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
|
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/ptrace.h>
#include <linux/personality.h>
#include <linux/freezer.h>
#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <asm/unistd.h>
#include <asm/fpu.h>
#include <asm/ptrace.h>
#include <asm/vdso.h>
struct rt_sigframe {
struct siginfo info;
struct ucontext uc;
};
#if IS_ENABLED(CONFIG_FPU)
static inline int restore_sigcontext_fpu(struct pt_regs *regs,
struct sigcontext __user *sc)
{
struct task_struct *tsk = current;
unsigned long used_math_flag;
int ret = 0;
clear_used_math();
__get_user_error(used_math_flag, &sc->used_math_flag, ret);
if (!used_math_flag)
return 0;
set_used_math();
#if IS_ENABLED(CONFIG_LAZY_FPU)
preempt_disable();
if (current == last_task_used_math) {
last_task_used_math = NULL;
disable_ptreg_fpu(regs);
}
preempt_enable();
#else
clear_fpu(regs);
#endif
return __copy_from_user(&tsk->thread.fpu, &sc->fpu,
sizeof(struct fpu_struct));
}
static inline int setup_sigcontext_fpu(struct pt_regs *regs,
struct sigcontext __user *sc)
{
struct task_struct *tsk = current;
int ret = 0;
__put_user_error(used_math(), &sc->used_math_flag, ret);
if (!used_math())
return ret;
preempt_disable();
#if IS_ENABLED(CONFIG_LAZY_FPU)
if (last_task_used_math == tsk)
save_fpu(last_task_used_math);
#else
unlazy_fpu(tsk);
#endif
ret = __copy_to_user(&sc->fpu, &tsk->thread.fpu,
sizeof(struct fpu_struct));
preempt_enable();
return ret;
}
#endif
static int restore_sigframe(struct pt_regs *regs,
struct rt_sigframe __user * sf)
{
sigset_t set;
int err;
err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
if (err == 0) {
set_current_blocked(&set);
}
__get_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err);
__get_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err);
__get_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err);
__get_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err);
__get_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err);
__get_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err);
__get_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err);
__get_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err);
__get_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err);
__get_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err);
__get_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err);
__get_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err);
__get_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err);
__get_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err);
__get_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err);
__get_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err);
__get_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err);
__get_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err);
__get_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err);
__get_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err);
__get_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err);
__get_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err);
__get_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err);
__get_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err);
__get_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err);
__get_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err);
__get_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err);
__get_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err);
__get_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err);
__get_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err);
__get_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err);
#if defined(CONFIG_HWZOL)
__get_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err);
__get_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err);
__get_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err);
#endif
#if IS_ENABLED(CONFIG_FPU)
err |= restore_sigcontext_fpu(regs, &sf->uc.uc_mcontext);
#endif
/*
* Avoid sys_rt_sigreturn() restarting.
*/
forget_syscall(regs);
return err;
}
asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
/*
* Since we stacked the signal on a 64-bit boundary,
* then 'sp' should be two-word aligned here. If it's
* not, then the user is trying to mess with us.
*/
if (regs->sp & 7)
goto badframe;
frame = (struct rt_sigframe __user *)regs->sp;
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
if (restore_sigframe(regs, frame))
goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return regs->uregs[0];
badframe:
force_sig(SIGSEGV);
return 0;
}
static int
setup_sigframe(struct rt_sigframe __user * sf, struct pt_regs *regs,
sigset_t * set)
{
int err = 0;
__put_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err);
__put_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err);
__put_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err);
__put_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err);
__put_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err);
__put_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err);
__put_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err);
__put_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err);
__put_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err);
__put_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err);
__put_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err);
__put_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err);
__put_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err);
__put_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err);
__put_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err);
__put_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err);
__put_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err);
__put_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err);
__put_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err);
__put_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err);
__put_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err);
__put_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err);
__put_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err);
__put_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err);
__put_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err);
__put_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err);
__put_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err);
__put_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err);
__put_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err);
__put_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err);
__put_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err);
#if defined(CONFIG_HWZOL)
__put_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err);
__put_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err);
__put_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err);
#endif
#if IS_ENABLED(CONFIG_FPU)
err |= setup_sigcontext_fpu(regs, &sf->uc.uc_mcontext);
#endif
__put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no,
err);
__put_user_error(current->thread.error_code,
&sf->uc.uc_mcontext.error_code, err);
__put_user_error(current->thread.address,
&sf->uc.uc_mcontext.fault_address, err);
__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
return err;
}
static inline void __user *get_sigframe(struct ksignal *ksig,
struct pt_regs *regs, int framesize)
{
unsigned long sp;
/* Default to using normal stack */
sp = regs->sp;
/*
* If we are on the alternate signal stack and would overflow it, don't.
