/* Copyright (c) 2011-2018, Scott Tsai * * All rights reserved. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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. */ #ifndef DEBUG_BREAK_H #ifdef _MSC_VER #define debug_break __debugbreak #else #ifdef __cplusplus extern "C" { #endif #define DEBUG_BREAK_USE_TRAP_INSTRUCTION 1 #define DEBUG_BREAK_USE_BULTIN_TRAP 2 #define DEBUG_BREAK_USE_SIGTRAP 3 #if defined(__i386__) || defined(__x86_64__) #define DEBUG_BREAK_IMPL DEBUG_BREAK_USE_TRAP_INSTRUCTION __inline__ static void trap_instruction(void) { __asm__ volatile("int $0x03"); } #elif defined(__thumb__) #define DEBUG_BREAK_IMPL DEBUG_BREAK_USE_TRAP_INSTRUCTION /* FIXME: handle __THUMB_INTERWORK__ */ __attribute__((gnu_inline, always_inline)) __inline__ static void trap_instruction(void) { /* See 'arm-linux-tdep.c' in GDB source. * Both instruction sequences below work. */ #if 1 /* 'eabi_linux_thumb_le_breakpoint' */ __asm__ volatile(".inst 0xde01"); #else /* 'eabi_linux_thumb2_le_breakpoint' */ __asm__ volatile(".inst.w 0xf7f0a000"); #endif /* Known problem: * After a breakpoint hit, can't 'stepi', 'step', or 'continue' in GDB. * 'step' would keep getting stuck on the same instruction. * * Workaround: use the new GDB commands 'debugbreak-step' and * 'debugbreak-continue' that become available * after you source the script from GDB: * * $ gdb -x debugbreak-gdb.py <... USUAL ARGUMENTS ...> * * 'debugbreak-step' would jump over the breakpoint instruction with * roughly equivalent of: * (gdb) set $instruction_len = 2 * (gdb) tbreak *($pc + $instruction_len) * (gdb) jump *($pc + $instruction_len) */ } #elif defined(__arm__) && !defined(__thumb__) #define DEBUG_BREAK_IMPL DEBUG_BREAK_USE_TRAP_INSTRUCTION __attribute__((gnu_inline, always_inline)) __inline__ static void trap_instruction(void) { /* See 'arm-linux-tdep.c' in GDB source, * 'eabi_linux_arm_le_breakpoint' */ __asm__ volatile(".inst 0xe7f001f0"); /* Known problem: * Same problem and workaround as Thumb mode */ } #elif defined(__aarch64__) && defined(__APPLE__) #define DEBUG_BREAK_IMPL DEBUG_BREAK_USE_BULTIN_TRAP #elif defined(__aarch64__) #define DEBUG_BREAK_IMPL DEBUG_BREAK_USE_TRAP_INSTRUCTION __attribute__((gnu_inline, always_inline)) __inline__ static void trap_instruction(void) { /* See 'aarch64-tdep.c' in GDB source, * 'aarch64_default_breakpoint' */ __asm__ volatile(".inst 0xd4200000"); } #elif defined(__powerpc__) /* PPC 32 or 64-bit, big or little endian */ #define DEBUG_BREAK_IMPL DEBUG_BREAK_USE_TRAP_INSTRUCTION __attribute__((gnu_inline, always_inline)) __inline__ static void trap_instruction(void) { /* See 'rs6000-tdep.c' in GDB source, * 'rs6000_breakpoint' */ __asm__ volatile(".4byte 0x7d821008"); /* Known problem: * After a breakpoint hit, can't 'stepi', 'step', or 'continue' in GDB. * 'step' stuck on the same instruction ("twge r2,r2"). * * The workaround is the same as ARM Thumb mode: use debugbreak-gdb.py * or manually jump over the instruction. */ } #else #define DEBUG_BREAK_IMPL DEBUG_BREAK_USE_SIGTRAP #endif #ifndef DEBUG_BREAK_IMPL #error "debugbreak.h is not supported on this target" #elif DEBUG_BREAK_IMPL == DEBUG_BREAK_USE_TRAP_INSTRUCTION __attribute__((gnu_inline, always_inline)) __inline__ static void debug_break(void) { trap_instruction(); } #elif DEBUG_BREAK_IMPL == DEBUG_BREAK_USE_BULTIN_TRAP __attribute__((gnu_inline, always_inline)) __inline__ static void debug_break(void) { __builtin_trap(); } #elif DEBUG_BREAK_IMPL == DEBUG_BREAK_USE_SIGTRAP #include <signal.h> __attribute__((gnu_inline, always_inline)) __inline__ static void debug_break(void) { raise(SIGTRAP); } #else #error "invalid DEBUG_BREAK_IMPL value" #endif #ifdef __cplusplus } #endif #endif /* ifdef _MSC_VER */ #endif /* ifndef DEBUG_BREAK_H */