diff options
Diffstat (limited to 'arch/mips/kernel/kgdb.c')
| -rw-r--r-- | arch/mips/kernel/kgdb.c | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c new file mode 100644 index 000000000..2c1e30ca7 --- /dev/null +++ b/arch/mips/kernel/kgdb.c @@ -0,0 +1,424 @@ +/* + * Originally written by Glenn Engel, Lake Stevens Instrument Division + * + * Contributed by HP Systems + * + * Modified for Linux/MIPS (and MIPS in general) by Andreas Busse + * Send complaints, suggestions etc. to <andy@waldorf-gmbh.de> + * + * Copyright (C) 1995 Andreas Busse + * + * Copyright (C) 2003 MontaVista Software Inc. + * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net + * + * Copyright (C) 2004-2005 MontaVista Software Inc. + * Author: Manish Lachwani, mlachwani@mvista.com or manish@koffee-break.com + * + * Copyright (C) 2007-2008 Wind River Systems, Inc. + * Author/Maintainer: Jason Wessel, jason.wessel@windriver.com + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ + +#include <linux/ptrace.h> /* for linux pt_regs struct */ +#include <linux/kgdb.h> +#include <linux/kdebug.h> +#include <linux/sched.h> +#include <linux/smp.h> +#include <asm/inst.h> +#include <asm/fpu.h> +#include <asm/cacheflush.h> +#include <asm/processor.h> +#include <asm/sigcontext.h> +#include <linux/uaccess.h> +#include <asm/irq_regs.h> + +static struct hard_trap_info { + unsigned char tt; /* Trap type code for MIPS R3xxx and R4xxx */ + unsigned char signo; /* Signal that we map this trap into */ +} hard_trap_info[] = { + { 6, SIGBUS }, /* instruction bus error */ + { 7, SIGBUS }, /* data bus error */ + { 9, SIGTRAP }, /* break */ +/* { 11, SIGILL }, */ /* CPU unusable */ + { 12, SIGFPE }, /* overflow */ + { 13, SIGTRAP }, /* trap */ + { 14, SIGSEGV }, /* virtual instruction cache coherency */ + { 15, SIGFPE }, /* floating point exception */ + { 23, SIGSEGV }, /* watch */ + { 31, SIGSEGV }, /* virtual data cache coherency */ + { 0, 0} /* Must be last */ +}; + +struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = +{ + { "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) }, + { "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) }, + { "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) }, + { "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) }, + { "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) }, + { "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) }, + { "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) }, + { "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) }, + { "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) }, + { "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) }, + { "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) }, + { "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) }, + { "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) }, + { "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) }, + { "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) }, + { "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) }, + { "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) }, + { "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) }, + { "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) }, + { "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) }, + { "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) }, + { "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) }, + { "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) }, + { "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) }, + { "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) }, + { "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) }, + { "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) }, + { "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) }, + { "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) }, + { "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) }, + { "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) }, + { "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) }, + { "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) }, + { "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) }, + { "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) }, + { "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) }, + { "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) }, + { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) }, + { "f0", GDB_SIZEOF_REG, 