Commit | Line | Data |
---|---|---|
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> |
a5510daa | 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> |
1da177e4 | 16 | |
ee90dabc | 17 | #include <asm/elf.h> |
1da177e4 | 18 | #include <asm/cacheflush.h> |
a5510daa | 19 | #include <asm/traps.h> |
1da177e4 | 20 | #include <asm/ucontext.h> |
1da177e4 | 21 | #include <asm/unistd.h> |
82c6f5a5 | 22 | #include <asm/vfp.h> |
1da177e4 | 23 | |
1da177e4 LT |
24 | /* |
25 | * For ARM syscalls, we encode the syscall number into the instruction. | |
26 | */ | |
ee4cd588 | 27 | #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE)) |
28 | #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE)) | |
1da177e4 | 29 | |
fcca538b NP |
30 | /* |
31 | * With EABI, the syscall number has to be loaded into r7. | |
32 | */ | |
33 | #define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE)) | |
34 | #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE)) | |
35 | ||
1da177e4 LT |
36 | /* |
37 | * For Thumb syscalls, we pass the syscall number via r7. We therefore | |
38 | * need two 16-bit instructions. | |
39 | */ | |
40 | #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE)) | |
41 | #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE)) | |
42 | ||
a5510daa | 43 | static const unsigned long sigreturn_codes[7] = { |
fcca538b NP |
44 | MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN, |
45 | MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN, | |
1da177e4 LT |
46 | }; |
47 | ||
a5510daa RK |
48 | static unsigned long signal_return_offset; |
49 | ||
3bec6ded | 50 | #ifdef CONFIG_CRUNCH |
65a5053b | 51 | static int preserve_crunch_context(struct crunch_sigframe __user *frame) |
3bec6ded LB |
52 | { |
53 | char kbuf[sizeof(*frame) + 8]; | |
54 | struct crunch_sigframe *kframe; | |
55 | ||
56 | /* the crunch context must be 64 bit aligned */ | |
57 | kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
58 | kframe->magic = CRUNCH_MAGIC; | |
59 | kframe->size = CRUNCH_STORAGE_SIZE; | |
60 | crunch_task_copy(current_thread_info(), &kframe->storage); | |
61 | return __copy_to_user(frame, kframe, sizeof(*frame)); | |
62 | } | |
63 | ||
65a5053b | 64 | static int restore_crunch_context(struct crunch_sigframe __user *frame) |
3bec6ded LB |
65 | { |
66 | char kbuf[sizeof(*frame) + 8]; | |
67 | struct crunch_sigframe *kframe; | |
68 | ||
69 | /* the crunch context must be 64 bit aligned */ | |
70 | kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
71 | if (__copy_from_user(kframe, frame, sizeof(*frame))) | |
72 | return -1; | |
73 | if (kframe->magic != CRUNCH_MAGIC || | |
74 | kframe->size != CRUNCH_STORAGE_SIZE) | |
75 | return -1; | |
76 | crunch_task_restore(current_thread_info(), &kframe->storage); | |
77 | return 0; | |
78 | } | |
79 | #endif | |
80 | ||
1da177e4 LT |
81 | #ifdef CONFIG_IWMMXT |
82 | ||
1da177e4 LT |
83 | static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) |
84 | { | |
69b04754 HD |
85 | char kbuf[sizeof(*frame) + 8]; |
86 | struct iwmmxt_sigframe *kframe; | |
1da177e4 LT |
87 | |
88 | /* the iWMMXt context must be 64 bit aligned */ | |
69b04754 | 89 | kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); |
85fe0681 DJ |
90 | kframe->magic = IWMMXT_MAGIC; |
91 | kframe->size = IWMMXT_STORAGE_SIZE; | |
69b04754 HD |
92 | iwmmxt_task_copy(current_thread_info(), &kframe->storage); |
93 | return __copy_to_user(frame, kframe, sizeof(*frame)); | |
1da177e4 LT |
94 | } |
95 | ||
96 | static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) | |
97 | { | |
69b04754 HD |
98 | char kbuf[sizeof(*frame) + 8]; |
99 | struct iwmmxt_sigframe *kframe; | |
100 | ||
101 | /* the iWMMXt context must be 64 bit aligned */ | |
102 | kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
103 | if (__copy_from_user(kframe, frame, sizeof(*frame))) | |
104 | return -1; | |
85fe0681 DJ |
