ptrace.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 * OpenRISC Linux
  4 *
  5 * Linux architectural port borrowing liberally from similar works of
  6 * others.  All original copyrights apply as per the original source
  7 * declaration.
  8 *
  9 * OpenRISC implementation:
 10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 12 * et al.
 13 */
 14#ifndef __ASM_OPENRISC_PTRACE_H
 15#define __ASM_OPENRISC_PTRACE_H
 16
 17
 18#include <asm/spr_defs.h>
 19#include <uapi/asm/ptrace.h>
 20#include <linux/compiler.h>
 21
 22/*
 23 * Make kernel PTrace/register structures opaque to userspace... userspace can
 24 * access thread state via the regset mechanism.  This allows us a bit of
 25 * flexibility in how we order the registers on the stack, permitting some
 26 * optimizations like packing call-clobbered registers together so that
 27 * they share a cacheline (not done yet, though... future optimization).
 28 */
 29
 30#ifndef __ASSEMBLER__
 31/*
 32 * This struct describes how the registers are laid out on the kernel stack
 33 * during a syscall or other kernel entry.
 34 *
 35 * This structure should always be cacheline aligned on the stack.
 36 * FIXME: I don't think that's the case right now.  The alignment is
 37 * taken care of elsewhere... head.S, process.c, etc.
 38 */
 39
 40struct pt_regs {
 41	union {
 42		struct {
 43			/* Named registers */
 44			long  sr;	/* Stored in place of r0 */
 45			long  sp;	/* r1 */
 46			long  gpr2;
 47			long  gpr3;
 48			long  gpr4;
 49			long  gpr5;
 50			long  gpr6;
 51			long  gpr7;
 52			long  gpr8;
 53			long  gpr9;
 54			long  gpr10;
 55			long  gpr11;
 56			long  gpr12;
 57			long  gpr13;
 58			long  gpr14;
 59			long  gpr15;
 60			long  gpr16;
 61			long  gpr17;
 62			long  gpr18;
 63			long  gpr19;
 64			long  gpr20;
 65			long  gpr21;
 66			long  gpr22;
 67			long  gpr23;
 68			long  gpr24;
 69			long  gpr25;
 70			long  gpr26;
 71			long  gpr27;
 72			long  gpr28;
 73			long  gpr29;
 74			long  gpr30;
 75			long  gpr31;
 76		};
 77		struct {
 78			/* Old style */
 79			long offset[2];
 80			long gprs[30];
 81		};
 82		struct {
 83			/* New style */
 84			long gpr[32];
 85		};
 86	};
 87	long  pc;
 88	/* For restarting system calls:
 89	 * Set to syscall number for syscall exceptions,
 90	 * -1 for all other exceptions.
 91	 */
 92	long  orig_gpr11;	/* For restarting system calls */
 93	long dummy;		/* Cheap alignment fix */
 94	long dummy2;		/* Cheap alignment fix */
 95};
 96
 97/* TODO: Rename this to REDZONE because that's what it is */
 98#define STACK_FRAME_OVERHEAD  128  /* size of minimum stack frame */
 99
100#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_gpr11)
101
102/* Helpers for working with the instruction pointer */
103static inline unsigned long instruction_pointer(struct pt_regs *regs)
104{
105	return (unsigned long)regs->pc;
106}
107static inline void instruction_pointer_set(struct pt_regs *regs,
108					   unsigned long val)
109{
110	regs->pc = val;
111}
112
113#define user_mode(regs)			(((regs)->sr & SPR_SR_SM) == 0)
114#define user_stack_pointer(regs)	((unsigned long)(regs)->sp)
115#define profile_pc(regs)		instruction_pointer(regs)
116
117/* Valid only for Kernel mode traps. */
118static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
119{
120	return (unsigned long)regs->sp;
121}
122
123static inline long regs_return_value(struct pt_regs *regs)
124{
125	return regs->gpr[11];
126}
127
128extern int regs_query_register_offset(const char *name);
129extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
130					       unsigned int n);
131
132/**
133 * regs_get_register() - get register value from its offset
134 * @regs:	pt_regs from which register value is gotten
135 * @offset:	offset of the register.
136 *
137 * regs_get_register returns the value of a register whose offset from @regs.
138 * The @offset is the offset of the register in struct pt_regs.
139 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
140 */
141static inline unsigned long regs_get_register(struct pt_regs *regs,
142					      unsigned int offset)
143{
144	if (unlikely(offset > MAX_REG_OFFSET))
145		return 0;
146
147	return *(unsigned long *)((unsigned long)regs + offset);
148}
149
150#endif /* __ASSEMBLER__ */
151
152/*
153 * Offsets used by 'ptrace' system call interface.
154 */
155#define PT_SR         0
156#define PT_SP         4
157#define PT_GPR2       8
158#define PT_GPR3       12
159#define PT_GPR4       16
160#define PT_GPR5       20
161#define PT_GPR6       24
162#define PT_GPR7       28
163#define PT_GPR8       32
164#define PT_GPR9       36
165#define PT_GPR10      40
166#define PT_GPR11      44
167#define PT_GPR12      48
168#define PT_GPR13      52
169#define PT_GPR14      56
170#define PT_GPR15      60
171#define PT_GPR16      64
172#define PT_GPR17      68
173#define PT_GPR18      72
174#define PT_GPR19      76
175#define PT_GPR20      80
176#define PT_GPR21      84
177#define PT_GPR22      88
178#define PT_GPR23      92
179#define PT_GPR24      96
180#define PT_GPR25      100
181#define PT_GPR26      104
182#define PT_GPR27      108
183#define PT_GPR28      112
184#define PT_GPR29      116
185#define PT_GPR30      120
186#define PT_GPR31      124
187#define PT_PC	      128
188#define PT_ORIG_GPR11 132
189
190#endif /* __ASM_OPENRISC_PTRACE_H */