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 #include <linux/kprobes.h> 20 #ifdef CONFIG_HAVE_ARCH_KGDB 21 #include <asm/kgdb.h> 22 #endif 23 24 #ifdef CONFIG_KGDB 25 struct pt_regs; 26 27 /** 28 * kgdb_skipexception - (optional) exit kgdb_handle_exception early 29 * @exception: Exception vector number 30 * @regs: Current &struct pt_regs. 31 * 32 * On some architectures it is required to skip a breakpoint 33 * exception when it occurs after a breakpoint has been removed. 34 * This can be implemented in the architecture specific portion of kgdb. 35 */ 36 extern int kgdb_skipexception(int exception, struct pt_regs *regs); 37 38 struct tasklet_struct; 39 struct task_struct; 40 struct uart_port; 41 42 /** 43 * kgdb_breakpoint - compiled in breakpoint 44 * 45 * This will be implemented as a static inline per architecture. This 46 * function is called by the kgdb core to execute an architecture 47 * specific trap to cause kgdb to enter the exception processing. 48 * 49 */ 50 void kgdb_breakpoint(void); 51 52 extern int kgdb_connected; 53 extern int kgdb_io_module_registered; 54 55 extern atomic_t kgdb_setting_breakpoint; 56 extern atomic_t kgdb_cpu_doing_single_step; 57 58 extern struct task_struct *kgdb_usethread; 59 extern struct task_struct *kgdb_contthread; 60 61 enum kgdb_bptype { 62 BP_BREAKPOINT = 0, 63 BP_HARDWARE_BREAKPOINT, 64 BP_WRITE_WATCHPOINT, 65 BP_READ_WATCHPOINT, 66 BP_ACCESS_WATCHPOINT, 67 BP_POKE_BREAKPOINT, 68 }; 69 70 enum kgdb_bpstate { 71 BP_UNDEFINED = 0, 72 BP_REMOVED, 73 BP_SET, 74 BP_ACTIVE 75 }; 76 77 struct kgdb_bkpt { 78 unsigned long bpt_addr; 79 unsigned char saved_instr[BREAK_INSTR_SIZE]; 80 enum kgdb_bptype type; 81 enum kgdb_bpstate state; 82 }; 83 84 struct dbg_reg_def_t { 85 char *name; 86 int size; 87 int offset; 88 }; 89 90 #ifndef DBG_MAX_REG_NUM 91 #define DBG_MAX_REG_NUM 0 92 #else 93 extern struct dbg_reg_def_t dbg_reg_def[]; 94 extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs); 95 extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs); 96 #endif 97 #ifndef KGDB_MAX_BREAKPOINTS 98 # define KGDB_MAX_BREAKPOINTS 1000 99 #endif 100 101 #define KGDB_HW_BREAKPOINT 1 102 103 /* 104 * Functions each KGDB-supporting architecture must provide: 105 */ 106 107 /** 108 * kgdb_arch_init - Perform any architecture specific initalization. 109 * 110 * This function will handle the initalization of any architecture 111 * specific callbacks. 112 */ 113 extern int kgdb_arch_init(void); 114 115 /** 116 * kgdb_arch_exit - Perform any architecture specific uninitalization. 117 * 118 * This function will handle the uninitalization of any architecture 119 * specific callbacks, for dynamic registration and unregistration. 120 */ 121 extern void kgdb_arch_exit(void); 122 123 /** 124 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs 125 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 126 * @regs: The &struct pt_regs of the current process. 127 * 128 * Convert the pt_regs in @regs into the format for registers that 129 * GDB expects, stored in @gdb_regs. 130 */ 131 extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs); 132 133 /** 134 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs 135 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 136 * @p: The &struct task_struct of the desired process. 137 * 138 * Convert the register values of the sleeping process in @p to 139 * the format that GDB expects. 140 * This function is called when kgdb does not have access to the 141 * &struct pt_regs and therefore it should fill the gdb registers 142 * @gdb_regs with what has been saved in &struct thread_struct 143 * thread field during switch_to. 144 */ 145 extern void 146 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p); 147 148 /** 149 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. 150 * @gdb_regs: A pointer to hold the registers we've received from GDB. 151 * @regs: A pointer to a &struct pt_regs to hold these values in. 152 * 153 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them 154 * in @regs. 155 */ 156 extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs); 157 158 /** 159 * kgdb_arch_handle_exception - Handle architecture specific GDB packets. 