summaryrefslogtreecommitdiffstats
path: root/arch/arm64/include/asm/ptrace.h
blob: 41b332c054ab824cb041591e4e3eb639a1b82154 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Based on arch/arm/include/asm/ptrace.h
 *
 * Copyright (C) 1996-2003 Russell King
 * Copyright (C) 2012 ARM Ltd.
 */
#ifndef __ASM_PTRACE_H
#define __ASM_PTRACE_H

#include <asm/cpufeature.h>

#include <uapi/asm/ptrace.h>

/* Current Exception Level values, as contained in CurrentEL */
#define CurrentEL_EL1		(1 << 2)
#define CurrentEL_EL2		(2 << 2)

#define INIT_PSTATE_EL1 \
	(PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL1h)
#define INIT_PSTATE_EL2 \
	(PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL2h)

/*
 * PMR values used to mask/unmask interrupts.
 *
 * GIC priority masking works as follows: if an IRQ's priority is a higher value
 * than the value held in PMR, that IRQ is masked. Lowering the value of PMR
 * means masking more IRQs (or at least that the same IRQs remain masked).
 *
 * To mask interrupts, we clear the most significant bit of PMR.
 *
 * Some code sections either automatically switch back to PSR.I or explicitly
 * require to not use priority masking. If bit GIC_PRIO_PSR_I_SET is included
 * in the priority mask, it indicates that PSR.I should be set and
 * interrupt disabling temporarily does not rely on IRQ priorities.
 */
#define GIC_PRIO_IRQON			0xe0
#define __GIC_PRIO_IRQOFF		(GIC_PRIO_IRQON & ~0x80)
#define __GIC_PRIO_IRQOFF_NS		0xa0
#define GIC_PRIO_PSR_I_SET		(1 << 4)

#define GIC_PRIO_IRQOFF							\
	({								\
		extern struct static_key_false gic_nonsecure_priorities;\
		u8 __prio = __GIC_PRIO_IRQOFF;				\
									\
		if (static_branch_unlikely(&gic_nonsecure_priorities))	\
			__prio = __GIC_PRIO_IRQOFF_NS;			\
									\
		__prio;							\
	})

/* Additional SPSR bits not exposed in the UABI */
#define PSR_MODE_THREAD_BIT	(1 << 0)
#define PSR_IL_BIT		(1 << 20)

/* AArch32-specific ptrace requests */
#define COMPAT_PTRACE_GETREGS		12
#define COMPAT_PTRACE_SETREGS		13
#define COMPAT_PTRACE_GET_THREAD_AREA	22
#define COMPAT_PTRACE_SET_SYSCALL	23
#define COMPAT_PTRACE_GETVFPREGS	27
#define COMPAT_PTRACE_SETVFPREGS	28
#define COMPAT_PTRACE_GETHBPREGS	29
#define COMPAT_PTRACE_SETHBPREGS	30

/* SPSR_ELx bits for exceptions taken from AArch32 */
#define PSR_AA32_MODE_MASK	0x0000001f
#define PSR_AA32_MODE_USR	0x00000010
#define PSR_AA32_MODE_FIQ	0x00000011
#define PSR_AA32_MODE_IRQ	0x00000012
#define PSR_AA32_MODE_SVC	0x00000013
#define PSR_AA32_MODE_ABT	0x00000017
#define PSR_AA32_MODE_HYP	0x0000001a
#define PSR_AA32_MODE_UND	0x0000001b
#define PSR_AA32_MODE_SYS	0x0000001f
#define PSR_AA32_T_BIT		0x00000020
#define PSR_AA32_F_BIT		0x00000040
#define PSR_AA32_I_BIT		0x00000080
#define PSR_AA32_A_BIT		0x00000100
#define PSR_AA32_E_BIT		0x00000200
#define PSR_AA32_PAN_BIT	0x00400000
#define PSR_AA32_SSBS_BIT	0x00800000
#define PSR_AA32_DIT_BIT	0x01000000
#define PSR_AA32_Q_BIT		0x08000000
#define PSR_AA32_V_BIT		0x10000000
#define PSR_AA32_C_BIT		0x20000000
#define PSR_AA32_Z_BIT		0x40000000
#define PSR_AA32_N_BIT		0x80000000
#define PSR_AA32_IT_MASK	0x0600fc00	/* If-Then execution state mask */
#define PSR_AA32_GE_MASK	0x000f0000

