1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * Copyright 2015 Regents of the University of California
5 * Copyright 2017 SiFive
6 *
7 * Copied from arch/tile/kernel/ptrace.c
8 */
9
10 #include <asm/vector.h>
11 #include <asm/ptrace.h>
12 #include <asm/syscall.h>
13 #include <asm/thread_info.h>
14 #include <asm/switch_to.h>
15 #include <linux/audit.h>
16 #include <linux/compat.h>
17 #include <linux/ptrace.h>
18 #include <linux/elf.h>
19 #include <linux/regset.h>
20 #include <linux/sched.h>
21 #include <linux/sched/task_stack.h>
22
23 enum riscv_regset {
24 REGSET_X,
25 #ifdef CONFIG_FPU
26 REGSET_F,
27 #endif
28 #ifdef CONFIG_RISCV_ISA_V
29 REGSET_V,
30 #endif
31 };
32
riscv_gpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)33 static int riscv_gpr_get(struct task_struct *target,
34 const struct user_regset *regset,
35 struct membuf to)
36 {
37 return membuf_write(&to, task_pt_regs(target),
38 sizeof(struct user_regs_struct));
39 }
40
riscv_gpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)41 static int riscv_gpr_set(struct task_struct *target,
42 const struct user_regset *regset,
43 unsigned int pos, unsigned int count,
44 const void *kbuf, const void __user *ubuf)
45 {
46 struct pt_regs *regs;
47
48 regs = task_pt_regs(target);
49 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
50 }
51
52 #ifdef CONFIG_FPU
riscv_fpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)53 static int riscv_fpr_get(struct task_struct *target,
54 const struct user_regset *regset,
55 struct membuf to)
56 {
57 struct __riscv_d_ext_state *fstate = &target->thread.fstate;
58
59 if (target == current)
60 fstate_save(current, task_pt_regs(current));
61
62 membuf_write(&to, fstate, offsetof(struct __riscv_d_ext_state, fcsr));
63 membuf_store(&to, fstate->fcsr);
64 return membuf_zero(&to, 4); // explicitly pad
65 }
66
riscv_fpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)67 static int riscv_fpr_set(struct task_struct *target,
68 const struct user_regset *regset,
69 unsigned int pos, unsigned int count,
70 const void *kbuf, const void __user *ubuf)
71 {
72 int ret;
73 struct __riscv_d_ext_state *fstate = &target->thread.fstate;
74
75 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
76 offsetof(struct __riscv_d_ext_state, fcsr));
77 if (!ret) {
78 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0,
79 offsetof(struct __riscv_d_ext_state, fcsr) +
80 sizeof(fstate->fcsr));
81 }
82
83 return ret;
84 }
85 #endif
86
87 #ifdef CONFIG_RISCV_ISA_V
riscv_vr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)88 static int riscv_vr_get(struct task_struct *target,
89 const struct user_regset *regset,
90 struct membuf to)
91 {
92 struct __riscv_v_ext_state *vstate = &target->thread.vstate;
93 struct __riscv_v_regset_state ptrace_vstate;
94
95 if (!riscv_v_vstate_query(task_pt_regs(target)))
96 return -EINVAL;
97
98 /*
99 * Ensure the vector registers have been saved to the memory before
100 * copying them to membuf.
