1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Based on arch/arm/kernel/signal.c
*
* Copyright (C) 1995-2009 Russell King
* Copyright (C) 2012 ARM Ltd.
* Modified by Will Deacon <will.deacon@arm.com>
*/
#include <linux/compat.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/ratelimit.h>
#include <asm/esr.h>
#include <asm/fpsimd.h>
#include <asm/signal32.h>
#include <asm/traps.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
#include <asm/vdso.h>
struct compat_vfp_sigframe {
compat_ulong_t magic;
compat_ulong_t size;
struct compat_user_vfp {
compat_u64 fpregs[32];
compat_ulong_t fpscr;
} ufp;
struct compat_user_vfp_exc {
compat_ulong_t fpexc;
compat_ulong_t fpinst;
compat_ulong_t fpinst2;
} ufp_exc;
} __attribute__((__aligned__(8)));
#define VFP_MAGIC 0x56465001
#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
#define FSR_WRITE_SHIFT (11)
struct compat_aux_sigframe {
struct compat_vfp_sigframe vfp;
/* Something that isn't a valid magic number for any coprocessor. */
unsigned long end_magic;
} __attribute__((__aligned__(8)));
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
{
compat_sigset_t cset;
cset.sig[0] = set->sig[0] & 0xffffffffull;
cset.sig[1] = set->sig[0] >> 32;
return copy_to_user(uset, &cset, sizeof(*uset));
}
static inline int get_sigset_t(sigset_t *set,
const compat_sigset_t __user *uset)
{
compat_sigset_t s32;
if (copy_from_user(&s32, uset, sizeof(*uset)))
return -EFAULT;
set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
return 0;
}
/*
* VFP save/restore code.
*
* We have to be careful with endianness, since the fpsimd context-switch
* code operates on 128-bit (Q) register values whereas the compat ABI
* uses an array of 64-bit (D) registers. Consequently, we need to swap
* the two halves of each Q register when running on a big-endian CPU.
*/
union __fpsimd_vreg {
__uint128_t raw;
struct {
#ifdef __AARCH64EB__
u64 hi;
u64 lo;
#else
u64 lo;
u64 hi;
#endif
};
};
static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
{
struct user_fpsimd_state const *fpsimd =
¤t->thread.uw.fpsimd_state;
compat_ulong_t magic = VFP_MAGIC;
compat_ulong_t size = VFP_STORAGE_SIZE;
compat_ulong_t fpscr, fpexc;
int i, err = 0;
/*
* Save the hardware registers to the fpsimd_state structure.
* Note that this also saves V16-31, which aren't visible
* in AArch32.
*/
fpsimd_signal_preserve_current_state();
/* Place structure header on the stack */
__put_user_error(magic, &frame->magic, err);
__put_user_error(size, &frame->size, err);
/*
* Now copy the FP registers. Since the registers are packed,
* we can copy the prefix we want (V0-V15) as it is.
*/
for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
union __fpsimd_vreg vreg = {
.raw = fpsimd->vregs[i >> 1],
};
__put_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
__put_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
}
/* Create an AArch32 fpscr from the fpsr and the fpcr. */
fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
__put_user_error(fpscr, &frame->ufp.fpscr, err);
/*
* The exception register aren't available so we fake up a
* basic FPEXC and zero everything else.
*/
fpexc = (1 << 30);
__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
__put_user_error(0, &frame->ufp_exc.fpinst, err);
__put_user_error(0, &frame->ufp_exc.fpinst2, err);
return err ? -EFAULT : 0;
}
static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
{
struct user_fpsimd_state fpsimd;
compat_ulong_t magic = VFP_MAGIC;
compat_ulong_t size = VFP_STORAGE_SIZE;
compat_ulong_t fpscr;
int i, err = 0;
__get_user_error(magic, &frame->magic, err);
__get_user_error(size, &frame->size, err);
if (err)
return -EFAULT;
if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
return -EINVAL;
/* Copy the FP registers into the start of the fpsimd_state. */
for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
union __fpsimd_vreg vreg;
__get_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
__get_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
fpsimd.vregs[i >> 1] = vreg.raw;
}
/* Extract the fpsr and the fpcr from the fpscr */
__get_user_error(fpscr, &frame->ufp.fpscr, err);
fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
/*
* We don't need to touch the exception register, so
* reload the hardware state.
*/
if (!err)
fpsimd_update_current_state(&fpsimd);
return err ? -EFAULT : 0;
}
static int compat_restore_sigframe(struct pt_regs *regs,
struct compat_sigframe __user *sf)
{
int err;
sigset_t set;
struct compat_aux_sigframe __user *aux;
unsigned long psr;
err = get_sigset_t(&set, &sf->uc.uc_sigmask);
if (err == 0) {
sigdelsetmask(&set, ~_BLOCKABLE);
set_current_blocked(&set);
}
__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
__get_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
regs->pstate = compat_psr_to_pstate(psr
|