arch/arc/kernel/ptrace.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  */

 #include <linux/ptrace.h>
 #include <linux/sched/task_stack.h>
 #include <linux/regset.h>
 #include <linux/unistd.h>
 #include <linux/elf.h>

 #define CREATE_TRACE_POINTS
 #include <trace/events/syscalls.h>

 struct pt_regs_offset {
 	const char *name;
 	int offset;
 };

 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 #define REG_OFFSET_END {.name = NULL, .offset = 0}

 #ifdef CONFIG_ISA_ARCOMPACT
 static const struct pt_regs_offset regoffset_table[] = {
 	REG_OFFSET_NAME(bta),
 	REG_OFFSET_NAME(lp_start),
 	REG_OFFSET_NAME(lp_end),
 	REG_OFFSET_NAME(lp_count),
 	REG_OFFSET_NAME(status32),
 	REG_OFFSET_NAME(ret),
 	REG_OFFSET_NAME(blink),
 	REG_OFFSET_NAME(fp),
 	REG_OFFSET_NAME(r26),
 	REG_OFFSET_NAME(r12),
 	REG_OFFSET_NAME(r11),
 	REG_OFFSET_NAME(r10),
 	REG_OFFSET_NAME(r9),
 	REG_OFFSET_NAME(r8),
 	REG_OFFSET_NAME(r7),
 	REG_OFFSET_NAME(r6),
 	REG_OFFSET_NAME(r5),
 	REG_OFFSET_NAME(r4),
 	REG_OFFSET_NAME(r3),
 	REG_OFFSET_NAME(r2),
 	REG_OFFSET_NAME(r1),
 	REG_OFFSET_NAME(r0),
 	REG_OFFSET_NAME(sp),
 	REG_OFFSET_NAME(orig_r0),
 	REG_OFFSET_NAME(event),
 	REG_OFFSET_NAME(user_r25),
 	REG_OFFSET_END,
 };

 #else

 static const struct pt_regs_offset regoffset_table[] = {
 	REG_OFFSET_NAME(orig_r0),
 	REG_OFFSET_NAME(event),
 	REG_OFFSET_NAME(bta),
 	REG_OFFSET_NAME(user_r25),
 	REG_OFFSET_NAME(r26),
 	REG_OFFSET_NAME(fp),
 	REG_OFFSET_NAME(sp),
 	REG_OFFSET_NAME(r12),
 	REG_OFFSET_NAME(r30),
 #ifdef CONFIG_ARC_HAS_ACCL_REGS
 	REG_OFFSET_NAME(r58),
 	REG_OFFSET_NAME(r59),
 #endif
 #ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
 	REG_OFFSET_NAME(DSP_CTRL),
 #endif
 	REG_OFFSET_NAME(r0),
 	REG_OFFSET_NAME(r1),
 	REG_OFFSET_NAME(r2),
 	REG_OFFSET_NAME(r3),
 	REG_OFFSET_NAME(r4),
 	REG_OFFSET_NAME(r5),
 	REG_OFFSET_NAME(r6),
 	REG_OFFSET_NAME(r7),
 	REG_OFFSET_NAME(r8),
 	REG_OFFSET_NAME(r9),
 	REG_OFFSET_NAME(r10),
 	REG_OFFSET_NAME(r11),
 	REG_OFFSET_NAME(blink),
 	REG_OFFSET_NAME(lp_end),
 	REG_OFFSET_NAME(lp_start),
 	REG_OFFSET_NAME(lp_count),
 	REG_OFFSET_NAME(ei),
 	REG_OFFSET_NAME(ldi),
 	REG_OFFSET_NAME(jli),
 	REG_OFFSET_NAME(ret),
 	REG_OFFSET_NAME(status32),
 	REG_OFFSET_END,
 };
 #endif

