1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Based on arch/arm/include/asm/ptrace.h
4 *
5 * Copyright (C) 1996-2003 Russell King
6 * Copyright (C) 2012 ARM Ltd.
7 */
8 #ifndef __ASM_PTRACE_H
9 #define __ASM_PTRACE_H
10
11 #include <asm/cpufeature.h>
12
13 #include <uapi/asm/ptrace.h>
14
15 /* Current Exception Level values, as contained in CurrentEL */
16 #define CurrentEL_EL1 (1 << 2)
17 #define CurrentEL_EL2 (2 << 2)
18
19 #define INIT_PSTATE_EL1 \
20 (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL1h)
21 #define INIT_PSTATE_EL2 \
22 (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL2h)
23
24 /*
25 * PMR values used to mask/unmask interrupts.
26 *
27 * GIC priority masking works as follows: if an IRQ's priority is a higher value
28 * than the value held in PMR, that IRQ is masked. Lowering the value of PMR
29 * means masking more IRQs (or at least that the same IRQs remain masked).
30 *
31 * To mask interrupts, we clear the most significant bit of PMR.
32 *
33 * Some code sections either automatically switch back to PSR.I or explicitly
34 * require to not use priority masking. If bit GIC_PRIO_PSR_I_SET is included
35 * in the priority mask, it indicates that PSR.I should be set and
36 * interrupt disabling temporarily does not rely on IRQ priorities.
37 */
38 #define GIC_PRIO_IRQON 0xe0
39 #define __GIC_PRIO_IRQOFF (GIC_PRIO_IRQON & ~0x80)
40 #define __GIC_PRIO_IRQOFF_NS 0xa0
41 #define GIC_PRIO_PSR_I_SET (1 << 4)
42
43 #define GIC_PRIO_IRQOFF \
44 ({ \
45 extern struct static_key_false gic_nonsecure_priorities;\
46 u8 __prio = __GIC_PRIO_IRQOFF; \
47 \
48 if (static_branch_unlikely(&gic_nonsecure_priorities)) \
49 __prio = __GIC_PRIO_IRQOFF_NS; \
50 \
51 __prio; \
52 })
53
54 /* Additional SPSR bits not exposed in the UABI */
55 #define PSR_MODE_THREAD_BIT (1 << 0)
56 #define PSR_IL_BIT (1 << 20)
57
58 /* AArch32-specific ptrace requests */
59 #define COMPAT_PTRACE_GETREGS 12
60 #define COMPAT_PTRACE_SETREGS 13
61 #define COMPAT_PTRACE_GET_THREAD_AREA 22
62 #define COMPAT_PTRACE_SET_SYSCALL 23
63 #define COMPAT_PTRACE_GETVFPREGS 27
64 #define COMPAT_PTRACE_SETVFPREGS 28
65 #define COMPAT_PTRACE_GETHBPREGS 29
66 #define COMPAT_PTRACE_SETHBPREGS 30
67
68 /* SPSR_ELx bits for exceptions taken from AArch32 */
69 #define PSR_AA32_MODE_MASK 0x0000001f
70 #define PSR_AA32_MODE_USR 0x00000010
71 #define PSR_AA32_MODE_FIQ 0x00000011
72 #define PSR_AA32_MODE_IRQ 0x00000012
73 #define PSR_AA32_MODE_SVC 0x00000013
74 #define PSR_AA32_MODE_ABT 0x00000017
75 #define PSR_AA32_MODE_HYP 0x0000001a
76 #define PSR_AA32_MODE_UND 0x0000001b
77 #define PSR_AA32_MODE_SYS 0x0000001f
78 #define PSR_AA32_T_BIT 0x00000020
79 #define PSR_AA32_F_BIT 0x00000040
80 #define PSR_AA32_I_BIT 0x00000080
81 #define PSR_AA32_A_BIT 0x00000100
82 #define PSR_AA32_E_BIT 0x00000200
83 #define PSR_AA32_PAN_BIT 0x00400000
84 #define PSR_AA32_SSBS_BIT 0x00800000
85 #define PSR_AA32_DIT_BIT 0x01000000
86 #define PSR_AA32_Q_BIT 0x08000000
87 #define PSR_AA32_V_BIT 0x10000000
88 #define PSR_AA32_C_BIT 0x20000000
89 #define PSR_AA32_Z_BIT 0x40000000
90 #define PSR_AA32_N_BIT 0x80000000
91 #define PSR_AA32_IT_MASK 0x0600fc00 /* If-Then execution state mask */
92 #define PSR_AA32_GE_MASK 0x000f0000
93
94 #ifdef CONFIG_CPU_BIG_ENDIAN
95 #define PSR_AA32_ENDSTATE PSR_AA32_E_BIT
96 #else
97 #define PSR_AA32_ENDSTATE 0
98 #endif
99
100 /* AArch32 CPSR bits, as seen in AArch32 */
101 #define COMPAT_PSR_DIT_BIT 0x00200000
102
103 /*
104 * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
105 * process is located in memory.
