1 /*
2 * Copyright (C) 2001 PPC64 Team, IBM Corp
3 *
4 * This struct defines the way the registers are stored on the
5 * kernel stack during a system call or other kernel entry.
6 *
7 * this should only contain volatile regs
8 * since we can keep non-volatile in the thread_struct
9 * should set this up when only volatiles are saved
10 * by intr code.
11 *
12 * Since this is going on the stack, *CARE MUST BE TAKEN* to insure
13 * that the overall structure is a multiple of 16 bytes in length.
14 *
15 * Note that the offsets of the fields in this struct correspond with
16 * the PT_* values below. This simplifies arch/powerpc/kernel/ptrace.c.
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23 #ifndef _ASM_POWERPC_PTRACE_H
24 #define _ASM_POWERPC_PTRACE_H
25
26 #include <uapi/asm/ptrace.h>
27
28
29 #ifdef __powerpc64__
30
31 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */
32 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */
33 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265)
34 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \
35 STACK_FRAME_OVERHEAD + 288)
36 #define STACK_FRAME_MARKER 12
37
38 /* Size of dummy stack frame allocated when calling signal handler. */
39 #define __SIGNAL_FRAMESIZE 128
40 #define __SIGNAL_FRAMESIZE32 64
41
42 #else /* __powerpc64__ */
43
44 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */
45 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */
46 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
47 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
48 #define STACK_FRAME_MARKER 2
49
50 /* Size of stack frame allocated when calling signal handler. */
51 #define __SIGNAL_FRAMESIZE 64
52
53 #endif /* __powerpc64__ */
54
55 #ifndef __ASSEMBLY__
56
57 #define GET_IP(regs) ((regs)->nip)
58 #define GET_USP(regs) ((regs)->gpr[1])
59 #define GET_FP(regs) (0)
60 #define SET_FP(regs, val)
61
62 #ifdef CONFIG_SMP
63 extern unsigned long profile_pc(struct pt_regs *regs);
64 #define profile_pc profile_pc
65 #endif
66
67 #include <asm-generic/ptrace.h>
68
69 #define kernel_stack_pointer(regs) ((regs)->gpr[1])
is_syscall_success(struct pt_regs * regs)70 static inline int is_syscall_success(struct pt_regs *regs)
71 {
72 return !(regs->ccr & 0x10000000);
73 }
74
regs_return_value(struct pt_regs * regs)75 static inline long regs_return_value(struct pt_regs *regs)
76 {
77 if (is_syscall_success(regs))
78 return regs->gpr[3];
79 else
80 return -regs->gpr[3];
81 }
82
83 #ifdef __powerpc64__
84 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
85 #else
86 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
87 #endif
88
89 #define force_successful_syscall_return() \
90 do { \
91 set_thread_flag(TIF_NOERROR); \
92 } while(0)
93
94 struct task_struct;
95 extern int ptrace_get_reg(struct task_struct *task, int regno,
96 unsigned long *data);
97 extern int ptrace_put_reg(struct task_struct *task, int regno,
98 unsigned long data);
99
100 #define current_pt_regs() \
101 ((struct pt_regs *)((unsigned long)current_thread_info() + THREAD_SIZE) - 1)
102 /*
103 * We use the least-significant bit of the trap field to indicate
104 * whether we have saved the full set of registers, or only a
105 * partial set. A 1 there means the partial set.
106 * On 4xx we use the next bit to indicate whether the exception
107 * is a critical exception (1 means it is).
108 */
109 #define FULL_REGS(regs) (((regs)->trap & 1) == 0)
110 #ifndef __powerpc64__
111 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0)
112 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0)
113 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0)
114 #endif /* ! __powerpc64__ */
115 #define TRAP(regs) ((regs)->trap & ~0xF)
116 #ifdef __powerpc64__
117 #define NV_REG_POISON 0xdeadbeefdeadbeefUL
118 #define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1)
119 #else
120 #define NV_REG_POISON 0xdeadbeef
121 #define CHECK_FULL_REGS(regs) \
122 do { \
123 if ((regs)->trap & 1) \
124 printk(KERN_CRIT "%s: partial register set\n", __func__); \
125 } while (0)
126 #endif /* __powerpc64__ */
127
128 #define arch_has_single_step() (1)
129 #define arch_has_block_step() (!cpu_has_feature(CPU_FTR_601))
130 #define ARCH_HAS_USER_SINGLE_STEP_INFO
131
132 /*
133 * kprobe-based event tracer support
134 */
135
136 #include <linux/stddef.h>
137 #include <linux/thread_info.h>
138 extern int regs_query_register_offset(const char *name);
139 extern const char *regs_query_register_name(unsigned int offset);
140 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
141
142 /**
143 * regs_get_register() - get register value from its offset
144 * @regs: pt_regs from which register value is gotten
145 * @offset: offset number of the register.
146 *
147 * regs_get_register returns the value of a register whose offset from @regs.
148 * The @offset is the offset of the register in struct pt_regs.
149 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
150 */
regs_get_register(struct pt_regs * regs,unsigned int offset)151 static inline unsigned long regs_get_register(struct pt_regs *regs,
152 unsigned int offset)
153 {
154 if (unlikely(offset > MAX_REG_OFFSET))
155 return 0;
156 return *(unsigned long *)((unsigned long)regs + offset);
157 }
158
159 /**
160 * regs_within_kernel_stack() - check the address in the stack
161 * @regs: pt_regs which contains kernel stack pointer.
162 * @addr: address which is checked.
163 *
164 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
165 * If @addr is within the kernel stack, it returns true. If not, returns false.
166 */
167
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)168 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
169 unsigned long addr)
170 {
171 return ((addr & ~(THREAD_SIZE - 1)) ==
172 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
173 }
174
175 /**
176 * regs_get_kernel_stack_nth() - get Nth entry of the stack
177 * @regs: pt_regs which contains kernel stack pointer.
178 * @n: stack entry number.
179 *
180 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
181 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
182 * this returns 0.
183 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)184 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
185 unsigned int n)
186 {
187 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
188 addr += n;
189 if (regs_within_kernel_stack(regs, (unsigned long)addr))
190 return *addr;
191 else
192 return 0;
193 }
194
195 #endif /* __ASSEMBLY__ */
196
197 #ifndef __powerpc64__
198 #else /* __powerpc64__ */
199 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
200 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */
201 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
202 #define PT_VRSAVE_32 (PT_VR0 + 33*4)
203 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */
204 #endif /* __powerpc64__ */
205 #endif /* _ASM_POWERPC_PTRACE_H */
206