 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
 {
 	struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
 	return tmp;
 }

 static int genregs_get(struct task_struct *target,
 		       const struct user_regset *regset,
 		       struct membuf to)
 {
 	const struct pt_regs *ptregs = task_pt_regs(target);
 	const struct callee_regs *cregs = task_callee_regs(target);
 	unsigned int stop_pc_val;

 	membuf_zero(&to, 4);	// pad
 	membuf_store(&to, ptregs->bta);
 	membuf_store(&to, ptregs->lp_start);
 	membuf_store(&to, ptregs->lp_end);
 	membuf_store(&to, ptregs->lp_count);
 	membuf_store(&to, ptregs->status32);
 	membuf_store(&to, ptregs->ret);
 	membuf_store(&to, ptregs->blink);
 	membuf_store(&to, ptregs->fp);
 	membuf_store(&to, ptregs->r26);	// gp
 	membuf_store(&to, ptregs->r12);
 	membuf_store(&to, ptregs->r11);
 	membuf_store(&to, ptregs->r10);
 	membuf_store(&to, ptregs->r9);
 	membuf_store(&to, ptregs->r8);
 	membuf_store(&to, ptregs->r7);
 	membuf_store(&to, ptregs->r6);
 	membuf_store(&to, ptregs->r5);
 	membuf_store(&to, ptregs->r4);
 	membuf_store(&to, ptregs->r3);
 	membuf_store(&to, ptregs->r2);
 	membuf_store(&to, ptregs->r1);
 	membuf_store(&to, ptregs->r0);
 	membuf_store(&to, ptregs->sp);
 	membuf_zero(&to, 4);	// pad2
 	membuf_store(&to, cregs->r25);
 	membuf_store(&to, cregs->r24);
 	membuf_store(&to, cregs->r23);
 	membuf_store(&to, cregs->r22);
 	membuf_store(&to, cregs->r21);
 	membuf_store(&to, cregs->r20);
 	membuf_store(&to, cregs->r19);
 	membuf_store(&to, cregs->r18);
 	membuf_store(&to, cregs->r17);
 	membuf_store(&to, cregs->r16);
 	membuf_store(&to, cregs->r15);
 	membuf_store(&to, cregs->r14);
 	membuf_store(&to, cregs->r13);
 	membuf_store(&to, target->thread.fault_address); // efa

 	if (in_brkpt_trap(ptregs)) {
 		stop_pc_val = target->thread.fault_address;
 		pr_debug("\t\tstop_pc (brk-pt)\n");
 	} else {
 		stop_pc_val = ptregs->ret;
 		pr_debug("\t\tstop_pc (others)\n");
 	}

 	return membuf_store(&to, stop_pc_val); // stop_pc
 }

 static int genregs_set(struct task_struct *target,
 		       const struct user_regset *regset,
 		       unsigned int pos, unsigned int count,
 		       const void *kbuf, const void __user *ubuf)
 {
 	const struct pt_regs *ptregs = task_pt_regs(target);
 	const struct callee_regs *cregs = task_callee_regs(target);
 	int ret = 0;

 #define REG_IN_CHUNK(FIRST, NEXT, PTR)	\
 	if (!ret)			\
 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
 			(void *)(PTR), \
 			offsetof(struct user_regs_struct, FIRST), \
 			offsetof(struct user_regs_struct, NEXT));

 #define REG_IN_ONE(LOC, PTR)		\
 	if (!ret)			\
 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
 			(void *)(PTR), \
 			offsetof(struct user_regs_struct, LOC), \
 			offsetof(struct user_regs_struct, LOC) + 4);

 #define REG_IGNORE_ONE(LOC)		\
 	if (!ret)			\
 		user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
 			offsetof(struct user_regs_struct, LOC), \
 			offsetof(struct user_regs_struct, LOC) + 4);

 	REG_IGNORE_ONE(pad);

 	REG_IN_ONE(scratch.bta, &ptregs->bta);
 	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
 	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
 	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);

 	REG_IGNORE_ONE(scratch.status32);

