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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/arm/kernel/signal.c | |
3 | * | |
ab72b007 | 4 | * Copyright (C) 1995-2009 Russell King |
1da177e4 LT |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
1da177e4 | 10 | #include <linux/errno.h> |
48be69a0 | 11 | #include <linux/random.h> |
1da177e4 | 12 | #include <linux/signal.h> |
1da177e4 | 13 | #include <linux/personality.h> |
33fa9b13 | 14 | #include <linux/uaccess.h> |
733e5e4b | 15 | #include <linux/tracehook.h> |
c7edc9e3 | 16 | #include <linux/uprobes.h> |
1da177e4 | 17 | |
ee90dabc | 18 | #include <asm/elf.h> |
1da177e4 | 19 | #include <asm/cacheflush.h> |
48be69a0 | 20 | #include <asm/traps.h> |
1da177e4 | 21 | #include <asm/ucontext.h> |
1da177e4 | 22 | #include <asm/unistd.h> |
82c6f5a5 | 23 | #include <asm/vfp.h> |
1da177e4 | 24 | |
574e2b51 | 25 | extern const unsigned long sigreturn_codes[7]; |
1da177e4 | 26 | |
48be69a0 RK |
27 | static unsigned long signal_return_offset; |
28 | ||
3bec6ded | 29 | #ifdef CONFIG_CRUNCH |
65a5053b | 30 | static int preserve_crunch_context(struct crunch_sigframe __user *frame) |
3bec6ded LB |
31 | { |
32 | char kbuf[sizeof(*frame) + 8]; | |
33 | struct crunch_sigframe *kframe; | |
34 | ||
35 | /* the crunch context must be 64 bit aligned */ | |
36 | kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
37 | kframe->magic = CRUNCH_MAGIC; | |
38 | kframe->size = CRUNCH_STORAGE_SIZE; | |
39 | crunch_task_copy(current_thread_info(), &kframe->storage); | |
40 | return __copy_to_user(frame, kframe, sizeof(*frame)); | |
41 | } | |
42 | ||
65a5053b | 43 | static int restore_crunch_context(struct crunch_sigframe __user *frame) |
3bec6ded LB |
44 | { |
45 | char kbuf[sizeof(*frame) + 8]; | |
46 | struct crunch_sigframe *kframe; | |
47 | ||
48 | /* the crunch context must be 64 bit aligned */ | |
49 | kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
50 | if (__copy_from_user(kframe, frame, sizeof(*frame))) | |
51 | return -1; | |
52 | if (kframe->magic != CRUNCH_MAGIC || | |
53 | kframe->size != CRUNCH_STORAGE_SIZE) | |
54 | return -1; | |
55 | crunch_task_restore(current_thread_info(), &kframe->storage); | |
56 | return 0; | |
57 | } | |
58 | #endif | |
59 | ||
1da177e4 LT |
60 | #ifdef CONFIG_IWMMXT |
61 | ||
1da177e4 LT |
62 | static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) |
63 | { | |
69b04754 HD |
64 | char kbuf[sizeof(*frame) + 8]; |
65 | struct iwmmxt_sigframe *kframe; | |
1da177e4 LT |
66 | |
67 | /* the iWMMXt context must be 64 bit aligned */ | |
69b04754 | 68 | kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); |
85fe0681 DJ |
69 | kframe->magic = IWMMXT_MAGIC; |
70 | kframe->size = IWMMXT_STORAGE_SIZE; | |
69b04754 HD |
71 | iwmmxt_task_copy(current_thread_info(), &kframe->storage); |
72 | return __copy_to_user(frame, kframe, sizeof(*frame)); | |
1da177e4 LT |
73 | } |
74 | ||
75 | static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) | |
76 | { | |
69b04754 HD |
77 | char kbuf[sizeof(*frame) + 8]; |
78 | struct iwmmxt_sigframe *kframe; | |
79 | ||
80 | /* the iWMMXt context must be 64 bit aligned */ | |
81 | kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
82 | if (__copy_from_user(kframe, frame, sizeof(*frame))) | |
83 | return -1; | |
85fe0681 DJ |
84 | if (kframe->magic != IWMMXT_MAGIC || |
85 | kframe->size != IWMMXT_STORAGE_SIZE) | |
69b04754 HD |
86 | return -1; |
87 | iwmmxt_task_restore(current_thread_info(), &kframe->storage); | |
88 | return 0; | |
1da177e4 LT |
89 | } |
90 | ||
91 | #endif | |
92 | ||
82c6f5a5 ID |
93 | #ifdef CONFIG_VFP |
94 | ||
95 | static int preserve_vfp_context(struct vfp_sigframe __user *frame) | |
96 | { | |
82c6f5a5 ID |
97 | const unsigned long magic = VFP_MAGIC; |
98 | const unsigned long size = VFP_STORAGE_SIZE; | |
99 | int err = 0; | |
100 | ||
82c6f5a5 ID |
101 | __put_user_error(magic, &frame->magic, err); |
102 | __put_user_error(size, &frame->size, err); | |
