283 lines
6.8 KiB
C
283 lines
6.8 KiB
C
/*
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* arch/arm/kernel/kgdb.c
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*
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* ARM KGDB support
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*
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* Copyright (c) 2002-2004 MontaVista Software, Inc
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* Copyright (c) 2008 Wind River Systems, Inc.
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*
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* Authors: George Davis <davis_g@mvista.com>
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* Deepak Saxena <dsaxena@plexity.net>
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*/
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#include <linux/irq.h>
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#include <linux/kdebug.h>
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#include <linux/kgdb.h>
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#include <linux/uaccess.h>
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#include <asm/patch.h>
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#include <asm/traps.h>
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struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
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{
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{ "r0", 4, offsetof(struct pt_regs, ARM_r0)},
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{ "r1", 4, offsetof(struct pt_regs, ARM_r1)},
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{ "r2", 4, offsetof(struct pt_regs, ARM_r2)},
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{ "r3", 4, offsetof(struct pt_regs, ARM_r3)},
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{ "r4", 4, offsetof(struct pt_regs, ARM_r4)},
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{ "r5", 4, offsetof(struct pt_regs, ARM_r5)},
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{ "r6", 4, offsetof(struct pt_regs, ARM_r6)},
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{ "r7", 4, offsetof(struct pt_regs, ARM_r7)},
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{ "r8", 4, offsetof(struct pt_regs, ARM_r8)},
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{ "r9", 4, offsetof(struct pt_regs, ARM_r9)},
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{ "r10", 4, offsetof(struct pt_regs, ARM_r10)},
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{ "fp", 4, offsetof(struct pt_regs, ARM_fp)},
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{ "ip", 4, offsetof(struct pt_regs, ARM_ip)},
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{ "sp", 4, offsetof(struct pt_regs, ARM_sp)},
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{ "lr", 4, offsetof(struct pt_regs, ARM_lr)},
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{ "pc", 4, offsetof(struct pt_regs, ARM_pc)},
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{ "f0", 12, -1 },
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{ "f1", 12, -1 },
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{ "f2", 12, -1 },
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{ "f3", 12, -1 },
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{ "f4", 12, -1 },
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{ "f5", 12, -1 },
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{ "f6", 12, -1 },
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{ "f7", 12, -1 },
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{ "fps", 4, -1 },
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{ "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
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};
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char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
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{
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if (regno >= DBG_MAX_REG_NUM || regno < 0)
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return NULL;
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if (dbg_reg_def[regno].offset != -1)
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memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
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dbg_reg_def[regno].size);
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else
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memset(mem, 0, dbg_reg_def[regno].size);
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return dbg_reg_def[regno].name;
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}
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int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
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{
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if (regno >= DBG_MAX_REG_NUM || regno < 0)
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return -EINVAL;
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if (dbg_reg_def[regno].offset != -1)
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memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
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dbg_reg_def[regno].size);
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return 0;
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}
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void
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sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
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{
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struct thread_info *ti;
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int regno;
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/* Just making sure... */
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if (task == NULL)
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return;
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/* Initialize to zero */
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for (regno = 0; regno < GDB_MAX_REGS; regno++)
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gdb_regs[regno] = 0;
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/* Otherwise, we have only some registers from switch_to() */
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ti = task_thread_info(task);
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gdb_regs[_R4] = ti->cpu_context.r4;
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gdb_regs[_R5] = ti->cpu_context.r5;
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gdb_regs[_R6] = ti->cpu_context.r6;
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gdb_regs[_R7] = ti->cpu_context.r7;
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gdb_regs[_R8] = ti->cpu_context.r8;
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gdb_regs[_R9] = ti->cpu_context.r9;
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gdb_regs[_R10] = ti->cpu_context.sl;
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gdb_regs[_FP] = ti->cpu_context.fp;
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gdb_regs[_SPT] = ti->cpu_context.sp;
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gdb_regs[_PC] = ti->cpu_context.pc;
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}
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void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
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{
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regs->ARM_pc = pc;
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}
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static int compiled_break;
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int kgdb_arch_handle_exception(int exception_vector, int signo,
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int err_code, char *remcom_in_buffer,
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char *remcom_out_buffer,
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struct pt_regs *linux_regs)
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{
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unsigned long addr;
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char *ptr;
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switch (remcom_in_buffer[0]) {
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case 'D':
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case 'k':
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case 'c':
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/*
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* Try to read optional parameter, pc unchanged if no parm.
