xref: /openbmc/linux/arch/openrisc/include/asm/ptrace.h (revision 275876e2)
1 /*
2  * OpenRISC Linux
3  *
4  * Linux architectural port borrowing liberally from similar works of
5  * others.  All original copyrights apply as per the original source
6  * declaration.
7  *
8  * OpenRISC implementation:
9  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
11  * et al.
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  */
18 #ifndef __ASM_OPENRISC_PTRACE_H
19 #define __ASM_OPENRISC_PTRACE_H
20 
21 
22 #include <asm/spr_defs.h>
23 #include <uapi/asm/ptrace.h>
24 
25 /*
26  * Make kernel PTrace/register structures opaque to userspace... userspace can
27  * access thread state via the regset mechanism.  This allows us a bit of
28  * flexibility in how we order the registers on the stack, permitting some
29  * optimizations like packing call-clobbered registers together so that
30  * they share a cacheline (not done yet, though... future optimization).
31  */
32 
33 #ifndef __ASSEMBLY__
34 /*
35  * This struct describes how the registers are laid out on the kernel stack
36  * during a syscall or other kernel entry.
37  *
38  * This structure should always be cacheline aligned on the stack.
39  * FIXME: I don't think that's the case right now.  The alignment is
40  * taken care of elsewhere... head.S, process.c, etc.
41  */
42 
43 struct pt_regs {
44 	union {
45 		struct {
46 			/* Named registers */
47 			long  sr;	/* Stored in place of r0 */
48 			long  sp;	/* r1 */
49 		};
50 		struct {
51 			/* Old style */
52 			long offset[2];
53 			long gprs[30];
54 		};
55 		struct {
56 			/* New style */
57 			long gpr[32];
58 		};
59 	};
60 	long  pc;
61 	/* For restarting system calls:
62 	 * Set to syscall number for syscall exceptions,
63 	 * -1 for all other exceptions.
64 	 */
65 	long  orig_gpr11;	/* For restarting system calls */
66 	long dummy;		/* Cheap alignment fix */
67 	long dummy2;		/* Cheap alignment fix */
68 };
69 
70 /* TODO: Rename this to REDZONE because that's what it is */
71 #define STACK_FRAME_OVERHEAD  128  /* size of minimum stack frame */
72 
73 #define instruction_pointer(regs)	((regs)->pc)
74 #define user_mode(regs)			(((regs)->sr & SPR_SR_SM) == 0)
75 #define user_stack_pointer(regs)	((unsigned long)(regs)->sp)
76 #define profile_pc(regs)		instruction_pointer(regs)
77 
78 static inline long regs_return_value(struct pt_regs *regs)
79 {
80 	return regs->gpr[11];
81 }
82 
83 #endif /* __ASSEMBLY__ */
84 
85 /*
86  * Offsets used by 'ptrace' system call interface.
87  */
88 #define PT_SR         0
89 #define PT_SP         4
90 #define PT_GPR2       8
91 #define PT_GPR3       12
92 #define PT_GPR4       16
93 #define PT_GPR5       20
94 #define PT_GPR6       24
95 #define PT_GPR7       28
96 #define PT_GPR8       32
97 #define PT_GPR9       36
98 #define PT_GPR10      40
99 #define PT_GPR11      44
100 #define PT_GPR12      48
101 #define PT_GPR13      52
102 #define PT_GPR14      56
103 #define PT_GPR15      60
104 #define PT_GPR16      64
105 #define PT_GPR17      68
106 #define PT_GPR18      72
107 #define PT_GPR19      76
108 #define PT_GPR20      80
109 #define PT_GPR21      84
110 #define PT_GPR22      88
111 #define PT_GPR23      92
112 #define PT_GPR24      96
113 #define PT_GPR25      100
114 #define PT_GPR26      104
115 #define PT_GPR27      108
116 #define PT_GPR28      112
117 #define PT_GPR29      116
118 #define PT_GPR30      120
119 #define PT_GPR31      124
120 #define PT_PC	      128
121 #define PT_ORIG_GPR11 132
122 #define PT_SYSCALLNO  136
123 
124 #endif /* __ASM_OPENRISC_PTRACE_H */
125