arch/arm/kernel/kgdb.c

   1 /*
   2  * arch/arm/kernel/kgdb.c
   3  *
   4  * ARM KGDB support
   5  *
   6  * Copyright (c) 2002-2004 MontaVista Software, Inc
   7  * Copyright (c) 2008 Wind River Systems, Inc.
   8  *
   9  * Authors:  George Davis <davis_g@mvista.com>
  10  *           Deepak Saxena <dsaxena@plexity.net>
  11  */
  12 #include <linux/irq.h>
  13 #include <linux/kgdb.h>
  14 #include <asm/traps.h>
  15
  16 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
  17 {
  18         { "r0", 4, offsetof(struct pt_regs, ARM_r0)},
  19         { "r1", 4, offsetof(struct pt_regs, ARM_r1)},
  20         { "r2", 4, offsetof(struct pt_regs, ARM_r2)},
  21         { "r3", 4, offsetof(struct pt_regs, ARM_r3)},
  22         { "r4", 4, offsetof(struct pt_regs, ARM_r4)},
  23         { "r5", 4, offsetof(struct pt_regs, ARM_r5)},
  24         { "r6", 4, offsetof(struct pt_regs, ARM_r6)},
  25         { "r7", 4, offsetof(struct pt_regs, ARM_r7)},
  26         { "r8", 4, offsetof(struct pt_regs, ARM_r8)},
  27         { "r9", 4, offsetof(struct pt_regs, ARM_r9)},
  28         { "r10", 4, offsetof(struct pt_regs, ARM_r10)},
  29         { "fp", 4, offsetof(struct pt_regs, ARM_fp)},
  30         { "ip", 4, offsetof(struct pt_regs, ARM_ip)},
  31         { "sp", 4, offsetof(struct pt_regs, ARM_sp)},
  32         { "lr", 4, offsetof(struct pt_regs, ARM_lr)},
  33         { "pc", 4, offsetof(struct pt_regs, ARM_pc)},
  34         { "f0", 12, -1 },
  35         { "f1", 12, -1 },
  36         { "f2", 12, -1 },
  37         { "f3", 12, -1 },
  38         { "f4", 12, -1 },
  39         { "f5", 12, -1 },
  40         { "f6", 12, -1 },
  41         { "f7", 12, -1 },
  42         { "fps", 4, -1 },
  43         { "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
  44 };
  45
  46 char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
  47 {
  48         if (regno >= DBG_MAX_REG_NUM || regno < 0)
  49                 return NULL;
  50
  51         if (dbg_reg_def[regno].offset != -1)
  52                 memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
  53                        dbg_reg_def[regno].size);
  54         else
  55                 memset(mem, 0, dbg_reg_def[regno].size);
  56         return dbg_reg_def[regno].name;
  57 }
  58
  59 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
  60 {
  61         if (regno >= DBG_MAX_REG_NUM || regno < 0)
  62                 return -EINVAL;
  63
  64         if (dbg_reg_def[regno].offset != -1)
  65                 memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
  66                        dbg_reg_def[regno].size);
  67         return 0;
  68 }
  69
  70 void
  71 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
  72 {
  73         struct pt_regs *thread_regs;
  74         int regno;
  75
  76         /* Just making sure... */
  77         if (task == NULL)
  78                 return;
  79
  80         /* Initialize to zero */
  81         for (regno = 0; regno < GDB_MAX_REGS; regno++)
  82                 gdb_regs[regno] = 0;
  83
  84         /* Otherwise, we have only some registers from switch_to() */
  85         thread_regs             = task_pt_regs(task);
  86         gdb_regs[_R0]           = thread_regs->ARM_r0;
  87         gdb_regs[_R1]           = thread_regs->ARM_r1;
  88         gdb_regs[_R2]           = thread_regs->ARM_r2;
  89         gdb_regs[_R3]           = thread_regs->ARM_r3;
  90         gdb_regs[_R4]           = thread_regs->ARM_r4;
  91         gdb_regs[_R5]           = thread_regs->ARM_r5;
  92         gdb_regs[_R6]           = thread_regs->ARM_r6;
  93         gdb_regs[_R7]           = thread_regs->ARM_r7;
  94         gdb_regs[_R8]           = thread_regs->ARM_r8;
  95         gdb_regs[_R9]           = thread_regs->ARM_r9;
  96         gdb_regs[_R10]          = thread_regs->ARM_r10;
  97         gdb_regs[_FP]           = thread_regs->ARM_fp;
  98         gdb_regs[_IP]           = thread_regs->ARM_ip;
  99         gdb_regs[_SPT]          = thread_regs->ARM_sp;
 100         gdb_regs[_LR]           = thread_regs->ARM_lr;
 101         gdb_regs[_PC]           = thread_regs->ARM_pc;
 102         gdb_regs[_CPSR]         = thread_regs->ARM_cpsr;
 103 }
 104
 105 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
 106 {
 107         regs->ARM_pc = pc;
 108 }
 109
 110 static int compiled_break;
 111
 112 int kgdb_arch_handle_exception(int exception_vector, int signo,
 113                                int err_code, char *remcom_in_buffer,
 114                                char *remcom_out_buffer,
 115                                struct pt_regs *linux_regs)
 116 {
 117         unsigned long addr;
 118         char *ptr;
 119
 120         switch (remcom_in_buffer[0]) {
 121         case 'D':
 122         case 'k':
 123         case 'c':
 124                 /*
 125                  * Try to read optional parameter, pc unchanged if no parm.