103 | ||
2498814f WD |
104 | if (err) |
105 | return -EFAULT; | |
106 | ||
107 | return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc); | |
82c6f5a5 ID |
108 | } |
109 | ||
110 | static int restore_vfp_context(struct vfp_sigframe __user *frame) | |
111 | { | |
82c6f5a5 ID |
112 | unsigned long magic; |
113 | unsigned long size; | |
82c6f5a5 ID |
114 | int err = 0; |
115 | ||
116 | __get_user_error(magic, &frame->magic, err); | |
117 | __get_user_error(size, &frame->size, err); | |
118 | ||
119 | if (err) | |
120 | return -EFAULT; | |
121 | if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE) | |
122 | return -EINVAL; | |
123 | ||
2498814f | 124 | return vfp_restore_user_hwstate(&frame->ufp, &frame->ufp_exc); |
82c6f5a5 ID |
125 | } |
126 | ||
127 | #endif | |
128 | ||
1da177e4 LT |
129 | /* |
130 | * Do a signal return; undo the signal stack. These are aligned to 64-bit. | |
131 | */ | |
132 | struct sigframe { | |
7d4fdc19 | 133 | struct ucontext uc; |
fcca538b | 134 | unsigned long retcode[2]; |
1da177e4 LT |
135 | }; |
136 | ||
137 | struct rt_sigframe { | |
1da177e4 | 138 | struct siginfo info; |
cb3504e8 | 139 | struct sigframe sig; |
1da177e4 LT |
140 | }; |
141 | ||
68071484 | 142 | static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) |
1da177e4 | 143 | { |
85fe0681 | 144 | struct aux_sigframe __user *aux; |
68071484 RK |
145 | sigset_t set; |
146 | int err; | |
147 | ||
148 | err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); | |
77097ae5 | 149 | if (err == 0) |
101d9b0d | 150 | set_current_blocked(&set); |
1da177e4 | 151 | |
68071484 RK |
152 | __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); |
153 | __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); | |
154 | __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); | |
155 | __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); | |
156 | __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); | |
157 | __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); | |
158 | __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); | |
159 | __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); | |
160 | __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); | |
161 | __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); | |
162 | __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); | |
163 | __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); | |
164 | __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); | |
165 | __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); | |
166 | __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); | |
167 | __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); | |
168 | __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); | |
1da177e4 LT |
169 | |
170 | err |= !valid_user_regs(regs); | |
171 | ||
85fe0681 | 172 | aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; |
3bec6ded LB |
173 | #ifdef CONFIG_CRUNCH |
174 | if (err == 0) | |
175 | err |= restore_crunch_context(&aux->crunch); | |
176 | #endif | |
1da177e4 LT |
177 | #ifdef CONFIG_IWMMXT |
178 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
179 | err |= restore_iwmmxt_context(&aux->iwmmxt); | |
180 | #endif | |
181 | #ifdef CONFIG_VFP | |
82c6f5a5 ID |
182 | if (err == 0) |
183 | err |= restore_vfp_context(&aux->vfp); | |
1da177e4 LT |
184 | #endif |
185 | ||
186 | return err; | |
187 | } | |
188 | ||
189 | asmlinkage int sys_sigreturn(struct pt_regs *regs) | |
190 | { | |
191 | struct sigframe __user *frame; | |
1da177e4 LT |
192 | |
193 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 194 | current->restart_block.fn = do_no_restart_syscall; |
1da177e4 LT |
195 | |
196 | /* | |
197 | * Since we stacked the signal on a 64-bit boundary, | |
198 | * then 'sp' should be word aligned here. If it's | |
199 | * not, then the user is trying to mess with us. | |
200 | */ | |
201 | if (regs->ARM_sp & 7) | |
202 | goto badframe; | |
203 | ||
