arch/arm64/include/asm/ptrace.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Based on arch/arm/include/asm/ptrace.h
  *
  * Copyright (C) 1996-2003 Russell King
  * Copyright (C) 2012 ARM Ltd.
  */
 #ifndef __ASM_PTRACE_H
 #define __ASM_PTRACE_H

 #include <asm/cpufeature.h>

 #include <uapi/asm/ptrace.h>

 /* Current Exception Level values, as contained in CurrentEL */
 #define CurrentEL_EL1		(1 << 2)
 #define CurrentEL_EL2		(2 << 2)

 #define INIT_PSTATE_EL1 \
 	(PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL1h)
 #define INIT_PSTATE_EL2 \
 	(PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL2h)

 /*
  * PMR values used to mask/unmask interrupts.
  *
  * GIC priority masking works as follows: if an IRQ's priority is a higher value
  * than the value held in PMR, that IRQ is masked. Lowering the value of PMR
  * means masking more IRQs (or at least that the same IRQs remain masked).
  *
  * To mask interrupts, we clear the most significant bit of PMR.
  *
  * Some code sections either automatically switch back to PSR.I or explicitly
  * require to not use priority masking. If bit GIC_PRIO_PSR_I_SET is included
  * in the priority mask, it indicates that PSR.I should be set and
  * interrupt disabling temporarily does not rely on IRQ priorities.
  */
 #define GIC_PRIO_IRQON			0xe0
 #define __GIC_PRIO_IRQOFF		(GIC_PRIO_IRQON & ~0x80)
 #define __GIC_PRIO_IRQOFF_NS		0xa0
 #define GIC_PRIO_PSR_I_SET		(1 << 4)

 #define GIC_PRIO_IRQOFF							\
 	({								\
 		extern struct static_key_false gic_nonsecure_priorities;\
 		u8 __prio = __GIC_PRIO_IRQOFF;				\
 									\
 		if (static_branch_unlikely(&gic_nonsecure_priorities))	\
 			__prio = __GIC_PRIO_IRQOFF_NS;			\
 									\
 		__prio;							\
 	})

 /* Additional SPSR bits not exposed in the UABI */
 #define PSR_MODE_THREAD_BIT	(1 << 0)
 #define PSR_IL_BIT		(1 << 20)

 /* AArch32-specific ptrace requests */
 #define COMPAT_PTRACE_GETREGS		12
 #define COMPAT_PTRACE_SETREGS		13
 #define COMPAT_PTRACE_GET_THREAD_AREA	22
 #define COMPAT_PTRACE_SET_SYSCALL	23
 #define COMPAT_PTRACE_GETVFPREGS	27
 #define COMPAT_PTRACE_SETVFPREGS	28
 #define COMPAT_PTRACE_GETHBPREGS	29
 #define COMPAT_PTRACE_SETHBPREGS	30

 /* SPSR_ELx bits for exceptions taken from AArch32 */
 #define PSR_AA32_MODE_MASK	0x0000001f
 #define PSR_AA32_MODE_USR	0x00000010
 #define PSR_AA32_MODE_FIQ	0x00000011
 #define PSR_AA32_MODE_IRQ	0x00000012
 #define PSR_AA32_MODE_SVC	0x00000013
 #define PSR_AA32_MODE_ABT	0x00000017
 #define PSR_AA32_MODE_HYP	0x0000001a
 #define PSR_AA32_MODE_UND	0x0000001b
 #define PSR_AA32_MODE_SYS	0x0000001f
 #define PSR_AA32_T_BIT		0x00000020
 #define PSR_AA32_F_BIT		0x00000040
 #define PSR_AA32_I_BIT		0x00000080
 #define PSR_AA32_A_BIT		0x00000100
 #define PSR_AA32_E_BIT		0x00000200
 #define PSR_AA32_PAN_BIT	0x00400000
 #define PSR_AA32_SSBS_BIT	0x00800000
 #define PSR_AA32_DIT_BIT	0x01000000
 #define PSR_AA32_Q_BIT		0x08000000
 #define PSR_AA32_V_BIT		0x10000000
 #define PSR_AA32_C_BIT		0x20000000
 #define PSR_AA32_Z_BIT		0x40000000
 #define PSR_AA32_N_BIT		0x80000000
 #define PSR_AA32_IT_MASK	0x0600fc00	/* If-Then execution state mask */
 #define PSR_AA32_GE_MASK	0x000f0000

