| /* |
| * AArch64 KGDB support |
| * |
| * Based on arch/arm/kernel/kgdb.c |
| * |
| * Copyright (C) 2013 Cavium Inc. |
| * Author: Vijaya Kumar K <vijaya.kumar@caviumnetworks.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <linux/irq.h> |
| #include <linux/kdebug.h> |
| #include <linux/kgdb.h> |
| #include <asm/traps.h> |
| |
| struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { |
| { "x0", 8, offsetof(struct pt_regs, regs[0])}, |
| { "x1", 8, offsetof(struct pt_regs, regs[1])}, |
| { "x2", 8, offsetof(struct pt_regs, regs[2])}, |
| { "x3", 8, offsetof(struct pt_regs, regs[3])}, |
| { "x4", 8, offsetof(struct pt_regs, regs[4])}, |
| { "x5", 8, offsetof(struct pt_regs, regs[5])}, |
| { "x6", 8, offsetof(struct pt_regs, regs[6])}, |
| { "x7", 8, offsetof(struct pt_regs, regs[7])}, |
| { "x8", 8, offsetof(struct pt_regs, regs[8])}, |
| { "x9", 8, offsetof(struct pt_regs, regs[9])}, |
| { "x10", 8, offsetof(struct pt_regs, regs[10])}, |
| { "x11", 8, offsetof(struct pt_regs, regs[11])}, |
| { "x12", 8, offsetof(struct pt_regs, regs[12])}, |
| { "x13", 8, offsetof(struct pt_regs, regs[13])}, |
| { "x14", 8, offsetof(struct pt_regs, regs[14])}, |
| { "x15", 8, offsetof(struct pt_regs, regs[15])}, |
| { "x16", 8, offsetof(struct pt_regs, regs[16])}, |
| { "x17", 8, offsetof(struct pt_regs, regs[17])}, |
| { "x18", 8, offsetof(struct pt_regs, regs[18])}, |
| { "x19", 8, offsetof(struct pt_regs, regs[19])}, |
| { "x20", 8, offsetof(struct pt_regs, regs[20])}, |
| { "x21", 8, offsetof(struct pt_regs, regs[21])}, |
| { "x22", 8, offsetof(struct pt_regs, regs[22])}, |
| { "x23", 8, offsetof(struct pt_regs, regs[23])}, |
| { "x24", 8, offsetof(struct pt_regs, regs[24])}, |
| { "x25", 8, offsetof(struct pt_regs, regs[25])}, |
| { "x26", 8, offsetof(struct pt_regs, regs[26])}, |
| { "x27", 8, offsetof(struct pt_regs, regs[27])}, |
| { "x28", 8, offsetof(struct pt_regs, regs[28])}, |
| { "x29", 8, offsetof(struct pt_regs, regs[29])}, |
| { "x30", 8, offsetof(struct pt_regs, regs[30])}, |
| { "sp", 8, offsetof(struct pt_regs, sp)}, |
| { "pc", 8, offsetof(struct pt_regs, pc)}, |
| { "pstate", 8, offsetof(struct pt_regs, pstate)}, |
| { "v0", 16, -1 }, |
| { "v1", 16, -1 }, |
| { "v2", 16, -1 }, |
| { "v3", 16, -1 }, |
| { "v4", 16, -1 }, |
| { "v5", 16, -1 }, |
| { "v6", 16, -1 }, |
| { "v7", 16, -1 }, |
| { "v8", 16, -1 }, |
| { "v9", 16, -1 }, |
| { "v10", 16, -1 }, |
| { "v11", 16, -1 }, |
| { "v12", 16, -1 }, |
| { "v13", 16, -1 }, |
| { "v14", 16, -1 }, |
| { "v15", 16, -1 }, |
| { "v16", 16, -1 }, |
| { "v17", 16, -1 }, |
| { "v18", 16, -1 }, |
| { "v19", 16, -1 }, |
| { "v20", 16, -1 }, |
| { "v21", 16, -1 }, |
| { "v22", 16, -1 }, |
| { "v23", 16, -1 }, |
| { "v24", 16, -1 }, |
| { "v25", 16, -1 }, |
| { "v26", 16, -1 }, |
| { "v27", 16, -1 }, |
| { "v28", 16, -1 }, |
| { "v29", 16, -1 }, |
| { "v30", 16, -1 }, |
| { "v31", 16, -1 }, |
| { "fpsr", 4, -1 }, |
| { "fpcr", 4, -1 }, |
| }; |
| |
| char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) |
| { |