204 | frame = (struct sigframe __user *)regs->ARM_sp; | |
205 | ||
206 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
207 | goto badframe; | |
1da177e4 | 208 | |
68071484 | 209 | if (restore_sigframe(regs, frame)) |
1da177e4 LT |
210 | goto badframe; |
211 | ||
1da177e4 LT |
212 | return regs->ARM_r0; |
213 | ||
214 | badframe: | |
215 | force_sig(SIGSEGV, current); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) | |
220 | { | |
221 | struct rt_sigframe __user *frame; | |
1da177e4 LT |
222 | |
223 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 224 | current->restart_block.fn = do_no_restart_syscall; |
1da177e4 LT |
225 | |
226 | /* | |
227 | * Since we stacked the signal on a 64-bit boundary, | |
228 | * then 'sp' should be word aligned here. If it's | |
229 | * not, then the user is trying to mess with us. | |
230 | */ | |
231 | if (regs->ARM_sp & 7) | |
232 | goto badframe; | |
233 | ||
234 | frame = (struct rt_sigframe __user *)regs->ARM_sp; | |
235 | ||
236 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
237 | goto badframe; | |
1da177e4 | 238 | |
68071484 | 239 | if (restore_sigframe(regs, &frame->sig)) |
1da177e4 LT |
240 | goto badframe; |
241 | ||
ec93ac86 | 242 | if (restore_altstack(&frame->sig.uc.uc_stack)) |
1da177e4 LT |
243 | goto badframe; |
244 | ||
1da177e4 LT |
245 | return regs->ARM_r0; |
246 | ||
247 | badframe: | |
248 | force_sig(SIGSEGV, current); | |
249 | return 0; | |
250 | } | |
251 | ||
252 | static int | |
aca6ca10 | 253 | setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set) |
1da177e4 | 254 | { |
85fe0681 | 255 | struct aux_sigframe __user *aux; |
1da177e4 LT |
256 | int err = 0; |
257 | ||
aca6ca10 RK |
258 | __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); |
259 | __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); | |
260 | __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); | |
261 | __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); | |
262 | __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); | |
263 | __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); | |
264 | __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); | |
265 | __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); | |
266 | __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); | |
267 | __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); | |
268 | __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); | |
269 | __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); | |
270 | __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); | |
271 | __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); | |
272 | __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); | |
273 | __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); | |
274 | __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); | |
275 | ||
276 | __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err); | |
277 | __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err); | |
278 | __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err); | |
279 | __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err); | |
280 | ||
281 | err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); | |
1da177e4 | 282 | |
85fe0681 | 283 | aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; |
3bec6ded LB |
284 | #ifdef CONFIG_CRUNCH |
285 | if (err == 0) | |
286 | err |= preserve_crunch_context(&aux->crunch); | |
287 | #endif | |
1da177e4 LT |
288 | #ifdef CONFIG_IWMMXT |
289 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
290 | err |= preserve_iwmmxt_context(&aux->iwmmxt); | |
291 | #endif | |
292 | #ifdef CONFIG_VFP | |
82c6f5a5 ID |
293 | if (err == 0) |
294 | err |= preserve_vfp_context(&aux->vfp); | |
1da177e4 | 295 | #endif |
85fe0681 | 296 | __put_user_error(0, &aux->end_magic, err); |
1da177e4 LT |
297 | |
298 | return err; | |
299 | } | |
300 | ||
301 | static inline void __user * | |
