include/linux/kgdb.h

   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 <asm/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 /**
  39  *      kgdb_disable_hw_debug - (optional) Disable hardware debugging hook
  40  *      @regs: Current &struct pt_regs.
  41  *
  42  *      This function will be called if the particular architecture must
  43  *      disable hardware debugging while it is processing gdb packets or
  44  *      handling exception.
  45  */
  46 extern void kgdb_disable_hw_debug(struct pt_regs *regs);
  47
  48 struct tasklet_struct;
  49 struct task_struct;
  50 struct uart_port;
  51
  52 /**
  53  *      kgdb_breakpoint - compiled in breakpoint
  54  *
  55  *      This will be implemented as a static inline per architecture.  This
  56  *      function is called by the kgdb core to execute an architecture
  57  *      specific trap to cause kgdb to enter the exception processing.
  58  *
  59  */
  60 void kgdb_breakpoint(void);
  61
  62 extern int kgdb_connected;
  63 extern int kgdb_io_module_registered;
  64
  65 extern atomic_t                 kgdb_setting_breakpoint;
  66 extern atomic_t                 kgdb_cpu_doing_single_step;
  67
  68 extern struct task_struct       *kgdb_usethread;
  69 extern struct task_struct       *kgdb_contthread;
  70
  71 enum kgdb_bptype {
  72         BP_BREAKPOINT = 0,
  73         BP_HARDWARE_BREAKPOINT,
  74         BP_WRITE_WATCHPOINT,
  75         BP_READ_WATCHPOINT,
  76         BP_ACCESS_WATCHPOINT
  77 };
  78
  79 enum kgdb_bpstate {
  80         BP_UNDEFINED = 0,
  81         BP_REMOVED,
  82         BP_SET,
  83         BP_ACTIVE
  84 };
  85
  86 struct kgdb_bkpt {
  87         unsigned long           bpt_addr;
  88         unsigned char           saved_instr[BREAK_INSTR_SIZE];
  89         enum kgdb_bptype        type;
  90         enum kgdb_bpstate       state;
  91 };
  92
  93 struct dbg_reg_def_t {
  94         char *name;
  95         int size;
  96         int offset;
  97 };
  98
  99 #ifndef DBG_MAX_REG_NUM
 100 #define DBG_MAX_REG_NUM 0
 101 #else
 102 extern struct dbg_reg_def_t dbg_reg_def[];
 103 extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs);
 104 extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs);
 105 #endif
 106 #ifndef KGDB_MAX_BREAKPOINTS
 107 # define KGDB_MAX_BREAKPOINTS   1000
 108 #endif
 109
 110 #define KGDB_HW_BREAKPOINT      1
 111
 112 /*
 113  * Functions each KGDB-supporting architecture must provide:
 114  */
 115
 116 /**
 117  *      kgdb_arch_init - Perform any architecture specific initalization.
 118  *
 119  *      This function will handle the initalization of any architecture
 120  *      specific callbacks.
 121  */
 122 extern int kgdb_arch_init(void);
 123
 124 /**
 125  *      kgdb_arch_exit - Perform any architecture specific uninitalization.
 126  *
 127  *      This function will handle the uninitalization of any architecture
 128  *      specific callbacks, for dynamic registration and unregistration.
 129  */
 130 extern void kgdb_arch_exit(void);
 131
 132 /**
 133  *      pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
 134  *      @gdb_regs: A pointer to hold the registers in the order GDB wants.
 135  *      @regs: The &struct pt_regs of the current process.
 136  *
 137  *      Convert the pt_regs in @regs into the format for registers that
 138  *      GDB expects, stored in @gdb_regs.
 139  */
 140 extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
 141
 142 /**
 143  *      sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
 144  *      @gdb_regs: A pointer to hold the registers in the order GDB wants.
 145  *      @p: The &struct task_struct of the desired process.
 146  *
 147  *      Convert the register values of the sleeping process in @p to
 148  *      the format that GDB expects.
 149  *      This function is called when kgdb does not have access to the
 150  *      &struct pt_regs and therefore it should fill the gdb registers
 151  *      @gdb_regs with what has been saved in &struct thread_struct
 152  *      thread field during switch_to.
 153  */
 154 extern void
 155 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
 156
 157 /**
 158  *      gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
 159  *      @gdb_regs: A pointer to hold the registers we've received from GDB.
 160  *      @regs: A pointer to a &struct pt_regs to hold these values in.
 161  *
 162  *      Convert the GDB regs in @gdb_regs into the pt_regs, and store them
 163  *      in @regs.
 164  */
 165 extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
 166
 167 /**
 168  *      kgdb_arch_handle_exception - Handle architecture specific GDB packets.
 169  *      @vector: The error vector of the exception that happened.
 170  *      @signo: The signal number of the exception that happened.
 171  *      @err_code: The error code of the exception that happened.
 172  *      @remcom_in_buffer: The buffer of the packet we have read.
 173  *      @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
 174  *      @regs: The &struct pt_regs of the current process.
 175  *
 176  *      This function MUST handle the 'c' and 's' command packets,
 177  *      as well packets to set / remove a hardware breakpoint, if used.