 #ifdef CONFIG_CPU_BIG_ENDIAN
 #define PSR_AA32_ENDSTATE	PSR_AA32_E_BIT
 #else
 #define PSR_AA32_ENDSTATE	0
 #endif

 /* AArch32 CPSR bits, as seen in AArch32 */
 #define COMPAT_PSR_DIT_BIT	0x00200000

 /*
  * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
  * process is located in memory.
  */
 #define COMPAT_PT_TEXT_ADDR		0x10000
 #define COMPAT_PT_DATA_ADDR		0x10004
 #define COMPAT_PT_TEXT_END_ADDR		0x10008

 /*
  * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
  * a syscall -- i.e., its most recent entry into the kernel from
  * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
  *
  * This must have the value -1, for ABI compatibility with ptrace etc.
  */
 #define NO_SYSCALL (-1)

 #ifndef __ASSEMBLY__
 #include <linux/bug.h>
 #include <linux/types.h>

 /* sizeof(struct user) for AArch32 */
 #define COMPAT_USER_SZ	296

 /* Architecturally defined mapping between AArch32 and AArch64 registers */
 #define compat_usr(x)	regs[(x)]
 #define compat_fp	regs[11]
 #define compat_sp	regs[13]
 #define compat_lr	regs[14]
 #define compat_sp_hyp	regs[15]
 #define compat_lr_irq	regs[16]
 #define compat_sp_irq	regs[17]
 #define compat_lr_svc	regs[18]
 #define compat_sp_svc	regs[19]
 #define compat_lr_abt	regs[20]
 #define compat_sp_abt	regs[21]
 #define compat_lr_und	regs[22]
 #define compat_sp_und	regs[23]
 #define compat_r8_fiq	regs[24]
 #define compat_r9_fiq	regs[25]
 #define compat_r10_fiq	regs[26]
 #define compat_r11_fiq	regs[27]
 #define compat_r12_fiq	regs[28]
 #define compat_sp_fiq	regs[29]
 #define compat_lr_fiq	regs[30]

 static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
 {
 	unsigned long pstate;

 	pstate = psr & ~COMPAT_PSR_DIT_BIT;

 	if (psr & COMPAT_PSR_DIT_BIT)
 		pstate |= PSR_AA32_DIT_BIT;

 	return pstate;
 }

 static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
 {
 	unsigned long psr;

 	psr = pstate & ~PSR_AA32_DIT_BIT;

 	if (pstate & PSR_AA32_DIT_BIT)
 		psr |= COMPAT_PSR_DIT_BIT;

 	return psr;
 }

 /*
  * This struct defines the way the registers are stored on the stack during an
  * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
  * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
  */
 struct pt_regs {
 	union {
 		struct user_pt_regs user_regs;
 		struct {
 			u64 regs[31];
 			u64 sp;
 			u64 pc;
 			u64 pstate;
 		};
 	};
 	u64 orig_x0;
 #ifdef __AARCH64EB__
 	u32 unused2;
 	s32 syscallno;
 #else
 	s32 syscallno;
 	u32 unused2;
 #endif
 	u64 sdei_ttbr1;
 	/* Only valid when ARM64_HAS_GIC_PRIO_MASKING is enabled. */
 	u64 pmr_save;
 	u64 stackframe[2];

 	/* Only valid for some EL1 exceptions. */
 	u64 lockdep_hardirqs;
 	u64 exit_rcu;
 };

 static inline bool in_syscall(struct pt_regs const *regs)
 {
 	return regs->syscallno != NO_SYSCALL;
 }

 static inline void forget_syscall(struct pt_regs *regs)
 {
 	regs->syscallno = NO_SYSCALL;
 }

 #define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)