7e243643 | 302 | get_sigframe(struct ksignal *ksig, struct pt_regs *regs, int framesize) |
1da177e4 | 303 | { |
7e243643 | 304 | unsigned long sp = sigsp(regs->ARM_sp, ksig); |
1da177e4 LT |
305 | void __user *frame; |
306 | ||
1da177e4 LT |
307 | /* |
308 | * ATPCS B01 mandates 8-byte alignment | |
309 | */ | |
310 | frame = (void __user *)((sp - framesize) & ~7); | |
311 | ||
312 | /* | |
313 | * Check that we can actually write to the signal frame. | |
314 | */ | |
315 | if (!access_ok(VERIFY_WRITE, frame, framesize)) | |
316 | frame = NULL; | |
317 | ||
318 | return frame; | |
319 | } | |
320 | ||
321 | static int | |
7e243643 AV |
322 | setup_return(struct pt_regs *regs, struct ksignal *ksig, |
323 | unsigned long __user *rc, void __user *frame) | |
1da177e4 | 324 | { |
7e243643 | 325 | unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler; |
1da177e4 LT |
326 | unsigned long retcode; |
327 | int thumb = 0; | |
53399053 RK |
328 | unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT); |
329 | ||
330 | cpsr |= PSR_ENDSTATE; | |
1da177e4 LT |
331 | |
332 | /* | |
333 | * Maybe we need to deliver a 32-bit signal to a 26-bit task. | |
334 | */ | |
7e243643 | 335 | if (ksig->ka.sa.sa_flags & SA_THIRTYTWO) |
1da177e4 LT |
336 | cpsr = (cpsr & ~MODE_MASK) | USR_MODE; |
337 | ||
338 | #ifdef CONFIG_ARM_THUMB | |
339 | if (elf_hwcap & HWCAP_THUMB) { | |
340 | /* | |
341 | * The LSB of the handler determines if we're going to | |
342 | * be using THUMB or ARM mode for this signal handler. | |
343 | */ | |
344 | thumb = handler & 1; | |
345 | ||
d71e1352 | 346 | #if __LINUX_ARM_ARCH__ >= 7 |
6ecf830e P |
347 | /* |
348 | * Clear the If-Then Thumb-2 execution state | |
349 | * ARM spec requires this to be all 000s in ARM mode | |
350 | * Snapdragon S4/Krait misbehaves on a Thumb=>ARM | |
351 | * signal transition without this. | |
352 | */ | |
353 | cpsr &= ~PSR_IT_MASK; | |
d71e1352 | 354 | #endif |
6ecf830e P |
355 | |
356 | if (thumb) { | |
357 | cpsr |= PSR_T_BIT; | |
d71e1352 | 358 | } else |
1da177e4 LT |
359 | cpsr &= ~PSR_T_BIT; |
360 | } | |
361 | #endif | |
362 | ||
7e243643 AV |
363 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
364 | retcode = (unsigned long)ksig->ka.sa.sa_restorer; | |
1da177e4 | 365 | } else { |
fcca538b | 366 | unsigned int idx = thumb << 1; |
1da177e4 | 367 | |
7e243643 | 368 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
fcca538b | 369 | idx += 3; |
1da177e4 | 370 | |
9dfc28b6 JA |
371 | /* |
372 | * Put the sigreturn code on the stack no matter which return | |
373 | * mechanism we use in order to remain ABI compliant | |
374 | */ | |
fcca538b NP |
375 | if (__put_user(sigreturn_codes[idx], rc) || |
376 | __put_user(sigreturn_codes[idx+1], rc+1)) | |
1da177e4 LT |
377 | return 1; |
378 | ||
8c0cc8a5 RK |
379 | #ifdef CONFIG_MMU |
380 | if (cpsr & MODE32_BIT) { | |
48be69a0 RK |
381 | struct mm_struct *mm = current->mm; |
382 | ||
e00d349e | 383 | /* |
48be69a0 RK |
384 | * 32-bit code can use the signal return page |
385 | * except when the MPU has protected the vectors | |
386 | * page from PL0 | |
e00d349e | 387 | */ |
48be69a0 RK |
388 | retcode = mm->context.sigpage + signal_return_offset + |
389 | (idx << 2) + thumb; | |
8c0cc8a5 RK |
390 | } else |
391 | #endif | |
392 | { | |
e00d349e RK |
393 | /* |
394 | * Ensure that the instruction cache sees | |
395 | * the return code written onto the stack. | |
396 | */ | |
397 | flush_icache_range((unsigned long)rc, | |
fcca538b | 398 | (unsigned long)(rc + 2)); |
e00d349e RK |
399 | |
400 | retcode = ((unsigned long)rc) + thumb; | |
401 | } | |
1da177e4 LT |
402 | } |
403 | ||
a4980448 | 404 | regs->ARM_r0 = ksig->sig; |
1da177e4 LT |
405 | regs->ARM_sp = (unsigned long)frame; |
406 | regs->ARM_lr = retcode; | |
407 | regs->ARM_pc = handler; | |
408 | regs->ARM_cpsr = cpsr; | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
413 | static int | |
7e243643 | 414 | setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
1da177e4 | 415 | { |
