xref: /linux/arch/arm64/include/asm/ptrace.h (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 /*
2  * Based on arch/arm/include/asm/ptrace.h
3  *
4  * Copyright (C) 1996-2003 Russell King
5  * Copyright (C) 2012 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 #ifndef __ASM_PTRACE_H
20 #define __ASM_PTRACE_H
21 
22 #include <uapi/asm/ptrace.h>
23 
24 /* Current Exception Level values, as contained in CurrentEL */
25 #define CurrentEL_EL1		(1 << 2)
26 #define CurrentEL_EL2		(2 << 2)
27 
28 /* AArch32-specific ptrace requests */
29 #define COMPAT_PTRACE_GETREGS		12
30 #define COMPAT_PTRACE_SETREGS		13
31 #define COMPAT_PTRACE_GET_THREAD_AREA	22
32 #define COMPAT_PTRACE_SET_SYSCALL	23
33 #define COMPAT_PTRACE_GETVFPREGS	27
34 #define COMPAT_PTRACE_SETVFPREGS	28
35 #define COMPAT_PTRACE_GETHBPREGS	29
36 #define COMPAT_PTRACE_SETHBPREGS	30
37 
38 /* SPSR_ELx bits for exceptions taken from AArch32 */
39 #define PSR_AA32_MODE_MASK	0x0000001f
40 #define PSR_AA32_MODE_USR	0x00000010
41 #define PSR_AA32_MODE_FIQ	0x00000011
42 #define PSR_AA32_MODE_IRQ	0x00000012
43 #define PSR_AA32_MODE_SVC	0x00000013
44 #define PSR_AA32_MODE_ABT	0x00000017
45 #define PSR_AA32_MODE_HYP	0x0000001a
46 #define PSR_AA32_MODE_UND	0x0000001b
47 #define PSR_AA32_MODE_SYS	0x0000001f
48 #define PSR_AA32_T_BIT		0x00000020
49 #define PSR_AA32_F_BIT		0x00000040
50 #define PSR_AA32_I_BIT		0x00000080
51 #define PSR_AA32_A_BIT		0x00000100
52 #define PSR_AA32_E_BIT		0x00000200
53 #define PSR_AA32_DIT_BIT	0x01000000
54 #define PSR_AA32_Q_BIT		0x08000000
55 #define PSR_AA32_V_BIT		0x10000000
56 #define PSR_AA32_C_BIT		0x20000000
57 #define PSR_AA32_Z_BIT		0x40000000
58 #define PSR_AA32_N_BIT		0x80000000
59 #define PSR_AA32_IT_MASK	0x0600fc00	/* If-Then execution state mask */
60 #define PSR_AA32_GE_MASK	0x000f0000
61 
62 #ifdef CONFIG_CPU_BIG_ENDIAN
63 #define PSR_AA32_ENDSTATE	PSR_AA32_E_BIT
64 #else
65 #define PSR_AA32_ENDSTATE	0
66 #endif
67 
68 /* AArch32 CPSR bits, as seen in AArch32 */
69 #define COMPAT_PSR_DIT_BIT	0x00200000
70 
71 /*
72  * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
73  * process is located in memory.
74  */
75 #define COMPAT_PT_TEXT_ADDR		0x10000
76 #define COMPAT_PT_DATA_ADDR		0x10004
77 #define COMPAT_PT_TEXT_END_ADDR		0x10008
78 
79 /*
80  * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
81  * a syscall -- i.e., its most recent entry into the kernel from
82  * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
83  *
84  * This must have the value -1, for ABI compatibility with ptrace etc.
85  */
86 #define NO_SYSCALL (-1)
87 
88 #ifndef __ASSEMBLY__
89 #include <linux/bug.h>
90 #include <linux/types.h>
91 
92 /* sizeof(struct user) for AArch32 */
93 #define COMPAT_USER_SZ	296
94 
95 /* Architecturally defined mapping between AArch32 and AArch64 registers */
96 #define compat_usr(x)	regs[(x)]
97 #define compat_fp	regs[11]
98 #define compat_sp	regs[13]
99 #define compat_lr	regs[14]
100 #define compat_sp_hyp	regs[15]
101 #define compat_lr_irq	regs[16]
102 #define compat_sp_irq	regs[17]
103 #define compat_lr_svc	regs[18]
104 #define compat_sp_svc	regs[19]
105 #define compat_lr_abt	regs[20]
106 #define compat_sp_abt	regs[21]
107 #define compat_lr_und	regs[22]
108 #define compat_sp_und	regs[23]
109 #define compat_r8_fiq	regs[24]
110 #define compat_r9_fiq	regs[25]
111 #define compat_r10_fiq	regs[26]
112 #define compat_r11_fiq	regs[27]
113 #define compat_r12_fiq	regs[28]
114 #define compat_sp_fiq	regs[29]
115 #define compat_lr_fiq	regs[30]
116 
117 static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
118 {
119 	unsigned long pstate;
120 
121 	pstate = psr & ~COMPAT_PSR_DIT_BIT;
122 
123 	if (psr & COMPAT_PSR_DIT_BIT)
124 		pstate |= PSR_AA32_DIT_BIT;
125 
126 	return pstate;
127 }
128 
129 static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
130 {
131 	unsigned long psr;
132 
133 	psr = pstate & ~PSR_AA32_DIT_BIT;
134 
135 	if (pstate & PSR_AA32_DIT_BIT)
136 		psr |= COMPAT_PSR_DIT_BIT;
137 
138 	return psr;
139 }
140 
141 /*
142  * This struct defines the way the registers are stored on the stack during an
143  * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
144  * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
145  */
146 struct pt_regs {
147 	union {
148 		struct user_pt_regs user_regs;
149 		struct {