0 }, + { "f1", GDB_SIZEOF_REG, 1 }, + { "f2", GDB_SIZEOF_REG, 2 }, + { "f3", GDB_SIZEOF_REG, 3 }, + { "f4", GDB_SIZEOF_REG, 4 }, + { "f5", GDB_SIZEOF_REG, 5 }, + { "f6", GDB_SIZEOF_REG, 6 }, + { "f7", GDB_SIZEOF_REG, 7 }, + { "f8", GDB_SIZEOF_REG, 8 }, + { "f9", GDB_SIZEOF_REG, 9 }, + { "f10", GDB_SIZEOF_REG, 10 }, + { "f11", GDB_SIZEOF_REG, 11 }, + { "f12", GDB_SIZEOF_REG, 12 }, + { "f13", GDB_SIZEOF_REG, 13 }, + { "f14", GDB_SIZEOF_REG, 14 }, + { "f15", GDB_SIZEOF_REG, 15 }, + { "f16", GDB_SIZEOF_REG, 16 }, + { "f17", GDB_SIZEOF_REG, 17 }, + { "f18", GDB_SIZEOF_REG, 18 }, + { "f19", GDB_SIZEOF_REG, 19 }, + { "f20", GDB_SIZEOF_REG, 20 }, + { "f21", GDB_SIZEOF_REG, 21 }, + { "f22", GDB_SIZEOF_REG, 22 }, + { "f23", GDB_SIZEOF_REG, 23 }, + { "f24", GDB_SIZEOF_REG, 24 }, + { "f25", GDB_SIZEOF_REG, 25 }, + { "f26", GDB_SIZEOF_REG, 26 }, + { "f27", GDB_SIZEOF_REG, 27 }, + { "f28", GDB_SIZEOF_REG, 28 }, + { "f29", GDB_SIZEOF_REG, 29 }, + { "f30", GDB_SIZEOF_REG, 30 }, + { "f31", GDB_SIZEOF_REG, 31 }, + { "fsr", GDB_SIZEOF_REG, 0 }, + { "fir", GDB_SIZEOF_REG, 0 }, +}; + +int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) +{ + int fp_reg; + + if (regno < 0 || regno >= DBG_MAX_REG_NUM) + return -EINVAL; + + if (dbg_reg_def[regno].offset != -1 && regno < 38) { + memcpy((void *)regs + dbg_reg_def[regno].offset, mem, + dbg_reg_def[regno].size); + } else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) { + /* FP registers 38 -> 69 */ + if (!(regs->cp0_status & ST0_CU1)) + return 0; + if (regno == 70) { + /* Process the fcr31/fsr (register 70) */ + memcpy((void *)¤t->thread.fpu.fcr31, mem, + dbg_reg_def[regno].size); + goto out_save; + } else if (regno == 71) { + /* Ignore the fir (register 71) */ + goto out_save; + } + fp_reg = dbg_reg_def[regno].offset; + memcpy((void *)¤t->thread.fpu.fpr[fp_reg], mem, + dbg_reg_def[regno].size); +out_save: + restore_fp(current); + } + + return 0; +} + +char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) +{ + int fp_reg; + + if (regno >= DBG_MAX_REG_NUM || regno < 0) + return NULL; + + if (dbg_reg_def[regno].offset != -1 && regno < 38) { + /* First 38 registers */ + memcpy(mem, (void *)regs + dbg_reg_def[regno].offset, + dbg_reg_def[regno].size); + } else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) { + /* FP registers 38 -> 69 */ + if (!(regs->cp0_status & ST0_CU1)) + goto out; + save_fp(current); + if (regno == 70) { + /* Process the fcr31/fsr (register 70) */ + memcpy(mem, (void *)¤t->thread.fpu.fcr31, + dbg_reg_def[regno].size); + goto out; + } else if (regno == 71) { + /* Ignore the fir (register 71) */ + memset(mem, 0, dbg_reg_def[regno].size); + goto out; + } + fp_reg = dbg_reg_def[regno].offset; + memcpy(mem, (void *)¤t->thread.fpu.fpr[fp_reg], + dbg_reg_def[regno].size); + } + +out: + return dbg_reg_def[regno].name; + +} + +void arch_kgdb_breakpoint(void) +{ + __asm__ __volatile__( + ".globl breakinst\n\t" + ".set\tnoreorder\n\t" + "nop\n" + "breakinst:\tbreak\n\t" + "nop\n\t" + ".set\treorder"); +} + +static void kgdb_call_nmi_hook(void *ignored) +{ + mm_segment_t old_fs; + + old_fs = get_fs(); + set_fs(get_ds()); + + kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); + + set_fs(old_fs); +} + +void kgdb_roundup_cpus(unsigned long flags) +{ + local_irq_enable(); + smp_call_function(kgdb_call_nmi_hook, NULL, 0); + local_irq_disable(); +} + +static int compute_signal(int tt) +{ + struct hard_trap_info *ht; + + for (ht = hard_trap_info; ht->tt && ht->signo; ht++) + if (ht->tt == tt) + return ht->signo; + + return SIGHUP; /* default for things we don't know about */ +} + +/* + * Similar to