106 */
107 #define COMPAT_PT_TEXT_ADDR 0x10000
108 #define COMPAT_PT_DATA_ADDR 0x10004
109 #define COMPAT_PT_TEXT_END_ADDR 0x10008
110
111 /*
112 * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
113 * a syscall -- i.e., its most recent entry into the kernel from
114 * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
115 *
116 * This must have the value -1, for ABI compatibility with ptrace etc.
117 */
118 #define NO_SYSCALL (-1)
119
120 #ifndef __ASSEMBLY__
121 #include <linux/bug.h>
122 #include <linux/types.h>
123
124 /* sizeof(struct user) for AArch32 */
125 #define COMPAT_USER_SZ 296
126
127 /* Architecturally defined mapping between AArch32 and AArch64 registers */
128 #define compat_usr(x) regs[(x)]
129 #define compat_fp regs[11]
130 #define compat_sp regs[13]
131 #define compat_lr regs[14]
132 #define compat_sp_hyp regs[15]
133 #define compat_lr_irq regs[16]
134 #define compat_sp_irq regs[17]
135 #define compat_lr_svc regs[18]
136 #define compat_sp_svc regs[19]
137 #define compat_lr_abt regs[20]
138 #define compat_sp_abt regs[21]
139 #define compat_lr_und regs[22]
140 #define compat_sp_und regs[23]
141 #define compat_r8_fiq regs[24]
142 #define compat_r9_fiq regs[25]
143 #define compat_r10_fiq regs[26]
144 #define compat_r11_fiq regs[27]
145 #define compat_r12_fiq regs[28]
146 #define compat_sp_fiq regs[29]
147 #define compat_lr_fiq regs[30]
148
compat_psr_to_pstate(const unsigned long psr)149 static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
150 {
151 unsigned long pstate;
152
153 pstate = psr & ~COMPAT_PSR_DIT_BIT;
154
155 if (psr & COMPAT_PSR_DIT_BIT)
156 pstate |= PSR_AA32_DIT_BIT;
157
158 return pstate;
159 }
160
pstate_to_compat_psr(const unsigned long pstate)161 static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
162 {
163 unsigned long psr;
164
165 psr = pstate & ~PSR_AA32_DIT_BIT;
166
167 if (pstate & PSR_AA32_DIT_BIT)
168 psr |= COMPAT_PSR_DIT_BIT;
169
170 return psr;
171 }
172
173 /*
174 * This struct defines the way the registers are stored on the stack during an
175 * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
176 * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
177 */
178 struct pt_regs {
179 union {
180 struct user_pt_regs user_regs;
181 struct {
182 u64 regs[31];
183 u64 sp;
184 u64 pc;
185 u64 pstate;
186 };
187 };
188 u64 orig_x0;
189 #ifdef __AARCH64EB__
190 u32 unused2;
191 s32 syscallno;
192 #else
193 s32 syscallno;
194 u32 unused2;
195 #endif
196
197 u64 orig_addr_limit;
198 /* Only valid when ARM64_HAS_IRQ_PRIO_MASKING is enabled. */
199 u64 pmr_save;
200 u64 stackframe[2];
201
202 /* Only valid for some EL1 exceptions. */
203 u64 lockdep_hardirqs;
204 u64 exit_rcu;
205 };
206
in_syscall(struct pt_regs const * regs)207 static inline bool in_syscall(struct pt_regs const *regs)
208 {
209 return regs->syscallno != NO_SYSCALL;
210 }
211
forget_syscall(struct pt_regs * regs)212 static inline void forget_syscall(struct pt_regs *regs)
213 {
214 regs->syscallno = NO_SYSCALL;
215 }
216
217 #define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)
218
219 #define arch_has_single_step() (1)
220
221 #ifdef CONFIG_COMPAT
222 #define compat_thumb_mode(regs) \
223 (((regs)->pstate & PSR_AA32_T_BIT))
224 #else
225 #define compat_thumb_mode(regs) (0)
226 #endif
227
228 #define user_mode(regs) \
229 (((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)
230
231 #define compat_user_mode(regs) \
232 (((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
233 (PSR_MODE32_BIT | PSR_MODE_EL0t))
234
235 #define processor_mode(regs) \
236 ((regs)->pstate & PSR_MODE_MASK)
237
238 #define irqs_priority_unmasked(regs) \
239 (system_uses_irq_prio_masking() ? \
240 (regs)->pmr_save == GIC_PRIO_IRQON : \
241 true)
242
243 #define interrupts_enabled(regs) \
244 (!((regs)->pstate & PSR_I_BIT) && irqs_priority_unmasked(regs))
245
246 #define fast_interrupts_enabled(regs) \
247 (!((regs)->pstate & PSR_F_BIT))
248
user_stack_pointer(struct pt_regs * regs)249 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
250 {
251 if (compat_user_mode(regs))
252 return regs->compat_sp;
253 return regs->sp;
254 }
255
256 extern int regs_query_register_offset(const char *name);
257 extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
258 unsigned int n);
259
260 /**
261 * regs_get_register() - get register value from its offset
262 * @regs: pt_regs from which register value is gotten
263 * @offset: offset of the register.