| if (regno >= DBG_MAX_REG_NUM || regno < 0) |
| return NULL; |
| |
| if (dbg_reg_def[regno].offset != -1) |
| memcpy(mem, (void *)regs + dbg_reg_def[regno].offset, |
| dbg_reg_def[regno].size); |
| else |
| memset(mem, 0, dbg_reg_def[regno].size); |
| return dbg_reg_def[regno].name; |
| } |
| |
| int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) |
| { |
| if (regno >= DBG_MAX_REG_NUM || regno < 0) |
| return -EINVAL; |
| |
| if (dbg_reg_def[regno].offset != -1) |
| memcpy((void *)regs + dbg_reg_def[regno].offset, mem, |
| dbg_reg_def[regno].size); |
| return 0; |
| } |
| |
| void |
| sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) |
| { |
| struct pt_regs *thread_regs; |
| |
| /* Initialize to zero */ |
| memset((char *)gdb_regs, 0, NUMREGBYTES); |
| thread_regs = task_pt_regs(task); |
| memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES); |
| } |
| |
| void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) |
| { |
| regs->pc = pc; |
| } |
| |
| static int compiled_break; |
| |
| static void kgdb_arch_update_addr(struct pt_regs *regs, |
| char *remcom_in_buffer) |
| { |
| unsigned long addr; |
| char *ptr; |
| |
| ptr = &remcom_in_buffer[1]; |
| if (kgdb_hex2long(&ptr, &addr)) |
| kgdb_arch_set_pc(regs, addr); |
| else if (compiled_break == 1) |
| kgdb_arch_set_pc(regs, regs->pc + 4); |
| |
| compiled_break = 0; |
| } |
| |
| int kgdb_arch_handle_exception(int exception_vector, int signo, |
| int err_code, char *remcom_in_buffer, |
| char *remcom_out_buffer, |
| struct pt_regs *linux_regs) |
| { |
| int err; |
| |
| switch (remcom_in_buffer[0]) { |
| case 'D': |
| case 'k': |
| /* |
| * Packet D (Detach), k (kill). No special handling |
| * is required here. Handle same as c packet. |
| */ |
| case 'c': |
| /* |
| * Packet c (Continue) to continue executing. |
| * Set pc to required address. |
| * Try to read optional parameter and set pc. |
| * If this was a compiled breakpoint, we need to move |
| * to the next instruction else we will just breakpoint |
| * over and over again. |
| */ |
| kgdb_arch_update_addr(linux_regs, remcom_in_buffer); |
| atomic_set(&kgdb_cpu_doing_single_step, -1); |
| kgdb_single_step = 0; |
| |
| /* |
| * Received continue command, disable single step |
| */ |
| if (kernel_active_single_step()) |
| kernel_disable_single_step(); |
| |
| err = 0; |
| break; |
| case 's': |
| /* |
| * Update step address value with address passed |
| * with step packet. |
| * On debug exception return PC is copied to ELR |
| * So just update PC. |
| * If no step address is passed, resume from the address |
| * pointed by PC. Do not update PC |
| */ |
| kgdb_arch_update_addr(linux_regs, remcom_in_buffer); |
| atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id()); |
| kgdb_single_step = 1; |
| |
| /* |
| * Enable single step handling |
| */ |
| if (!kernel_active_single_step()) |
| kernel_enable_single_step(linux_regs); |
| err = 0; |
| break; |
| default: |
| err = -1; |
| } |
| return err; |
| } |
| |