regs_to_gdb_regs() except that process is sleeping and so + * we may not be able to get all the info. + */ +void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) +{ + int reg; +#if (KGDB_GDB_REG_SIZE == 32) + u32 *ptr = (u32 *)gdb_regs; +#else + u64 *ptr = (u64 *)gdb_regs; +#endif + + for (reg = 0; reg < 16; reg++) + *(ptr++) = 0; + + /* S0 - S7 */ + *(ptr++) = p->thread.reg16; + *(ptr++) = p->thread.reg17; + *(ptr++) = p->thread.reg18; + *(ptr++) = p->thread.reg19; + *(ptr++) = p->thread.reg20; + *(ptr++) = p->thread.reg21; + *(ptr++) = p->thread.reg22; + *(ptr++) = p->thread.reg23; + + for (reg = 24; reg < 28; reg++) + *(ptr++) = 0; + + /* GP, SP, FP, RA */ + *(ptr++) = (long)p; + *(ptr++) = p->thread.reg29; + *(ptr++) = p->thread.reg30; + *(ptr++) = p->thread.reg31; + + *(ptr++) = p->thread.cp0_status; + + /* lo, hi */ + *(ptr++) = 0; + *(ptr++) = 0; + + /* + * BadVAddr, Cause + * Ideally these would come from the last exception frame up the stack + * but that requires unwinding, otherwise we can't know much for sure. + */ + *(ptr++) = 0; + *(ptr++) = 0; + + /* + * PC + * use return address (RA), i.e. the moment after return from resume() + */ + *(ptr++) = p->thread.reg31; +} + +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) +{ + regs->cp0_epc = pc; +} + +/* + * Calls linux_debug_hook before the kernel dies. If KGDB is enabled, + * then try to fall into the debugger + */ +static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd, + void *ptr) +{ + struct die_args *args = (struct die_args *)ptr; + struct pt_regs *regs = args->regs; + int trap = (regs->cp0_cause & 0x7c) >> 2; + mm_segment_t old_fs; + +#ifdef CONFIG_KPROBES + /* + * Return immediately if the kprobes fault notifier has set + * DIE_PAGE_FAULT. + */ + if (cmd == DIE_PAGE_FAULT) + return NOTIFY_DONE; +#endif /* CONFIG_KPROBES */ + + /* Userspace events, ignore. */ + if (user_mode(regs)) + return NOTIFY_DONE; + + /* Kernel mode. Set correct address limit */ + old_fs = get_fs(); + set_fs(get_ds()); + + if (atomic_read(&kgdb_active) != -1) + kgdb_nmicallback(smp_processor_id(), regs); + + if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs)) { + set_fs(old_fs); + return NOTIFY_DONE; + } + + if (atomic_read(&kgdb_setting_breakpoint)) + if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst)) + regs->cp0_epc += 4; + + /* In SMP mode, __flush_cache_all does IPI */ + local_irq_enable(); + __flush_cache_all(); + + set_fs(old_fs); + return NOTIFY_STOP; +} + +#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP +int kgdb_ll_trap(int cmd, const char *str, + struct pt_regs *regs, long err, int trap, int sig) +{ + struct die_args args = { + .regs = regs, + .str = str, + .err = err, + .trapnr = trap, + .signr = sig, + + }; + + if (!kgdb_io_module_registered) + return NOTIFY_DONE; + + return kgdb_mips_notify(NULL, cmd, &args); +} +#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ + +static struct notifier_block kgdb_notifier = { + .notifier_call = kgdb_mips_notify, +}; + +/* + * Handle the 'c' command + */ +int kgdb_arch_handle_exception(int vector, int signo, int err_code, + char *remcom_in_buffer, char *remcom_out_buffer, + struct pt_regs *regs) +{ + char *ptr; + unsigned long address; + + switch (remcom_in_buffer[0]) { + case 'c': + /* handle the optional parameter */ + ptr = &remcom_in_buffer[1]; + if (kgdb_hex2long(&ptr, &address)) + regs->cp0_epc = address; + + return 0; + } + + return -1; +} + +struct kgdb_arch arch_kgdb_ops; + +int kgdb_arch_init(void) +{ + union mips_instruction insn = { + .r_format = { + .opcode = spec_op, + .func = break_op, + } + }; + memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE); + + register_die_notifier(&kgdb_notifier); + + return 0; +} + +/* + * kgdb_arch_exit - Perform any architecture specific uninitalization. + * + * This function will handle the uninitalization of any architecture + * specific callbacks, for dynamic registration and unregistration. + */ +void kgdb_arch_exit(void) +{ + unregister_die_notifier(&kgdb_notifier); +} |