 	REG_IN_ONE(scratch.ret, &ptregs->ret);
 	REG_IN_ONE(scratch.blink, &ptregs->blink);
 	REG_IN_ONE(scratch.fp, &ptregs->fp);
 	REG_IN_ONE(scratch.gp, &ptregs->r26);
 	REG_IN_ONE(scratch.r12, &ptregs->r12);
 	REG_IN_ONE(scratch.r11, &ptregs->r11);
 	REG_IN_ONE(scratch.r10, &ptregs->r10);
 	REG_IN_ONE(scratch.r9, &ptregs->r9);
 	REG_IN_ONE(scratch.r8, &ptregs->r8);
 	REG_IN_ONE(scratch.r7, &ptregs->r7);
 	REG_IN_ONE(scratch.r6, &ptregs->r6);
 	REG_IN_ONE(scratch.r5, &ptregs->r5);
 	REG_IN_ONE(scratch.r4, &ptregs->r4);
 	REG_IN_ONE(scratch.r3, &ptregs->r3);
 	REG_IN_ONE(scratch.r2, &ptregs->r2);
 	REG_IN_ONE(scratch.r1, &ptregs->r1);
 	REG_IN_ONE(scratch.r0, &ptregs->r0);
 	REG_IN_ONE(scratch.sp, &ptregs->sp);

 	REG_IGNORE_ONE(pad2);

 	REG_IN_ONE(callee.r25, &cregs->r25);
 	REG_IN_ONE(callee.r24, &cregs->r24);
 	REG_IN_ONE(callee.r23, &cregs->r23);
 	REG_IN_ONE(callee.r22, &cregs->r22);
 	REG_IN_ONE(callee.r21, &cregs->r21);
 	REG_IN_ONE(callee.r20, &cregs->r20);
 	REG_IN_ONE(callee.r19, &cregs->r19);
 	REG_IN_ONE(callee.r18, &cregs->r18);
 	REG_IN_ONE(callee.r17, &cregs->r17);
 	REG_IN_ONE(callee.r16, &cregs->r16);
 	REG_IN_ONE(callee.r15, &cregs->r15);
 	REG_IN_ONE(callee.r14, &cregs->r14);
 	REG_IN_ONE(callee.r13, &cregs->r13);

 	REG_IGNORE_ONE(efa);			/* efa update invalid */
 	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */

 	return ret;
 }

 #ifdef CONFIG_ISA_ARCV2
 static int arcv2regs_get(struct task_struct *target,
 		       const struct user_regset *regset,
 		       struct membuf to)
 {
 	const struct pt_regs *regs = task_pt_regs(target);

 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
 		/*
 		 * itemized copy not needed like above as layout of regs (r30,r58,r59)
 		 * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
 		 */
 		return membuf_write(&to, &regs->r30, sizeof(struct user_regs_arcv2));


 	membuf_write(&to, &regs->r30, 4); /* r30 only */
 	return membuf_zero(&to, sizeof(struct user_regs_arcv2) - 4);
 }

 static int arcv2regs_set(struct task_struct *target,
 		       const struct user_regset *regset,
 		       unsigned int pos, unsigned int count,
 		       const void *kbuf, const void __user *ubuf)
 {
 	const struct pt_regs *regs = task_pt_regs(target);
 	int ret, copy_sz;

 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
 		copy_sz = sizeof(struct user_regs_arcv2);
 	else
 		copy_sz = 4;	/* r30 only */

 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
 				  0, copy_sz);

 	return ret;
 }

 #endif

 enum arc_getset {
 	REGSET_CMN,
 	REGSET_ARCV2,
 };

 static const struct user_regset arc_regsets[] = {
 	[REGSET_CMN] = {
 	       .core_note_type = NT_PRSTATUS,
 	       .n = ELF_NGREG,
 	       .size = sizeof(unsigned long),
 	       .align = sizeof(unsigned long),
 	       .regset_get = genregs_get,
 	       .set = genregs_set,
 	},
 #ifdef CONFIG_ISA_ARCV2
 	[REGSET_ARCV2] = {
 	       .core_note_type = NT_ARC_V2,
 	       .n = ELF_ARCV2REG,
 	       .size = sizeof(unsigned long),
 	       .align = sizeof(unsigned long),
 	       .regset_get = arcv2regs_get,
 	       .set = arcv2regs_set,
 	},
 #endif
 };

 static const struct user_regset_view user_arc_view = {
 	.name		= "arc",
 	.e_machine	= EM_ARC_INUSE,
 	.regsets	= arc_regsets,
 	.n		= ARRAY_SIZE(arc_regsets)
 };

