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 <uapi/asm/ptrace.h>
23 #include <asm/asm-const.h>
24
25 #ifndef __ASSEMBLY__
26 struct pt_regs
27 {
28 union {
29 struct user_pt_regs user_regs;
30 struct {
31 unsigned long gpr[32];
32 unsigned long nip;
33 unsigned long msr;
34 unsigned long orig_gpr3;
35 unsigned long ctr;
36 unsigned long link;
37 unsigned long xer;
38 unsigned long ccr;
39 #ifdef CONFIG_PPC64
40 unsigned long softe;
41 #else
42 unsigned long mq;
43 #endif
44 unsigned long trap;
45 unsigned long dar;
46 unsigned long dsisr;
47 unsigned long result;
48 };
49 };
50
51 union {
52 struct {
53 #ifdef CONFIG_PPC64
54 unsigned long ppr;
55 #endif
56 union {
57 #ifdef CONFIG_PPC_KUAP
58 unsigned long kuap;
59 #endif
60 #ifdef CONFIG_PPC_PKEY
61 unsigned long amr;
62 #endif
63 };
64 #ifdef CONFIG_PPC_PKEY
65 unsigned long iamr;
66 #endif
67 };
68 unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */
69 };
70 };
71 #endif
72
73
74 #define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs))
75
76 #ifdef __powerpc64__
77
78 /*
79 * Size of redzone that userspace is allowed to use below the stack
80 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in
81 * the new ELFv2 little-endian ABI, so we allow the larger amount.
82 *
83 * For kernel code we allow a 288-byte redzone, in order to conserve
84 * kernel stack space; gcc currently only uses 288 bytes, and will
85 * hopefully allow explicit control of the redzone size in future.
86 */
87 #define USER_REDZONE_SIZE 512
88 #define KERNEL_REDZONE_SIZE 288
89
90 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */
91 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */
92 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265)
93 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \
94 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)
95 #define STACK_FRAME_MARKER 12
96
97 #ifdef PPC64_ELF_ABI_v2
98 #define STACK_FRAME_MIN_SIZE 32
99 #else
100 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD
101 #endif
102
103 /* Size of dummy stack frame allocated when calling signal handler. */
104 #define __SIGNAL_FRAMESIZE 128
105 #define __SIGNAL_FRAMESIZE32 64
106
107 #else /* __powerpc64__ */
108
109 #define USER_REDZONE_SIZE 0
110 #define KERNEL_REDZONE_SIZE 0
111 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */
112 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */
113 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
114 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
115 #define STACK_FRAME_MARKER 2
116 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD
117
118 /* Size of stack frame allocated when calling signal handler. */
119 #define __SIGNAL_FRAMESIZE 64
120
121 #endif /* __powerpc64__ */
122
123 #ifndef __ASSEMBLY__
124
instruction_pointer(struct pt_regs * regs)125 static inline unsigned long instruction_pointer(struct pt_regs *regs)
126 {
127 return regs->nip;
128 }
129
instruction_pointer_set(struct pt_regs * regs,unsigned long val)130 static inline void instruction_pointer_set(struct pt_regs *regs,
131 unsigned long val)
132 {
133 regs->nip = val;
134 }
135
user_stack_pointer(struct pt_regs * regs)136 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
137 {
138 return regs->gpr[1];
139 }
140
frame_pointer(struct pt_regs * regs)141 static inline unsigned long frame_pointer(struct pt_regs *regs)
142 {
143 return 0;
144 }
145
146 #ifdef CONFIG_SMP
147 extern unsigned long profile_pc(struct pt_regs *regs);
148 #else
149 #define profile_pc(regs) instruction_pointer(regs)
150 #endif
151
152 long do_syscall_trace_enter(struct pt_regs *regs);
153 void do_syscall_trace_leave(struct pt_regs *regs);
154
155 #define kernel_stack_pointer(regs) ((regs)->gpr[1])
is_syscall_success(struct pt_regs * regs)156 static inline int is_syscall_success(struct pt_regs *regs)
157 {
158 return !(regs->ccr & 0x10000000);
159 }
160
regs_return_value(struct pt_regs * regs)161 static inline long regs_return_value(struct pt_regs *regs)
162 {
163 if (is_syscall_success(regs))
164 return regs->gpr[3];
165 else
166 return -regs->gpr[3];
167 }
168
regs_set_return_value(struct pt_regs * regs,unsigned long rc)169 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
170 {
171 regs->gpr[3] = rc;
172 }
173
174 #ifdef __powerpc64__
175 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
176 #else
177 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
178 #endif
179
180 #define force_successful_syscall_return() \
181 do { \
182 set_thread_flag(TIF_NOERROR); \
183 } while(0)
184
185 #define current_pt_regs() \
186 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
187
188 /*
189 * The 4 low bits (0xf) are available as flags to overload the trap word,
190 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK
191 * must cover the bits used as flags, including bit 0 which is used as the
192 * "norestart" bit.
