1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * Copyright (C) 2001 PPC64 Team, IBM Corp
4 *
5 * This struct defines the way the registers are stored on the
6 * kernel stack during a system call or other kernel entry.
7 *
8 * this should only contain volatile regs
9 * since we can keep non-volatile in the thread_struct
10 * should set this up when only volatiles are saved
11 * by intr code.
12 *
13 * Since this is going on the stack, *CARE MUST BE TAKEN* to insure
14 * that the overall structure is a multiple of 16 bytes in length.
15 *
16 * Note that the offsets of the fields in this struct correspond with
17 * the PT_* values below. This simplifies arch/powerpc/kernel/ptrace.c.
18 */
19 #ifndef _ASM_POWERPC_PTRACE_H
20 #define _ASM_POWERPC_PTRACE_H
21
22 #include <linux/err.h>
23 #include <uapi/asm/ptrace.h>
24 #include <asm/asm-const.h>
25 #include <asm/reg.h>
26
27 #ifndef __ASSEMBLY__
28 struct pt_regs
29 {
30 union {
31 struct user_pt_regs user_regs;
32 struct {
33 unsigned long gpr[32];
34 unsigned long nip;
35 unsigned long msr;
36 unsigned long orig_gpr3;
37 unsigned long ctr;
38 unsigned long link;
39 unsigned long xer;
40 unsigned long ccr;
41 #ifdef CONFIG_PPC64
42 unsigned long softe;
43 #else
44 unsigned long mq;
45 #endif
46 unsigned long trap;
47 union {
48 unsigned long dar;
49 unsigned long dear;
50 };
51 union {
52 unsigned long dsisr;
53 unsigned long esr;
54 };
55 unsigned long result;
56 };
57 };
58 #if defined(CONFIG_PPC64) || defined(CONFIG_PPC_KUAP)
59 union {
60 struct {
61 #ifdef CONFIG_PPC64
62 unsigned long ppr;
63 unsigned long exit_result;
64 #endif
65 union {
66 #ifdef CONFIG_PPC_KUAP
67 unsigned long kuap;
68 #endif
69 #ifdef CONFIG_PPC_PKEY
70 unsigned long amr;
71 #endif
72 };
73 #ifdef CONFIG_PPC_PKEY
74 unsigned long iamr;
75 #endif
76 };
77 unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */
78 };
79 #endif
80 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
81 struct { /* Must be a multiple of 16 bytes */
82 unsigned long mas0;
83 unsigned long mas1;
84 unsigned long mas2;
85 unsigned long mas3;
86 unsigned long mas6;
87 unsigned long mas7;
88 unsigned long srr0;
89 unsigned long srr1;
90 unsigned long csrr0;
91 unsigned long csrr1;
92 unsigned long dsrr0;
93 unsigned long dsrr1;
94 };
95 #endif
96 };
97 #endif
98
99
100 // Always displays as "REGS" in memory dumps
101 #ifdef CONFIG_CPU_BIG_ENDIAN
102 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x52454753)
103 #else
104 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x53474552)
105 #endif
106
107 #ifdef __powerpc64__
108
109 /*
110 * Size of redzone that userspace is allowed to use below the stack
111 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in
112 * the new ELFv2 little-endian ABI, so we allow the larger amount.
113 *
114 * For kernel code we allow a 288-byte redzone, in order to conserve
115 * kernel stack space; gcc currently only uses 288 bytes, and will
116 * hopefully allow explicit control of the redzone size in future.
117 */
118 #define USER_REDZONE_SIZE 512
119 #define KERNEL_REDZONE_SIZE 288
120
121 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */
122
123 #ifdef CONFIG_PPC64_ELF_ABI_V2
124 #define STACK_FRAME_MIN_SIZE 32
125 #define STACK_USER_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE + 16)
126 #define STACK_INT_FRAME_REGS (STACK_FRAME_MIN_SIZE + 16)
127 #define STACK_INT_FRAME_MARKER STACK_FRAME_MIN_SIZE
128 #define STACK_SWITCH_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE + 16)
129 #define STACK_SWITCH_FRAME_REGS (STACK_FRAME_MIN_SIZE + 16)
130 #else
131 /*
132 * The ELFv1 ABI specifies 48 bytes plus a minimum 64 byte parameter save
133 * area. This parameter area is not used by calls to C from interrupt entry,
134 * so the second from last one of those is used for the frame marker.