| static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr) |
| { |
| if (user_mode(regs)) |
| return DBG_HOOK_ERROR; |
| |
| kgdb_handle_exception(1, SIGTRAP, 0, regs); |
| return DBG_HOOK_HANDLED; |
| } |
| |
| static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr) |
| { |
| if (user_mode(regs)) |
| return DBG_HOOK_ERROR; |
| |
| compiled_break = 1; |
| kgdb_handle_exception(1, SIGTRAP, 0, regs); |
| |
| return DBG_HOOK_HANDLED; |
| } |
| |
| static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr) |
| { |
| if (user_mode(regs)) |
| return DBG_HOOK_ERROR; |
| |
| kgdb_handle_exception(1, SIGTRAP, 0, regs); |
| return DBG_HOOK_HANDLED; |
| } |
| |
| static struct break_hook kgdb_brkpt_hook = { |
| .esr_mask = 0xffffffff, |
| .esr_val = (u32)ESR_ELx_VAL_BRK64(KGDB_DYN_DBG_BRK_IMM), |
| .fn = kgdb_brk_fn |
| }; |
| |
| static struct break_hook kgdb_compiled_brkpt_hook = { |
| .esr_mask = 0xffffffff, |
| .esr_val = (u32)ESR_ELx_VAL_BRK64(KGDB_COMPILED_DBG_BRK_IMM), |
| .fn = kgdb_compiled_brk_fn |
| }; |
| |
| static struct step_hook kgdb_step_hook = { |
| .fn = kgdb_step_brk_fn |
| }; |
| |
| static void kgdb_call_nmi_hook(void *ignored) |
| { |
| kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); |
| } |
| |
| void kgdb_roundup_cpus(unsigned long flags) |
| { |
| local_irq_enable(); |
| smp_call_function(kgdb_call_nmi_hook, NULL, 0); |
| local_irq_disable(); |
| } |
| |
| static int __kgdb_notify(struct die_args *args, unsigned long cmd) |
| { |
| struct pt_regs *regs = args->regs; |
| |
| if (kgdb_handle_exception(1, args->signr, cmd, regs)) |
| return NOTIFY_DONE; |
| return NOTIFY_STOP; |
| } |
| |
| static int |
| kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) |
| { |
| unsigned long flags; |
| int ret; |
| |
| local_irq_save(flags); |
| ret = __kgdb_notify(ptr, cmd); |
| local_irq_restore(flags); |
| |
| return ret; |
| } |
| |
| static struct notifier_block kgdb_notifier = { |
| .notifier_call = kgdb_notify, |
| /* |
| * Want to be lowest priority |
| */ |
| .priority = -INT_MAX, |
| }; |
| |
| /* |
| * kgdb_arch_init - Perform any architecture specific initalization. |
| * This function will handle the initalization of any architecture |
| * specific callbacks. |
| */ |
| int kgdb_arch_init(void) |
| { |
| int ret = register_die_notifier(&kgdb_notifier); |
| |
| if (ret != 0) |
| return ret; |
| |
| register_break_hook(&kgdb_brkpt_hook); |
| register_break_hook(&kgdb_compiled_brkpt_hook); |
| register_step_hook(&kgdb_step_hook); |
| 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_break_hook(&kgdb_brkpt_hook); |
| unregister_break_hook(&kgdb_compiled_brkpt_hook); |
| unregister_step_hook(&kgdb_step_hook); |
| unregister_die_notifier(&kgdb_notifier); |
| } |
| |
| /* |
| * ARM instructions are always in LE. |
| * Break instruction is encoded in LE format |
| */ |
| struct kgdb_arch arch_kgdb_ops = { |
| .gdb_bpt_instr = { |
| KGDB_DYN_BRK_INS_BYTE(0), |
| KGDB_DYN_BRK_INS_BYTE(1), |
| KGDB_DYN_BRK_INS_BYTE(2), |
| KGDB_DYN_BRK_INS_BYTE(3), |
| } |
| }; |