 #define arch_has_single_step()	(1)

 #ifdef CONFIG_COMPAT
 #define compat_thumb_mode(regs) \
 	(((regs)->pstate & PSR_AA32_T_BIT))
 #else
 #define compat_thumb_mode(regs) (0)
 #endif

 #define user_mode(regs)	\
 	(((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)

 #define compat_user_mode(regs)	\
 	(((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
 	 (PSR_MODE32_BIT | PSR_MODE_EL0t))

 #define processor_mode(regs) \
 	((regs)->pstate & PSR_MODE_MASK)

 #define irqs_priority_unmasked(regs)					\
 	(system_uses_irq_prio_masking() ?				\
 		(regs)->pmr_save == GIC_PRIO_IRQON :			\
 		true)

 #define interrupts_enabled(regs)			\
 	(!((regs)->pstate & PSR_I_BIT) && irqs_priority_unmasked(regs))

 #define fast_interrupts_enabled(regs) \
 	(!((regs)->pstate & PSR_F_BIT))

 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 {
 	if (compat_user_mode(regs))
 		return regs->compat_sp;
 	return regs->sp;
 }

 extern int regs_query_register_offset(const char *name);
 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 					       unsigned int n);

 /**
  * regs_get_register() - get register value from its offset
  * @regs:	pt_regs from which register value is gotten
  * @offset:	offset of the register.
  *
  * regs_get_register returns the value of a register whose offset from @regs.
  * The @offset is the offset of the register in struct pt_regs.
  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
  */
 static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
 {
 	u64 val = 0;

 	WARN_ON(offset & 7);

 	offset >>= 3;
 	switch (offset) {
 	case 0 ... 30:
 		val = regs->regs[offset];
 		break;
 	case offsetof(struct pt_regs, sp) >> 3:
 		val = regs->sp;
 		break;
 	case offsetof(struct pt_regs, pc) >> 3:
 		val = regs->pc;
 		break;
 	case offsetof(struct pt_regs, pstate) >> 3:
 		val = regs->pstate;
 		break;
 	default:
 		val = 0;
 	}

 	return val;
 }

 /*
  * Read a register given an architectural register index r.
  * This handles the common case where 31 means XZR, not SP.
  */
 static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
 {
 	return (r == 31) ? 0 : regs->regs[r];
 }

 /*
  * Write a register given an architectural register index r.
  * This handles the common case where 31 means XZR, not SP.
  */
 static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
 				     unsigned long val)
 {
 	if (r != 31)
 		regs->regs[r] = val;
 }

 /* Valid only for Kernel mode traps. */
 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 {
 	return regs->sp;
 }

 static inline unsigned long regs_return_value(struct pt_regs *regs)
 {
 	unsigned long val = regs->regs[0];

 	/*
 	 * Audit currently uses regs_return_value() instead of
 	 * syscall_get_return_value(). Apply the same sign-extension here until
 	 * audit is updated to use syscall_get_return_value().
 	 */
 	if (compat_user_mode(regs))
 		val = sign_extend64(val, 31);

 	return val;
 }

 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
 {
 	regs->regs[0] = rc;
 }

 /**
  * 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);

 static inline unsigned long instruction_pointer(struct pt_regs *regs)
 {
 	return regs->pc;
 }
 static inline void instruction_pointer_set(struct pt_regs *regs,
 		unsigned long val)
 {
 	regs->pc = val;
 }

 static inline unsigned long frame_pointer(struct pt_regs *regs)
 {
 	return regs->regs[29];
 }

 #define procedure_link_pointer(regs)	((regs)->regs[30])

 static inline void procedure_link_pointer_set(struct pt_regs *regs,
 					   unsigned long val)
 {
 	procedure_link_pointer(regs) = val;
 }

 extern unsigned long profile_pc(struct pt_regs *regs);

 #endif /* __ASSEMBLY__ */
 #endif
	/* SPDX-License-Identifier: GPL-2.0-only */
	/*
	* Based on arch/arm/include/asm/ptrace.h
	*
	* Copyright (C) 1996-2003 Russell King
	* Copyright (C) 2012 ARM Ltd.
	*/
	#ifndef __ASM_PTRACE_H
	#define __ASM_PTRACE_H

