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12#include <linux/errno.h>
13#include <linux/signal.h>
14#include <linux/personality.h>
15#include <linux/uaccess.h>
16#include <linux/tracehook.h>
17#include <linux/elf.h>
18#include <linux/unistd.h>
19
20#include <asm/cacheflush.h>
21#include <asm/ucontext.h>
22
23
24
25
26#define SWI_SYS_SIGRETURN (0xff000000)
27#define SWI_SYS_RT_SIGRETURN (0xff000000 | (__NR_rt_sigreturn))
28#define SWI_SYS_RESTART (0xff000000 | (__NR_restart_syscall))
29
30#define KERN_SIGRETURN_CODE (KUSER_VECPAGE_BASE + 0x00000500)
31#define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes))
32
33const unsigned long sigreturn_codes[3] = {
34 SWI_SYS_SIGRETURN, SWI_SYS_RT_SIGRETURN,
35};
36
37const unsigned long syscall_restart_code[2] = {
38 SWI_SYS_RESTART,
39 0x69efc004,
40};
41
42
43
44
45struct sigframe {
46 struct ucontext uc;
47 unsigned long retcode[2];
48};
49
50struct rt_sigframe {
51 struct siginfo info;
52 struct sigframe sig;
53};
54
55static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf)
56{
57 sigset_t set;
58 int err;
59
60 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
61 if (err == 0)
62 set_current_blocked(&set);
63
64 err |= __get_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
65 err |= __get_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
66 err |= __get_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
67 err |= __get_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
68 err |= __get_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
69 err |= __get_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
70 err |= __get_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
71 err |= __get_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
72 err |= __get_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
73 err |= __get_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
74 err |= __get_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
75 err |= __get_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
76 err |= __get_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
77 err |= __get_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
78 err |= __get_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
79 err |= __get_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
80 err |= __get_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
81 err |= __get_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
82 err |= __get_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
83 err |= __get_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
84 err |= __get_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
85 err |= __get_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
86 err |= __get_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
87 err |= __get_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
88 err |= __get_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
89 err |= __get_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
90 err |= __get_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
91 err |= __get_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
92 err |= __get_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
93 err |= __get_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
94 err |= __get_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
95 err |= __get_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
96 err |= __get_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);
97
98 err |= !valid_user_regs(regs);
99
100 return err;
101}
102
103asmlinkage int __sys_rt_sigreturn(struct pt_regs *regs)
104{
105 struct rt_sigframe __user *frame;
106
107
108 current->restart_block.fn = do_no_restart_syscall;
109
110
111
112
113
114
115 if (regs->UCreg_sp & 7)
116 goto badframe;
117
118 frame = (struct rt_sigframe __user *)regs->UCreg_sp;
119
120 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
121 goto badframe;
122
123 if (restore_sigframe(regs, &frame->sig))
124 goto badframe;
125
126 if (restore_altstack(&frame->sig.uc.uc_stack))
127 goto badframe;
128
129 return regs->UCreg_00;
130
131badframe:
132 force_sig(SIGSEGV, current);
133 return 0;
134}
135
136static int setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs,
137 sigset_t *set)
138{
139 int err = 0;
140
141 err |= __put_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
142 err |= __put_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
143 err |= __put_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
144 err |= __put_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
145 err |= __put_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
146 err |= __put_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
147 err |= __put_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
148 err |= __put_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
149 err |= __put_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
150 err |= __put_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
151 err |= __put_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
152 err |= __put_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
153 err |= __put_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
154 err |= __put_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
155 err |= __put_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
156 err |= __put_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
157 err |= __put_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
158 err |= __put_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
159 err |= __put_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
160 err |= __put_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
161 err |= __put_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
162 err |= __put_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
163 err |= __put_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
164 err |= __put_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
165 err |= __put_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