 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 {
 	return &user_arc_view;
 }

 void ptrace_disable(struct task_struct *child)
 {
 }

 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
 	int ret = -EIO;

 	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);

 	switch (request) {
 	case PTRACE_GET_THREAD_AREA:
 		ret = put_user(task_thread_info(child)->thr_ptr,
 			       (unsigned long __user *)data);
 		break;
 	default:
 		ret = ptrace_request(child, request, addr, data);
 		break;
 	}

 	return ret;
 }

 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		if (ptrace_report_syscall_entry(regs))
 			return ULONG_MAX;

 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 		trace_sys_enter(regs, syscall_get_nr(current, regs));
 #endif

 	return regs->r8;
 }

 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		ptrace_report_syscall_exit(regs, 0);

 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
 	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
 		trace_sys_exit(regs, regs_return_value(regs));
 #endif
 }

 int regs_query_register_offset(const char *name)
 {
 	const struct pt_regs_offset *roff;

 	for (roff = regoffset_table; roff->name != NULL; roff++)
 		if (!strcmp(roff->name, name))
 			return roff->offset;
 	return -EINVAL;
 }

 const char *regs_query_register_name(unsigned int offset)
 {
 	const struct pt_regs_offset *roff;
 	for (roff = regoffset_table; roff->name != NULL; roff++)
 		if (roff->offset == offset)
 			return roff->name;
 	return NULL;
 }

 bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 {
 	return (addr & ~(THREAD_SIZE - 1))  ==
 		(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
 }

 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 {
 	unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);

 	addr += n;
 	if (regs_within_kernel_stack(regs, (unsigned long)addr))
 		return *addr;
 	else
 		return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
	*/

	#include <linux/ptrace.h>
	#include <linux/sched/task_stack.h>
	#include <linux/regset.h>
	#include <linux/unistd.h>
	#include <linux/elf.h>

	#define CREATE_TRACE_POINTS
	#include <trace/events/syscalls.h>

	struct pt_regs_offset {
	const char *name;
	int offset;
	};

	#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
	#define REG_OFFSET_END {.name = NULL, .offset = 0}

	#ifdef CONFIG_ISA_ARCOMPACT
	static const struct pt_regs_offset regoffset_table[] = {
	REG_OFFSET_NAME(bta),
	REG_OFFSET_NAME(lp_start),
	REG_OFFSET_NAME(lp_end),
	REG_OFFSET_NAME(lp_count),
	REG_OFFSET_NAME(status32),
	REG_OFFSET_NAME(ret),
	REG_OFFSET_NAME(blink),
	REG_OFFSET_NAME(fp),
	REG_OFFSET_NAME(r26),
	REG_OFFSET_NAME(r12),
	REG_OFFSET_NAME(r11),
	REG_OFFSET_NAME(r10),
	REG_OFFSET_NAME(r9),
	REG_OFFSET_NAME(r8),
	REG_OFFSET_NAME(r7),
	REG_OFFSET_NAME(r6),
	REG_OFFSET_NAME(r5),
	REG_OFFSET_NAME(r4),
	REG_OFFSET_NAME(r3),
	REG_OFFSET_NAME(r2),
	REG_OFFSET_NAME(r1),
	REG_OFFSET_NAME(r0),
	REG_OFFSET_NAME(sp),
	REG_OFFSET_NAME(orig_r0),
	REG_OFFSET_NAME(event),
	REG_OFFSET_NAME(user_r25),
	REG_OFFSET_END,
	};