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* If this was a compiled breakpoint, we need to move
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* to the next instruction or we will just breakpoint
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* over and over again.
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*/
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ptr = &remcom_in_buffer[1];
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if (kgdb_hex2long(&ptr, &addr))
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linux_regs->ARM_pc = addr;
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else if (compiled_break == 1)
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linux_regs->ARM_pc += 4;
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compiled_break = 0;
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return 0;
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}
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return -1;
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}
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static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
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{
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kgdb_handle_exception(1, SIGTRAP, 0, regs);
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return 0;
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}
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static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
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{
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compiled_break = 1;
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kgdb_handle_exception(1, SIGTRAP, 0, regs);
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return 0;
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}
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static struct undef_hook kgdb_brkpt_hook = {
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.instr_mask = 0xffffffff,
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.instr_val = KGDB_BREAKINST,
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.cpsr_mask = MODE_MASK,
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.cpsr_val = SVC_MODE,
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.fn = kgdb_brk_fn
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};
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static struct undef_hook kgdb_compiled_brkpt_hook = {
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.instr_mask = 0xffffffff,
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.instr_val = KGDB_COMPILED_BREAK,
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.cpsr_mask = MODE_MASK,
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.cpsr_val = SVC_MODE,
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.fn = kgdb_compiled_brk_fn
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};
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static void kgdb_call_nmi_hook(void *ignored)
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{
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kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
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}
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void kgdb_roundup_cpus(unsigned long flags)
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{
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local_irq_enable();
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smp_call_function(kgdb_call_nmi_hook, NULL, 0);
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local_irq_disable();
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}
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static int __kgdb_notify(struct die_args *args, unsigned long cmd)
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{
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struct pt_regs *regs = args->regs;
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if (kgdb_handle_exception(1, args->signr, cmd, regs))
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return NOTIFY_DONE;
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return NOTIFY_STOP;
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}
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static int
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kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
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{
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unsigned long flags;
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int ret;
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local_irq_save(flags);
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ret = __kgdb_notify(ptr, cmd);
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local_irq_restore(flags);
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return ret;
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}
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static struct notifier_block kgdb_notifier = {
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.notifier_call = kgdb_notify,
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.priority = -INT_MAX,
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};
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/**
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* kgdb_arch_init - Perform any architecture specific initalization.
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*
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* This function will handle the initalization of any architecture
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* specific callbacks.
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*/
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int kgdb_arch_init(void)
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{
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int ret = register_die_notifier(&kgdb_notifier);
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if (ret != 0)
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return ret;
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register_undef_hook(&kgdb_brkpt_hook);
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register_undef_hook(&kgdb_compiled_brkpt_hook);
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return 0;
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}
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/**
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* kgdb_arch_exit - Perform any architecture specific uninitalization.
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*
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* This function will handle the uninitalization of any architecture
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* specific callbacks, for dynamic registration and unregistration.
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*/
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void kgdb_arch_exit(void)
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{
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unregister_undef_hook(&kgdb_brkpt_hook);
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unregister_undef_hook(&kgdb_compiled_brkpt_hook);
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unregister_die_notifier(&kgdb_notifier);
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}
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int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
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{
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int err;
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/* patch_text() only supports int-sized breakpoints */
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BUILD_BUG_ON(sizeof(int) != BREAK_INSTR_SIZE);
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err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
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BREAK_INSTR_SIZE);
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if (err)
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return err;
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/* Machine is already stopped, so we can use __patch_text() directly */
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__patch_text((void *)bpt->bpt_addr,
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*(unsigned int *)arch_kgdb_ops.gdb_bpt_instr);
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return err;
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}
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int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
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{
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/* Machine is already stopped, so we can use __patch_text() directly */
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__patch_text((void *)bpt->bpt_addr, *(unsigned int *)bpt->saved_instr);
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return 0;
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}
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/*
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* Register our undef instruction hooks with ARM undef core.
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* We regsiter a hook specifically looking for the KGB break inst
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* and we handle the normal undef case within the do_undefinstr
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* handler.
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*/
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struct kgdb_arch arch_kgdb_ops = {
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#ifndef __ARMEB__
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.gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
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#else /* ! __ARMEB__ */
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.gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
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#endif
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};
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