264 *
265 * regs_get_register returns the value of a register whose offset from @regs.
266 * The @offset is the offset of the register in struct pt_regs.
267 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
268 */
regs_get_register(struct pt_regs * regs,unsigned int offset)269 static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
270 {
271 u64 val = 0;
272
273 WARN_ON(offset & 7);
274
275 offset >>= 3;
276 switch (offset) {
277 case 0 ... 30:
278 val = regs->regs[offset];
279 break;
280 case offsetof(struct pt_regs, sp) >> 3:
281 val = regs->sp;
282 break;
283 case offsetof(struct pt_regs, pc) >> 3:
284 val = regs->pc;
285 break;
286 case offsetof(struct pt_regs, pstate) >> 3:
287 val = regs->pstate;
288 break;
289 default:
290 val = 0;
291 }
292
293 return val;
294 }
295
296 /*
297 * Read a register given an architectural register index r.
298 * This handles the common case where 31 means XZR, not SP.
299 */
pt_regs_read_reg(const struct pt_regs * regs,int r)300 static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
301 {
302 return (r == 31) ? 0 : regs->regs[r];
303 }
304
305 /*
306 * Write a register given an architectural register index r.
307 * This handles the common case where 31 means XZR, not SP.
308 */
pt_regs_write_reg(struct pt_regs * regs,int r,unsigned long val)309 static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
310 unsigned long val)
311 {
312 if (r != 31)
313 regs->regs[r] = val;
314 }
315
316 /* Valid only for Kernel mode traps. */
kernel_stack_pointer(struct pt_regs * regs)317 static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
318 {
319 return regs->sp;
320 }
321
regs_return_value(struct pt_regs * regs)322 static inline unsigned long regs_return_value(struct pt_regs *regs)
323 {
324 unsigned long val = regs->regs[0];
325
326 /*
327 * Audit currently uses regs_return_value() instead of
328 * syscall_get_return_value(). Apply the same sign-extension here until
329 * audit is updated to use syscall_get_return_value().
330 */
331 if (compat_user_mode(regs))
332 val = sign_extend64(val, 31);
333
334 return val;
335 }
336
regs_set_return_value(struct pt_regs * regs,unsigned long rc)337 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
338 {
339 regs->regs[0] = rc;
340 }
341
342 /**
343 * regs_get_kernel_argument() - get Nth function argument in kernel
344 * @regs: pt_regs of that context
345 * @n: function argument number (start from 0)
346 *
347 * regs_get_argument() returns @n th argument of the function call.
348 *
349 * Note that this chooses the most likely register mapping. In very rare
350 * cases this may not return correct data, for example, if one of the
351 * function parameters is 16 bytes or bigger. In such cases, we cannot
352 * get access the parameter correctly and the register assignment of
353 * subsequent parameters will be shifted.
354 */
regs_get_kernel_argument(struct pt_regs * regs,unsigned int n)355 static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
356 unsigned int n)
357 {
358 #define NR_REG_ARGUMENTS 8
359 if (n < NR_REG_ARGUMENTS)
360 return pt_regs_read_reg(regs, n);
361 return 0;
362 }
363
364 /* We must avoid circular header include via sched.h */
365 struct task_struct;
366 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);
367
instruction_pointer(struct pt_regs * regs)368 static inline unsigned long instruction_pointer(struct pt_regs *regs)
369 {
370 return regs->pc;
371 }
instruction_pointer_set(struct pt_regs * regs,unsigned long val)372 static inline void instruction_pointer_set(struct pt_regs *regs,
373 unsigned long val)
374 {
375 regs->pc = val;
376 }
377
frame_pointer(struct pt_regs * regs)378 static inline unsigned long frame_pointer(struct pt_regs *regs)
379 {
380 return regs->regs[29];
381 }
382
383 #define procedure_link_pointer(regs) ((regs)->regs[30])
384
procedure_link_pointer_set(struct pt_regs * regs,unsigned long val)385 static inline void procedure_link_pointer_set(struct pt_regs *regs,
386 unsigned long val)
387 {
388 procedure_link_pointer(regs) = val;
389 }
390
391 extern unsigned long profile_pc(struct pt_regs *regs);
392
393 #endif /* __ASSEMBLY__ */
394 #endif
395