	#else

	static const struct pt_regs_offset regoffset_table[] = {
	REG_OFFSET_NAME(orig_r0),
	REG_OFFSET_NAME(event),
	REG_OFFSET_NAME(bta),
	REG_OFFSET_NAME(user_r25),
	REG_OFFSET_NAME(r26),
	REG_OFFSET_NAME(fp),
	REG_OFFSET_NAME(sp),
	REG_OFFSET_NAME(r12),
	REG_OFFSET_NAME(r30),
	#ifdef CONFIG_ARC_HAS_ACCL_REGS
	REG_OFFSET_NAME(r58),
	REG_OFFSET_NAME(r59),
	#endif
	#ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
	REG_OFFSET_NAME(DSP_CTRL),
	#endif
	REG_OFFSET_NAME(r0),
	REG_OFFSET_NAME(r1),
	REG_OFFSET_NAME(r2),
	REG_OFFSET_NAME(r3),
	REG_OFFSET_NAME(r4),
	REG_OFFSET_NAME(r5),
	REG_OFFSET_NAME(r6),
	REG_OFFSET_NAME(r7),
	REG_OFFSET_NAME(r8),
	REG_OFFSET_NAME(r9),
	REG_OFFSET_NAME(r10),
	REG_OFFSET_NAME(r11),
	REG_OFFSET_NAME(blink),
	REG_OFFSET_NAME(lp_end),
	REG_OFFSET_NAME(lp_start),
	REG_OFFSET_NAME(lp_count),
	REG_OFFSET_NAME(ei),
	REG_OFFSET_NAME(ldi),
	REG_OFFSET_NAME(jli),
	REG_OFFSET_NAME(ret),
	REG_OFFSET_NAME(status32),
	REG_OFFSET_END,
	};
	#endif

	static struct callee_regs task_callee_regs(struct task_struct tsk)
	{
	struct callee_regs tmp = (struct callee_regs )tsk->thread.callee_reg;
	return tmp;
	}

	static int genregs_get(struct task_struct *target,
	const struct user_regset *regset,
	struct membuf to)
	{
	const struct pt_regs *ptregs = task_pt_regs(target);
	const struct callee_regs *cregs = task_callee_regs(target);
	unsigned int stop_pc_val;

	membuf_zero(&to, 4); // pad
	membuf_store(&to, ptregs->bta);
	membuf_store(&to, ptregs->lp_start);
	membuf_store(&to, ptregs->lp_end);
	membuf_store(&to, ptregs->lp_count);
	membuf_store(&to, ptregs->status32);
	membuf_store(&to, ptregs->ret);
	membuf_store(&to, ptregs->blink);
	membuf_store(&to, ptregs->fp);
	membuf_store(&to, ptregs->r26); // gp
	membuf_store(&to, ptregs->r12);
	membuf_store(&to, ptregs->r11);
	membuf_store(&to, ptregs->r10);
	membuf_store(&to, ptregs->r9);
	membuf_store(&to, ptregs->r8);
	membuf_store(&to, ptregs->r7);
	membuf_store(&to, ptregs->r6);
	membuf_store(&to, ptregs->r5);
	membuf_store(&to, ptregs->r4);
	membuf_store(&to, ptregs->r3);
	membuf_store(&to, ptregs->r2);
	membuf_store(&to, ptregs->r1);
	membuf_store(&to, ptregs->r0);
	membuf_store(&to, ptregs->sp);
	membuf_zero(&to, 4); // pad2
	membuf_store(&to, cregs->r25);
	membuf_store(&to, cregs->r24);
	membuf_store(&to, cregs->r23);
	membuf_store(&to, cregs->r22);
	membuf_store(&to, cregs->r21);
	membuf_store(&to, cregs->r20);
	membuf_store(&to, cregs->r19);
	membuf_store(&to, cregs->r18);
	membuf_store(&to, cregs->r17);
	membuf_store(&to, cregs->r16);
	membuf_store(&to, cregs->r15);
	membuf_store(&to, cregs->r14);
	membuf_store(&to, cregs->r13);
	membuf_store(&to, target->thread.fault_address); // efa