7e243643 | 416 | struct sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); |
1da177e4 LT |
417 | int err = 0; |
418 | ||
419 | if (!frame) | |
420 | return 1; | |
421 | ||
ca195cfe RK |
422 | /* |
423 | * Set uc.uc_flags to a value which sc.trap_no would never have. | |
424 | */ | |
425 | __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err); | |
1da177e4 | 426 | |
aca6ca10 | 427 | err |= setup_sigframe(frame, regs, set); |
1da177e4 | 428 | if (err == 0) |
7e243643 | 429 | err = setup_return(regs, ksig, frame->retcode, frame); |
1da177e4 LT |
430 | |
431 | return err; | |
432 | } | |
433 | ||
434 | static int | |
7e243643 | 435 | setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
1da177e4 | 436 | { |
7e243643 | 437 | struct rt_sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); |
1da177e4 LT |
438 | int err = 0; |
439 | ||
440 | if (!frame) | |
441 | return 1; | |
442 | ||
7e243643 | 443 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
1da177e4 | 444 | |
cb3504e8 RK |
445 | __put_user_error(0, &frame->sig.uc.uc_flags, err); |
446 | __put_user_error(NULL, &frame->sig.uc.uc_link, err); | |
1da177e4 | 447 | |
ec93ac86 | 448 | err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp); |
aca6ca10 | 449 | err |= setup_sigframe(&frame->sig, regs, set); |
1da177e4 | 450 | if (err == 0) |
7e243643 | 451 | err = setup_return(regs, ksig, frame->sig.retcode, frame); |
1da177e4 LT |
452 | |
453 | if (err == 0) { | |
454 | /* | |
455 | * For realtime signals we must also set the second and third | |
456 | * arguments for the signal handler. | |
457 | * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06 | |
458 | */ | |
459 | regs->ARM_r1 = (unsigned long)&frame->info; | |
cb3504e8 | 460 | regs->ARM_r2 = (unsigned long)&frame->sig.uc; |
1da177e4 LT |
461 | } |
462 | ||
463 | return err; | |
464 | } | |
465 | ||
1da177e4 LT |
466 | /* |
467 | * OK, we're invoking a handler | |
468 | */ | |
7e243643 | 469 | static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 470 | { |
b7f9a11a | 471 | sigset_t *oldset = sigmask_to_save(); |
1da177e4 LT |
472 | int ret; |
473 | ||
1da177e4 LT |
474 | /* |
475 | * Set up the stack frame | |
476 | */ | |
7e243643 AV |
477 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
478 | ret = setup_rt_frame(ksig, oldset, regs); | |
1da177e4 | 479 | else |
7e243643 | 480 | ret = setup_frame(ksig, oldset, regs); |
1da177e4 LT |
481 | |
482 | /* | |
483 | * Check that the resulting registers are actually sane. | |
484 | */ | |
485 | ret |= !valid_user_regs(regs); | |
486 | ||
7e243643 | 487 | signal_setup_done(ret, ksig, 0); |
1da177e4 LT |
488 | } |
489 | ||
490 | /* | |
491 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
492 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
493 | * mistake. | |
494 | * | |
495 | * Note that we go through the signals twice: once to check the signals that | |
496 | * the kernel can handle, and then we build all the user-level signal handling | |
497 | * stack-frames in one go after that. | |
498 | */ | |
81783786 | 499 | static int do_signal(struct pt_regs *regs, int syscall) |
1da177e4 | 500 | { |
2af68df0 | 501 | unsigned int retval = 0, continue_addr = 0, restart_addr = 0; |
7e243643 | 502 | struct ksignal ksig; |
81783786 | 503 | int restart = 0; |
1da177e4 | 504 | |
2af68df0 AB |
505 | /* |
506 | * If we were from a system call, check for system call restarting... | |
507 | */ | |
508 | if (syscall) { | |
509 | continue_addr = regs->ARM_pc; | |
510 | restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4); | |
511 | retval = regs->ARM_r0; | |
512 | ||
513 | /* | |
514 | * Prepare for system call restart. We do this here so that a | |
515 | * debugger will see the already changed PSW. | |
516 | */ | |
517 | switch (retval) { | |
81783786 | 518 | case -ERESTART_RESTARTBLOCK: |
66285217 | 519 | restart -= 2; |
2af68df0 AB |
520 | case -ERESTARTNOHAND: |
521 | case -ERESTARTSYS: | |