101 */
102 if (target == current)
103 riscv_v_vstate_save(current, task_pt_regs(current));
104
105 ptrace_vstate.vstart = vstate->vstart;
106 ptrace_vstate.vl = vstate->vl;
107 ptrace_vstate.vtype = vstate->vtype;
108 ptrace_vstate.vcsr = vstate->vcsr;
109 ptrace_vstate.vlenb = vstate->vlenb;
110
111 /* Copy vector header from vstate. */
112 membuf_write(&to, &ptrace_vstate, sizeof(struct __riscv_v_regset_state));
113
114 /* Copy all the vector registers from vstate. */
115 return membuf_write(&to, vstate->datap, riscv_v_vsize);
116 }
117
riscv_vr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)118 static int riscv_vr_set(struct task_struct *target,
119 const struct user_regset *regset,
120 unsigned int pos, unsigned int count,
121 const void *kbuf, const void __user *ubuf)
122 {
123 int ret;
124 struct __riscv_v_ext_state *vstate = &target->thread.vstate;
125 struct __riscv_v_regset_state ptrace_vstate;
126
127 if (!riscv_v_vstate_query(task_pt_regs(target)))
128 return -EINVAL;
129
130 /* Copy rest of the vstate except datap */
131 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ptrace_vstate, 0,
132 sizeof(struct __riscv_v_regset_state));
133 if (unlikely(ret))
134 return ret;
135
136 if (vstate->vlenb != ptrace_vstate.vlenb)
137 return -EINVAL;
138
139 vstate->vstart = ptrace_vstate.vstart;
140 vstate->vl = ptrace_vstate.vl;
141 vstate->vtype = ptrace_vstate.vtype;
142 vstate->vcsr = ptrace_vstate.vcsr;
143
144 /* Copy all the vector registers. */
145 pos = 0;
146 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vstate->datap,
147 0, riscv_v_vsize);
148 return ret;
149 }
150 #endif
151
152 static const struct user_regset riscv_user_regset[] = {
153 [REGSET_X] = {
154 .core_note_type = NT_PRSTATUS,
155 .n = ELF_NGREG,
156 .size = sizeof(elf_greg_t),
157 .align = sizeof(elf_greg_t),
158 .regset_get = riscv_gpr_get,
159 .set = riscv_gpr_set,
160 },
161 #ifdef CONFIG_FPU
162 [REGSET_F] = {
163 .core_note_type = NT_PRFPREG,
164 .n = ELF_NFPREG,
165 .size = sizeof(elf_fpreg_t),
166 .align = sizeof(elf_fpreg_t),
167 .regset_get = riscv_fpr_get,
168 .set = riscv_fpr_set,
169 },
170 #endif
171 #ifdef CONFIG_RISCV_ISA_V
172 [REGSET_V] = {
173 .core_note_type = NT_RISCV_VECTOR,
174 .align = 16,
175 .n = ((32 * RISCV_MAX_VLENB) +
176 sizeof(struct __riscv_v_regset_state)) / sizeof(__u32),
177 .size = sizeof(__u32),
178 .regset_get = riscv_vr_get,
179 .set = riscv_vr_set,
180 },
181 #endif
182 };
183
184 static const struct user_regset_view riscv_user_native_view = {
185 .name = "riscv",
186 .e_machine = EM_RISCV,
187 .regsets = riscv_user_regset,
188 .n = ARRAY_SIZE(riscv_user_regset),
189 };
190
191 struct pt_regs_offset {
192 const char *name;
193 int offset;
194 };
195
196 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
197 #define REG_OFFSET_END {.name = NULL, .offset = 0}
198
199 static const struct pt_regs_offset regoffset_table[] = {
200 REG_OFFSET_NAME(epc),
201 REG_OFFSET_NAME(ra),
202 REG_OFFSET_NAME(sp),
203 REG_OFFSET_NAME(gp),
204 REG_OFFSET_NAME(tp),
205 REG_OFFSET_NAME(t0),
206 REG_OFFSET_NAME(t1),
207 REG_OFFSET_NAME(t2),
208 REG_OFFSET_NAME(s0),
209 REG_OFFSET_NAME(s1),
210 REG_OFFSET_NAME(a0),
211 REG_OFFSET_NAME(a1),
212 REG_OFFSET_NAME(a2),
213 REG_OFFSET_NAME(a3),
214 REG_OFFSET_NAME(a4),
215 REG_OFFSET_NAME(a5),
216 REG_OFFSET_NAME(a6),
217 REG_OFFSET_NAME(a7),
218 REG_OFFSET_NAME(s2),
219 REG_OFFSET_NAME(s3),
220 REG_OFFSET_NAME(s4),
221 REG_OFFSET_NAME(s5),
222 REG_OFFSET_NAME(s6),
223 REG_OFFSET_NAME(s7),
224 REG_OFFSET_NAME(s8),
225 REG_OFFSET_NAME(s9),
226 REG_OFFSET_NAME(s10),
227 REG_OFFSET_NAME(s11),
228 REG_OFFSET_NAME(t3),
229 REG_OFFSET_NAME(t4),
230 REG_OFFSET_NAME(t5),
231 REG_OFFSET_NAME(t6),
232 REG_OFFSET_NAME(status),
233 REG_OFFSET_NAME(badaddr),
234 REG_OFFSET_NAME(cause),
235 REG_OFFSET_NAME(orig_a0),
236 REG_OFFSET_END,
237 };
238
239 /**
240 * regs_query_register_offset() - query register offset from its name
241 * @name: the name of a register
242 *
243 * regs_query_register_offset() returns the offset of a register in struct
244 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
245 */
regs_query_register_offset(const char * name)246 int regs_query_register_offset(const char *name)
247 {
248 const struct pt_regs_offset *roff;
249
250 for (roff = regoffset_table; roff->name != NULL; roff++)
251 if (!strcmp(roff->name, name))
252 return roff->offset;
253 return -EINVAL;
254 }
255
256 /**
257 * regs_within_kernel_stack() - check the address in the stack
258 * @regs: pt_regs which contains kernel stack pointer.
