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_roundup_cpus - Get other CPUs into a holding pattern 181 * @flags: Current IRQ state 182 * 183 * On SMP systems, we need to get the attention of the other CPUs 184 * and get them into a known state. This should do what is needed 185 * to get the other CPUs to call kgdb_wait(). Note that on some arches, 186 * the NMI approach is not used for rounding up all the CPUs. For example, 187 * in case of MIPS, smp_call_function() is used to roundup CPUs. In 188 * this case, we have to make sure that interrupts are enabled before 189 * calling smp_call_function(). The argument to this function is 190 * the flags that will be used when restoring the interrupts. There is 191 * local_irq_save() call before kgdb_roundup_cpus(). 192 * 193 * On non-SMP systems, this is not called. 194 */ 195 extern void kgdb_roundup_cpus(unsigned long flags); 196 197 /** 198 * kgdb_arch_set_pc - Generic call back to the program counter 199 * @regs: Current &struct pt_regs. 200 * @pc: The new value for the program counter 201 * 202 * This function handles updating the program counter and requires an 203 * architecture specific implementation. 204 */ 205 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); 206 207 208 /* Optional functions. */ 209 extern int kgdb_validate_break_address(unsigned long addr); 210 extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt); 211 extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt); 212 213 /** 214 * kgdb_arch_late - Perform any architecture specific initalization. 215 * 216 * This function will handle the late initalization of any 217 * architecture specific callbacks. This is an optional function for 218 * handling things like late initialization of hw breakpoints. The 219 * default implementation does nothing. 220 */ 221 extern void kgdb_arch_late(void); 222 223 224 /** 225 * struct kgdb_arch - Describe architecture specific values. 226 * @gdb_bpt_instr: The instruction to trigger a breakpoint. 227 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. 228 * @set_breakpoint: Allow an architecture to specify how to set a software 229 * breakpoint. 230 * @remove_breakpoint: Allow an architecture to specify how to remove a 231 * software breakpoint. 232 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware 233 * breakpoint. 234 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a 235 * hardware breakpoint. 236 * @disable_hw_break: Allow an architecture to specify how to disable 237 * hardware breakpoints for a single cpu. 238 * @remove_all_hw_break: Allow an architecture to specify how to remove all 239 * hardware breakpoints. 240 * @correct_hw_break: Allow an architecture to specify how to correct the 241 * hardware debug registers. 242 * @enable_nmi: Manage NMI-triggered entry to KGDB 243 */ 244 struct kgdb_arch { 245 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; 246 unsigned long flags; 247 248 int (*set_breakpoint)(unsigned long, char *); 249 int (*remove_breakpoint)(unsigned long, char *); 250 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 251 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 252 void (*disable_hw_break)(struct pt_regs *regs); 253 void (*remove_all_hw_break)(void); 254 void (*correct_hw_break)(void); 255 256 void (*enable_nmi)(bool on); 257 }; 258 259 /** 260 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. 261 * @name: Name of the I/O driver. 262 * @read_char: Pointer to a function that will return one char. 263 * @write_char: Pointer to a function that will write one char. 264 * @flush: Pointer to a function that will flush any pending writes. 265 * @init: Pointer to a function that will initialize the device. 266 * @pre_exception: Pointer to a function that will do any prep work for 267 * the I/O driver. 268 * @post_exception: Pointer to a function that will do any cleanup work 269 * for the I/O driver. 270 * @is_console: 1 if the end device is a console 0 if the I/O device is 271 * not a console 272 */ 273 struct kgdb_io { 274 const char *name; 275 int (*read_char) (void); 276 void (*write_char) (u8); 277 void (*flush) (void); 278 int (*init) (void); 279 void (*pre_exception) (void); 280 void (*post_exception) (void); 281 int is_console; 282 }; 283 284 extern struct kgdb_arch arch_kgdb_ops; 285 286 extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs); 287 288 #ifdef CONFIG_SERIAL_KGDB_NMI 289 extern int kgdb_register_nmi_console(void); 290 extern int kgdb_unregister_nmi_console(void); 291 extern bool kgdb_nmi_poll_knock(void); 292 #else 293 static inline int kgdb_register_nmi_console(void) { return 0; } 294 static inline int kgdb_unregister_nmi_console(void) { return 0; } 295 static inline bool kgdb_nmi_poll_knock(void) { return 1; } 296 #endif 297 298 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 299 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 300 extern struct kgdb_io *dbg_io_ops; 301 302 extern int kgdb_hex2long(char **ptr, unsigned long *long_val); 303 extern char *kgdb_mem2hex(char *mem, char *buf, int count); 304 extern int kgdb_hex2mem(char *buf, char *mem, int count); 305 306 extern int kgdb_isremovedbreak(unsigned long addr); 307 extern void kgdb_schedule_breakpoint(void); 308 309 extern int 310 kgdb_handle_exception(int ex_vector, int signo, int err_code, 311 struct pt_regs *regs); 312 extern int kgdb_nmicallback(int cpu, void *regs); 313 extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code, 314 atomic_t *snd_rdy); 315 extern void gdbstub_exit(int status); 316 317 extern int kgdb_single_step; 318 extern atomic_t kgdb_active; 319 #define in_dbg_master() \ 320 (raw_smp_processor_id() == atomic_read(&kgdb_active)) 321 extern bool dbg_is_early; 322 extern void __init dbg_late_init(void); 323 #else /* ! CONFIG_KGDB */ 324 #define in_dbg_master() (0) 325 #define dbg_late_init() 326 #endif /* ! CONFIG_KGDB */ 327 #endif /* _KGDB_H_ */ 328