105 | if (kframe->magic != IWMMXT_MAGIC || |
106 | kframe->size != IWMMXT_STORAGE_SIZE) | |
69b04754 HD |
107 | return -1; |
108 | iwmmxt_task_restore(current_thread_info(), &kframe->storage); | |
109 | return 0; | |
1da177e4 LT |
110 | } |
111 | ||
112 | #endif | |
113 | ||
82c6f5a5 ID |
114 | #ifdef CONFIG_VFP |
115 | ||
116 | static int preserve_vfp_context(struct vfp_sigframe __user *frame) | |
117 | { | |
82c6f5a5 ID |
118 | const unsigned long magic = VFP_MAGIC; |
119 | const unsigned long size = VFP_STORAGE_SIZE; | |
120 | int err = 0; | |
121 | ||
82c6f5a5 ID |
122 | __put_user_error(magic, &frame->magic, err); |
123 | __put_user_error(size, &frame->size, err); | |
124 | ||
2498814f WD |
125 | if (err) |
126 | return -EFAULT; | |
127 | ||
128 | return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc); | |
82c6f5a5 ID |
129 | } |
130 | ||
131 | static int restore_vfp_context(struct vfp_sigframe __user *frame) | |
132 | { | |
82c6f5a5 ID |
133 | unsigned long magic; |
134 | unsigned long size; | |
82c6f5a5 ID |
135 | int err = 0; |
136 | ||
137 | __get_user_error(magic, &frame->magic, err); | |
138 | __get_user_error(size, &frame->size, err); | |
139 | ||
140 | if (err) | |
141 | return -EFAULT; | |
142 | if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE) | |
143 | return -EINVAL; | |
144 | ||
2498814f | 145 | return vfp_restore_user_hwstate(&frame->ufp, &frame->ufp_exc); |
82c6f5a5 ID |
146 | } |
147 | ||
148 | #endif | |
149 | ||
1da177e4 LT |
150 | /* |
151 | * Do a signal return; undo the signal stack. These are aligned to 64-bit. | |
152 | */ | |
153 | struct sigframe { | |
7d4fdc19 | 154 | struct ucontext uc; |
fcca538b | 155 | unsigned long retcode[2]; |
1da177e4 LT |
156 | }; |
157 | ||
158 | struct rt_sigframe { | |
1da177e4 | 159 | struct siginfo info; |
cb3504e8 | 160 | struct sigframe sig; |
1da177e4 LT |
161 | }; |
162 | ||
68071484 | 163 | static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) |
1da177e4 | 164 | { |
85fe0681 | 165 | struct aux_sigframe __user *aux; |
68071484 RK |
166 | sigset_t set; |
167 | int err; | |
168 | ||
169 | err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); | |
77097ae5 | 170 | if (err == 0) |
101d9b0d | 171 | set_current_blocked(&set); |
1da177e4 | 172 | |
68071484 RK |
173 | __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); |
174 | __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); | |
175 | __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); | |
176 | __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); | |
177 | __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); | |
178 | __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); | |
179 | __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); | |
180 | __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); | |
181 | __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); | |
182 | __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); | |
183 | __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); | |
184 | __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); | |
185 | __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); | |
186 | __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); | |
187 | __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); | |
188 | __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); | |
189 | __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); | |
1da177e4 LT |
190 | |
191 | err |= !valid_user_regs(regs); | |
192 | ||
85fe0681 | 193 | aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; |
3bec6ded LB |
194 | #ifdef CONFIG_CRUNCH |
195 | if (err == 0) | |
196 | err |= restore_crunch_context(&aux->crunch); | |
197 | #endif | |
1da177e4 LT |
198 | #ifdef CONFIG_IWMMXT |
199 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
200 | err |= restore_iwmmxt_context(&aux->iwmmxt); | |
201 | #endif | |
