xref: /openbmc/linux/arch/arm64/include/asm/ptrace.h (revision e3d786a3)
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 /* Additional SPSR bits not exposed in the UABI */
29 #define PSR_IL_BIT		(1 << 20)
30 
31 /* AArch32-specific ptrace requests */
32 #define COMPAT_PTRACE_GETREGS		12
33 #define COMPAT_PTRACE_SETREGS		13
34 #define COMPAT_PTRACE_GET_THREAD_AREA	22
35 #define COMPAT_PTRACE_SET_SYSCALL	23
36 #define COMPAT_PTRACE_GETVFPREGS	27
37 #define COMPAT_PTRACE_SETVFPREGS	28
38 #define COMPAT_PTRACE_GETHBPREGS	29
39 #define COMPAT_PTRACE_SETHBPREGS	30
40 
41 /* SPSR_ELx bits for exceptions taken from AArch32 */
42 #define PSR_AA32_MODE_MASK	0x0000001f
43 #define PSR_AA32_MODE_USR	0x00000010
44 #define PSR_AA32_MODE_FIQ	0x00000011
45 #define PSR_AA32_MODE_IRQ	0x00000012
46 #define PSR_AA32_MODE_SVC	0x00000013
47 #define PSR_AA32_MODE_ABT	0x00000017
48 #define PSR_AA32_MODE_HYP	0x0000001a
49 #define PSR_AA32_MODE_UND	0x0000001b
50 #define PSR_AA32_MODE_SYS	0x0000001f
51 #define PSR_AA32_T_BIT		0x00000020
52 #define PSR_AA32_F_BIT		0x00000040
53 #define PSR_AA32_I_BIT		0x00000080
54 #define PSR_AA32_A_BIT		0x00000100
55 #define PSR_AA32_E_BIT		0x00000200
56 #define PSR_AA32_SSBS_BIT	0x00800000
57 #define PSR_AA32_DIT_BIT	0x01000000
58 #define PSR_AA32_Q_BIT		0x08000000
59 #define PSR_AA32_V_BIT		0x10000000
60 #define PSR_AA32_C_BIT		0x20000000
61 #define PSR_AA32_Z_BIT		0x40000000
62 #define PSR_AA32_N_BIT		0x80000000
63 #define PSR_AA32_IT_MASK	0x0600fc00	/* If-Then execution state mask */
64 #define PSR_AA32_GE_MASK	0x000f0000
65 
66 #ifdef CONFIG_CPU_BIG_ENDIAN
67 #define PSR_AA32_ENDSTATE	PSR_AA32_E_BIT
68 #else
69 #define PSR_AA32_ENDSTATE	0
70 #endif
71 
72 /* AArch32 CPSR bits, as seen in AArch32 */
73 #define COMPAT_PSR_DIT_BIT	0x00200000
74 
75 /*
76  * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
77  * process is located in memory.
78  */
79 #define COMPAT_PT_TEXT_ADDR		0x10000
80 #define COMPAT_PT_DATA_ADDR		0x10004
81 #define COMPAT_PT_TEXT_END_ADDR		0x10008
82 
83 /*
84  * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
85  * a syscall -- i.e., its most recent entry into the kernel from
86  * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
87  *
88  * This must have the value -1, for ABI compatibility with ptrace etc.
89  */
90 #define NO_SYSCALL (-1)
91 
92 #ifndef __ASSEMBLY__
93 #include <linux/bug.h>
94 #include <linux/types.h>
95 
96 /* sizeof(struct user) for AArch32 */
97 #define COMPAT_USER_SZ	296
98 
99 /* Architecturally defined mapping between AArch32 and AArch64 registers */
100 #define compat_usr(x)	regs[(x)]
101 #define compat_fp	regs[11]
102 #define compat_sp	regs[13]
103 #define compat_lr	regs[14]
104 #define compat_sp_hyp	regs[15]
105 #define compat_lr_irq	regs[16]
106 #define compat_sp_irq	regs[17]
107 #define compat_lr_svc	regs[18]
108 #define compat_sp_svc	regs[19]
109 #define compat_lr_abt	regs[20]
110 #define compat_sp_abt	regs[21]
111 #define compat_lr_und	regs[22]
112 #define compat_sp_und	regs[23]
113 #define compat_r8_fiq	regs[24]
114 #define compat_r9_fiq	regs[25]
115 #define compat_r10_fiq	regs[26]
116 #define compat_r11_fiq	regs[27]
117 #define compat_r12_fiq	regs[28]
118 #define compat_sp_fiq	regs[29]
119 #define compat_lr_fiq	regs[30]
120 
121 static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
122 {
123 	unsigned long pstate;
124 
125 	pstate = psr & ~COMPAT_PSR_DIT_BIT;
126 
127 	if (psr & COMPAT_PSR_DIT_BIT)
128 		pstate |= PSR_AA32_DIT_BIT;
129 
130 	return pstate;
131 }
132 
133 static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
134 {
135 	unsigned long psr;
136 
137 	psr = pstate & ~PSR_AA32_DIT_BIT;
138 
139 	if (pstate & PSR_AA32_DIT_BIT)
140 		psr |= COMPAT_PSR_DIT_BIT;
141 
142 	return psr;
143 }
144 
145 /*
146  * This struct defines the way the registers are stored on the stack during an
147  * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
148  * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
149  */
150 struct pt_regs {
151 	union {
152 		struct user_pt_regs user_regs;
153 		struct {
154 			u64 regs[31];
155 			u64 sp;
156 			u64 pc;
157 			u64 pstate;
158 		};
159 	};
160 	u64 orig_x0;
