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Linux kernel mirror (for testing)
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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#include <linux/irqchip/arm-gic-v3-prio.h>
25
26#define GIC_PRIO_IRQON GICV3_PRIO_UNMASKED
27#define GIC_PRIO_IRQOFF GICV3_PRIO_IRQ
28
29#define GIC_PRIO_PSR_I_SET GICV3_PRIO_PSR_I_SET
30
31/* Additional SPSR bits not exposed in the UABI */
32#define PSR_MODE_THREAD_BIT (1 << 0)
33#define PSR_IL_BIT (1 << 20)
34
35/* AArch32-specific ptrace requests */
36#define COMPAT_PTRACE_GETREGS 12
37#define COMPAT_PTRACE_SETREGS 13
38#define COMPAT_PTRACE_GET_THREAD_AREA 22
39#define COMPAT_PTRACE_SET_SYSCALL 23
40#define COMPAT_PTRACE_GETVFPREGS 27
41#define COMPAT_PTRACE_SETVFPREGS 28
42#define COMPAT_PTRACE_GETHBPREGS 29
43#define COMPAT_PTRACE_SETHBPREGS 30
44
45/* SPSR_ELx bits for exceptions taken from AArch32 */
46#define PSR_AA32_MODE_MASK 0x0000001f
47#define PSR_AA32_MODE_USR 0x00000010
48#define PSR_AA32_MODE_FIQ 0x00000011
49#define PSR_AA32_MODE_IRQ 0x00000012
50#define PSR_AA32_MODE_SVC 0x00000013
51#define PSR_AA32_MODE_ABT 0x00000017
52#define PSR_AA32_MODE_HYP 0x0000001a
53#define PSR_AA32_MODE_UND 0x0000001b
54#define PSR_AA32_MODE_SYS 0x0000001f
55#define PSR_AA32_T_BIT 0x00000020
56#define PSR_AA32_F_BIT 0x00000040
57#define PSR_AA32_I_BIT 0x00000080
58#define PSR_AA32_A_BIT 0x00000100
59#define PSR_AA32_E_BIT 0x00000200
60#define PSR_AA32_PAN_BIT 0x00400000
61#define PSR_AA32_SSBS_BIT 0x00800000
62#define PSR_AA32_DIT_BIT 0x01000000
63#define PSR_AA32_Q_BIT 0x08000000
64#define PSR_AA32_V_BIT 0x10000000
65#define PSR_AA32_C_BIT 0x20000000
66#define PSR_AA32_Z_BIT 0x40000000
67#define PSR_AA32_N_BIT 0x80000000
68#define PSR_AA32_IT_MASK 0x0600fc00 /* If-Then execution state mask */
69#define PSR_AA32_GE_MASK 0x000f0000
70
71#ifdef CONFIG_CPU_BIG_ENDIAN
72#define PSR_AA32_ENDSTATE PSR_AA32_E_BIT
73#else
74#define PSR_AA32_ENDSTATE 0
75#endif
76
77/* AArch32 CPSR bits, as seen in AArch32 */
78#define COMPAT_PSR_DIT_BIT 0x00200000
79
80/*
81 * These are 'magic' values for PTRACE_PEEKUSR that return info about where a
82 * process is located in memory.
83 */
84#define COMPAT_PT_TEXT_ADDR 0x10000
85#define COMPAT_PT_DATA_ADDR 0x10004
86#define COMPAT_PT_TEXT_END_ADDR 0x10008
87
88/*
89 * If pt_regs.syscallno == NO_SYSCALL, then the thread is not executing
90 * a syscall -- i.e., its most recent entry into the kernel from
91 * userspace was not via SVC, or otherwise a tracer cancelled the syscall.
92 *
93 * This must have the value -1, for ABI compatibility with ptrace etc.