160 * @vector: The error vector of the exception that happened. 161 * @signo: The signal number of the exception that happened. 162 * @err_code: The error code of the exception that happened. 163 * @remcom_in_buffer: The buffer of the packet we have read. 164 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. 165 * @regs: The &struct pt_regs of the current process. 166 * 167 * This function MUST handle the 'c' and 's' command packets, 168 * as well packets to set / remove a hardware breakpoint, if used. 169 * If there are additional packets which the hardware needs to handle, 170 * they are handled here. The code should return -1 if it wants to 171 * process more packets, and a %0 or %1 if it wants to exit from the 172 * kgdb callback. 173 */ 174 extern int 175 kgdb_arch_handle_exception(int vector, int signo, int err_code, 176 char *remcom_in_buffer, 177 char *remcom_out_buffer, 178 struct pt_regs *regs); 179 180 /** 181 * kgdb_arch_handle_qxfer_pkt - Handle architecture specific GDB XML 182 * packets. 183 * @remcom_in_buffer: The buffer of the packet we have read. 184 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. 185 */ 186 187 extern void 188 kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer, 189 char *remcom_out_buffer); 190 191 /** 192 * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU 193 * @ignored: This parameter is only here to match the prototype. 194 * 195 * If you're using the default implementation of kgdb_roundup_cpus() 196 * this function will be called per CPU. If you don't implement 197 * kgdb_call_nmi_hook() a default will be used. 198 */ 199 200 extern void kgdb_call_nmi_hook(void *ignored); 201 202 /** 203 * kgdb_roundup_cpus - Get other CPUs into a holding pattern 204 * 205 * On SMP systems, we need to get the attention of the other CPUs 206 * and get them into a known state. This should do what is needed 207 * to get the other CPUs to call kgdb_wait(). Note that on some arches, 208 * the NMI approach is not used for rounding up all the CPUs. Normally 209 * those architectures can just not implement this and get the default. 210 * 211 * On non-SMP systems, this is not called. 212 */ 213 extern void kgdb_roundup_cpus(void); 214 215 /** 216 * kgdb_arch_set_pc - Generic call back to the program counter 217 * @regs: Current &struct pt_regs. 218 * @pc: The new value for the program counter 219 * 220 * This function handles updating the program counter and requires an 221 * architecture specific implementation. 222 */ 223 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); 224 225 226 /* Optional functions. */ 227 extern int kgdb_validate_break_address(unsigned long addr); 228 extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt); 229 extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt); 230 231 /** 232 * kgdb_arch_late - Perform any architecture specific initalization. 233 * 234 * This function will handle the late initalization of any 235 * architecture specific callbacks. This is an optional function for 236 * handling things like late initialization of hw breakpoints. The 237 * default implementation does nothing. 238 */ 239 extern void kgdb_arch_late(void); 240 241 242 /** 243 * struct kgdb_arch - Describe architecture specific values. 244 * @gdb_bpt_instr: The instruction to trigger a breakpoint. 245 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. 246 * @set_breakpoint: Allow an architecture to specify how to set a software 247 * breakpoint. 248 * @remove_breakpoint: Allow an architecture to specify how to remove a 249 * software breakpoint. 250 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware 251 * breakpoint. 252 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a 253 * hardware breakpoint. 254 * @disable_hw_break: Allow an architecture to specify how to disable 255 * hardware breakpoints for a single cpu. 256 * @remove_all_hw_break: Allow an architecture to specify how to remove all 257 * hardware breakpoints. 258 * @correct_hw_break: Allow an architecture to specify how to correct the 259 * hardware debug registers. 