] = { .name = "SIMD floating point" },
[30] = { .name = "security",
.error_code_printer = &print_raw_error_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");
}
}
void exception_handler(void);
void exception_handler(void)
{
struct exception_state *state =
(void *)((u8 *)exception_stack_end - sizeof(*state));
struct exception_info *info = NULL;
if (state->vector < ARRAY_SIZE(exceptions))
info = &exceptions[state->vector];
if (info)
printf("Exception %d (%s)\n", state->vector, info->name);
else
printf("Unrecognized exception %d\n", state->vector);
if (info->error_code_printer) {
printf("Error code: ");
info->error_code_printer(state->error_code);
printf("\n");
}
printf("EIP: 0x%08x\n", state->eip);
printf("CS: 0x%04x\n", state->cs);
printf("EFLAGS: 0x%08x\n", state->eflags);
printf("EAX: 0x%08x\n", state->eax);
printf("ECX: 0x%08x\n", state->ecx);
printf("EDX: 0x%08x\n", state->edx);
printf("EBX: 0x%08x\n", state->ebx);
printf("ESP: 0x%08x\n", state->esp);
printf("EBP: 0x%08x\n", state->ebp);
printf("ESI: 0x%08x\n", state->esi);
printf("EDI: 0x%08x\n", state->edi);
printf("DS: 0x%04x\n", state->ds);
printf("ES: 0x%04x\n", state->es);
printf("SS: 0x%04x\n", state->ss);
printf("FS: 0x%04x\n", state->fs);
printf("GS: 0x%04x\n", state->gs);
dump_stack(state->esp, 512);
halt();
}
void exception_init_asm(void);
void exception_init(void)
{
exception_stack_end = exception_stack + sizeof(exception_stack);
exception_init_asm();
}
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