259 * @addr: address which is checked.
260 *
261 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
262 * If @addr is within the kernel stack, it returns true. If not, returns false.
263 */
regs_within_kernel_stack(struct pt_regs * regs,unsigned long addr)264 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
265 {
266 return (addr & ~(THREAD_SIZE - 1)) ==
267 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1));
268 }
269
270 /**
271 * regs_get_kernel_stack_nth() - get Nth entry of the stack
272 * @regs: pt_regs which contains kernel stack pointer.
273 * @n: stack entry number.
274 *
275 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
276 * is specified by @regs. If the @n th entry is NOT in the kernel stack,
277 * this returns 0.
278 */
regs_get_kernel_stack_nth(struct pt_regs * regs,unsigned int n)279 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
280 {
281 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
282
283 addr += n;
284 if (regs_within_kernel_stack(regs, (unsigned long)addr))
285 return *addr;
286 else
287 return 0;
288 }
289
ptrace_disable(struct task_struct * child)290 void ptrace_disable(struct task_struct *child)
291 {
292 }
293
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)294 long arch_ptrace(struct task_struct *child, long request,
295 unsigned long addr, unsigned long data)
296 {
297 long ret = -EIO;
298
299 switch (request) {
300 default:
301 ret = ptrace_request(child, request, addr, data);
302 break;
303 }
304
305 return ret;
306 }
307
308 #ifdef CONFIG_COMPAT
compat_riscv_gpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)309 static int compat_riscv_gpr_get(struct task_struct *target,
310 const struct user_regset *regset,
311 struct membuf to)
312 {
313 struct compat_user_regs_struct cregs;
314
315 regs_to_cregs(&cregs, task_pt_regs(target));
316
317 return membuf_write(&to, &cregs,
318 sizeof(struct compat_user_regs_struct));
319 }
320
compat_riscv_gpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)321 static int compat_riscv_gpr_set(struct task_struct *target,
322 const struct user_regset *regset,
323 unsigned int pos, unsigned int count,
324 const void *kbuf, const void __user *ubuf)
325 {
326 int ret;
327 struct compat_user_regs_struct cregs;
328
329 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &cregs, 0, -1);
330
331 cregs_to_regs(&cregs, task_pt_regs(target));
332
333 return ret;
334 }
335
336 static const struct user_regset compat_riscv_user_regset[] = {
337 [REGSET_X] = {
338 .core_note_type = NT_PRSTATUS,
339 .n = ELF_NGREG,
340 .size = sizeof(compat_elf_greg_t),
341 .align = sizeof(compat_elf_greg_t),
342 .regset_get = compat_riscv_gpr_get,
343 .set = compat_riscv_gpr_set,
344 },
345 #ifdef CONFIG_FPU
346 [REGSET_F] = {
347 .core_note_type = NT_PRFPREG,
348 .n = ELF_NFPREG,
349 .size = sizeof(elf_fpreg_t),
350 .align = sizeof(elf_fpreg_t),
351 .regset_get = riscv_fpr_get,
352 .set = riscv_fpr_set,
353 },
354 #endif
355 };
356
357 static const struct user_regset_view compat_riscv_user_native_view = {
358 .name = "riscv",
359 .e_machine = EM_RISCV,
360 .regsets = compat_riscv_user_regset,
361 .n = ARRAY_SIZE(compat_riscv_user_regset),
362 };
363
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)364 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
365 compat_ulong_t caddr, compat_ulong_t cdata)
366 {
367 long ret = -EIO;
368
369 switch (request) {
370 default:
371 ret = compat_ptrace_request(child, request, caddr, cdata);
372 break;
373 }
374
375 return ret;
376 }
377 #endif /* CONFIG_COMPAT */
378
task_user_regset_view(struct task_struct * task)379 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
380 {
381 #ifdef CONFIG_COMPAT
382 if (test_tsk_thread_flag(task, TIF_32BIT))
383 return &compat_riscv_user_native_view;
384 else
385 #endif
386 return &riscv_user_native_view;
387 }
388