ptrace.h
/* 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)
/*
* 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 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_PSR_I_SET (1 << 4)
/* Additional SPSR bits not exposed in the UABI */
#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_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 orig_addr_limit;
/* Only valid when ARM64_HAS_IRQ_PRIO_MASKING is enabled. */
u64 pmr_save;
u64 stackframe[2];
};
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)
{
return regs->regs[0];
}
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