94 */
95#define NO_SYSCALL (-1)
96
97#ifndef __ASSEMBLER__
98#include <linux/bug.h>
99#include <linux/types.h>
100
101#include <asm/stacktrace/frame.h>
102
103/* sizeof(struct user) for AArch32 */
104#define COMPAT_USER_SZ 296
105
106/* Architecturally defined mapping between AArch32 and AArch64 registers */
107#define compat_usr(x) regs[(x)]
108#define compat_fp regs[11]
109#define compat_sp regs[13]
110#define compat_lr regs[14]
111#define compat_sp_hyp regs[15]
112#define compat_lr_irq regs[16]
113#define compat_sp_irq regs[17]
114#define compat_lr_svc regs[18]
115#define compat_sp_svc regs[19]
116#define compat_lr_abt regs[20]
117#define compat_sp_abt regs[21]
118#define compat_lr_und regs[22]
119#define compat_sp_und regs[23]
120#define compat_r8_fiq regs[24]
121#define compat_r9_fiq regs[25]
122#define compat_r10_fiq regs[26]
123#define compat_r11_fiq regs[27]
124#define compat_r12_fiq regs[28]
125#define compat_sp_fiq regs[29]
126#define compat_lr_fiq regs[30]
127
128static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
129{
130 unsigned long pstate;
131
132 pstate = psr & ~COMPAT_PSR_DIT_BIT;
133
134 if (psr & COMPAT_PSR_DIT_BIT)
135 pstate |= PSR_AA32_DIT_BIT;
136
137 return pstate;
138}
139
140static inline unsigned long pstate_to_compat_psr(const unsigned long pstate)
141{
142 unsigned long psr;
143
144 psr = pstate & ~PSR_AA32_DIT_BIT;
145
146 if (pstate & PSR_AA32_DIT_BIT)
147 psr |= COMPAT_PSR_DIT_BIT;
148
149 return psr;
150}
151
152/*
153 * This struct defines the way the registers are stored on the stack during an
154 * exception. struct user_pt_regs must form a prefix of struct pt_regs.
155 */
156struct pt_regs {
157 union {
158 struct user_pt_regs user_regs;
159 struct {
160 u64 regs[31];
161 u64 sp;
162 u64 pc;
163 u64 pstate;
164 };
165 };
166 u64 orig_x0;
167 s32 syscallno;
168 u32 pmr;
169
170 u64 sdei_ttbr1;
171 struct frame_record_meta stackframe;
172};
173
174/* For correct stack alignment, pt_regs has to be a multiple of 16 bytes. */
175static_assert(IS_ALIGNED(sizeof(struct pt_regs), 16));
176
177static inline bool in_syscall(struct pt_regs const *regs)
178{
179 return regs->syscallno != NO_SYSCALL;
180}
181
182static inline void forget_syscall(struct pt_regs *regs)
183{
184 regs->syscallno = NO_SYSCALL;
185}
186
187#define MAX_REG_OFFSET offsetof(struct pt_regs, pstate)
188
189#define arch_has_single_step() (1)
190
191#ifdef CONFIG_COMPAT
192#define compat_thumb_mode(regs) \
193 (((regs)->pstate & PSR_AA32_T_BIT))
194#else
195#define compat_thumb_mode(regs) (0)
196#endif
197
198#define user_mode(regs) \
199 (((regs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)
200
201#define compat_user_mode(regs) \
202 (((regs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
203 (PSR_MODE32_BIT | PSR_MODE_EL0t))
204
205#define processor_mode(regs) \
206 ((regs)->pstate & PSR_MODE_MASK)
207
208#define irqs_priority_unmasked(regs) \
209 (system_uses_irq_prio_masking() ? \
210 (regs)->pmr == GIC_PRIO_IRQON : \
211 true)
212
213static __always_inline bool regs_irqs_disabled(const struct pt_regs *regs)
214{
215 return (regs->pstate & PSR_I_BIT) || !irqs_priority_unmasked(regs);
216}
217
218#define interrupts_enabled(regs) (!regs_irqs_disabled(regs))
219
220static inline unsigned long user_stack_pointer(struct pt_regs *regs)
221{
222 if (compat_user_mode(regs))
223 return regs->compat_sp;
224 return regs->sp;
225}
226
227extern int regs_query_register_offset(const char *name);
228extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
229 unsigned int n);
230
231/**
232 * regs_get_register() - get register value from its offset
233 * @regs: pt_regs from which register value is gotten
234 * @offset: offset of the register.