* Return an always-bogus address instead so we will die with SIGSEGV.
*/
if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
return (void __user __force *)(-1UL);
/* This is the X/Open sanctioned signal stack switching. */
sp = (sigsp(sp, ksig) - framesize);
/*
* nds32 mandates 8-byte alignment
*/
sp &= ~0x7UL;
return (void __user *)sp;
}
static int
setup_return(struct pt_regs *regs, struct ksignal *ksig, void __user * frame)
{
unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler;
unsigned long retcode;
retcode = VDSO_SYMBOL(current->mm->context.vdso, rt_sigtramp);
regs->uregs[0] = ksig->sig;
regs->sp = (unsigned long)frame;
regs->lp = retcode;
regs->ipc = handler;
return 0;
}
static int
setup_rt_frame(struct ksignal *ksig, sigset_t * set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame =
get_sigframe(ksig, regs, sizeof(*frame));
int err = 0;
if (!access_ok(frame, sizeof(*frame)))
return -EFAULT;
__put_user_error(0, &frame->uc.uc_flags, err);
__put_user_error(NULL, &frame->uc.uc_link, err);
err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
err |= setup_sigframe(frame, regs, set);
if (err == 0) {
setup_return(regs, ksig, frame);
if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
regs->uregs[1] = (unsigned long)&frame->info;
regs->uregs[2] = (unsigned long)&frame->uc;
}
}
return err;
}
/*
* OK, we're invoking a handler
*/
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
int ret;
sigset_t *oldset = sigmask_to_save();
if (in_syscall(regs)) {
/* Avoid additional syscall restarting via ret_slow_syscall. */
forget_syscall(regs);
switch (regs->uregs[0]) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->uregs[0] = -EINTR;
break;
case -ERESTARTSYS:
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
regs->uregs[0] = -EINTR;
break;
}
fallthrough;
case -ERESTARTNOINTR:
regs->uregs[0] = regs->orig_r0;
regs->ipc -= 4;
break;
}
}
/*
* Set up the stack frame
*/
ret = setup_rt_frame(ksig, oldset, regs);
signal_setup_done(ret, ksig, 0);
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
static void do_signal(struct pt_regs *regs)
{
struct ksignal ksig;
if (get_signal(&ksig)) {
handle_signal(&ksig, regs);
return;
}
/*
* If we were from a system call, check for system call restarting...
*/
if (in_syscall(regs)) {
/* Restart the system call - no handlers present */
/* Avoid additional syscall restarting via ret_slow_syscall. */
forget_syscall(regs);
switch (regs->uregs[0]) {
case -ERESTART_RESTARTBLOCK:
regs->uregs[15] = __NR_restart_syscall;
fallthrough;
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->uregs[0] = regs->orig_r0;
regs->ipc -= 0x4;
break;
}
}
restore_saved_sigmask();
}
asmlinkage void
do_notify_resume(struct pt_regs *regs, unsigned int thread_flags)
{
if (thread_flags & _TIF_SIGPENDING)
do_signal(regs);
if (thread_flags & _TIF_NOTIFY_RESUME)
tracehook_notify_resume(regs);
}
|
