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/serial_8250.h> 17 #include <linux/linkage.h> 18 #include <linux/init.h> 19 #include <linux/atomic.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_roundup_cpus - Get other CPUs into a holding pattern 182 * @flags: Current IRQ state 183 * 184 * On SMP systems, we need to get the attention of the other CPUs 185 * and get them into a known state. This should do what is needed 186 * to get the other CPUs to call kgdb_wait(). Note that on some arches, 187 * the NMI approach is not used for rounding up all the CPUs. For example, 188 * in case of MIPS, smp_call_function() is used to roundup CPUs. In 189 * this case, we have to make sure that interrupts are enabled before 190 * calling smp_call_function(). The argument to this function is 191 * the flags that will be used when restoring the interrupts. There is 192 * local_irq_save() call before kgdb_roundup_cpus(). 193 * 194 * On non-SMP systems, this is not called. 195 */ 196 extern void kgdb_roundup_cpus(unsigned long flags); 197 198 /** 199 * kgdb_arch_set_pc - Generic call back to the program counter 200 * @regs: Current &struct pt_regs. 201 * @pc: The new value for the program counter 202 * 203 * This function handles updating the program counter and requires an 204 * architecture specific implementation. 205 */ 206 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); 207 208 209 /* Optional functions. */ 210 extern int kgdb_validate_break_address(unsigned long addr); 211 extern int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt); 212 extern int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt); 213 214 /** 215 * kgdb_arch_late - Perform any architecture specific initalization. 216 * 217 * This function will handle the late initalization of any 218 * architecture specific callbacks. This is an optional function for 219 * handling things like late initialization of hw breakpoints. The 220 * default implementation does nothing. 221 */ 222 extern void kgdb_arch_late(void); 223 224 225 /** 226 * struct kgdb_arch - Describe architecture specific values. 227 * @gdb_bpt_instr: The instruction to trigger a breakpoint. 228 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. 229 * @set_breakpoint: Allow an architecture to specify how to set a software 230 * breakpoint. 231 * @remove_breakpoint: Allow an architecture to specify how to remove a 232 * software breakpoint. 233 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware 234 * breakpoint. 235 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a 236 * hardware breakpoint. 237 * @disable_hw_break: Allow an architecture to specify how to disable 238 * hardware breakpoints for a single cpu. 239 * @remove_all_hw_break: Allow an architecture to specify how to remove all 240 * hardware breakpoints. 241 * @correct_hw_break: Allow an architecture to specify how to correct the 242 * hardware debug registers. 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 }; 256 257 /** 258 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. 259 * @name: Name of the I/O driver. 260 * @read_char: Pointer to a function that will return one char. 261 * @write_char: Pointer to a function that will write one char. 262 * @flush: Pointer to a function that will flush any pending writes. 263 * @init: Pointer to a function that will initialize the device. 264 * @pre_exception: Pointer to a function that will do any prep work for 265 * the I/O driver. 266 * @post_exception: Pointer to a function that will do any cleanup work 267 * for the I/O driver. 268 * @is_console: 1 if the end device is a console 0 if the I/O device is 269 * not a console 270 */ 271 struct kgdb_io { 272 const char *name; 273 int (*read_char) (void); 274 void (*write_char) (u8); 275 void (*flush) (void); 276 int (*init) (void); 277 void (*pre_exception) (void); 278 void (*post_exception) (void); 279 int is_console; 280 }; 281 282 extern struct kgdb_arch arch_kgdb_ops; 283 284 extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); 285 286 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 287 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 288 extern struct kgdb_io *dbg_io_ops; 289 290 extern int kgdb_hex2long(char **ptr, unsigned long *long_val); 291 extern char *kgdb_mem2hex(char *mem, char *buf, int count); 292 extern int kgdb_hex2mem(char *buf, char *mem, int count); 293 294 extern int kgdb_isremovedbreak(unsigned long addr); 295 extern void kgdb_schedule_breakpoint(void); 296 297 extern int 298 kgdb_handle_exception(int ex_vector, int signo, int err_code, 299 struct pt_regs *regs); 300 extern int kgdb_nmicallback(int cpu, void *regs); 301 extern void gdbstub_exit(int status); 302 303 extern int kgdb_single_step; 304 extern atomic_t kgdb_active; 305 #define in_dbg_master() \ 306 (raw_smp_processor_id() == atomic_read(&kgdb_active)) 307 extern bool dbg_is_early; 308 extern void __init dbg_late_init(void); 309 #else /* ! CONFIG_KGDB */ 310 #define in_dbg_master() (0) 311 #define dbg_late_init() 312 #endif /* ! CONFIG_KGDB */ 313 #endif /* _KGDB_H_ */ 314