522 | case -ERESTARTNOINTR: | |
81783786 | 523 | restart++; |
2af68df0 AB |
524 | regs->ARM_r0 = regs->ARM_ORIG_r0; |
525 | regs->ARM_pc = restart_addr; | |
526 | break; | |
2af68df0 AB |
527 | } |
528 | } | |
529 | ||
2af68df0 AB |
530 | /* |
531 | * Get the signal to deliver. When running under ptrace, at this | |
532 | * point the debugger may change all our registers ... | |
533 | */ | |
81783786 AV |
534 | /* |
535 | * Depending on the signal settings we may need to revert the | |
536 | * decision to restart the system call. But skip this if a | |
537 | * debugger has chosen to restart at a different PC. | |
538 | */ | |
7e243643 AV |
539 | if (get_signal(&ksig)) { |
540 | /* handler */ | |
541 | if (unlikely(restart) && regs->ARM_pc == restart_addr) { | |
ad82cc08 WD |
542 | if (retval == -ERESTARTNOHAND || |
543 | retval == -ERESTART_RESTARTBLOCK | |
2af68df0 | 544 | || (retval == -ERESTARTSYS |
7e243643 | 545 | && !(ksig.ka.sa.sa_flags & SA_RESTART))) { |
2af68df0 AB |
546 | regs->ARM_r0 = -EINTR; |
547 | regs->ARM_pc = continue_addr; | |
548 | } | |
549 | } | |
7e243643 AV |
550 | handle_signal(&ksig, regs); |
551 | } else { | |
552 | /* no handler */ | |
553 | restore_saved_sigmask(); | |
554 | if (unlikely(restart) && regs->ARM_pc == restart_addr) { | |
555 | regs->ARM_pc = continue_addr; | |
556 | return restart; | |
557 | } | |
1da177e4 | 558 | } |
7e243643 | 559 | return 0; |
1da177e4 LT |
560 | } |
561 | ||
81783786 | 562 | asmlinkage int |
0a267fa6 | 563 | do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) |
1da177e4 | 564 | { |
3302cadd RK |
565 | /* |
566 | * The assembly code enters us with IRQs off, but it hasn't | |
567 | * informed the tracing code of that for efficiency reasons. | |
568 | * Update the trace code with the current status. | |
569 | */ | |
570 | trace_hardirqs_off(); | |
0a267fa6 AV |
571 | do { |
572 | if (likely(thread_flags & _TIF_NEED_RESCHED)) { | |
573 | schedule(); | |
574 | } else { | |
575 | if (unlikely(!user_mode(regs))) | |
81783786 | 576 | return 0; |
0a267fa6 AV |
577 | local_irq_enable(); |
578 | if (thread_flags & _TIF_SIGPENDING) { | |
66285217 AV |
579 | int restart = do_signal(regs, syscall); |
580 | if (unlikely(restart)) { | |
81783786 AV |
581 | /* |
582 | * Restart without handlers. | |
583 | * Deal with it without leaving | |
584 | * the kernel space. | |
585 | */ | |
66285217 | 586 | return restart; |
81783786 | 587 | } |
0a267fa6 | 588 | syscall = 0; |
c7edc9e3 | 589 | } else if (thread_flags & _TIF_UPROBE) { |
c7edc9e3 | 590 | uprobe_notify_resume(regs); |
0a267fa6 AV |
591 | } else { |
592 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
593 | tracehook_notify_resume(regs); | |
594 | } | |
595 | } | |
596 | local_irq_disable(); | |
597 | thread_flags = current_thread_info()->flags; | |
598 | } while (thread_flags & _TIF_WORK_MASK); | |
81783786 | 599 | return 0; |
1da177e4 | 600 | } |
48be69a0 | 601 | |
48be69a0 RK |
602 | struct page *get_signal_page(void) |
603 | { | |
e0d40756 RK |
604 | unsigned long ptr; |
605 | unsigned offset; | |
606 | struct page *page; | |
607 | void *addr; | |
48be69a0 | 608 | |
e0d40756 | 609 | page = alloc_pages(GFP_KERNEL, 0); |
48be69a0 | 610 | |
e0d40756 RK |
611 | if (!page) |
612 | return NULL; | |
48be69a0 | 613 | |
e0d40756 | 614 | addr = page_address(page); |
48be69a0 | 615 | |
e0d40756 RK |
616 | /* Give the signal return code some randomness */ |
617 | offset = 0x200 + (get_random_int() & 0x7fc); | |
618 | signal_return_offset = offset; | |
48be69a0 | 619 | |
e0d40756 RK |
620 | /* |
621 | * Copy signal return handlers into the vector page, and | |
622 | * set sigreturn to be a pointer to these. | |
623 | */ | |
624 | memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes)); | |
48be69a0 | 625 | |
e0d40756 RK |
626 | ptr = (unsigned long)addr + offset; |
627 | flush_icache_range(ptr, ptr + sizeof(sigreturn_codes)); | |
48be69a0 | 628 | |
e0d40756 | 629 | return page; |
48be69a0 | 630 | } |