	#include <asm/cpufeature.h>

	#include <uapi/asm/ptrace.h>

	/* Current Exception Level values, as contained in CurrentEL */
	#define CurrentEL_EL1 (1 << 2)
	#define CurrentEL_EL2 (2 << 2)

	#define INIT_PSTATE_EL1 \
	(PSR_D_BIT \| PSR_A_BIT \| PSR_I_BIT \| PSR_F_BIT \| PSR_MODE_EL1h)
	#define INIT_PSTATE_EL2 \
	(PSR_D_BIT \| PSR_A_BIT \| PSR_I_BIT \| PSR_F_BIT \| PSR_MODE_EL2h)

	/*
	* PMR values used to mask/unmask interrupts.
	*
	* GIC priority masking works as follows: if an IRQ's priority is a higher value
	* than the value held in PMR, that IRQ is masked. Lowering the value of PMR
	* means masking more IRQs (or at least that the same IRQs remain masked).
	*
	* To mask interrupts, we clear the most significant bit of PMR.
	*
	* Some code sections either automatically switch back to PSR.I or explicitly
	* require to not use priority masking. If bit GIC_PRIO_PSR_I_SET is included
	* in the priority mask, it indicates that PSR.I should be set and
	* interrupt disabling temporarily does not rely on IRQ priorities.
	*/
	#define GIC_PRIO_IRQON 0xe0
	#define __GIC_PRIO_IRQOFF (GIC_PRIO_IRQON & ~0x80)
	#define __GIC_PRIO_IRQOFF_NS 0xa0
	#define GIC_PRIO_PSR_I_SET (1 << 4)

	#define GIC_PRIO_IRQOFF \
	({ \
	extern struct static_key_false gic_nonsecure_priorities;\
	u8 __prio = __GIC_PRIO_IRQOFF; \
	\
	if (static_branch_unlikely(&gic_nonsecure_priorities)) \
	__prio = __GIC_PRIO_IRQOFF_NS; \
	\
	__prio; \
	})

	/* Additional SPSR bits not exposed in the UABI */
	#define PSR_MODE_THREAD_BIT (1 << 0)
	#define PSR_IL_BIT (1 << 20)

	/* AArch32-specific ptrace requests */
	#define COMPAT_PTRACE_GETREGS 12
	#define COMPAT_PTRACE_SETREGS 13
	#define COMPAT_PTRACE_GET_THREAD_AREA 22
	#define COMPAT_PTRACE_SET_SYSCALL 23
	#define COMPAT_PTRACE_GETVFPREGS 27
	#define COMPAT_PTRACE_SETVFPREGS 28
	#define COMPAT_PTRACE_GETHBPREGS 29
	#define COMPAT_PTRACE_SETHBPREGS 30

	/* SPSR_ELx bits for exceptions taken from AArch32 */
	#define PSR_AA32_MODE_MASK 0x0000001f
	#define PSR_AA32_MODE_USR 0x00000010
	#define PSR_AA32_MODE_FIQ 0x00000011
	#define PSR_AA32_MODE_IRQ 0x00000012
	#define PSR_AA32_MODE_SVC 0x00000013
	#define PSR_AA32_MODE_ABT 0x00000017
	#define PSR_AA32_MODE_HYP 0x0000001a
	#define PSR_AA32_MODE_UND 0x0000001b
	#define PSR_AA32_MODE_SYS 0x0000001f
	#define PSR_AA32_T_BIT 0x00000020
	#define PSR_AA32_F_BIT 0x00000040
	#define PSR_AA32_I_BIT 0x00000080
	#define PSR_AA32_A_BIT 0x00000100
	#define PSR_AA32_E_BIT 0x00000200
	#define PSR_AA32_PAN_BIT 0x00400000
	#define PSR_AA32_SSBS_BIT 0x00800000
	#define PSR_AA32_DIT_BIT 0x01000000
	#define PSR_AA32_Q_BIT 0x08000000
	#define PSR_AA32_V_BIT 0x10000000
	#define PSR_AA32_C_BIT 0x20000000
	#define PSR_AA32_Z_BIT 0x40000000
	#define PSR_AA32_N_BIT 0x80000000
	#define PSR_AA32_IT_MASK 0x0600fc00 /* If-Then execution state mask */
	#define PSR_AA32_GE_MASK 0x000f0000