260 * @enable_nmi: Manage NMI-triggered entry to KGDB 261 */ 262 struct kgdb_arch { 263 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; 264 unsigned long flags; 265 266 int (*set_breakpoint)(unsigned long, char *); 267 int (*remove_breakpoint)(unsigned long, char *); 268 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 269 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 270 void (*disable_hw_break)(struct pt_regs *regs); 271 void (*remove_all_hw_break)(void); 272 void (*correct_hw_break)(void); 273 274 void (*enable_nmi)(bool on); 275 }; 276 277 /** 278 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. 279 * @name: Name of the I/O driver. 280 * @read_char: Pointer to a function that will return one char. 281 * @write_char: Pointer to a function that will write one char. 282 * @flush: Pointer to a function that will flush any pending writes. 283 * @init: Pointer to a function that will initialize the device. 284 * @deinit: Pointer to a function that will deinit the device. Implies that 285 * this I/O driver is temporary and expects to be replaced. Called when 286 * an I/O driver is replaced or explicitly unregistered. 287 * @pre_exception: Pointer to a function that will do any prep work for 288 * the I/O driver. 289 * @post_exception: Pointer to a function that will do any cleanup work 290 * for the I/O driver. 291 * @cons: valid if the I/O device is a console; else NULL. 292 */ 293 struct kgdb_io { 294 const char *name; 295 int (*read_char) (void); 296 void (*write_char) (u8); 297 void (*flush) (void); 298 int (*init) (void); 299 void (*deinit) (void); 300 void (*pre_exception) (void); 301 void (*post_exception) (void); 302 struct console *cons; 303 }; 304 305 extern const struct kgdb_arch arch_kgdb_ops; 306 307 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs); 308 309 #ifdef CONFIG_SERIAL_KGDB_NMI 310 extern int kgdb_register_nmi_console(void); 311 extern int kgdb_unregister_nmi_console(void); 312 extern bool kgdb_nmi_poll_knock(void); 313 #else 314 static inline int kgdb_register_nmi_console(void) { return 0; } 315 static inline int kgdb_unregister_nmi_console(void) { return 0; } 316 static inline bool kgdb_nmi_poll_knock(void) { return true; } 317 #endif 318 319 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 320 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 321 extern struct kgdb_io *dbg_io_ops; 322 323 extern int kgdb_hex2long(char **ptr, unsigned long *long_val); 324 extern char *kgdb_mem2hex(char *mem, char *buf, int count); 325 extern int kgdb_hex2mem(char *buf, char *mem, int count); 326 327 extern int kgdb_isremovedbreak(unsigned long addr); 328 extern int kgdb_has_hit_break(unsigned long addr); 329 330 extern int 331 kgdb_handle_exception(int ex_vector, int signo, int err_code, 332 struct pt_regs *regs); 333 extern int kgdb_nmicallback(int cpu, void *regs); 334 extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code, 335 atomic_t *snd_rdy); 336 extern void gdbstub_exit(int status); 337 338 /* 339 * kgdb and kprobes both use the same (kprobe) blocklist (which makes sense 340 * given they are both typically hooked up to the same trap meaning on most 341 * architectures one cannot be used to debug the other) 342 * 343 * However on architectures where kprobes is not (yet) implemented we permit 344 * breakpoints everywhere rather than blocking everything by default. 345 */ 346 static inline bool kgdb_within_blocklist(unsigned long addr) 347 { 348 #ifdef CONFIG_KGDB_HONOUR_BLOCKLIST 349 return within_kprobe_blacklist(addr); 350 #else 351 return false; 352 #endif 353 } 354 355 extern int kgdb_single_step; 356 extern atomic_t kgdb_active; 357 #define in_dbg_master() \ 358 (irqs_disabled() && (smp_processor_id() == atomic_read(&kgdb_active))) 359 extern bool dbg_is_early; 360 extern void __init dbg_late_init(void); 361 extern void kgdb_panic(const char *msg); 362 extern void kgdb_free_init_mem(void); 363 #else /* ! CONFIG_KGDB */ 364 #define in_dbg_master() (0) 365 #define dbg_late_init() 366 static inline void kgdb_panic(const char *msg) {} 367 static inline void kgdb_free_init_mem(void) { } 368 #endif /* ! CONFIG_KGDB */ 369 #endif /* _KGDB_H_ */ 370