202 | #ifdef CONFIG_VFP | |
82c6f5a5 ID |
203 | if (err == 0) |
204 | err |= restore_vfp_context(&aux->vfp); | |
1da177e4 LT |
205 | #endif |
206 | ||
207 | return err; | |
208 | } | |
209 | ||
210 | asmlinkage int sys_sigreturn(struct pt_regs *regs) | |
211 | { | |
212 | struct sigframe __user *frame; | |
1da177e4 LT |
213 | |
214 | /* Always make any pending restarted system calls return -EINTR */ | |
215 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
216 | ||
217 | /* | |
218 | * Since we stacked the signal on a 64-bit boundary, | |
219 | * then 'sp' should be word aligned here. If it's | |
220 | * not, then the user is trying to mess with us. | |
221 | */ | |
222 | if (regs->ARM_sp & 7) | |
223 | goto badframe; | |
224 | ||
225 | frame = (struct sigframe __user *)regs->ARM_sp; | |
226 | ||
227 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
228 | goto badframe; | |
1da177e4 | 229 | |
68071484 | 230 | if (restore_sigframe(regs, frame)) |
1da177e4 LT |
231 | goto badframe; |
232 | ||
1da177e4 LT |
233 | return regs->ARM_r0; |
234 | ||
235 | badframe: | |
236 | force_sig(SIGSEGV, current); | |
237 | return 0; | |
238 | } | |
239 | ||
240 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) | |
241 | { | |
242 | struct rt_sigframe __user *frame; | |
1da177e4 LT |
243 | |
244 | /* Always make any pending restarted system calls return -EINTR */ | |
245 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
246 | ||
247 | /* | |
248 | * Since we stacked the signal on a 64-bit boundary, | |
249 | * then 'sp' should be word aligned here. If it's | |
250 | * not, then the user is trying to mess with us. | |
251 | */ | |
252 | if (regs->ARM_sp & 7) | |
253 | goto badframe; | |
254 | ||
255 | frame = (struct rt_sigframe __user *)regs->ARM_sp; | |
256 | ||
257 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
258 | goto badframe; | |
1da177e4 | 259 | |
68071484 | 260 | if (restore_sigframe(regs, &frame->sig)) |
1da177e4 LT |
261 | goto badframe; |
262 | ||
ec93ac86 | 263 | if (restore_altstack(&frame->sig.uc.uc_stack)) |
1da177e4 LT |
264 | goto badframe; |
265 | ||
1da177e4 LT |
266 | return regs->ARM_r0; |
267 | ||
268 | badframe: | |
269 | force_sig(SIGSEGV, current); | |
270 | return 0; | |
271 | } | |
272 | ||
273 | static int | |
aca6ca10 | 274 | setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set) |
1da177e4 | 275 | { |
85fe0681 | 276 | struct aux_sigframe __user *aux; |
1da177e4 LT |
277 | int err = 0; |
278 | ||
aca6ca10 RK |
279 | __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); |
280 | __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); | |
281 | __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); | |
282 | __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); | |
283 | __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); | |
284 | __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); | |
285 | __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); | |
286 | __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); | |
287 | __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); | |
288 | __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); | |
289 | __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); | |
290 | __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); | |
291 | __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); | |
292 | __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); | |
293 | __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); | |
294 | __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); | |
295 | __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); | |
296 | ||
297 | __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err); | |
298 | __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err); | |
299 | __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err); | |
