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
26 #ifndef __ASSEMBLY__
27 struct pt_regs
28 {
29 union {
30 struct user_pt_regs user_regs;
31 struct {
32 unsigned long gpr[32];
33 unsigned long nip;
34 unsigned long msr;
35 unsigned long orig_gpr3;
36 unsigned long ctr;
37 unsigned long link;
38 unsigned long xer;
39 unsigned long ccr;
40 #ifdef CONFIG_PPC64
41 unsigned long softe;
42 #else
43 unsigned long mq;
44 #endif
45 unsigned long trap;
46 unsigned long dar;
47 unsigned long dsisr;
48 unsigned long result;
49 };
50 };
51
52 union {
53 struct {
54 #ifdef CONFIG_PPC64
55 unsigned long ppr;
56 #endif
57 #ifdef CONFIG_PPC_KUAP
58 unsigned long kuap;
59 #endif
60 };
61 unsigned long __pad[2]; /* Maintain 16 byte interrupt stack alignment */
62 };
63 };
64 #endif
65
66
67 #define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs))
68
69 #ifdef __powerpc64__
70
71 /*
72 * Size of redzone that userspace is allowed to use below the stack
73 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in
74 * the new ELFv2 little-endian ABI, so we allow the larger amount.
75 *
76 * For kernel code we allow a 288-byte redzone, in order to conserve
77 * kernel stack space; gcc currently only uses 288 bytes, and will
78 * hopefully allow explicit control of the redzone size in future.
79 */
80 #define USER_REDZONE_SIZE 512
81 #define KERNEL_REDZONE_SIZE 288
82
83 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */
84 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */
85 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265)
86 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \
87 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE)
88 #define STACK_FRAME_MARKER 12
89
90 #ifdef PPC64_ELF_ABI_v2
91 #define STACK_FRAME_MIN_SIZE 32
92 #else
93 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD
94 #endif
95
96 /* Size of dummy stack frame allocated when calling signal handler. */
97 #define __SIGNAL_FRAMESIZE 128
98 #define __SIGNAL_FRAMESIZE32 64
99
100 #else /* __powerpc64__ */
101
102 #define USER_REDZONE_SIZE 0
103 #define KERNEL_REDZONE_SIZE 0
104 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */
105 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */
106 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773)
107 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
108 #define STACK_FRAME_MARKER 2
109 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD
110
111 /* Size of stack frame allocated when calling signal handler. */
112 #define __SIGNAL_FRAMESIZE 64
113
114 #endif /* __powerpc64__ */
115
116 #ifndef __ASSEMBLY__
117
instruction_pointer(struct pt_regs * regs)118 static inline unsigned long instruction_pointer(struct pt_regs *regs)
119 {
120 return regs->nip;
121 }
122
instruction_pointer_set(struct pt_regs * regs,unsigned long val)123 static inline void instruction_pointer_set(struct pt_regs *regs,
124 unsigned long val)
125 {
126 regs->nip = val;
127 }
128
user_stack_pointer(struct pt_regs * regs)129 static inline unsigned long user_stack_pointer(struct pt_regs *regs)
130 {
131 return regs->gpr[1];
132 }
133
frame_pointer(struct pt_regs * regs)134 static inline unsigned long frame_pointer(struct pt_regs *regs)
135 {
136 return 0;
137 }
138
139 #ifdef CONFIG_SMP
140 extern unsigned long profile_pc(struct pt_regs *regs);
141 #else
142 #define profile_pc(regs) instruction_pointer(regs)
143 #endif
144
145 long do_syscall_trace_enter(struct pt_regs *regs);
146 void do_syscall_trace_leave(struct pt_regs *regs);
147
148 #ifdef __powerpc64__
149 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1)
150 #else
151 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0)
152 #endif
153
154 #define force_successful_syscall_return() \
155 do { \
156 set_thread_flag(TIF_NOERROR); \
157 } while(0)
158
159 struct task_struct;
160 extern int ptrace_get_reg(struct task_struct *task, int regno,
161 unsigned long *data);
162 extern int ptrace_put_reg(struct task_struct *task, int regno,
163 unsigned long data);
164
165 #define current_pt_regs() \
166 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1)
167
168 #ifdef __powerpc64__
169 #ifdef CONFIG_PPC_BOOK3S
170 #define TRAP_FLAGS_MASK 0x10
171 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK)
172 #define FULL_REGS(regs) true
173 #define SET_FULL_REGS(regs) do { } while (0)
174 #else
175 #define TRAP_FLAGS_MASK 0x11
176 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK)
177 #define FULL_REGS(regs) (((regs)->trap & 1) == 0)
178 #define SET_FULL_REGS(regs) ((regs)->trap &= ~1)
179 #endif
180 #define CHECK_FULL_REGS(regs) BUG_ON(!FULL_REGS(regs))
181 #define NV_REG_POISON 0xdeadbeefdeadbeefUL
182 #else
183 /*
184 * We use the least-significant bit of the trap field to indicate
185 * whether we have saved the full set of registers, or only a
186 * partial set. A 1 there means the partial set.
