arm64: ptrace: Add function argument access API

	select HAVE_PERF_REGS

	select HAVE_PERF_USER_STACK_DUMP

	select HAVE_REGS_AND_STACK_ACCESS_API

	select HAVE_FUNCTION_ARG_ACCESS_API

	select HAVE_RCU_TABLE_FREE

	select HAVE_RCU_TABLE_INVALIDATE

	select HAVE_RSEQ

	return regs->regs[0];

}

/**

 * regs_get_kernel_argument() - get Nth function argument in kernel

 * @regs:	pt_regs of that context

 * @n:		function argument number (start from 0)

 *

 * regs_get_argument() returns @n th argument of the function call.

 *

 * Note that this chooses the most likely register mapping. In very rare

 * cases this may not return correct data, for example, if one of the

 * function parameters is 16 bytes or bigger. In such cases, we cannot

 * get access the parameter correctly and the register assignment of

 * subsequent parameters will be shifted.

 */

static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,

						     unsigned int n)

{

#define NR_REG_ARGUMENTS 8

	if (n < NR_REG_ARGUMENTS)

		return pt_regs_read_reg(regs, n);

	return 0;

}

/* We must avoid circular header include via sched.h */

struct task_struct;

int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);