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/*
* Copyright 2014 Google Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but without any warranty; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <exception.h>
#include <gdb.h>
#include <libpayload.h>
static const u8 type_to_signal[] = {
[EXC_DE] = GDB_SIGFPE,
[EXC_DB] = GDB_SIGTRAP,
[EXC_NMI] = GDB_SIGKILL,
[EXC_BP] = GDB_SIGTRAP,
[EXC_OF] = GDB_SIGFPE,
[EXC_BR] = GDB_SIGSEGV,
[EXC_UD] = GDB_SIGILL,
[EXC_NM] = GDB_SIGEMT,
[EXC_DF] = GDB_SIGKILL,
[EXC_TS] = GDB_SIGSEGV,
[EXC_NP] = GDB_SIGSEGV,
[EXC_SS] = GDB_SIGBUS,
[EXC_GP] = GDB_SIGSEGV,
[EXC_PF] = GDB_SIGSEGV,
[EXC_MF] = GDB_SIGEMT,
[EXC_AC] = GDB_SIGBUS,
[EXC_MC] = GDB_SIGKILL,
[EXC_XF] = GDB_SIGFPE,
[EXC_SX] = GDB_SIGFPE,
};
static int gdb_exception_hook(u32 type)
{
if (type >= ARRAY_SIZE(type_to_signal) || !type_to_signal[type])
return 0;
gdb_command_loop(type_to_signal[type]);
return 1;
}
void gdb_arch_init(void)
{
exception_install_hook(&gdb_exception_hook);
}
void gdb_arch_enter(void)
{
u32 *esp;
asm volatile ("mov %%esp, %0" : "=r"(esp) );
/* Avoid reentrant exceptions, just call the hook if in one already. */
if (esp >= exception_stack && esp <= exception_stack_end)
gdb_exception_hook(EXC_BP);
else
asm volatile ("int3");
}
int gdb_arch_set_single_step(int on)
{
const u32 tf_bit = 1 << 8;
if (on)
exception_state->regs.eflags |= tf_bit;
else
exception_state->regs.eflags &= ~tf_bit;
return 0;
}
void gdb_arch_encode_regs(struct gdb_message *message)
{
gdb_message_encode_bytes(message, &exception_state->regs,
sizeof(exception_state->regs));
}
void gdb_arch_decode_regs(int offset, struct gdb_message *message)
{
gdb_message_decode_bytes(message, offset, &exception_state->regs,
sizeof(exception_state->regs));
}
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