1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Author: Hanlu Li <lihanlu@loongson.cn>
4 * Huacai Chen <chenhuacai@loongson.cn>
5 *
6 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
7 *
8 * Derived from MIPS:
9 * Copyright (C) 1992 Ross Biro
10 * Copyright (C) Linus Torvalds
11 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
12 * Copyright (C) 1996 David S. Miller
13 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
14 * Copyright (C) 1999 MIPS Technologies, Inc.
15 * Copyright (C) 2000 Ulf Carlsson
16 */
17 #include <linux/kernel.h>
18 #include <linux/audit.h>
19 #include <linux/compiler.h>
20 #include <linux/context_tracking.h>
21 #include <linux/elf.h>
22 #include <linux/errno.h>
23 #include <linux/mm.h>
24 #include <linux/ptrace.h>
25 #include <linux/regset.h>
26 #include <linux/sched.h>
27 #include <linux/sched/task_stack.h>
28 #include <linux/security.h>
29 #include <linux/smp.h>
30 #include <linux/stddef.h>
31 #include <linux/seccomp.h>
32 #include <linux/uaccess.h>
33
34 #include <asm/byteorder.h>
35 #include <asm/cpu.h>
36 #include <asm/cpu-info.h>
37 #include <asm/fpu.h>
38 #include <asm/loongarch.h>
39 #include <asm/page.h>
40 #include <asm/pgtable.h>
41 #include <asm/processor.h>
42 #include <asm/reg.h>
43 #include <asm/syscall.h>
44
init_fp_ctx(struct task_struct * target)45 static void init_fp_ctx(struct task_struct *target)
46 {
47 /* The target already has context */
48 if (tsk_used_math(target))
49 return;
50
51 /* Begin with data registers set to all 1s... */
52 memset(&target->thread.fpu.fpr, ~0, sizeof(target->thread.fpu.fpr));
53 set_stopped_child_used_math(target);
54 }
55
56 /*
57 * Called by kernel/ptrace.c when detaching..
58 *
59 * Make sure single step bits etc are not set.
60 */
ptrace_disable(struct task_struct * child)61 void ptrace_disable(struct task_struct *child)
62 {
63 /* Don't load the watchpoint registers for the ex-child. */
64 clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
65 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
66 }
67
68 /* regset get/set implementations */
69
gpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)70 static int gpr_get(struct task_struct *target,
71 const struct user_regset *regset,
72 struct membuf to)
73 {
74 int r;
75 struct pt_regs *regs = task_pt_regs(target);
76
77 r = membuf_write(&to, ®s->regs, sizeof(u64) * GPR_NUM);
78 r = membuf_write(&to, ®s->orig_a0, sizeof(u64));
79 r = membuf_write(&to, ®s->csr_era, sizeof(u64));
80 r = membuf_write(&to, ®s->csr_badvaddr, sizeof(u64));
81
82 return r;
83 }
84
gpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)85 static int gpr_set(struct task_struct *target,
86 const struct user_regset *regset,
87 unsigned int pos, unsigned int count,
88 const void *kbuf, const void __user *ubuf)
89 {
90 int err;
91 int a0_start = sizeof(u64) * GPR_NUM;
92 int era_start = a0_start + sizeof(u64);
93 int badvaddr_start = era_start + sizeof(u64);
94 struct pt_regs *regs = task_pt_regs(target);
95
96 err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
97 ®s->regs,
98 0, a0_start);
99 err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
100 ®s->orig_a0,
101 a0_start, a0_start + sizeof(u64));
102 err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
103 ®s->csr_era,
104 era_start, era_start + sizeof(u64));
105 err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
106 ®s->csr_badvaddr,
107 badvaddr_start, badvaddr_start + sizeof(u64));
108
109 return err;
110 }
111
112
113 /*
114 * Get the general floating-point registers.
115 */
gfpr_get(struct task_struct * target,struct membuf * to)116 static int gfpr_get(struct task_struct *target, struct membuf *to)
117 {
118 return membuf_write(to, &target->thread.fpu.fpr,
119 sizeof(elf_fpreg_t) * NUM_FPU_REGS);
120 }
121
gfpr_get_simd(struct task_struct * target,struct membuf * to)122 static int gfpr_get_simd(struct task_struct *target, struct membuf *to)
123 {
124 int i, r;
125 u64 fpr_val;
126
127 BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
128 for (i = 0; i < NUM_FPU_REGS; i++) {
129 fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
130 r = membuf_write(to, &fpr_val, sizeof(elf_fpreg_t));
131 }
132
133 return r;
134 }
135
136 /*
137 * Choose the appropriate helper for general registers, and then copy
138 * the FCC and FCSR registers separately.