300 | __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err); | |
301 | ||
302 | err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); | |
1da177e4 | 303 | |
85fe0681 | 304 | aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; |
3bec6ded LB |
305 | #ifdef CONFIG_CRUNCH |
306 | if (err == 0) | |
307 | err |= preserve_crunch_context(&aux->crunch); | |
308 | #endif | |
1da177e4 LT |
309 | #ifdef CONFIG_IWMMXT |
310 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
311 | err |= preserve_iwmmxt_context(&aux->iwmmxt); | |
312 | #endif | |
313 | #ifdef CONFIG_VFP | |
82c6f5a5 ID |
314 | if (err == 0) |
315 | err |= preserve_vfp_context(&aux->vfp); | |
1da177e4 | 316 | #endif |
85fe0681 | 317 | __put_user_error(0, &aux->end_magic, err); |
1da177e4 LT |
318 | |
319 | return err; | |
320 | } | |
321 | ||
322 | static inline void __user * | |
7e243643 | 323 | get_sigframe(struct ksignal *ksig, struct pt_regs *regs, int framesize) |
1da177e4 | 324 | { |
7e243643 | 325 | unsigned long sp = sigsp(regs->ARM_sp, ksig); |
1da177e4 LT |
326 | void __user *frame; |
327 | ||
1da177e4 LT |
328 | /* |
329 | * ATPCS B01 mandates 8-byte alignment | |
330 | */ | |
331 | frame = (void __user *)((sp - framesize) & ~7); | |
332 | ||
333 | /* | |
334 | * Check that we can actually write to the signal frame. | |
335 | */ | |
336 | if (!access_ok(VERIFY_WRITE, frame, framesize)) | |
337 | frame = NULL; | |
338 | ||
339 | return frame; | |
340 | } | |
341 | ||
7e243643 AV |
342 | /* |
343 | * translate the signal | |
344 | */ | |
345 | static inline int map_sig(int sig) | |
346 | { | |
347 | struct thread_info *thread = current_thread_info(); | |
348 | if (sig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) | |
349 | sig = thread->exec_domain->signal_invmap[sig]; | |
350 | return sig; | |
351 | } | |
352 | ||
1da177e4 | 353 | static int |
7e243643 AV |
354 | setup_return(struct pt_regs *regs, struct ksignal *ksig, |
355 | unsigned long __user *rc, void __user *frame) | |
1da177e4 | 356 | { |
7e243643 | 357 | unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler; |
1da177e4 LT |
358 | unsigned long retcode; |
359 | int thumb = 0; | |
53399053 RK |
360 | unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT); |
361 | ||
362 | cpsr |= PSR_ENDSTATE; | |
1da177e4 LT |
363 | |
364 | /* | |
365 | * Maybe we need to deliver a 32-bit signal to a 26-bit task. | |
366 | */ | |
7e243643 | 367 | if (ksig->ka.sa.sa_flags & SA_THIRTYTWO) |
1da177e4 LT |
368 | cpsr = (cpsr & ~MODE_MASK) | USR_MODE; |
369 | ||
370 | #ifdef CONFIG_ARM_THUMB | |
371 | if (elf_hwcap & HWCAP_THUMB) { | |
372 | /* | |
373 | * The LSB of the handler determines if we're going to | |
374 | * be using THUMB or ARM mode for this signal handler. | |
375 | */ | |
376 | thumb = handler & 1; | |
377 | ||
d71e1352 | 378 | if (thumb) { |
1da177e4 | 379 | cpsr |= PSR_T_BIT; |
d71e1352 CM |
380 | #if __LINUX_ARM_ARCH__ >= 7 |
381 | /* clear the If-Then Thumb-2 execution state */ | |
382 | cpsr &= ~PSR_IT_MASK; | |
383 | #endif | |
384 | } else | |
1da177e4 LT |
385 | cpsr &= ~PSR_T_BIT; |
386 | } | |
387 | #endif | |
388 | ||
7e243643 AV |
389 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
390 | retcode = (unsigned long)ksig->ka.sa.sa_restorer; | |
1da177e4 | 391 | } else { |
fcca538b | 392 | unsigned int idx = thumb << 1; |
1da177e4 | 393 | |
7e243643 | 394 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
fcca538b | 395 | idx += 3; |
1da177e4 | 396 | |
fcca538b NP |
397 | if (__put_user(sigreturn_codes[idx], rc) || |
398 | __put_user(sigreturn_codes[idx+1], rc+1)) | |
1da177e4 LT |
399 | return 1; |
400 | ||
0a73f943 | 401 | #ifdef CONFIG_MMU |
e00d349e | 402 | if (cpsr & MODE32_BIT) { |
a5510daa | 403 | struct mm_struct *mm = current->mm; |
e00d349e | 404 | /* |
a5510daa RK |
405 | * 32-bit code can use the signal return page |
406 | * except when the MPU has protected the vectors | |