166 err |= __put_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
167 err |= __put_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
168 err |= __put_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
169 err |= __put_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
170 err |= __put_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
171 err |= __put_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
172 err |= __put_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
173 err |= __put_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);
174
175 err |= __put_user(current->thread.trap_no,
176 &sf->uc.uc_mcontext.trap_no);
177 err |= __put_user(current->thread.error_code,
178 &sf->uc.uc_mcontext.error_code);
179 err |= __put_user(current->thread.address,
180 &sf->uc.uc_mcontext.fault_address);
181 err |= __put_user(set->sig[0], &sf->uc.uc_mcontext.oldmask);
182
183 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
184
185 return err;
186}
187
188static inline void __user *get_sigframe(struct k_sigaction *ka,
189 struct pt_regs *regs, int framesize)
190{
191 unsigned long sp = regs->UCreg_sp;
192 void __user *frame;
193
194
195
196
197 if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
198 sp = current->sas_ss_sp + current->sas_ss_size;
199
200
201
202
203 frame = (void __user *)((sp - framesize) & ~7);
204
205
206
207
208 if (!access_ok(VERIFY_WRITE, frame, framesize))
209 frame = NULL;
210
211 return frame;
212}
213
214static int setup_return(struct pt_regs *regs, struct k_sigaction *ka,
215 unsigned long __user *rc, void __user *frame, int usig)
216{
217 unsigned long handler = (unsigned long)ka->sa.sa_handler;
218 unsigned long retcode;
219 unsigned long asr = regs->UCreg_asr & ~PSR_f;
220
221 unsigned int idx = 0;
222
223 if (ka->sa.sa_flags & SA_SIGINFO)
224 idx += 1;
225
226 if (__put_user(sigreturn_codes[idx], rc) ||
227 __put_user(sigreturn_codes[idx+1], rc+1))
228 return 1;
229
230 retcode = KERN_SIGRETURN_CODE + (idx << 2);
231
232 regs->UCreg_00 = usig;
233 regs->UCreg_sp = (unsigned long)frame;
234 regs->UCreg_lr = retcode;
235 regs->UCreg_pc = handler;
236 regs->UCreg_asr = asr;
237
238 return 0;
239}
240
241static int setup_frame(struct ksignal *ksig, sigset_t *set,
242 struct pt_regs *regs)
243{
244 struct sigframe __user *frame = get_sigframe(&ksig->ka, regs, sizeof(*frame));
245 int err = 0;
246
247 if (!frame)
248 return 1;
249
250
251
252
253 err |= __put_user(0x5ac3c35a, &frame->uc.uc_flags);
254
255 err |= setup_sigframe(frame, regs, set);
256 if (err == 0)
257 err |= setup_return(regs, &ksig->ka, frame->retcode, frame,
258 ksig->sig);
259
260 return err;
261}
262
263static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
264 struct pt_regs *regs)
265{
266 struct rt_sigframe __user *frame =
267 get_sigframe(&ksig->ka, regs, sizeof(*frame));
268 int err = 0;
269
270 if (!frame)
271 return 1;
272
273 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
274
275 err |= __put_user(0, &frame->sig.uc.uc_flags);
276 err |= __put_user(NULL, &frame->sig.uc.uc_link);
277 err |= __save_altstack(&frame->sig.uc.uc_stack, regs->UCreg_sp);
278 err |= setup_sigframe(&frame->sig, regs, set);
279 if (err == 0)
280 err |= setup_return(regs, &ksig->ka, frame->sig.retcode, frame,
281 ksig->sig);
282
283 if (err == 0) {
284
285
286
287
288 regs->UCreg_01 = (unsigned long)&frame->info;
289 regs->UCreg_02 = (unsigned long)&frame->sig.uc;
290 }
291
292 return err;
293}
294
295static inline void setup_syscall_restart(struct pt_regs *regs)
296{
297 regs->UCreg_00 = regs->UCreg_ORIG_00;
298 regs->UCreg_pc -= 4;
299}
300
301
302
303
304static void handle_signal(struct ksignal *ksig, struct pt_regs *regs,
305 int syscall)
306{
307 struct thread_info *thread = current_thread_info();
308 sigset_t *oldset = sigmask_to_save();
309 int usig = ksig->sig;
310 int ret;
311
312
313
314
315 if (syscall) {
316 switch (regs->UCreg_00) {
317 case -ERESTART_RESTARTBLOCK:
318 case -ERESTARTNOHAND:
319 regs->UCreg_00 = -EINTR;
320 break;
321 case -ERESTARTSYS:
322 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
323 regs->UCreg_00 = -EINTR;
324 break;
325 }
326
327 case -ERESTARTNOINTR:
328 setup_syscall_restart(regs);
329 }
330 }
331
332
333
334
335 if (usig < 32 && thread->exec_domain
336 && thread->exec_domain->signal_invmap)
337 usig = thread->exec_domain->signal_invmap[usig];
338
339
340
341
342 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
343 ret = setup_rt_frame(ksig, oldset, regs);
344 else
345 ret = setup_frame(ksig, oldset, regs);
346
347
348
349
350 ret |= !valid_user_regs(regs);
351
352 signal_setup_done(ret, ksig, 0);
353}
354
355
356
357
358
359
360
361
362
363
364static void do_signal(struct pt_regs *regs, int syscall)
365{
366 struct ksignal ksig;
367
368
369
370
371
372
373
374 if (!user_mode(regs))
375 return;
376
377 if (get_signal(&ksig)) {
378 handle_signal(&ksig, regs, syscall);
379 return;
380 }
381
382
383
384
385 if (syscall) {
386 if (regs->UCreg_00 == -ERESTART_RESTARTBLOCK) {
387 u32 __user *usp;
388
389 regs->UCreg_sp -= 4;
390 usp = (u32 __user *)regs->UCreg_sp;
391
392 if (put_user(regs->UCreg_pc, usp) == 0) {
393 regs->UCreg_pc = KERN_RESTART_CODE;
394 } else {
395 regs->UCreg_sp += 4;
396 force_sigsegv(0, current);
397 }
398 }
399 if (regs->UCreg_00 == -ERESTARTNOHAND ||
400 regs->UCreg_00 == -ERESTARTSYS ||
401 regs->UCreg_00 == -ERESTARTNOINTR) {
402 setup_syscall_restart(regs);
403 }
404 }
405
406
407
408 restore_saved_sigmask();
409}
410
411asmlinkage void do_notify_resume(struct pt_regs *regs,
412 unsigned int thread_flags, int syscall)
413{
414 if (thread_flags & _TIF_SIGPENDING)
415 do_signal(regs, syscall);
416
417 if (thread_flags & _TIF_NOTIFY_RESUME) {
418 clear_thread_flag(TIF_NOTIFY_RESUME);
419 tracehook_notify_resume(regs);
420 }
421}
422
423
424
425
426
427void __init early_signal_init(void)
428{
429 memcpy((void *)kuser_vecpage_to_vectors(KERN_SIGRETURN_CODE),
430 sigreturn_codes, sizeof(sigreturn_codes));
431 memcpy((void *)kuser_vecpage_to_vectors(KERN_RESTART_CODE),
432 syscall_restart_code, sizeof(syscall_restart_code));
433
434}
435