#ifdef CONFIG_CPU_BIG_ENDIAN
#define PSR_AA32_ENDSTATE	PSR_AA32_E_BIT
#else
#define PSR_AA32_ENDSTATE	0
#endif

/* AArch32 CPSR bits, as seen in AArch32 */
#define COMPAT_PSR_DIT_BIT	0x00200000

/*
 * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
 * process is located in memory.
 */
#define COMPAT_PT_TEXT_ADDR		0x10000
#define COMPAT_PT_DATA_ADDR		0x10004
#define COMPAT_PT_TEXT_END_ADDR		0x10008

/*
 * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
 * a syscall -- i.e., its most recent entry into the kernel from
 * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
 *
 * This must have the value -1, for ABI compatibility with ptrace etc.
 */
#define NO_SYSCALL (-1)

#ifndef __ASSEMBLY__
#include <linux/bug.h>
#include <linux/types.h>

/* sizeof(struct user) for AArch32 */
#define COMPAT_USER_SZ	296

/* Architecturally defined mapping between AArch32 and AArch64 registers */
#define compat_usr(x)	regs[(x)]
#define compat_fp	regs[11]
#define compat_sp	regs[13]
#define compat_lr	regs[14]
#define compat_sp_hyp	regs[15]
#define compat_lr_irq	regs[16]
#define compat_sp_irq	regs[17]
#define compat_lr_svc	regs[18]
#define compat_sp_svc	regs[19]
#define compat_lr_abt	regs[20]
#define compat_sp_abt	regs[21]
#define compat_lr_und	regs[22]
#define compat_sp_und	regs[23]
#define compat_r8_fiq	regs[24]
#define compat_r9_fiq	regs[25]
#define compat_r10_fiq	regs[26]
#define compat_r11_fiq	regs[27]
#define compat_r12_fiq	regs[28]
#define compat_sp_fiq	regs[29]
#define compat_lr_fiq	regs[30]

static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
{
	unsigned long pstate;

	pstate = psr & ~COMPAT_PSR_DIT_BIT;

	if (psr & COMPAT_PSR_DIT_BIT)
		pstate |= PSR_AA32_DIT_BIT;

	return pstate;
}

static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
{
	unsigned long psr;

	psr = pstate & ~PSR_AA32_DIT_BIT;

	if (pstate & PSR_AA32_DIT_BIT)
		psr |= COMPAT_PSR_DIT_BIT;

	return psr;
}

/*
 * This struct defines the way the registers are stored on the stack during an
 * exception. Note that sizeof(struct pt_regs) has to be a multiple of 16 (for
 * stack alignment). struct user_pt_regs must form a prefix of struct pt_regs.
 */
struct pt_regs {
	union {
		struct user_pt_regs user_regs;
		struct {
			u64 regs[31];
			u64 sp;
			u64 pc;
			u64 pstate;
		};
	};
	u64 orig_x0;
#ifdef __AARCH64EB__
	u32 unused2;
	s32 syscallno;
#else
	s32 syscallno;
	u32 unused2;
#endif
	u64 sdei_ttbr1;
	/* Only valid when ARM64_HAS_IRQ_PRIO_MASKING is enabled. */
	u64 pmr_save;
	u64 stackframe[2];

	/* Only valid for some EL1 exceptions. */
	u64 lockdep_hardirqs;
	u64 exit_rcu;
};

static inline bool in_syscall(struct pt_regs const *regs)
{
	return regs->syscallno != NO_SYSCALL;
}

static inline void forget_syscall(struct pt_regs *regs)
{
	regs->syscallno = NO_SYSCALL;
}

#define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)

#define arch_has_single_step()	(1)

#ifdef CONFIG_COMPAT
#define compat_thumb_mode(regs) \
	(((regs)->pstate & PSR_AA32_T_BIT))
#else
#define compat_thumb_mode(regs) (0)
#endif

#define user_mode(regs)	\
	(((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)

