/* * 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 * * 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 /* for linux pt_regs struct */ #include #include #include #include #include #include #include #include #include #include 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 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; #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; if (atomic_read(&kgdb_active) != -1) kgdb_nmicallback(smp_processor_id(), regs); if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs)) 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(); 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; } const struct kgdb_arch arch_kgdb_ops = { #ifdef CONFIG_CPU_BIG_ENDIAN .gdb_bpt_instr = { spec_op << 2, 0x00, 0x00, break_op }, #else .gdb_bpt_instr = { break_op, 0x00, 0x00, spec_op << 2 }, #endif }; int kgdb_arch_init(void) { 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); }