407 | * page from PL0 | |
e00d349e | 408 | */ |
a5510daa RK |
409 | retcode = mm->context.sigpage + signal_return_offset + |
410 | (idx << 2) + thumb; | |
0a73f943 RK |
411 | } else |
412 | #endif | |
413 | { | |
e00d349e RK |
414 | /* |
415 | * Ensure that the instruction cache sees | |
416 | * the return code written onto the stack. | |
417 | */ | |
418 | flush_icache_range((unsigned long)rc, | |
fcca538b | 419 | (unsigned long)(rc + 2)); |
e00d349e RK |
420 | |
421 | retcode = ((unsigned long)rc) + thumb; | |
422 | } | |
1da177e4 LT |
423 | } |
424 | ||
7e243643 | 425 | regs->ARM_r0 = map_sig(ksig->sig); |
1da177e4 LT |
426 | regs->ARM_sp = (unsigned long)frame; |
427 | regs->ARM_lr = retcode; | |
428 | regs->ARM_pc = handler; | |
429 | regs->ARM_cpsr = cpsr; | |
430 | ||
431 | return 0; | |
432 | } | |
433 | ||
434 | static int | |
7e243643 | 435 | setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
1da177e4 | 436 | { |
7e243643 | 437 | struct sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); |
1da177e4 LT |
438 | int err = 0; |
439 | ||
440 | if (!frame) | |
441 | return 1; | |
442 | ||
ca195cfe RK |
443 | /* |
444 | * Set uc.uc_flags to a value which sc.trap_no would never have. | |
445 | */ | |
446 | __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err); | |
1da177e4 | 447 | |
aca6ca10 | 448 | err |= setup_sigframe(frame, regs, set); |
1da177e4 | 449 | if (err == 0) |
7e243643 | 450 | err = setup_return(regs, ksig, frame->retcode, frame); |
1da177e4 LT |
451 | |
452 | return err; | |
453 | } | |
454 | ||
455 | static int | |
7e243643 | 456 | setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
1da177e4 | 457 | { |
7e243643 | 458 | struct rt_sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); |
1da177e4 LT |
459 | int err = 0; |
460 | ||
461 | if (!frame) | |
462 | return 1; | |
463 | ||
7e243643 | 464 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
1da177e4 | 465 | |
cb3504e8 RK |
466 | __put_user_error(0, &frame->sig.uc.uc_flags, err); |
467 | __put_user_error(NULL, &frame->sig.uc.uc_link, err); | |
1da177e4 | 468 | |
ec93ac86 | 469 | err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp); |
aca6ca10 | 470 | err |= setup_sigframe(&frame->sig, regs, set); |
1da177e4 | 471 | if (err == 0) |
7e243643 | 472 | err = setup_return(regs, ksig, frame->sig.retcode, frame); |
1da177e4 LT |
473 | |
474 | if (err == 0) { | |
475 | /* | |
476 | * For realtime signals we must also set the second and third | |
477 | * arguments for the signal handler. | |
478 | * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06 | |
479 | */ | |
480 | regs->ARM_r1 = (unsigned long)&frame->info; | |
cb3504e8 | 481 | regs->ARM_r2 = (unsigned long)&frame->sig.uc; |
1da177e4 LT |
482 | } |
483 | ||
484 | return err; | |
485 | } | |
486 | ||
1da177e4 LT |
487 | /* |
488 | * OK, we're invoking a handler | |
489 | */ | |
7e243643 | 490 | static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 491 | { |
b7f9a11a | 492 | sigset_t *oldset = sigmask_to_save(); |
1da177e4 LT |
493 | int ret; |
494 | ||
1da177e4 LT |
495 | /* |
496 | * Set up the stack frame | |
497 | */ | |
7e243643 AV |
498 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
499 | ret = setup_rt_frame(ksig, oldset, regs); | |
1da177e4 | 500 | else |
7e243643 | 501 | ret = setup_frame(ksig, oldset, regs); |
1da177e4 LT |
502 | |
503 | /* | |
504 | * Check that the resulting registers are actually sane. | |
505 | */ | |
506 | ret |= !valid_user_regs(regs); | |
507 | ||
7e243643 | 508 | signal_setup_done(ret, ksig, 0); |
1da177e4 LT |
509 | } |
510 | ||
511 | /* | |
512 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
513 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
514 | * mistake. | |
515 | * | |
516 | * Note that we go through the signals twice: once to check the signals that | |
517 | * the kernel can handle, and then we build all the user-level signal handling | |