161 #ifdef __AARCH64EB__
162 	u32 unused2;
163 	s32 syscallno;
164 #else
165 	s32 syscallno;
166 	u32 unused2;
167 #endif
168 
169 	u64 orig_addr_limit;
170 	u64 unused;	// maintain 16 byte alignment
171 	u64 stackframe[2];
172 };
173 
174 static inline bool in_syscall(struct pt_regs const *regs)
175 {
176 	return regs->syscallno != NO_SYSCALL;
177 }
178 
179 static inline void forget_syscall(struct pt_regs *regs)
180 {
181 	regs->syscallno = NO_SYSCALL;
182 }
183 
184 #define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)
185 
186 #define arch_has_single_step()	(1)
187 
188 #ifdef CONFIG_COMPAT
189 #define compat_thumb_mode(regs) \
190 	(((regs)->pstate & PSR_AA32_T_BIT))
191 #else
192 #define compat_thumb_mode(regs) (0)
193 #endif
194 
195 #define user_mode(regs)	\
196 	(((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)
197 
198 #define compat_user_mode(regs)	\
199 	(((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
200 	 (PSR_MODE32_BIT | PSR_MODE_EL0t))
201 
202 #define processor_mode(regs) \
203 	((regs)->pstate & PSR_MODE_MASK)
204 
205 #define interrupts_enabled(regs) \
206 	(!((regs)->pstate & PSR_I_BIT))
207 
208 #define fast_interrupts_enabled(regs) \
209 	(!((regs)->pstate & PSR_F_BIT))
210 
211 #define GET_USP(regs) \
212 	(!compat_user_mode(regs) ? (regs)->sp : (regs)->compat_sp)
213 
214 #define SET_USP(ptregs, value) \
215 	(!compat_user_mode(regs) ? ((regs)->sp = value) : ((regs)->compat_sp = value))
216 
217 extern int regs_query_register_offset(const char *name);
218 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
219 					       unsigned int n);
220 
221 /**
222  * regs_get_register() - get register value from its offset
223  * @regs:	pt_regs from which register value is gotten
224  * @offset:	offset of the register.
225  *
226  * regs_get_register returns the value of a register whose offset from @regs.
227  * The @offset is the offset of the register in struct pt_regs.
228  * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
229  */
230 static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
231 {
232 	u64 val = 0;
233 
234 	WARN_ON(offset & 7);
235 
236 	offset >>= 3;
237 	switch (offset) {
238 	case 0 ... 30:
239 		val = regs->regs[offset];
240 		break;
241 	case offsetof(struct pt_regs, sp) >> 3:
242 		val = regs->sp;
243 		break;
244 	case offsetof(struct pt_regs, pc) >> 3:
245 		val = regs->pc;
246 		break;
247 	case offsetof(struct pt_regs, pstate) >> 3:
248 		val = regs->pstate;
249 		break;
250 	default:
251 		val = 0;
252 	}
253 
254 	return val;
255 }
256 
257 /*
258  * Read a register given an architectural register index r.
259  * This handles the common case where 31 means XZR, not SP.
260  */
261 static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
262 {
263 	return (r == 31) ? 0 : regs->regs[r];
264 }
265 
266 /*
267  * Write a register given an architectural register index r.
268  * This handles the common case where 31 means XZR, not SP.
269  */
270 static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
271 				     unsigned long val)
272 {
273 	if (r != 31)
274 		regs->regs[r] = val;
275 }
276 
277 /* Valid only for Kernel mode traps. */
278 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
279 {
280 	return regs->sp;
281 }
282 
283 static inline unsigned long regs_return_value(struct pt_regs *regs)
284 {
285 	return regs->regs[0];
286 }
287 
288 /* We must avoid circular header include via sched.h */
289 struct task_struct;
290 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);
291 
292 #define GET_IP(regs)		((unsigned long)(regs)->pc)
293 #define SET_IP(regs, value)	((regs)->pc = ((u64) (value)))
294 
295 #define GET_FP(ptregs)		((unsigned long)(ptregs)->regs[29])
296 #define SET_FP(ptregs, value)	((ptregs)->regs[29] = ((u64) (value)))
297 
298 #include <asm-generic/ptrace.h>
299 
300 #define procedure_link_pointer(regs)	((regs)->regs[30])
301 
302 static inline void procedure_link_pointer_set(struct pt_regs *regs,
303 					   unsigned long val)
304 {
305 	procedure_link_pointer(regs) = val;
306 }
307 
308 #undef profile_pc
309 extern unsigned long profile_pc(struct pt_regs *regs);
310 
311 #endif /* __ASSEMBLY__ */
312 #endif
313