	if (in_brkpt_trap(ptregs)) {
	stop_pc_val = target->thread.fault_address;
	pr_debug("\t\tstop_pc (brk-pt)\n");
	} else {
	stop_pc_val = ptregs->ret;
	pr_debug("\t\tstop_pc (others)\n");
	}

	return membuf_store(&to, stop_pc_val); // stop_pc
	}

	static int genregs_set(struct task_struct *target,
	const struct user_regset *regset,
	unsigned int pos, unsigned int count,
	const void kbuf, const void __user ubuf)
	{
	const struct pt_regs *ptregs = task_pt_regs(target);
	const struct callee_regs *cregs = task_callee_regs(target);
	int ret = 0;

	#define REG_IN_CHUNK(FIRST, NEXT, PTR) \
	if (!ret) \
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
	(void *)(PTR), \
	offsetof(struct user_regs_struct, FIRST), \
	offsetof(struct user_regs_struct, NEXT));

	#define REG_IN_ONE(LOC, PTR) \
	if (!ret) \
	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
	(void *)(PTR), \
	offsetof(struct user_regs_struct, LOC), \
	offsetof(struct user_regs_struct, LOC) + 4);

	#define REG_IGNORE_ONE(LOC) \
	if (!ret) \
	user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
	offsetof(struct user_regs_struct, LOC), \
	offsetof(struct user_regs_struct, LOC) + 4);

	REG_IGNORE_ONE(pad);

	REG_IN_ONE(scratch.bta, &ptregs->bta);
	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);

	REG_IGNORE_ONE(scratch.status32);

	REG_IN_ONE(scratch.ret, &ptregs->ret);
	REG_IN_ONE(scratch.blink, &ptregs->blink);
	REG_IN_ONE(scratch.fp, &ptregs->fp);
	REG_IN_ONE(scratch.gp, &ptregs->r26);
	REG_IN_ONE(scratch.r12, &ptregs->r12);
	REG_IN_ONE(scratch.r11, &ptregs->r11);
	REG_IN_ONE(scratch.r10, &ptregs->r10);
	REG_IN_ONE(scratch.r9, &ptregs->r9);
	REG_IN_ONE(scratch.r8, &ptregs->r8);
	REG_IN_ONE(scratch.r7, &ptregs->r7);
	REG_IN_ONE(scratch.r6, &ptregs->r6);
	REG_IN_ONE(scratch.r5, &ptregs->r5);
	REG_IN_ONE(scratch.r4, &ptregs->r4);
	REG_IN_ONE(scratch.r3, &ptregs->r3);
	REG_IN_ONE(scratch.r2, &ptregs->r2);
	REG_IN_ONE(scratch.r1, &ptregs->r1);
	REG_IN_ONE(scratch.r0, &ptregs->r0);
	REG_IN_ONE(scratch.sp, &ptregs->sp);

	REG_IGNORE_ONE(pad2);

	REG_IN_ONE(callee.r25, &cregs->r25);
	REG_IN_ONE(callee.r24, &cregs->r24);
	REG_IN_ONE(callee.r23, &cregs->r23);
	REG_IN_ONE(callee.r22, &cregs->r22);
	REG_IN_ONE(callee.r21, &cregs->r21);
	REG_IN_ONE(callee.r20, &cregs->r20);
	REG_IN_ONE(callee.r19, &cregs->r19);
	REG_IN_ONE(callee.r18, &cregs->r18);
	REG_IN_ONE(callee.r17, &cregs->r17);
	REG_IN_ONE(callee.r16, &cregs->r16);
	REG_IN_ONE(callee.r15, &cregs->r15);
	REG_IN_ONE(callee.r14, &cregs->r14);
	REG_IN_ONE(callee.r13, &cregs->r13);

	REG_IGNORE_ONE(efa); /* efa update invalid */
	REG_IGNORE_ONE(stop_pc); /* PC updated via @ret */

	return ret;
	}

	#ifdef CONFIG_ISA_ARCV2
	static int arcv2regs_get(struct task_struct *target,
	const struct user_regset *regset,
	struct membuf to)
	{
	const struct pt_regs *regs = task_pt_regs(target);