235 *
236 * regs_get_register returns the value of a register whose offset from @regs.
237 * The @offset is the offset of the register in struct pt_regs.
238 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
239 */
240static inline u64 regs_get_register(struct pt_regs *regs, unsigned int offset)
241{
242 u64 val = 0;
243
244 WARN_ON(offset & 7);
245
246 offset >>= 3;
247 switch (offset) {
248 case 0 ... 30:
249 val = regs->regs[offset];
250 break;
251 case offsetof(struct pt_regs, sp) >> 3:
252 val = regs->sp;
253 break;
254 case offsetof(struct pt_regs, pc) >> 3:
255 val = regs->pc;
256 break;
257 case offsetof(struct pt_regs, pstate) >> 3:
258 val = regs->pstate;
259 break;
260 default:
261 val = 0;
262 }
263
264 return val;
265}
266
267/*
268 * Read a register given an architectural register index r.
269 * This handles the common case where 31 means XZR, not SP.
270 */
271static inline unsigned long pt_regs_read_reg(const struct pt_regs *regs, int r)
272{
273 return (r == 31) ? 0 : regs->regs[r];
274}
275
276/*
277 * Write a register given an architectural register index r.
278 * This handles the common case where 31 means XZR, not SP.
279 */
280static inline void pt_regs_write_reg(struct pt_regs *regs, int r,
281 unsigned long val)
282{
283 if (r != 31)
284 regs->regs[r] = val;
285}
286
287/* Valid only for Kernel mode traps. */
288static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
289{
290 return regs->sp;
291}
292
293static inline unsigned long regs_return_value(struct pt_regs *regs)
294{
295 unsigned long val = regs->regs[0];
296
297 /*
298 * Audit currently uses regs_return_value() instead of
299 * syscall_get_return_value(). Apply the same sign-extension here until
300 * audit is updated to use syscall_get_return_value().
301 */
302 if (compat_user_mode(regs))
303 val = sign_extend64(val, 31);
304
305 return val;
306}
307
308static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
309{
310 regs->regs[0] = rc;
311}
312
313/**
314 * regs_get_kernel_argument() - get Nth function argument in kernel
315 * @regs: pt_regs of that context
316 * @n: function argument number (start from 0)
317 *
318 * regs_get_argument() returns @n th argument of the function call.
319 *
320 * Note that this chooses the most likely register mapping. In very rare
321 * cases this may not return correct data, for example, if one of the
322 * function parameters is 16 bytes or bigger. In such cases, we cannot
323 * get access the parameter correctly and the register assignment of
324 * subsequent parameters will be shifted.
325 */
326static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
327 unsigned int n)
328{
329#define NR_REG_ARGUMENTS 8
330 if (n < NR_REG_ARGUMENTS)
331 return pt_regs_read_reg(regs, n);
332 return 0;
333}
334
335/* We must avoid circular header include via sched.h */
336struct task_struct;
337int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task);
338
339static inline unsigned long instruction_pointer(struct pt_regs *regs)
340{
341 return regs->pc;
342}
343static inline void instruction_pointer_set(struct pt_regs *regs,
344 unsigned long val)
345{
346 regs->pc = val;
347}
348
349static inline unsigned long frame_pointer(struct pt_regs *regs)
350{
351 return regs->regs[29];
352}
353
354#define procedure_link_pointer(regs) ((regs)->regs[30])
355
356static inline void procedure_link_pointer_set(struct pt_regs *regs,
357 unsigned long val)
358{
359 procedure_link_pointer(regs) = val;
360}
361
362extern unsigned long profile_pc(struct pt_regs *regs);
363
364#endif /* __ASSEMBLER__ */
365#endif