135 */
136 #define STACK_FRAME_MIN_SIZE 112
137 #define STACK_USER_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE)
138 #define STACK_INT_FRAME_REGS STACK_FRAME_MIN_SIZE
139 #define STACK_INT_FRAME_MARKER (STACK_FRAME_MIN_SIZE - 16)
140 #define STACK_SWITCH_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE)
141 #define STACK_SWITCH_FRAME_REGS STACK_FRAME_MIN_SIZE
142 #endif
143
144 /* Size of dummy stack frame allocated when calling signal handler. */
145 #define __SIGNAL_FRAMESIZE 128
146 #define __SIGNAL_FRAMESIZE32 64
147
148 #else /* __powerpc64__ */
149
150 #define USER_REDZONE_SIZE 0
151 #define KERNEL_REDZONE_SIZE 0
152 #define STACK_FRAME_MIN_SIZE 16
153 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */
154 #define STACK_USER_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE)
155 #define STACK_INT_FRAME_REGS STACK_FRAME_MIN_SIZE
156 #define STACK_INT_FRAME_MARKER (STACK_FRAME_MIN_SIZE - 8)
157 #define STACK_SWITCH_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_MIN_SIZE)
158 #define STACK_SWITCH_FRAME_REGS STACK_FRAME_MIN_SIZE
159
160 /* Size of stack frame allocated when calling signal handler. */
161 #define __SIGNAL_FRAMESIZE 64
162
163 #endif /* __powerpc64__ */
164
165 #define STACK_INT_FRAME_SIZE (KERNEL_REDZONE_SIZE + STACK_USER_INT_FRAME_SIZE)
166 #define STACK_INT_FRAME_MARKER_LONGS (STACK_INT_FRAME_MARKER/sizeof(long))
167
168 #ifndef __ASSEMBLY__
169 #include <asm/paca.h>
170
171 #ifdef CONFIG_SMP
172 extern unsigned long profile_pc(struct pt_regs *regs);
173 #else
174 #define profile_pc(regs) instruction_pointer(regs)
175 #endif
176
177 long do_syscall_trace_enter(struct pt_regs *regs);
178 void do_syscall_trace_leave(struct pt_regs *regs);
179
180 static inline void set_return_regs_changed(void)
181 {
182 #ifdef CONFIG_PPC_BOOK3S_64
183 WRITE_ONCE(local_paca->hsrr_valid, 0);
184 WRITE_ONCE(local_paca->srr_valid, 0);
185 #endif
186 }
187
188 static inline void regs_set_return_ip(struct pt_regs *regs, unsigned long ip)
189 {
190 regs->nip = ip;
191 set_return_regs_changed();
192 }
193
194 static inline void regs_set_return_msr(struct pt_regs *regs, unsigned long msr)
195 {
196 regs->msr = msr;
197 set_return_regs_changed();
198 }
199
200 static inline void regs_add_return_ip(struct pt_regs *regs, long offset)
201 {
202 regs_set_return_ip(regs, regs->nip + offset);
203 }
204
205 static inline unsigned long instruction_pointer(struct pt_regs *regs)
206 {
207 return regs->nip;
208 }
209
210 static inline void instruction_pointer_set(struct pt_regs *regs,
211 unsigned long val)
212 {
213 regs_set_return_ip(regs, val);
214 }
215
216 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
217 {
218 return regs->gpr[1];
219 }
220
221 static inline unsigned long frame_pointer(struct pt_regs *regs)
222 {
223 return 0;
224 }
225
226 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
227
228 #define force_successful_syscall_return() \
229 do { \
230 set_thread_flag(TIF_NOERROR); \
231 } while(0)
232
233 #define current_pt_regs() \
234 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
235
236 /*
237 * The 4 low bits (0xf) are available as flags to overload the trap word,
238 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK
239 * must cover the bits used as flags, including bit 0 which is used as the
240 * "norestart" bit.
241 */
242 #ifdef __powerpc64__
243 #define TRAP_FLAGS_MASK 0x1
244 #else
245 /*
246 * On 4xx we use bit 1 in the trap word to indicate whether the exception
247 * is a critical exception (1 means it is).