	#ifdef CONFIG_CPU_BIG_ENDIAN
	#define PSR_AA32_ENDSTATE PSR_AA32_E_BIT
	#else
	#define PSR_AA32_ENDSTATE 0
	#endif

	/* AArch32 CPSR bits, as seen in AArch32 */
	#define COMPAT_PSR_DIT_BIT 0x00200000

	/*
	* These are 'magic' values for PTRACE_PEEKUSR that return info about where a
	* process is located in memory.
	*/
	#define COMPAT_PT_TEXT_ADDR 0x10000
	#define COMPAT_PT_DATA_ADDR 0x10004
	#define COMPAT_PT_TEXT_END_ADDR 0x10008

	/*
	* If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
	* a syscall -- i.e., its most recent entry into the kernel from
	* userspace was not via SVC, or otherwise a tracer cancelled the syscall.
	*
	* This must have the value -1, for ABI compatibility with ptrace etc.
	*/
	#define NO_SYSCALL (-1)

	#ifndef __ASSEMBLY__
	#include <linux/bug.h>
	#include <linux/types.h>

	/* sizeof(struct user) for AArch32 */
	#define COMPAT_USER_SZ 296

	/* Architecturally defined mapping between AArch32 and AArch64 registers */
	#define compat_usr(x) regs[(x)]
	#define compat_fp regs[11]
	#define compat_sp regs[13]
	#define compat_lr regs[14]
	#define compat_sp_hyp regs[15]
	#define compat_lr_irq regs[16]
	#define compat_sp_irq regs[17]
	#define compat_lr_svc regs[18]
	#define compat_sp_svc regs[19]
	#define compat_lr_abt regs[20]
	#define compat_sp_abt regs[21]
	#define compat_lr_und regs[22]
	#define compat_sp_und regs[23]
	#define compat_r8_fiq regs[24]
	#define compat_r9_fiq regs[25]
	#define compat_r10_fiq regs[26]
	#define compat_r11_fiq regs[27]
	#define compat_r12_fiq regs[28]
	#define compat_sp_fiq regs[29]
	#define compat_lr_fiq regs[30]

	static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
	{
	unsigned long pstate;

	pstate = psr & ~COMPAT_PSR_DIT_BIT;

	if (psr & COMPAT_PSR_DIT_BIT)
	pstate \|= PSR_AA32_DIT_BIT;

	return pstate;
	}

	static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
	{
	unsigned long psr;

	psr = pstate & ~PSR_AA32_DIT_BIT;

	if (pstate & PSR_AA32_DIT_BIT)
	psr \|= COMPAT_PSR_DIT_BIT;

	return psr;
	}

	/*
	* This struct defines the way the registers are stored on the stack during an
	* exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
	* stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
	*/
	struct pt_regs {
	union {
	struct user_pt_regs user_regs;
	struct {
	u64 regs[31];
	u64 sp;
	u64 pc;
	u64 pstate;
	};
	};
	u64 orig_x0;
	#ifdef __AARCH64EB__
	u32 unused2;
	s32 syscallno;
	#else
	s32 syscallno;
	u32 unused2;
	#endif
	u64 sdei_ttbr1;
	/* Only valid when ARM64_HAS_GIC_PRIO_MASKING is enabled. */
	u64 pmr_save;
	u64 stackframe[2];

	/* Only valid for some EL1 exceptions. */
	u64 lockdep_hardirqs;
	u64 exit_rcu;
	};

	static inline bool in_syscall(struct pt_regs const *regs)
	{
	return regs->syscallno != NO_SYSCALL;
	}

	static inline void forget_syscall(struct pt_regs *regs)
	{
	regs->syscallno = NO_SYSCALL;
	}