 126                  * If this was a compiled breakpoint, we need to move
 127                  * to the next instruction or we will just breakpoint
 128                  * over and over again.
 129                  */
 130                 ptr = &remcom_in_buffer[1];
 131                 if (kgdb_hex2long(&ptr, &addr))
 132                         linux_regs->ARM_pc = addr;
 133                 else if (compiled_break == 1)
 134                         linux_regs->ARM_pc += 4;
 135
 136                 compiled_break = 0;
 137
 138                 return 0;
 139         }
 140
 141         return -1;
 142 }
 143
 144 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
 145 {
 146         kgdb_handle_exception(1, SIGTRAP, 0, regs);
 147
 148         return 0;
 149 }
 150
 151 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
 152 {
 153         compiled_break = 1;
 154         kgdb_handle_exception(1, SIGTRAP, 0, regs);
 155
 156         return 0;
 157 }
 158
 159 static struct undef_hook kgdb_brkpt_hook = {
 160         .instr_mask             = 0xffffffff,
 161         .instr_val              = KGDB_BREAKINST,
 162         .fn                     = kgdb_brk_fn
 163 };
 164
 165 static struct undef_hook kgdb_compiled_brkpt_hook = {
 166         .instr_mask             = 0xffffffff,
 167         .instr_val              = KGDB_COMPILED_BREAK,
 168         .fn                     = kgdb_compiled_brk_fn
 169 };
 170
 171 static void kgdb_call_nmi_hook(void *ignored)
 172 {
 173        kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
 174 }
 175
 176 void kgdb_roundup_cpus(unsigned long flags)
 177 {
 178        local_irq_enable();
 179        smp_call_function(kgdb_call_nmi_hook, NULL, 0);
 180        local_irq_disable();
 181 }
 182
 183 /**
 184  *      kgdb_arch_init - Perform any architecture specific initalization.
 185  *
 186  *      This function will handle the initalization of any architecture
 187  *      specific callbacks.
 188  */
 189 int kgdb_arch_init(void)
 190 {
 191         register_undef_hook(&kgdb_brkpt_hook);
 192         register_undef_hook(&kgdb_compiled_brkpt_hook);
 193
 194         return 0;
 195 }
 196
 197 /**
 198  *      kgdb_arch_exit - Perform any architecture specific uninitalization.
 199  *
 200  *      This function will handle the uninitalization of any architecture
 201  *      specific callbacks, for dynamic registration and unregistration.
 202  */
 203 void kgdb_arch_exit(void)
 204 {
 205         unregister_undef_hook(&kgdb_brkpt_hook);
 206         unregister_undef_hook(&kgdb_compiled_brkpt_hook);
 207 }
 208
 209 /*
 210  * Register our undef instruction hooks with ARM undef core.
 211  * We regsiter a hook specifically looking for the KGB break inst
 212  * and we handle the normal undef case within the do_undefinstr
 213  * handler.
 214  */
 215 struct kgdb_arch arch_kgdb_ops = {
 216 #ifndef __ARMEB__
 217         .gdb_bpt_instr          = {0xfe, 0xde, 0xff, 0xe7}
 218 #else /* ! __ARMEB__ */
 219         .gdb_bpt_instr          = {0xe7, 0xff, 0xde, 0xfe}
 220 #endif
 221 };