1 /* 2 * This provides the callbacks and functions that KGDB needs to share between 3 * the core, I/O and arch-specific portions. 4 * 5 * Author: Amit Kale <amitkale@linsyssoft.com> and 6 * Tom Rini <trini@kernel.crashing.org> 7 * 8 * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc. 9 * This file is licensed under the terms of the GNU General Public License 10 * version 2. This program is licensed "as is" without any warranty of any 11 * kind, whether express or implied. 12 */ 13 #ifndef _KGDB_H_ 14 #define _KGDB_H_ 15 16 #include <linux/linkage.h> 17 #include <linux/init.h> 18 #include <linux/atomic.h> 19 #ifdef CONFIG_HAVE_ARCH_KGDB 20 #include <asm/kgdb.h> 21 #endif 22 23 #ifdef CONFIG_KGDB 24 struct pt_regs; 25 26 /** 27 * kgdb_skipexception - (optional) exit kgdb_handle_exception early 28 * @exception: Exception vector number 29 * @regs: Current &struct pt_regs. 30 * 31 * On some architectures it is required to skip a breakpoint 32 * exception when it occurs after a breakpoint has been removed. 33 * This can be implemented in the architecture specific portion of kgdb. 34 */ 35 extern int kgdb_skipexception(int exception, struct pt_regs *regs); 36 37 struct tasklet_struct; 38 struct task_struct; 39 struct uart_port; 40 41 /** 42 * kgdb_breakpoint - compiled in breakpoint 43 * 44 * This will be implemented as a static inline per architecture. This 45 * function is called by the kgdb core to execute an architecture 46 * specific trap to cause kgdb to enter the exception processing. 47 * 48 */ 49 void kgdb_breakpoint(void); 50 51 extern int kgdb_connected; 52 extern int kgdb_io_module_registered; 53 54 extern atomic_t kgdb_setting_breakpoint; 55 extern atomic_t kgdb_cpu_doing_single_step; 56 57 extern struct task_struct *kgdb_usethread; 58 extern struct task_struct *kgdb_contthread; 59 60 enum kgdb_bptype { 61 BP_BREAKPOINT = 0, 62 BP_HARDWARE_BREAKPOINT, 63 BP_WRITE_WATCHPOINT, 64 BP_READ_WATCHPOINT, 65 BP_ACCESS_WATCHPOINT, 66 BP_POKE_BREAKPOINT, 67 }; 68 69 enum kgdb_bpstate { 70 BP_UNDEFINED = 0, 71 BP_REMOVED, 72 BP_SET, 73 BP_ACTIVE 74 }; 75 76 struct kgdb_bkpt { 77 unsigned long bpt_addr; 78 unsigned char saved_instr[BREAK_INSTR_SIZE]; 79 enum kgdb_bptype type; 80 enum kgdb_bpstate state; 81 }; 82 83 struct dbg_reg_def_t { 84 char *name; 85 int size; 86 int offset; 87 }; 88 89 #ifndef DBG_MAX_REG_NUM 90 #define DBG_MAX_REG_NUM 0 91 #else 92 extern struct dbg_reg_def_t dbg_reg_def[]; 93 extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs); 94 extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs); 95 #endif 96 #ifndef KGDB_MAX_BREAKPOINTS 97 # define KGDB_MAX_BREAKPOINTS 1000 98 #endif 99 100 #define KGDB_HW_BREAKPOINT 1 101 102 /* 103 * Functions each KGDB-supporting architecture must provide: 104 */ 105 106 /** 107 * kgdb_arch_init - Perform any architecture specific initalization. 108 * 109 * This function will handle the initalization of any architecture 110 * specific callbacks. 111 */ 112 extern int kgdb_arch_init(void); 113 114 /** 115 * kgdb_arch_exit - Perform any architecture specific uninitalization. 116 * 117 * This function will handle the uninitalization of any architecture 118 * specific callbacks, for dynamic registration and unregistration. 119 */ 120 extern void kgdb_arch_exit(void); 121 122 /** 123 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs 124 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 125 * @regs: The &struct pt_regs of the current process. 126 * 127 * Convert the pt_regs in @regs into the format for registers that 128 * GDB expects, stored in @gdb_regs. 129 */ 130 extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs); 131 132 /** 133 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs 134 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 135 * @p: The &struct task_struct of the desired process. 136 * 137 * Convert the register values of the sleeping process in @p to 138 * the format that GDB expects. 