187 * On 4xx we use the next bit to indicate whether the exception
188 * is a critical exception (1 means it is).
189 */
190 #define TRAP_FLAGS_MASK 0x1F
191 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK)
192 #define FULL_REGS(regs) (((regs)->trap & 1) == 0)
193 #define SET_FULL_REGS(regs) ((regs)->trap &= ~1)
194 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0)
195 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0)
196 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0)
197 #define NV_REG_POISON 0xdeadbeef
198 #define CHECK_FULL_REGS(regs) \
199 do { \
200 if ((regs)->trap & 1) \
201 printk(KERN_CRIT "%s: partial register set\n", __func__); \
202 } while (0)
203 #endif /* __powerpc64__ */
204
set_trap(struct pt_regs * regs,unsigned long val)205 static inline void set_trap(struct pt_regs *regs, unsigned long val)
206 {
207 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK);
208 }
209
trap_is_scv(struct pt_regs * regs)210 static inline bool trap_is_scv(struct pt_regs *regs)
211 {
212 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000);
213 }
214
trap_is_syscall(struct pt_regs * regs)215 static inline bool trap_is_syscall(struct pt_regs *regs)
216 {
217 return (trap_is_scv(regs) || TRAP(regs) == 0xc00);
218 }
219
trap_norestart(struct pt_regs * regs)220 static inline bool trap_norestart(struct pt_regs *regs)
221 {
222 return regs->trap & 0x10;
223 }
224
set_trap_norestart(struct pt_regs * regs)225 static inline void set_trap_norestart(struct pt_regs *regs)
226 {
227 regs->trap |= 0x10;
228 }
229
230 #define kernel_stack_pointer(regs) ((regs)->gpr[1])
is_syscall_success(struct pt_regs * regs)231 static inline int is_syscall_success(struct pt_regs *regs)
232 {
233 if (trap_is_scv(regs))
234 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]);
235 else
236 return !(regs->ccr & 0x10000000);
237 }
238
regs_return_value(struct pt_regs * regs)239 static inline long regs_return_value(struct pt_regs *regs)
240 {
241 if (trap_is_scv(regs))
242 return regs->gpr[3];
243
244 if (is_syscall_success(regs))
245 return regs->gpr[3];
246 else
247 return -regs->gpr[3];
248 }
249
regs_set_return_value(struct pt_regs * regs,unsigned long rc)250 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
251 {
252 regs->gpr[3] = rc;
253 }
254
255 #define arch_has_single_step() (1)
256 #define arch_has_block_step() (true)
257 #define ARCH_HAS_USER_SINGLE_STEP_REPORT
258
259 /*
260 * kprobe-based event tracer support
261 */
262
263 #include <linux/stddef.h>
264 #include <linux/thread_info.h>
265 extern int regs_query_register_offset(const char *name);
266 extern const char *regs_query_register_name(unsigned int offset);
267 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr))
268
269 /**
270 * regs_get_register() - get register value from its offset
271 * @regs: pt_regs from which register value is gotten
272 * @offset: offset number of the register.
273 *
274 * regs_get_register returns the value of a register whose offset from @regs.
275 * The @offset is the offset of the register in struct pt_regs.
276 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
277 */
regs_get_register(struct pt_regs * regs,unsigned int offset)278 static inline unsigned long regs_get_register(struct pt_regs *regs,
279 unsigned int offset)
280 {
281 if (unlikely(offset > MAX_REG_OFFSET))
282 return 0;
283 return *(unsigned long *)((unsigned long)regs + offset);
284 }
285
286 /**
287 * regs_within_kernel_stack() - check the address in the stack
288 * @regs: pt_regs which contains kernel stack pointer.
289 * @addr: address which is checked.
290 *
291 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
292 * If @addr is within the kernel stack, it returns true. If not, returns false.
293 */
294
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)295 static inline bool regs_within_kernel_stack(struct pt_regs *regs,
296 unsigned long addr)
297 {
298 return ((addr & ~(THREAD_SIZE - 1)) ==
299 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
300 }
301
302 /**
303 * regs_get_kernel_stack_nth() - get Nth entry of the stack
304 * @regs: pt_regs which contains kernel stack pointer.
305 * @n: stack entry number.
306 *
307 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
308 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
309 * this returns 0.
310 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)311 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
312 unsigned int n)
313 {
314 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
315 addr += n;
316 if (regs_within_kernel_stack(regs, (unsigned long)addr))
317 return *addr;
318 else
319 return 0;
320 }
321
322 #endif /* __ASSEMBLY__ */
323
324 #ifndef __powerpc64__
325 /* We need PT_SOFTE defined at all time to avoid #ifdefs */
326 #define PT_SOFTE PT_MQ
327 #else /* __powerpc64__ */
328 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */
329 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */
330 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3)
331 #define PT_VRSAVE_32 (PT_VR0 + 33*4)
332 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */
333 #endif /* __powerpc64__ */
334 #endif /* _ASM_POWERPC_PTRACE_H */
335