	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
	/*
	* itemized copy not needed like above as layout of regs (r30,r58,r59)
	* is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
	*/
	return membuf_write(&to, &regs->r30, sizeof(struct user_regs_arcv2));


	membuf_write(&to, &regs->r30, 4); /* r30 only */
	return membuf_zero(&to, sizeof(struct user_regs_arcv2) - 4);
	}

	static int arcv2regs_set(struct task_struct *target,
	const struct user_regset *regset,
	unsigned int pos, unsigned int count,
	const void kbuf, const void __user ubuf)
	{
	const struct pt_regs *regs = task_pt_regs(target);
	int ret, copy_sz;

	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
	copy_sz = sizeof(struct user_regs_arcv2);
	else
	copy_sz = 4; /* r30 only */

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
	0, copy_sz);

	return ret;
	}

	#endif

	enum arc_getset {
	REGSET_CMN,
	REGSET_ARCV2,
	};

	static const struct user_regset arc_regsets[] = {
	[REGSET_CMN] = {
	.core_note_type = NT_PRSTATUS,
	.n = ELF_NGREG,
	.size = sizeof(unsigned long),
	.align = sizeof(unsigned long),
	.regset_get = genregs_get,
	.set = genregs_set,
	},
	#ifdef CONFIG_ISA_ARCV2
	[REGSET_ARCV2] = {
	.core_note_type = NT_ARC_V2,
	.n = ELF_ARCV2REG,
	.size = sizeof(unsigned long),
	.align = sizeof(unsigned long),
	.regset_get = arcv2regs_get,
	.set = arcv2regs_set,
	},
	#endif
	};

	static const struct user_regset_view user_arc_view = {
	.name = "arc",
	.e_machine = EM_ARC_INUSE,
	.regsets = arc_regsets,
	.n = ARRAY_SIZE(arc_regsets)
	};

	const struct user_regset_view task_user_regset_view(struct task_struct task)
	{
	return &user_arc_view;
	}

	void ptrace_disable(struct task_struct *child)
	{
	}

	long arch_ptrace(struct task_struct *child, long request,
	unsigned long addr, unsigned long data)
	{
	int ret = -EIO;

	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);

	switch (request) {
	case PTRACE_GET_THREAD_AREA:
	ret = put_user(task_thread_info(child)->thr_ptr,
	(unsigned long __user *)data);
	break;
	default:
	ret = ptrace_request(child, request, addr, data);
	break;
	}

	return ret;
	}

	asmlinkage int syscall_trace_entry(struct pt_regs *regs)
	{
	if (test_thread_flag(TIF_SYSCALL_TRACE))
	if (ptrace_report_syscall_entry(regs))
	return ULONG_MAX;

	#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
	trace_sys_enter(regs, syscall_get_nr(current, regs));
	#endif

	return regs->r8;
	}

	asmlinkage void syscall_trace_exit(struct pt_regs *regs)
	{
	if (test_thread_flag(TIF_SYSCALL_TRACE))
	ptrace_report_syscall_exit(regs, 0);

	#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
	trace_sys_exit(regs, regs_return_value(regs));
	#endif
	}

	int regs_query_register_offset(const char *name)
	{
	const struct pt_regs_offset *roff;

	for (roff = regoffset_table; roff->name != NULL; roff++)
	if (!strcmp(roff->name, name))
	return roff->offset;
	return -EINVAL;
	}

	const char *regs_query_register_name(unsigned int offset)
	{
	const struct pt_regs_offset *roff;
	for (roff = regoffset_table; roff->name != NULL; roff++)
	if (roff->offset == offset)
	return roff->name;
	return NULL;
	}

	bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
	{
	return (addr & ~(THREAD_SIZE - 1)) ==
	(kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
	}

	unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
	{
	unsigned long addr = (unsigned long )kernel_stack_pointer(regs);

	addr += n;
	if (regs_within_kernel_stack(regs, (unsigned long)addr))
	return *addr;
	else
	return 0;
	}