359 lines
9.0 KiB
C
359 lines
9.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* AArch64 KGDB support
|
|
*
|
|
* Based on arch/arm/kernel/kgdb.c
|
|
*
|
|
* Copyright (C) 2013 Cavium Inc.
|
|
* Author: Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>
|
|
*/
|
|
|
|
#include <linux/bug.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/kdebug.h>
|
|
#include <linux/kgdb.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/sched/task_stack.h>
|
|
|
|
#include <asm/debug-monitors.h>
|
|
#include <asm/insn.h>
|
|
#include <asm/patching.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)},
|
|
/*
|
|
* struct pt_regs thinks PSTATE is 64-bits wide but gdb remote
|
|
* protocol disagrees. Therefore we must extract only the lower
|
|
* 32-bits. Look for the big comment in asm/kgdb.h for more
|
|
* detail.
|
|
*/
|
|
{ "pstate", 4, offsetof(struct pt_regs, pstate)
|
|
#ifdef CONFIG_CPU_BIG_ENDIAN
|
|
+ 4
|
|
#endif
|
|
},
|
|
{ "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 cpu_context *cpu_context = &task->thread.cpu_context;
|
|
|
|
/* Initialize to zero */
|
|
memset((char *)gdb_regs, 0, NUMREGBYTES);
|
|
|
|
gdb_regs[19] = cpu_context->x19;
|
|
gdb_regs[20] = cpu_context->x20;
|
|
gdb_regs[21] = cpu_context->x21;
|
|
gdb_regs[22] = cpu_context->x22;
|
|
gdb_regs[23] = cpu_context->x23;
|
|
gdb_regs[24] = cpu_context->x24;
|
|
gdb_regs[25] = cpu_context->x25;
|
|
gdb_regs[26] = cpu_context->x26;
|
|
gdb_regs[27] = cpu_context->x27;
|
|
gdb_regs[28] = cpu_context->x28;
|
|
gdb_regs[29] = cpu_context->fp;
|
|
|
|
gdb_regs[31] = cpu_context->sp;
|
|
gdb_regs[32] = cpu_context->pc;
|
|
}
|
|
|
|
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);
|
|
else
|
|
kernel_rewind_single_step(linux_regs);
|
|
err = 0;
|
|
break;
|
|
default:
|
|
err = -1;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int kgdb_brk_fn(struct pt_regs *regs, unsigned long esr)
|
|
{
|
|
kgdb_handle_exception(1, SIGTRAP, 0, regs);
|
|
return DBG_HOOK_HANDLED;
|
|
}
|
|
NOKPROBE_SYMBOL(kgdb_brk_fn)
|
|
|
|
static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned long esr)
|
|
{
|
|
compiled_break = 1;
|
|
kgdb_handle_exception(1, SIGTRAP, 0, regs);
|
|
|
|
return DBG_HOOK_HANDLED;
|
|
}
|
|
NOKPROBE_SYMBOL(kgdb_compiled_brk_fn);
|
|
|
|
static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned long esr)
|
|
{
|
|
if (!kgdb_single_step)
|
|
return DBG_HOOK_ERROR;
|
|
|
|
kgdb_handle_exception(0, SIGTRAP, 0, regs);
|
|
return DBG_HOOK_HANDLED;
|
|
}
|
|
NOKPROBE_SYMBOL(kgdb_step_brk_fn);
|
|
|
|
static struct break_hook kgdb_brkpt_hook = {
|
|
.fn = kgdb_brk_fn,
|
|
.imm = KGDB_DYN_DBG_BRK_IMM,
|
|
};
|
|
|
|
static struct break_hook kgdb_compiled_brkpt_hook = {
|
|
.fn = kgdb_compiled_brk_fn,
|
|
.imm = KGDB_COMPILED_DBG_BRK_IMM,
|
|
};
|
|
|
|
static struct step_hook kgdb_step_hook = {
|
|
.fn = kgdb_step_brk_fn
|
|
};
|
|
|
|
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 initialization.
|
|
* This function will handle the initialization of any architecture
|
|
* specific callbacks.
|
|
*/
|
|
int kgdb_arch_init(void)
|
|
{
|
|
int ret = register_die_notifier(&kgdb_notifier);
|
|
|
|
if (ret != 0)
|
|
return ret;
|
|
|
|
register_kernel_break_hook(&kgdb_brkpt_hook);
|
|
register_kernel_break_hook(&kgdb_compiled_brkpt_hook);
|
|
register_kernel_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_kernel_break_hook(&kgdb_brkpt_hook);
|
|
unregister_kernel_break_hook(&kgdb_compiled_brkpt_hook);
|
|
unregister_kernel_step_hook(&kgdb_step_hook);
|
|
unregister_die_notifier(&kgdb_notifier);
|
|
}
|
|
|
|
const struct kgdb_arch arch_kgdb_ops;
|
|
|
|
int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
|
|
{
|
|
int err;
|
|
|
|
BUILD_BUG_ON(AARCH64_INSN_SIZE != BREAK_INSTR_SIZE);
|
|
|
|
err = aarch64_insn_read((void *)bpt->bpt_addr, (u32 *)bpt->saved_instr);
|
|
if (err)
|
|
return err;
|
|
|
|
return aarch64_insn_write((void *)bpt->bpt_addr,
|
|
(u32)AARCH64_BREAK_KGDB_DYN_DBG);
|
|
}
|
|
|
|
int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
|
|
{
|
|
return aarch64_insn_write((void *)bpt->bpt_addr,
|
|
*(u32 *)bpt->saved_instr);
|
|
}
|