1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * arch/arm/include/asm/ptrace.h
4 *
5 * Copyright (C) 1996-2003 Russell King
6 */
7 #ifndef __ASM_ARM_PTRACE_H
8 #define __ASM_ARM_PTRACE_H
9
10 #include <uapi/asm/ptrace.h>
11
12 #ifndef __ASSEMBLY__
13 #include <linux/bitfield.h>
14 #include <linux/types.h>
15
16 struct pt_regs {
17 unsigned long uregs[18];
18 };
19
20 struct svc_pt_regs {
21 struct pt_regs regs;
22 u32 dacr;
23 u32 ttbcr;
24 };
25
26 #define to_svc_pt_regs(r) container_of(r, struct svc_pt_regs, regs)
27
28 #define user_mode(regs) \
29 (((regs)->ARM_cpsr & 0xf) == 0)
30
31 #ifdef CONFIG_ARM_THUMB
32 #define thumb_mode(regs) \
33 (((regs)->ARM_cpsr & PSR_T_BIT))
34 #else
35 #define thumb_mode(regs) (0)
36 #endif
37
38 #ifndef CONFIG_CPU_V7M
39 #define isa_mode(regs) \
40 (FIELD_GET(PSR_J_BIT, (regs)->ARM_cpsr) << 1 | \
41 FIELD_GET(PSR_T_BIT, (regs)->ARM_cpsr))
42 #else
43 #define isa_mode(regs) 1 /* Thumb */
44 #endif
45
46 #define processor_mode(regs) \
47 ((regs)->ARM_cpsr & MODE_MASK)
48
49 #define interrupts_enabled(regs) \
50 (!((regs)->ARM_cpsr & PSR_I_BIT))
51
52 #define fast_interrupts_enabled(regs) \
53 (!((regs)->ARM_cpsr & PSR_F_BIT))
54
55 /* Are the current registers suitable for user mode?
56 * (used to maintain security in signal handlers)
57 */
58 static inline int valid_user_regs(struct pt_regs *regs)
59 {
60 #ifndef CONFIG_CPU_V7M
61 unsigned long mode = regs->ARM_cpsr & MODE_MASK;
62
63 /*
64 * Always clear the F (FIQ) and A (delayed abort) bits
65 */
66 regs->ARM_cpsr &= ~(PSR_F_BIT | PSR_A_BIT);
67
68 if ((regs->ARM_cpsr & PSR_I_BIT) == 0) {
69 if (mode == USR_MODE)
70 return 1;
71 if (elf_hwcap & HWCAP_26BIT && mode == USR26_MODE)
72 return 1;
73 }
74
75 /*
76 * Force CPSR to something logical...
77 */
78 regs->ARM_cpsr &= PSR_f | PSR_s | PSR_x | PSR_T_BIT | MODE32_BIT;
79 if (!(elf_hwcap & HWCAP_26BIT))
80 regs->ARM_cpsr |= USR_MODE;
81
82 return 0;
83 #else /* ifndef CONFIG_CPU_V7M */
84 return 1;
85 #endif
86 }
87
88 static inline long regs_return_value(struct pt_regs *regs)
89 {
90 return regs->ARM_r0;
91 }
92
93 #define instruction_pointer(regs) (regs)->ARM_pc
94
95 #ifdef CONFIG_THUMB2_KERNEL
96 #define frame_pointer(regs) (regs)->ARM_r7
97 #else
98 #define frame_pointer(regs) (regs)->ARM_fp
99 #endif
100
101 static inline void instruction_pointer_set(struct pt_regs *regs,
102 unsigned long val)
103 {
104 instruction_pointer(regs) = val;
105 }
106
107 #ifdef CONFIG_SMP
108 extern unsigned long profile_pc(struct pt_regs *regs);
109 #else
110 #define profile_pc(regs) instruction_pointer(regs)
111 #endif
112
113 #define predicate(x) ((x) & 0xf0000000)
114 #define PREDICATE_ALWAYS 0xe0000000
115
116 /*
117 * True if instr is a 32-bit thumb instruction. This works if instr
118 * is the first or only half-word of a thumb instruction. It also works
119 * when instr holds all 32-bits of a wide thumb instruction if stored
120 * in the form (first_half<<16)|(second_half)
121 */
122 #define is_wide_instruction(instr) ((unsigned)(instr) >= 0xe800)
123
124 /*
125 * kprobe-based event tracer support
126 */
127 #include <linux/compiler.h>
128 #define MAX_REG_OFFSET (offsetof(struct pt_regs, ARM_ORIG_r0))
129
130 extern int regs_query_register_offset(const char *name);
131 extern const char *regs_query_register_name(unsigned int offset);
132 extern bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr);
133 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
134 unsigned int n);
135
136 /**
137 * regs_get_register() - get register value from its offset
138 * @regs: pt_regs from which register value is gotten
139 * @offset: offset number of the register.
140 *
141 * regs_get_register returns the value of a register whose offset from @regs.
142 * The @offset is the offset of the register in struct pt_regs.
143 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
144 */
145 static inline unsigned long regs_get_register(struct pt_regs *regs,
146 unsigned int offset)
147 {
148 if (unlikely(offset > MAX_REG_OFFSET))
149 return 0;
150 return *(unsigned long *)((unsigned long)regs + offset);
151 }
152
153 /* Valid only for Kernel mode traps. */
154 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
155 {
156 return regs->ARM_sp;
157 }
158
159 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
160 {
161 return regs->ARM_sp;
162 }
163
164 #define current_pt_regs(void) ({ (struct pt_regs *) \
165 ((current_stack_pointer | (THREAD_SIZE - 1)) - 7) - 1; \
166 })
167
168 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
169 {
170 regs->ARM_r0 = rc;
171 }
172
173 /*
174 * Update ITSTATE after normal execution of an IT block instruction.
175 *
176 * The 8 IT state bits are split into two parts in CPSR:
177 * ITSTATE<1:0> are in CPSR<26:25>
178 * ITSTATE<7:2> are in CPSR<15:10>
179 */
180 static inline unsigned long it_advance(unsigned long cpsr)
181 {
182 if ((cpsr & 0x06000400) == 0) {
183 /* ITSTATE<2:0> == 0 means end of IT block, so clear IT state */
184 cpsr &= ~PSR_IT_MASK;
185 } else {
186 /* We need to shift left ITSTATE<4:0> */
187 const unsigned long mask = 0x06001c00; /* Mask ITSTATE<4:0> */
188 unsigned long it = cpsr & mask;
189 it <<= 1;
190 it |= it >> (27 - 10); /* Carry ITSTATE<2> to correct place */
191 it &= mask;
192 cpsr &= ~mask;
193 cpsr |= it;
194 }
195 return cpsr;
196 }
197
198 int syscall_trace_enter(struct pt_regs *regs);
199 void syscall_trace_exit(struct pt_regs *regs);
200
201 #endif /* __ASSEMBLY__ */
202 #endif
203
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