193 */
194 #ifdef __powerpc64__
195 #define TRAP_FLAGS_MASK 0x1
196 #else
197 /*
198 * On 4xx we use bit 1 in the trap word to indicate whether the exception
199 * is a critical exception (1 means it is).
200 */
201 #define TRAP_FLAGS_MASK 0xf
202 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0)
203 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0)
204 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0)
205 #endif /* __powerpc64__ */
206 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK)
207
set_trap(struct pt_regs * regs,unsigned long val)208 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val)
209 {
210 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK);
211 }
212
trap_is_scv(struct pt_regs * regs)213 static inline bool trap_is_scv(struct pt_regs *regs)
214 {
215 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000);
216 }
217
trap_is_unsupported_scv(struct pt_regs * regs)218 static inline bool trap_is_unsupported_scv(struct pt_regs *regs)
219 {
220 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0;
221 }
222
trap_is_syscall(struct pt_regs * regs)223 static inline bool trap_is_syscall(struct pt_regs *regs)
224 {
225 return (trap_is_scv(regs) || TRAP(regs) == 0xc00);
226 }
227
trap_norestart(struct pt_regs * regs)228 static inline bool trap_norestart(struct pt_regs *regs)
229 {
230 return regs->trap & 0x1;
231 }
232
set_trap_norestart(struct pt_regs * regs)233 static __always_inline void set_trap_norestart(struct pt_regs *regs)
234 {
235 regs->trap |= 0x1;
236 }
237
238 #define arch_has_single_step() (1)
239 #define arch_has_block_step() (true)
240 #define ARCH_HAS_USER_SINGLE_STEP_REPORT
241
242 /*
243 * kprobe-based event tracer support
244 */
245
246 #include <linux/stddef.h>
247 #include <linux/thread_info.h>
248 extern int regs_query_register_offset(const char *name);
249 extern const char *regs_query_register_name(unsigned int offset);
250 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
251
252 /**
253 * regs_get_register() - get register value from its offset
254 * @regs: pt_regs from which register value is gotten
255 * @offset: offset number of the register.
256 *
257 * regs_get_register returns the value of a register whose offset from @regs.
258 * The @offset is the offset of the register in struct pt_regs.
259 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
260 */
regs_get_register(struct pt_regs * regs,unsigned int offset)261 static inline unsigned long regs_get_register(struct pt_regs *regs,
262 unsigned int offset)
263 {
264 if (unlikely(offset > MAX_REG_OFFSET))
265 return 0;
266 return *(unsigned long *)((unsigned long)regs + offset);
267 }
268
269 /**
270 * regs_within_kernel_stack() - check the address in the stack
271 * @regs: pt_regs which contains kernel stack pointer.
272 * @addr: address which is checked.
273 *
274 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
275 * If @addr is within the kernel stack, it returns true. If not, returns false.
276 */
277
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)278 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
279 unsigned long addr)
280 {
281 return ((addr & ~(THREAD_SIZE - 1)) ==
282 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
283 }
284
285 /**
286 * regs_get_kernel_stack_nth() - get Nth entry of the stack
287 * @regs: pt_regs which contains kernel stack pointer.
288 * @n: stack entry number.
289 *
290 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
291 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
292 * this returns 0.
293 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)294 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
295 unsigned int n)
296 {
297 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
298 addr += n;
299 if (regs_within_kernel_stack(regs, (unsigned long)addr))
300 return *addr;
301 else
302 return 0;
303 }
304
305 #endif /* __ASSEMBLY__ */
306
307 #ifndef __powerpc64__
308 /* We need PT_SOFTE defined at all time to avoid #ifdefs */
309 #define PT_SOFTE PT_MQ
310 #else /* __powerpc64__ */
311 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
312 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */
313 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
314 #define PT_VRSAVE_32 (PT_VR0 + 33*4)
315 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */
316 #endif /* __powerpc64__ */
317 #endif /* _ASM_POWERPC_PTRACE_H */
318