139 * This function is called when kgdb does not have access to the 140 * &struct pt_regs and therefore it should fill the gdb registers 141 * @gdb_regs with what has been saved in &struct thread_struct 142 * thread field during switch_to. 143 */ 144 extern void 145 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p); 146 147 /** 148 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. 149 * @gdb_regs: A pointer to hold the registers we've received from GDB. 150 * @regs: A pointer to a &struct pt_regs to hold these values in. 151 * 152 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them 153 * in @regs. 154 */ 155 extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs); 156 157 /** 158 * kgdb_arch_handle_exception - Handle architecture specific GDB packets. 159 * @vector: The error vector of the exception that happened. 160 * @signo: The signal number of the exception that happened. 161 * @err_code: The error code of the exception that happened. 162 * @remcom_in_buffer: The buffer of the packet we have read. 163 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. 164 * @regs: The &struct pt_regs of the current process. 165 * 166 * This function MUST handle the 'c' and 's' command packets, 167 * as well packets to set / remove a hardware breakpoint, if used. 168 * If there are additional packets which the hardware needs to handle, 169 * they are handled here. The code should return -1 if it wants to 170 * process more packets, and a %0 or %1 if it wants to exit from the 171 * kgdb callback. 172 */ 173 extern int 174 kgdb_arch_handle_exception(int vector, int signo, int err_code, 175 char *remcom_in_buffer, 176 char *remcom_out_buffer, 177 struct pt_regs *regs); 178 179 /** 180 * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU 181 * @ignored: This parameter is only here to match the prototype. 182 * 183 * If you're using the default implementation of kgdb_roundup_cpus() 184 * this function will be called per CPU. If you don't implement 185 * kgdb_call_nmi_hook() a default will be used. 186 */ 187 188 extern void kgdb_call_nmi_hook(void *ignored); 189 190 /** 191 * kgdb_roundup_cpus - Get other CPUs into a holding pattern 192 * 193 * On SMP systems, we need to get the attention of the other CPUs 194 * and get them into a known state. This should do what is needed 195 * to get the other CPUs to call kgdb_wait(). Note that on some arches, 196 * the NMI approach is not used for rounding up all the CPUs. Normally 197 * those architectures can just not implement this and get the default. 198 * 199 * On non-SMP systems, this is not called. 200 */ 201 extern void kgdb_roundup_cpus(void); 202 203 /** 204 * kgdb_arch_set_pc - Generic call back to the program counter 205 * @regs: Current &struct pt_regs. 206 * @pc: The new value for the program counter 207 * 208 * This function handles updating the program counter and requires an 209 * architecture specific implementation. 210 */ 211 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); 212 213 214 /* Optional functions. */ 215 extern int kgdb_validate_break_address(unsigned long addr); 216 extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt); 217 extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt); 218 219 /** 220 * kgdb_arch_late - Perform any architecture specific initalization. 221 * 222 * This function will handle the late initalization of any 223 * architecture specific callbacks. This is an optional function for 224 * handling things like late initialization of hw breakpoints. The 225 * default implementation does nothing. 226 */ 227 extern void kgdb_arch_late(void); 228 229 230 /** 231 * struct kgdb_arch - Describe architecture specific values. 232 * @gdb_bpt_instr: The instruction to trigger a breakpoint. 233 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. 234 * @set_breakpoint: Allow an architecture to specify how to set a software 235 * breakpoint. 236 * @remove_breakpoint: Allow an architecture to specify how to remove a 237 * software breakpoint. 