/* * 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)); }