248 */
249 #define TRAP_FLAGS_MASK 0xf
250 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0)
251 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0)
252 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0)
253 #endif /* __powerpc64__ */
254 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK)
255
256 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val)
257 {
258 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK);
259 }
260
261 static inline bool trap_is_scv(struct pt_regs *regs)
262 {
263 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000);
264 }
265
266 static inline bool trap_is_unsupported_scv(struct pt_regs *regs)
267 {
268 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0;
269 }
270
271 static inline bool trap_is_syscall(struct pt_regs *regs)
272 {
273 return (trap_is_scv(regs) || TRAP(regs) == 0xc00);
274 }
275
276 static inline bool trap_norestart(struct pt_regs *regs)
277 {
278 return regs->trap & 0x1;
279 }
280
281 static __always_inline void set_trap_norestart(struct pt_regs *regs)
282 {
283 regs->trap |= 0x1;
284 }
285
286 #define kernel_stack_pointer(regs) ((regs)->gpr[1])
287 static inline int is_syscall_success(struct pt_regs *regs)
288 {
289 if (trap_is_scv(regs))
290 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]);
291 else
292 return !(regs->ccr & 0x10000000);
293 }
294
295 static inline long regs_return_value(struct pt_regs *regs)
296 {
297 if (trap_is_scv(regs))
298 return regs->gpr[3];
299
300 if (is_syscall_success(regs))
301 return regs->gpr[3];
302 else
303 return -regs->gpr[3];
304 }
305
306 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
307 {
308 regs->gpr[3] = rc;
309 }
310
311 static inline bool cpu_has_msr_ri(void)
312 {
313 return !IS_ENABLED(CONFIG_BOOKE);
314 }
315
316 static inline bool regs_is_unrecoverable(struct pt_regs *regs)
317 {
318 return unlikely(cpu_has_msr_ri() && !(regs->msr & MSR_RI));
319 }
320
321 static inline void regs_set_recoverable(struct pt_regs *regs)
322 {
323 if (cpu_has_msr_ri())
324 regs_set_return_msr(regs, regs->msr | MSR_RI);
325 }
326
327 static inline void regs_set_unrecoverable(struct pt_regs *regs)
328 {
329 if (cpu_has_msr_ri())
330 regs_set_return_msr(regs, regs->msr & ~MSR_RI);
331 }
332
333 #define arch_has_single_step() (1)
334 #define arch_has_block_step() (true)
335 #define ARCH_HAS_USER_SINGLE_STEP_REPORT
336
337 /*
338 * kprobe-based event tracer support
339 */
340
341 #include <linux/stddef.h>
342 #include <linux/thread_info.h>
343 extern int regs_query_register_offset(const char *name);
344 extern const char *regs_query_register_name(unsigned int offset);
345 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
346
347 /**
348 * regs_get_register() - get register value from its offset
349 * @regs: pt_regs from which register value is gotten
350 * @offset: offset number of the register.
351 *
352 * regs_get_register returns the value of a register whose offset from @regs.
353 * The @offset is the offset of the register in struct pt_regs.
354 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
355 */
356 static inline unsigned long regs_get_register(struct pt_regs *regs,
357 unsigned int offset)
358 {
359 if (unlikely(offset > MAX_REG_OFFSET))
360 return 0;
361 return *(unsigned long *)((unsigned long)regs + offset);
362 }
363
364 /**
365 * regs_within_kernel_stack() - check the address in the stack
366 * @regs: pt_regs which contains kernel stack pointer.
367 * @addr: address which is checked.
368 *
369 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
370 * If @addr is within the kernel stack, it returns true. If not, returns false.
371 */
372
373 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
374 unsigned long addr)
375 {
376 return ((addr & ~(THREAD_SIZE - 1)) ==
377 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
378 }
379
380 /**
381 * regs_get_kernel_stack_nth() - get Nth entry of the stack
382 * @regs: pt_regs which contains kernel stack pointer.
383 * @n: stack entry number.
384 *
385 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
386 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
387 * this returns 0.
388 */
389 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
390 unsigned int n)
391 {
392 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
393 addr += n;
394 if (regs_within_kernel_stack(regs, (unsigned long)addr))
395 return *addr;
396 else
397 return 0;
398 }
399
400 /**
401 * regs_get_kernel_argument() - get Nth function argument in kernel
402 * @regs: pt_regs of that context
403 * @n: function argument number (start from 0)
404 *
405 * We support up to 8 arguments and assume they are sent in through the GPRs.
406 * This will fail for fp/vector arguments, but those aren't usually found in
407 * kernel code. This is expected to be called from kprobes or ftrace with regs.
408 */
409 static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs, unsigned int n)
410 {
411 #define NR_REG_ARGUMENTS 8
412 if (n < NR_REG_ARGUMENTS)
413 return regs_get_register(regs, offsetof(struct pt_regs, gpr[3 + n]));
414 return 0;
415 }
416
417 #endif /* __ASSEMBLY__ */
418
419 #ifndef __powerpc64__
420 /* We need PT_SOFTE defined at all time to avoid #ifdefs */
421 #define PT_SOFTE PT_MQ
422 #else /* __powerpc64__ */
423 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
424 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */
425 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
426 #define PT_VRSAVE_32 (PT_VR0 + 33*4)
427 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */
428 #endif /* __powerpc64__ */
429 #endif /* _ASM_POWERPC_PTRACE_H */
430
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