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50#include <linux/signal.h>
51#include <linux/ptrace.h>
52#include <linux/personality.h>
53#include <linux/uaccess.h>
54#include <linux/syscalls.h>
55#include <linux/tracehook.h>
56#include <asm/ucontext.h>
57
58struct rt_sigframe {
59 struct siginfo info;
60 struct ucontext uc;
61#define MAGIC_SIGALTSTK 0x07302004
62 unsigned int sigret_magic;
63};
64
65static int
66stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs,
67 sigset_t *set)
68{
69 int err;
70 struct user_regs_struct uregs;
71
72 uregs.scratch.bta = regs->bta;
73 uregs.scratch.lp_start = regs->lp_start;
74 uregs.scratch.lp_end = regs->lp_end;
75 uregs.scratch.lp_count = regs->lp_count;
76 uregs.scratch.status32 = regs->status32;
77 uregs.scratch.ret = regs->ret;
78 uregs.scratch.blink = regs->blink;
79 uregs.scratch.fp = regs->fp;
80 uregs.scratch.gp = regs->r26;
81 uregs.scratch.r12 = regs->r12;
82 uregs.scratch.r11 = regs->r11;
83 uregs.scratch.r10 = regs->r10;
84 uregs.scratch.r9 = regs->r9;
85 uregs.scratch.r8 = regs->r8;
86 uregs.scratch.r7 = regs->r7;
87 uregs.scratch.r6 = regs->r6;
88 uregs.scratch.r5 = regs->r5;
89 uregs.scratch.r4 = regs->r4;
90 uregs.scratch.r3 = regs->r3;
91 uregs.scratch.r2 = regs->r2;
92 uregs.scratch.r1 = regs->r1;
93 uregs.scratch.r0 = regs->r0;
94 uregs.scratch.sp = regs->sp;
95
96 err = __copy_to_user(&(sf->uc.uc_mcontext.regs.scratch), &uregs.scratch,
97 sizeof(sf->uc.uc_mcontext.regs.scratch));
98 err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t));
99
100 return err;
101}
102
103static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf)
104{
105 sigset_t set;
106 int err;
107 struct user_regs_struct uregs;
108
109 err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
110 err |= __copy_from_user(&uregs.scratch,
111 &(sf->uc.uc_mcontext.regs.scratch),
112 sizeof(sf->uc.uc_mcontext.regs.scratch));
113 if (err)
114 return err;
115
116 set_current_blocked(&set);
117 regs->bta = uregs.scratch.bta;
118 regs->lp_start = uregs.scratch.lp_start;
119 regs->lp_end = uregs.scratch.lp_end;
120 regs->lp_count = uregs.scratch.lp_count;
121 regs->status32 = uregs.scratch.status32;
122 regs->ret = uregs.scratch.ret;
123 regs->blink = uregs.scratch.blink;
124 regs->fp = uregs.scratch.fp;
125 regs->r26 = uregs.scratch.gp;
126 regs->r12 = uregs.scratch.r12;
127 regs->r11 = uregs.scratch.r11;
128 regs->r10 = uregs.scratch.r10;
129 regs->r9 = uregs.scratch.r9;
130 regs->r8 = uregs.scratch.r8;
131 regs->r7 = uregs.scratch.r7;
132 regs->r6 = uregs.scratch.r6;
133 regs->r5 = uregs.scratch.r5;
134 regs->r4 = uregs.scratch.r4;
135 regs->r3 = uregs.scratch.r3;
136 regs->r2 = uregs.scratch.r2;
137 regs->r1 = uregs.scratch.r1;
138 regs->r0 = uregs.scratch.r0;
139 regs->sp = uregs.scratch.sp;
140
141 return 0;
142}
143
144static inline int is_do_ss_needed(unsigned int magic)
145{
146 if (MAGIC_SIGALTSTK == magic)
147 return 1;
148 else
149 return 0;
150}
151
152SYSCALL_DEFINE0(rt_sigreturn)
153{
154 struct rt_sigframe __user *sf;
155 unsigned int magic;
156 struct pt_regs *regs = current_pt_regs();
157
158
159 current->restart_block.fn = do_no_restart_syscall;
160
161
162
163
164
165 if (regs->sp & 3)
166 goto badframe;
167
168 sf = (struct rt_sigframe __force __user *)(regs->sp);
169
170 if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
171 goto badframe;
172
173 if (__get_user(magic, &sf->sigret_magic))
174 goto badframe;
175
176 if (unlikely(is_do_ss_needed(magic)))
177 if (restore_altstack(&sf->uc.uc_stack))
178 goto badframe;
179
180 if (restore_usr_regs(regs, sf))