	#define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)

	#define arch_has_single_step() (1)

	#ifdef CONFIG_COMPAT
	#define compat_thumb_mode(regs) \
	(((regs)->pstate & PSR_AA32_T_BIT))
	#else
	#define compat_thumb_mode(regs) (0)
	#endif

	#define user_mode(regs) \
	(((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)

	#define compat_user_mode(regs) \
	(((regs)->pstate & (PSR_MODE32_BIT \| PSR_MODE_MASK)) == \
	(PSR_MODE32_BIT \| PSR_MODE_EL0t))

	#define processor_mode(regs) \
	((regs)->pstate & PSR_MODE_MASK)

	#define irqs_priority_unmasked(regs) \
	(system_uses_irq_prio_masking() ? \
	(regs)->pmr_save == GIC_PRIO_IRQON : \
	true)

	#define interrupts_enabled(regs) \
	(!((regs)->pstate & PSR_I_BIT) && irqs_priority_unmasked(regs))

	#define fast_interrupts_enabled(regs) \
	(!((regs)->pstate & PSR_F_BIT))

	static inline unsigned long user_stack_pointer(struct pt_regs *regs)
	{
	if (compat_user_mode(regs))
	return regs->compat_sp;
	return regs->sp;
	}

	extern int regs_query_register_offset(const char *name);
	extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
	unsigned int n);

	/**
	* regs_get_register() - get register value from its offset
	* @regs: pt_regs from which register value is gotten
	* @offset: offset of the register.
	*
	* regs_get_register returns the value of a register whose offset from @regs.
	* The @offset is the offset of the register in struct pt_regs.
	* If @offset is bigger than MAX_REG_OFFSET, this returns 0.
	*/
	static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
	{
	u64 val = 0;

	WARN_ON(offset & 7);

	offset >>= 3;
	switch (offset) {
	case 0 ... 30:
	val = regs->regs[offset];
	break;
	case offsetof(struct pt_regs, sp) >> 3:
	val = regs->sp;
	break;
	case offsetof(struct pt_regs, pc) >> 3:
	val = regs->pc;
	break;
	case offsetof(struct pt_regs, pstate) >> 3:
	val = regs->pstate;
	break;
	default:
	val = 0;
	}

	return val;
	}

	/*
	* Read a register given an architectural register index r.
	* This handles the common case where 31 means XZR, not SP.
	*/
	static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
	{
	return (r == 31) ? 0 : regs->regs[r];
	}

	/*
	* Write a register given an architectural register index r.
	* This handles the common case where 31 means XZR, not SP.
	*/
	static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
	unsigned long val)
	{
	if (r != 31)
	regs->regs[r] = val;
	}

	/* Valid only for Kernel mode traps. */
	static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
	{
	return regs->sp;
	}

	static inline unsigned long regs_return_value(struct pt_regs *regs)
	{
	unsigned long val = regs->regs[0];

	/*
	* Audit currently uses regs_return_value() instead of
	* syscall_get_return_value(). Apply the same sign-extension here until
	* audit is updated to use syscall_get_return_value().
	*/
	if (compat_user_mode(regs))
	val = sign_extend64(val, 31);

	return val;
	}

	static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
	{
	regs->regs[0] = rc;
	}

	/**
	* 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);

	static inline unsigned long instruction_pointer(struct pt_regs *regs)
	{
	return regs->pc;
	}
	static inline void instruction_pointer_set(struct pt_regs *regs,
	unsigned long val)
	{
	regs->pc = val;
	}

	static inline unsigned long frame_pointer(struct pt_regs *regs)
	{
	return regs->regs[29];
	}

	#define procedure_link_pointer(regs) ((regs)->regs[30])

	static inline void procedure_link_pointer_set(struct pt_regs *regs,
	unsigned long val)
	{
	procedure_link_pointer(regs) = val;
	}

	extern unsigned long profile_pc(struct pt_regs *regs);

	#endif /* __ASSEMBLY__ */
	#endif