215 lines
		
	
	
		
			6.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			215 lines
		
	
	
		
			6.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  * arch/hexagon/kernel/kgdb.c - Hexagon KGDB Support
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|  *
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|  * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
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|  */
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| 
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| #include <linux/irq.h>
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| #include <linux/sched.h>
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| #include <linux/sched/task_stack.h>
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| #include <linux/kdebug.h>
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| #include <linux/kgdb.h>
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| 
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| /* All registers are 4 bytes, for now */
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| #define GDB_SIZEOF_REG 4
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| 
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| /* The register names are used during printing of the regs;
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|  * Keep these at three letters to pretty-print. */
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| struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
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| 	{ " r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, r00)},
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| 	{ " r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, r01)},
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| 	{ " r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r02)},
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| 	{ " r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r03)},
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| 	{ " r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r04)},
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| 	{ " r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r05)},
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| 	{ " r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r06)},
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| 	{ " r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r07)},
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| 	{ " r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r08)},
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| 	{ " r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r09)},
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| 	{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10)},
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| 	{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11)},
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| 	{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12)},
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| 	{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13)},
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| 	{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14)},
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| 	{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15)},
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| 	{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, r16)},
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| 	{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, r17)},
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| 	{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, r18)},
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| 	{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, r19)},
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| 	{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, r20)},
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| 	{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, r21)},
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| 	{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, r22)},
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| 	{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, r23)},
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| 	{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, r24)},
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| 	{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, r25)},
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| 	{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, r26)},
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| 	{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, r27)},
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| 	{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, r28)},
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| 	{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, r29)},
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| 	{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, r30)},
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| 	{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, r31)},
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| 
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| 	{ "usr", GDB_SIZEOF_REG, offsetof(struct pt_regs, usr)},
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| 	{ "preds", GDB_SIZEOF_REG, offsetof(struct pt_regs, preds)},
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| 	{ " m0", GDB_SIZEOF_REG, offsetof(struct pt_regs, m0)},
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| 	{ " m1", GDB_SIZEOF_REG, offsetof(struct pt_regs, m1)},
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| 	{ "sa0", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa0)},
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| 	{ "sa1", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa1)},
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| 	{ "lc0", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc0)},
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| 	{ "lc1", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc1)},
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| 	{ " gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)},
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| 	{ "ugp", GDB_SIZEOF_REG, offsetof(struct pt_regs, ugp)},
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| 	{ "cs0", GDB_SIZEOF_REG, offsetof(struct pt_regs, cs0)},
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| 	{ "cs1", GDB_SIZEOF_REG, offsetof(struct pt_regs, cs1)},
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| 	{ "psp", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmpsp)},
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| 	{ "elr", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmel)},
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| 	{ "est", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmest)},
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| 	{ "badva", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmbadva)},
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| 	{ "restart_r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, restart_r0)},
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| 	{ "syscall_nr", GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)},
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| };
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| 
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| const struct kgdb_arch arch_kgdb_ops = {
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| 	/* trap0(#0xDB) 0x0cdb0054 */
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| 	.gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c},
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| };
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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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| 
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| 	*((unsigned long *) mem) = *((unsigned long *) ((void *)regs +
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| 		dbg_reg_def[regno].offset));
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| 
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| 	return dbg_reg_def[regno].name;
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| }
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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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| 
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| 	*((unsigned long *) ((void *)regs + dbg_reg_def[regno].offset)) =
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| 		*((unsigned long *) mem);
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| 
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| 	return 0;
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| }
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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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| 	instruction_pointer(regs) = pc;
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| }
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| 
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| 
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| /*  Not yet working  */
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| void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
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| 				 struct task_struct *task)
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| {
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| 	struct pt_regs *thread_regs;
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| 
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| 	if (task == NULL)
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| 		return;
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| 
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| 	/* Initialize to zero */
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| 	memset(gdb_regs, 0, NUMREGBYTES);
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| 
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| 	/* Otherwise, we have only some registers from switch_to() */
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| 	thread_regs = task_pt_regs(task);
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| 	gdb_regs[0] = thread_regs->r00;
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| }
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| 
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| /**
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|  * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
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|  * @vector: The error vector of the exception that happened.
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|  * @signo: The signal number of the exception that happened.
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|  * @err_code: The error code of the exception that happened.
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|  * @remcom_in_buffer: The buffer of the packet we have read.
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|  * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
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|  * @regs: The &struct pt_regs of the current process.
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|  *
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|  * This function MUST handle the 'c' and 's' command packets,
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|  * as well packets to set / remove a hardware breakpoint, if used.
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|  * If there are additional packets which the hardware needs to handle,
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|  * they are handled here.  The code should return -1 if it wants to
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|  * process more packets, and a %0 or %1 if it wants to exit from the
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|  * kgdb callback.
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|  *
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|  * Not yet working.
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|  */
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| int kgdb_arch_handle_exception(int vector, int signo, int err_code,
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| 			       char *remcom_in_buffer, char *remcom_out_buffer,
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| 			       struct pt_regs *linux_regs)
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| {
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| 	switch (remcom_in_buffer[0]) {
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| 	case 's':
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| 	case 'c':
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| 		return 0;
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| 	}
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| 	/* Stay in the debugger. */
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| 	return -1;
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| }
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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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| 	/* cpu roundup */
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| 	if (atomic_read(&kgdb_active) != -1) {
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| 		kgdb_nmicallback(smp_processor_id(), args->regs);
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| 		return NOTIFY_STOP;
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| 	}
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| 
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| 	if (user_mode(args->regs))
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| 		return NOTIFY_DONE;
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| 
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| 	if (kgdb_handle_exception(args->trapnr & 0xff, args->signr, args->err,
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| 				    args->regs))
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| 		return NOTIFY_DONE;
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| 
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| 	return NOTIFY_STOP;
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| }
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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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| 
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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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| 
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| 	return ret;
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| }
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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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| 
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| 	/*
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| 	 * Lowest-prio notifier priority, we want to be notified last:
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| 	 */
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| 	.priority = -INT_MAX,
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| };
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| 
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| /**
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|  * kgdb_arch_init - Perform any architecture specific initialization.
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|  *
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|  * This function will handle the initialization 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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| 	return register_die_notifier(&kgdb_notifier);
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| }
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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_die_notifier(&kgdb_notifier);
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| }
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