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