181 goto badframe;
182
183
184 syscall_wont_restart(regs);
185
186
187
188
189
190
191
192
193 regs->status32 |= STATUS_U_MASK;
194
195 return regs->r0;
196
197badframe:
198 force_sig(SIGSEGV, current);
199 return 0;
200}
201
202
203
204
205static inline void __user *get_sigframe(struct ksignal *ksig,
206 struct pt_regs *regs,
207 unsigned long framesize)
208{
209 unsigned long sp = sigsp(regs->sp, ksig);
210 void __user *frame;
211
212
213
214
215
216
217 frame = (void __user *)((sp - framesize) & ~7);
218
219
220 if (!access_ok(VERIFY_WRITE, frame, framesize))
221 frame = NULL;
222
223 return frame;
224}
225
226static int
227setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
228{
229 struct rt_sigframe __user *sf;
230 unsigned int magic = 0;
231 int err = 0;
232
233 sf = get_sigframe(ksig, regs, sizeof(struct rt_sigframe));
234 if (!sf)
235 return 1;
236
237
238
239
240
241
242
243
244 err |= stash_usr_regs(sf, regs, set);
245
246
247
248
249
250
251
252 if (unlikely(ksig->ka.sa.sa_flags & SA_SIGINFO)) {
253 err |= copy_siginfo_to_user(&sf->info, &ksig->info);
254 err |= __put_user(0, &sf->uc.uc_flags);
255 err |= __put_user(NULL, &sf->uc.uc_link);
256 err |= __save_altstack(&sf->uc.uc_stack, regs->sp);
257
258
259 regs->r1 = (unsigned long)&sf->info;
260 regs->r2 = (unsigned long)&sf->uc;
261
262
263
264
265
266 magic = MAGIC_SIGALTSTK;
267 }
268
269 err |= __put_user(magic, &sf->sigret_magic);
270 if (err)
271 return err;
272
273
274 regs->r0 = ksig->sig;
275
276
277 regs->ret = (unsigned long)ksig->ka.sa.sa_handler;
278
279
280
281
282
283 if(!(ksig->ka.sa.sa_flags & SA_RESTORER))
284 return 1;
285
286 regs->blink = (unsigned long)ksig->ka.sa.sa_restorer;
287
288
289 regs->sp = (unsigned long)sf;
290
291
292
293
294
295 regs->status32 &= ~STATUS_DE_MASK;
296 regs->status32 |= STATUS_L_MASK;
297
298 return err;
299}
300
301static void arc_restart_syscall(struct k_sigaction *ka, struct pt_regs *regs)
302{
303 switch (regs->r0) {
304 case -ERESTART_RESTARTBLOCK:
305 case -ERESTARTNOHAND:
306
307
308
309
310
311
312 regs->r0 = -EINTR;
313 break;
314
315 case -ERESTARTSYS:
316
317
318
319
320
321 if (!(ka->sa.sa_flags & SA_RESTART)) {
322 regs->r0 = -EINTR;
323 break;
324 }
325
326
327 case -ERESTARTNOINTR:
328
329
330
331
332
333
334
335
336
337
338 regs->r0 = regs->orig_r0;
339 regs->ret -= is_isa_arcv2() ? 2 : 4;
340 break;
341 }
342}
343
344
345
346
347static void
348handle_signal(struct ksignal *ksig, struct pt_regs *regs)
349{
350 sigset_t *oldset = sigmask_to_save();
351 int failed;
352
353
354 failed = setup_rt_frame(ksig, oldset, regs);
355
356 signal_setup_done(failed, ksig, 0);
357}
358
359void do_signal(struct pt_regs *regs)
360{
361 struct ksignal ksig;
362 int restart_scall;
363
364 restart_scall = in_syscall(regs) && syscall_restartable(regs);
365
366 if (get_signal(&ksig)) {
367 if (restart_scall) {
368 arc_restart_syscall(&ksig.ka, regs);
369 syscall_wont_restart(regs);
370 }
371 handle_signal(&ksig, regs);
372 return;
373 }
374
375 if (restart_scall) {
376
377 if (regs->r0 == -ERESTARTNOHAND ||
378 regs->r0 == -ERESTARTSYS || regs->r0 == -ERESTARTNOINTR) {
379 regs->r0 = regs->orig_r0;
380 regs->ret -= is_isa_arcv2() ? 2 : 4;
381 } else if (regs->r0 == -ERESTART_RESTARTBLOCK) {
382 regs->r8 = __NR_restart_syscall;
383 regs->ret -= is_isa_arcv2() ? 2 : 4;
384 }
385 syscall_wont_restart(regs);
386 }
387
388
389 restore_saved_sigmask();
390}
391
392void do_notify_resume(struct pt_regs *regs)
393{
394
395
396
397
398 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
399 tracehook_notify_resume(regs);
400}
401