#define compat_user_mode(regs)	\
	(((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
	 (PSR_MODE32_BIT | PSR_MODE_EL0t))

#define processor_mode(regs) \
	((regs)->pstate & PSR_MODE_MASK)

#define irqs_priority_unmasked(regs)					\
	(system_uses_irq_prio_masking() ?				\
		(regs)->pmr_save == GIC_PRIO_IRQON :			\
		true)

#define interrupts_enabled(regs)			\
	(!((regs)->pstate & PSR_I_BIT) && irqs_priority_unmasked(regs))

#define fast_interrupts_enabled(regs) \
	(!((regs)->pstate & PSR_F_BIT))

static inline unsigned long user_stack_pointer(struct pt_regs *regs)
{
	if (compat_user_mode(regs))
		return regs->compat_sp;
	return regs->sp;
}

extern int regs_query_register_offset(const char *name);
extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
					       unsigned int n);

/**
 * regs_get_register() - get register value from its offset
 * @regs:	pt_regs from which register value is gotten
 * @offset:	offset of the register.
 *
 * regs_get_register returns the value of a register whose offset from @regs.
 * The @offset is the offset of the register in struct pt_regs.
 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 */
static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
{
	u64 val = 0;

	WARN_ON(offset & 7);

	offset >>= 3;
	switch (offset) {
	case 0 ... 30:
		val = regs->regs[offset];
		break;
	case offsetof(struct pt_regs, sp) >> 3:
		val = regs->sp;
		break;
	case offsetof(struct pt_regs, pc) >> 3:
		val = regs->pc;
		break;
	case offsetof(struct pt_regs, pstate) >> 3:
		val = regs->pstate;
		break;
	default:
		val = 0;
	}

	return val;
}

/*
 * Read a register given an architectural register index r.
 * This handles the common case where 31 means XZR, not SP.
 */
static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
{
	return (r == 31) ? 0 : regs->regs[r];
}

/*
 * Write a register given an architectural register index r.
 * This handles the common case where 31 means XZR, not SP.
 */
static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
				     unsigned long val)
{
	if (r != 31)
		regs->regs[r] = val;
}

/* Valid only for Kernel mode traps. */
static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
{
	return regs->sp;
}

static inline unsigned long regs_return_value(struct pt_regs *regs)
{
	unsigned long val = regs->regs[0];

	/*
	 * Audit currently uses regs_return_value() instead of
	 * syscall_get_return_value(). Apply the same sign-extension here until
	 * audit is updated to use syscall_get_return_value().
	 */
	if (compat_user_mode(regs))
		val = sign_extend64(val, 31);

	return val;
}

static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
{
	regs->regs[0] = rc;
}

/**
 * regs_get_kernel_argument() - get Nth function argument in kernel
 * @regs:	pt_regs of that context
 * @n:		function argument number (start from 0)
 *
 * regs_get_argument() returns @n th argument of the function call.
 *
 * Note that this chooses the most likely register mapping. In very rare
 * cases this may not return correct data, for example, if one of the
 * function parameters is 16 bytes or bigger. In such cases, we cannot
 * get access the parameter correctly and the register assignment of
 * subsequent parameters will be shifted.
 */
static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
						     unsigned int n)
{
#define NR_REG_ARGUMENTS 8
	if (n < NR_REG_ARGUMENTS)
		return pt_regs_read_reg(regs, n);
	return 0;
}

/* We must avoid circular header include via sched.h */
struct task_struct;
int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);

static inline unsigned long instruction_pointer(struct pt_regs *regs)
{
	return regs->pc;
}
static inline void instruction_pointer_set(struct pt_regs *regs,
		unsigned long val)
{
	regs->pc = val;
}

static inline unsigned long frame_pointer(struct pt_regs *regs)
{
	return regs->regs[29];
}

#define procedure_link_pointer(regs)	((regs)->regs[30])

static inline void procedure_link_pointer_set(struct pt_regs *regs,
					   unsigned long val)
{
	procedure_link_pointer(regs) = val;
}

extern unsigned long profile_pc(struct pt_regs *regs);

#endif /* __ASSEMBLY__ */
#endif