 178  *      If there are additional packets which the hardware needs to handle,
 179  *      they are handled here.  The code should return -1 if it wants to
 180  *      process more packets, and a %0 or %1 if it wants to exit from the
 181  *      kgdb callback.
 182  */
 183 extern int
 184 kgdb_arch_handle_exception(int vector, int signo, int err_code,
 185                            char *remcom_in_buffer,
 186                            char *remcom_out_buffer,
 187                            struct pt_regs *regs);
 188
 189 /**
 190  *      kgdb_roundup_cpus - Get other CPUs into a holding pattern
 191  *      @flags: Current IRQ state
 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. For example,
 197  *      in case of MIPS, smp_call_function() is used to roundup CPUs. In
 198  *      this case, we have to make sure that interrupts are enabled before
 199  *      calling smp_call_function(). The argument to this function is
 200  *      the flags that will be used when restoring the interrupts. There is
 201  *      local_irq_save() call before kgdb_roundup_cpus().
 202  *
 203  *      On non-SMP systems, this is not called.
 204  */
 205 extern void kgdb_roundup_cpus(unsigned long flags);
 206
 207 /**
 208  *      kgdb_arch_set_pc - Generic call back to the program counter
 209  *      @regs: Current &struct pt_regs.
 210  *  @pc: The new value for the program counter
 211  *
 212  *      This function handles updating the program counter and requires an
 213  *      architecture specific implementation.
 214  */
 215 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc);
 216
 217
 218 /* Optional functions. */
 219 extern int kgdb_validate_break_address(unsigned long addr);
 220 extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
 221 extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle);
 222
 223 /**
 224  *      kgdb_arch_late - Perform any architecture specific initalization.
 225  *
 226  *      This function will handle the late initalization of any
 227  *      architecture specific callbacks.  This is an optional function for
 228  *      handling things like late initialization of hw breakpoints.  The
 229  *      default implementation does nothing.
 230  */
 231 extern void kgdb_arch_late(void);
 232
 233
 234 /**
 235  * struct kgdb_arch - Describe architecture specific values.
 236  * @gdb_bpt_instr: The instruction to trigger a breakpoint.
 237  * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
 238  * @set_breakpoint: Allow an architecture to specify how to set a software
 239  * breakpoint.
 240  * @remove_breakpoint: Allow an architecture to specify how to remove a
 241  * software breakpoint.
 242  * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
 243  * breakpoint.
 244  * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
 245  * hardware breakpoint.
 246  * @remove_all_hw_break: Allow an architecture to specify how to remove all
 247  * hardware breakpoints.
 248  * @correct_hw_break: Allow an architecture to specify how to correct the
 249  * hardware debug registers.
 250  */
 251 struct kgdb_arch {
 252         unsigned char           gdb_bpt_instr[BREAK_INSTR_SIZE];
 253         unsigned long           flags;
 254
 255         int     (*set_breakpoint)(unsigned long, char *);
 256         int     (*remove_breakpoint)(unsigned long, char *);
 257         int     (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
 258         int     (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
 259         void    (*remove_all_hw_break)(void);
 260         void    (*correct_hw_break)(void);
 261 };
 262
 263 /**
 264  * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
 265  * @name: Name of the I/O driver.
 266  * @read_char: Pointer to a function that will return one char.
 267  * @write_char: Pointer to a function that will write one char.
 268  * @flush: Pointer to a function that will flush any pending writes.
 269  * @init: Pointer to a function that will initialize the device.
 270  * @pre_exception: Pointer to a function that will do any prep work for
 271  * the I/O driver.
 272  * @post_exception: Pointer to a function that will do any cleanup work
 273  * for the I/O driver.
 274  * @is_console: 1 if the end device is a console 0 if the I/O device is
 275  * not a console
 276  */
 277 struct kgdb_io {
 278         const char              *name;
 279         int                     (*read_char) (void);
 280         void                    (*write_char) (u8);
 281         void                    (*flush) (void);
 282         int                     (*init) (void);
 283         void                    (*pre_exception) (void);
 284         void                    (*post_exception) (void);
 285         int                     is_console;
 286 };
 287
 288 extern struct kgdb_arch         arch_kgdb_ops;
 289
 290 extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs);
 291
 292 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
 293 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
 294 extern struct kgdb_io *dbg_io_ops;
 295
 296 extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
 297 extern char *kgdb_mem2hex(char *mem, char *buf, int count);
 298 extern int kgdb_hex2mem(char *buf, char *mem, int count);
 299
 300 extern int kgdb_isremovedbreak(unsigned long addr);
 301 extern void kgdb_schedule_breakpoint(void);
 302
 303 extern int
 304 kgdb_handle_exception(int ex_vector, int signo, int err_code,
 305                       struct pt_regs *regs);
 306 extern int kgdb_nmicallback(int cpu, void *regs);
 307
 308 extern int                      kgdb_single_step;
 309 extern atomic_t                 kgdb_active;
 310 #define in_dbg_master() \
 311         (raw_smp_processor_id() == atomic_read(&kgdb_active))
 312 extern bool dbg_is_early;
 313 extern void __init dbg_late_init(void);
 314 #else /* ! CONFIG_KGDB */
 315 #define in_dbg_master() (0)
 316 #define dbg_late_init()
 317 #endif /* ! CONFIG_KGDB */
 318 #endif /* _KGDB_H_ */