238 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware 239 * breakpoint. 240 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a 241 * hardware breakpoint. 242 * @disable_hw_break: Allow an architecture to specify how to disable 243 * hardware breakpoints for a single cpu. 244 * @remove_all_hw_break: Allow an architecture to specify how to remove all 245 * hardware breakpoints. 246 * @correct_hw_break: Allow an architecture to specify how to correct the 247 * hardware debug registers. 248 * @enable_nmi: Manage NMI-triggered entry to KGDB 249 */ 250 struct kgdb_arch { 251 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; 252 unsigned long flags; 253 254 int (*set_breakpoint)(unsigned long, char *); 255 int (*remove_breakpoint)(unsigned long, char *); 256 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 257 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 258 void (*disable_hw_break)(struct pt_regs *regs); 259 void (*remove_all_hw_break)(void); 260 void (*correct_hw_break)(void); 261 262 void (*enable_nmi)(bool on); 263 }; 264 265 /** 266 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. 267 * @name: Name of the I/O driver. 268 * @read_char: Pointer to a function that will return one char. 269 * @write_char: Pointer to a function that will write one char. 270 * @flush: Pointer to a function that will flush any pending writes. 271 * @init: Pointer to a function that will initialize the device. 272 * @deinit: Pointer to a function that will deinit the device. Implies that 273 * this I/O driver is temporary and expects to be replaced. Called when 274 * an I/O driver is replaced or explicitly unregistered. 275 * @pre_exception: Pointer to a function that will do any prep work for 276 * the I/O driver. 277 * @post_exception: Pointer to a function that will do any cleanup work 278 * for the I/O driver. 279 * @is_console: 1 if the end device is a console 0 if the I/O device is 280 * not a console 281 */ 282 struct kgdb_io { 283 const char *name; 284 int (*read_char) (void); 285 void (*write_char) (u8); 286 void (*flush) (void); 287 int (*init) (void); 288 void (*deinit) (void); 289 void (*pre_exception) (void); 290 void (*post_exception) (void); 291 int is_console; 292 }; 293 294 extern const struct kgdb_arch arch_kgdb_ops; 295 296 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs); 297 298 #ifdef CONFIG_SERIAL_KGDB_NMI 299 extern int kgdb_register_nmi_console(void); 300 extern int kgdb_unregister_nmi_console(void); 301 extern bool kgdb_nmi_poll_knock(void); 302 #else 303 static inline int kgdb_register_nmi_console(void) { return 0; } 304 static inline int kgdb_unregister_nmi_console(void) { return 0; } 305 static inline bool kgdb_nmi_poll_knock(void) { return true; } 306 #endif 307 308 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 309 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 310 extern struct kgdb_io *dbg_io_ops; 311 312 extern int kgdb_hex2long(char **ptr, unsigned long *long_val); 313 extern char *kgdb_mem2hex(char *mem, char *buf, int count); 314 extern int kgdb_hex2mem(char *buf, char *mem, int count); 315 316 extern int kgdb_isremovedbreak(unsigned long addr); 317 extern void kgdb_schedule_breakpoint(void); 318 319 extern int 320 kgdb_handle_exception(int ex_vector, int signo, int err_code, 321 struct pt_regs *regs); 322 extern int kgdb_nmicallback(int cpu, void *regs); 323 extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code, 324 atomic_t *snd_rdy); 325 extern void gdbstub_exit(int status); 326 327 extern int kgdb_single_step; 328 extern atomic_t kgdb_active; 329 #define in_dbg_master() \ 330 (irqs_disabled() && (smp_processor_id() == atomic_read(&kgdb_active))) 331 extern bool dbg_is_early; 332 extern void __init dbg_late_init(void); 333 extern void kgdb_panic(const char *msg); 334 #else /* ! CONFIG_KGDB */ 335 #define in_dbg_master() (0) 336 #define dbg_late_init() 337 static inline void kgdb_panic(const char *msg) {} 338 #endif /* ! CONFIG_KGDB */ 339 #endif /* _KGDB_H_ */ 340