150 			u64 regs[31];
151 			u64 sp;
152 			u64 pc;
153 			u64 pstate;
154 		};
155 	};
156 	u64 orig_x0;
157 #ifdef __AARCH64EB__
158 	u32 unused2;
159 	s32 syscallno;
160 #else
161 	s32 syscallno;
162 	u32 unused2;
163 #endif
164 
165 	u64 orig_addr_limit;
166 	u64 unused;	// maintain 16 byte alignment
167 	u64 stackframe[2];
168 };
169 
170 static inline bool in_syscall(struct pt_regs const *regs)
171 {
172 	return regs->syscallno != NO_SYSCALL;
173 }
174 
175 static inline void forget_syscall(struct pt_regs *regs)
176 {
177 	regs->syscallno = NO_SYSCALL;
178 }
179 
180 #define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)
181 
182 #define arch_has_single_step()	(1)
183 
184 #ifdef CONFIG_COMPAT
185 #define compat_thumb_mode(regs) \
186 	(((regs)->pstate & PSR_AA32_T_BIT))
187 #else
188 #define compat_thumb_mode(regs) (0)
189 #endif
190 
191 #define user_mode(regs)	\
192 	(((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)
193 
194 #define compat_user_mode(regs)	\
195 	(((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
196 	 (PSR_MODE32_BIT | PSR_MODE_EL0t))
197 
198 #define processor_mode(regs) \
199 	((regs)->pstate & PSR_MODE_MASK)
200 
201 #define interrupts_enabled(regs) \
202 	(!((regs)->pstate & PSR_I_BIT))
203 
204 #define fast_interrupts_enabled(regs) \
205 	(!((regs)->pstate & PSR_F_BIT))
206 
207 #define GET_USP(regs) \
208 	(!compat_user_mode(regs) ? (regs)->sp : (regs)->compat_sp)
209 
210 #define SET_USP(ptregs, value) \
211 	(!compat_user_mode(regs) ? ((regs)->sp = value) : ((regs)->compat_sp = value))
212 
213 extern int regs_query_register_offset(const char *name);
214 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
215 					       unsigned int n);
216 
217 /**
218  * regs_get_register() - get register value from its offset
219  * @regs:	pt_regs from which register value is gotten
220  * @offset:	offset of the register.
221  *
222  * regs_get_register returns the value of a register whose offset from @regs.
223  * The @offset is the offset of the register in struct pt_regs.
224  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
225  */
226 static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
227 {
228 	u64 val = 0;
229 
230 	WARN_ON(offset & 7);
231 
232 	offset >>= 3;
233 	switch (offset) {
234 	case 0 ... 30:
235 		val = regs->regs[offset];
236 		break;
237 	case offsetof(struct pt_regs, sp) >> 3:
238 		val = regs->sp;
239 		break;
240 	case offsetof(struct pt_regs, pc) >> 3:
241 		val = regs->pc;
242 		break;
243 	case offsetof(struct pt_regs, pstate) >> 3:
244 		val = regs->pstate;
245 		break;
246 	default:
247 		val = 0;
248 	}
249 
250 	return val;
251 }
252 
253 /*
254  * Read a register given an architectural register index r.
255  * This handles the common case where 31 means XZR, not SP.
256  */
257 static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
258 {
259 	return (r == 31) ? 0 : regs->regs[r];
260 }
261 
262 /*
263  * Write a register given an architectural register index r.
264  * This handles the common case where 31 means XZR, not SP.
265  */
266 static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
267 				     unsigned long val)
268 {
269 	if (r != 31)
270 		regs->regs[r] = val;
271 }
272 
273 /* Valid only for Kernel mode traps. */
274 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
275 {
276 	return regs->sp;
277 }
278 
279 static inline unsigned long regs_return_value(struct pt_regs *regs)
280 {
281 	return regs->regs[0];
282 }
283 
284 /* We must avoid circular header include via sched.h */
285 struct task_struct;
286 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);
287 
288 #define GET_IP(regs)		((unsigned long)(regs)->pc)
289 #define SET_IP(regs, value)	((regs)->pc = ((u64) (value)))
290 
291 #define GET_FP(ptregs)		((unsigned long)(ptregs)->regs[29])
292 #define SET_FP(ptregs, value)	((ptregs)->regs[29] = ((u64) (value)))
293 
294 #include <asm-generic/ptrace.h>
295 
296 #define procedure_link_pointer(regs)	((regs)->regs[30])
297 
298 static inline void procedure_link_pointer_set(struct pt_regs *regs,
299 					   unsigned long val)
300 {
301 	procedure_link_pointer(regs) = val;
302 }
303 
304 #undef profile_pc
305 extern unsigned long profile_pc(struct pt_regs *regs);
306 
307 #endif /* __ASSEMBLY__ */
308 #endif
309