139 */
fpr_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)140 static int fpr_get(struct task_struct *target,
141 const struct user_regset *regset,
142 struct membuf to)
143 {
144 int r;
145
146 if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
147 r = gfpr_get(target, &to);
148 else
149 r = gfpr_get_simd(target, &to);
150
151 r = membuf_write(&to, &target->thread.fpu.fcc, sizeof(target->thread.fpu.fcc));
152 r = membuf_write(&to, &target->thread.fpu.fcsr, sizeof(target->thread.fpu.fcsr));
153
154 return r;
155 }
156
gfpr_set(struct task_struct * target,unsigned int * pos,unsigned int * count,const void ** kbuf,const void __user ** ubuf)157 static int gfpr_set(struct task_struct *target,
158 unsigned int *pos, unsigned int *count,
159 const void **kbuf, const void __user **ubuf)
160 {
161 return user_regset_copyin(pos, count, kbuf, ubuf,
162 &target->thread.fpu.fpr,
163 0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
164 }
165
gfpr_set_simd(struct task_struct * target,unsigned int * pos,unsigned int * count,const void ** kbuf,const void __user ** ubuf)166 static int gfpr_set_simd(struct task_struct *target,
167 unsigned int *pos, unsigned int *count,
168 const void **kbuf, const void __user **ubuf)
169 {
170 int i, err;
171 u64 fpr_val;
172
173 BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
174 for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
175 err = user_regset_copyin(pos, count, kbuf, ubuf,
176 &fpr_val, i * sizeof(elf_fpreg_t),
177 (i + 1) * sizeof(elf_fpreg_t));
178 if (err)
179 return err;
180 set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
181 }
182
183 return 0;
184 }
185
186 /*
187 * Choose the appropriate helper for general registers, and then copy
188 * the FCC register separately.
189 */
fpr_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)190 static int fpr_set(struct task_struct *target,
191 const struct user_regset *regset,
192 unsigned int pos, unsigned int count,
193 const void *kbuf, const void __user *ubuf)
194 {
195 const int fcc_start = NUM_FPU_REGS * sizeof(elf_fpreg_t);
196 const int fcsr_start = fcc_start + sizeof(u64);
197 int err;
198
199 BUG_ON(count % sizeof(elf_fpreg_t));
200 if (pos + count > sizeof(elf_fpregset_t))
201 return -EIO;
202
203 init_fp_ctx(target);
204
205 if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
206 err = gfpr_set(target, &pos, &count, &kbuf, &ubuf);
207 else
208 err = gfpr_set_simd(target, &pos, &count, &kbuf, &ubuf);
209 if (err)
210 return err;
211
212 err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
213 &target->thread.fpu.fcc, fcc_start,
214 fcc_start + sizeof(u64));
215 err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
216 &target->thread.fpu.fcsr, fcsr_start,
217 fcsr_start + sizeof(u32));
218
219 return err;
220 }
221
cfg_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)222 static int cfg_get(struct task_struct *target,
223 const struct user_regset *regset,
224 struct membuf to)
225 {
226 int i, r;
227 u32 cfg_val;
228
229 i = 0;
230 while (to.left > 0) {
231 cfg_val = read_cpucfg(i++);
232 r = membuf_write(&to, &cfg_val, sizeof(u32));
233 }
234
235 return r;
236 }
237
238 /*
239 * CFG registers are read-only.
240 */
cfg_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)241 static int cfg_set(struct task_struct *target,
242 const struct user_regset *regset,
243 unsigned int pos, unsigned int count,
244 const void *kbuf, const void __user *ubuf)
245 {
246 return 0;
247 }
248
249 struct pt_regs_offset {
250 const char *name;
251 int offset;
252 };
253
254 #define REG_OFFSET_NAME(n, r) {.name = #n, .offset = offsetof(struct pt_regs, r)}
255 #define REG_OFFSET_END {.name = NULL, .offset = 0}
256
257 static const struct pt_regs_offset regoffset_table[] = {
258 REG_OFFSET_NAME(r0, regs[0]),
259 REG_OFFSET_NAME(r1, regs[1]),
260 REG_OFFSET_NAME(r2, regs[2]),
261 REG_OFFSET_NAME(r3, regs[3]),
262 REG_OFFSET_NAME(r4, regs[4]),
263 REG_OFFSET_NAME(r5, regs[5]),
264 REG_OFFSET_NAME(r6, regs[6]),
265 REG_OFFSET_NAME(r7, regs[7]),
266 REG_OFFSET_NAME(r8, regs[8]),
267 REG_OFFSET_NAME(r9, regs[9]),
268 REG_OFFSET_NAME(r10, regs[10]),
269 REG_OFFSET_NAME(r11, regs[11]),
270 REG_OFFSET_NAME(r12, regs[12]),
271 REG_OFFSET_NAME(r13, regs[13]),
272 REG_OFFSET_NAME(r14, regs[14]),
273 REG_OFFSET_NAME(r15, regs[15]),
274 REG_OFFSET_NAME(r16, regs[16]),
275 REG_OFFSET_NAME(r17, regs[17]),
276 REG_OFFSET_NAME(r18, regs[18]),
277 REG_OFFSET_NAME(r19, regs[19]),
278 REG_OFFSET_NAME(r20, regs[20]),
279 REG_OFFSET_NAME(r21, regs[21]),
280 REG_OFFSET_NAME(r22, regs[22]),
281 REG_OFFSET_NAME(r23, regs[23]),
282 REG_OFFSET_NAME(r24, regs[24]),
283 REG_OFFSET_NAME(r25, regs[25]),
284 REG_OFFSET_NAME(r26, regs[26]),
285 REG_OFFSET_NAME(r27, regs[27]),
286 REG_OFFSET_NAME(r28, regs[28]),
287 REG_OFFSET_NAME(r29, regs[29]),
288 REG_OFFSET_NAME(r30, regs[30]),
289 REG_OFFSET_NAME(r31, regs[31]),
290 REG_OFFSET_NAME(orig_a0, orig_a0),
291 REG_OFFSET_NAME(csr_era, csr_era),
292 REG_OFFSET_NAME(csr_badvaddr, csr_badvaddr),
293 REG_OFFSET_NAME(csr_crmd, csr_crmd),
294 REG_OFFSET_NAME(csr_prmd, csr_prmd),
295 REG_OFFSET_NAME(csr_euen, csr_euen),
296 REG_OFFSET_NAME(csr_ecfg, csr_ecfg),
297 REG_OFFSET_NAME(csr_estat, csr_estat),
298 REG_OFFSET_END,
299 };
300
301 /**
302 * regs_query_register_offset() - query register offset from its name
303 * @name: the name of a register
304 *
305 * regs_query_register_offset() returns the offset of a register in struct
306 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
307 */
regs_query_register_offset(const char * name)308 int regs_query_register_offset(const char *name)
309 {
310 const struct pt_regs_offset *roff;
311
312 for (roff = regoffset_table; roff->name != NULL; roff++)
313 if (!strcmp(roff->name, name))
314 return roff->offset;
315 return -EINVAL;
316 }
317
318 enum loongarch_regset {
319 REGSET_GPR,
320 REGSET_FPR,
321 REGSET_CPUCFG,
322 };
323
324 static const struct user_regset loongarch64_regsets[] = {
325 [REGSET_GPR] = {
326 .core_note_type = NT_PRSTATUS,
327 .n = ELF_NGREG,
328 .size = sizeof(elf_greg_t),
329 .align = sizeof(elf_greg_t),
330 .regset_get = gpr_get,
331 .set = gpr_set,
332 },
333 [REGSET_FPR] = {
334 .core_note_type = NT_PRFPREG,
335 .n = ELF_NFPREG,
336 .size = sizeof(elf_fpreg_t),
337 .align = sizeof(elf_fpreg_t),
338 .regset_get = fpr_get,
339 .set = fpr_set,
340 },
341 [REGSET_CPUCFG] = {
342 .core_note_type = NT_LOONGARCH_CPUCFG,
343 .n = 64,
344 .size = sizeof(u32),
345 .align = sizeof(u32),
346 .regset_get = cfg_get,
347 .set = cfg_set,
348 },
349 };
350
351 static const struct user_regset_view user_loongarch64_view = {
352 .name = "loongarch64",
353 .e_machine = ELF_ARCH,
354 .regsets = loongarch64_regsets,
355 .n = ARRAY_SIZE(loongarch64_regsets),
356 };
357
358
task_user_regset_view(struct task_struct * task)359 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
360 {
361 return &user_loongarch64_view;
362 }
363
read_user(struct task_struct * target,unsigned long addr,unsigned long __user * data)364 static inline int read_user(struct task_struct *target, unsigned long addr,
365 unsigned long __user *data)
366 {
367 unsigned long tmp = 0;
368
369 switch (addr) {
370 case 0 ... 31:
371 tmp = task_pt_regs(target)->regs[addr];
372 break;
373 case ARG0:
374 tmp = task_pt_regs(target)->orig_a0;
375 break;
376 case PC:
377 tmp = task_pt_regs(target)->csr_era;
378 break;
379 case BADVADDR:
380 tmp = task_pt_regs(target)->csr_badvaddr;
381 break;
382 default:
383 return -EIO;
384 }
385
386 return put_user(tmp, data);
387 }
388
write_user(struct task_struct * target,unsigned long addr,unsigned long data)389 static inline int write_user(struct task_struct *target, unsigned long addr,
390 unsigned long data)
391 {
392 switch (addr) {
393 case 0 ... 31:
394 task_pt_regs(target)->regs[addr] = data;
395 break;
396 case ARG0:
397 task_pt_regs(target)->orig_a0 = data;
398 break;
399 case PC:
400 task_pt_regs(target)->csr_era = data;
401 break;
402 case BADVADDR:
403 task_pt_regs(target)->csr_badvaddr = data;
404 break;
405 default:
406 return -EIO;
407 }
408
409 return 0;
410 }
411
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)412 long arch_ptrace(struct task_struct *child, long request,
413 unsigned long addr, unsigned long data)
414 {
415 int ret;
416 unsigned long __user *datap = (void __user *) data;
417
418 switch (request) {
419 case PTRACE_PEEKUSR:
420 ret = read_user(child, addr, datap);
421 break;
422
423 case PTRACE_POKEUSR:
424 ret = write_user(child, addr, data);
425 break;
426
427 default:
428 ret = ptrace_request(child, request, addr, data);
429 break;
430 }
431
432 return ret;
433 }
434