518 | * stack-frames in one go after that. | |
519 | */ | |
81783786 | 520 | static int do_signal(struct pt_regs *regs, int syscall) |
1da177e4 | 521 | { |
2af68df0 | 522 | unsigned int retval = 0, continue_addr = 0, restart_addr = 0; |
7e243643 | 523 | struct ksignal ksig; |
81783786 | 524 | int restart = 0; |
1da177e4 | 525 | |
2af68df0 AB |
526 | /* |
527 | * If we were from a system call, check for system call restarting... | |
528 | */ | |
529 | if (syscall) { | |
530 | continue_addr = regs->ARM_pc; | |
531 | restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4); | |
532 | retval = regs->ARM_r0; | |
533 | ||
534 | /* | |
535 | * Prepare for system call restart. We do this here so that a | |
536 | * debugger will see the already changed PSW. | |
537 | */ | |
538 | switch (retval) { | |
81783786 | 539 | case -ERESTART_RESTARTBLOCK: |
66285217 | 540 | restart -= 2; |
2af68df0 AB |
541 | case -ERESTARTNOHAND: |
542 | case -ERESTARTSYS: | |
543 | case -ERESTARTNOINTR: | |
81783786 | 544 | restart++; |
2af68df0 AB |
545 | regs->ARM_r0 = regs->ARM_ORIG_r0; |
546 | regs->ARM_pc = restart_addr; | |
547 | break; | |
2af68df0 AB |
548 | } |
549 | } | |
550 | ||
2af68df0 AB |
551 | /* |
552 | * Get the signal to deliver. When running under ptrace, at this | |
553 | * point the debugger may change all our registers ... | |
554 | */ | |
81783786 AV |
555 | /* |
556 | * Depending on the signal settings we may need to revert the | |
557 | * decision to restart the system call. But skip this if a | |
558 | * debugger has chosen to restart at a different PC. | |
559 | */ | |
7e243643 AV |
560 | if (get_signal(&ksig)) { |
561 | /* handler */ | |
562 | if (unlikely(restart) && regs->ARM_pc == restart_addr) { | |
ad82cc08 WD |
563 | if (retval == -ERESTARTNOHAND || |
564 | retval == -ERESTART_RESTARTBLOCK | |
2af68df0 | 565 | || (retval == -ERESTARTSYS |
7e243643 | 566 | && !(ksig.ka.sa.sa_flags & SA_RESTART))) { |
2af68df0 AB |
567 | regs->ARM_r0 = -EINTR; |
568 | regs->ARM_pc = continue_addr; | |
569 | } | |
570 | } | |
7e243643 AV |
571 | handle_signal(&ksig, regs); |
572 | } else { | |
573 | /* no handler */ | |
574 | restore_saved_sigmask(); | |
575 | if (unlikely(restart) && regs->ARM_pc == restart_addr) { | |
576 | regs->ARM_pc = continue_addr; | |
577 | return restart; | |
578 | } | |
1da177e4 | 579 | } |
7e243643 | 580 | return 0; |
1da177e4 LT |
581 | } |
582 | ||
81783786 | 583 | asmlinkage int |
0a267fa6 | 584 | do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) |
1da177e4 | 585 | { |
0a267fa6 AV |
586 | do { |
587 | if (likely(thread_flags & _TIF_NEED_RESCHED)) { | |
588 | schedule(); | |
589 | } else { | |
590 | if (unlikely(!user_mode(regs))) | |
81783786 | 591 | return 0; |
0a267fa6 AV |
592 | local_irq_enable(); |
593 | if (thread_flags & _TIF_SIGPENDING) { | |
66285217 AV |
594 | int restart = do_signal(regs, syscall); |
595 | if (unlikely(restart)) { | |
81783786 AV |
596 | /* |
597 | * Restart without handlers. | |
598 | * Deal with it without leaving | |
599 | * the kernel space. | |
600 | */ | |
66285217 | 601 | return restart; |
81783786 | 602 | } |
0a267fa6 AV |
603 | syscall = 0; |
604 | } else { | |
605 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
606 | tracehook_notify_resume(regs); | |
607 | } | |
608 | } | |
609 | local_irq_disable(); | |
610 | thread_flags = current_thread_info()->flags; | |
611 | } while (thread_flags & _TIF_WORK_MASK); | |
81783786 | 612 | return 0; |
1da177e4 | 613 | } |
a5510daa | 614 | |
a5510daa RK |
615 | struct page *get_signal_page(void) |
616 | { | |
17ef3295 RK |
617 | unsigned long ptr; |
618 | unsigned offset; | |
619 | struct page *page; | |
620 | void *addr; | |
a5510daa | 621 | |
17ef3295 | 622 | page = alloc_pages(GFP_KERNEL, 0); |
a5510daa | 623 | |
17ef3295 RK |
624 | if (!page) |
625 | return NULL; | |
a5510daa | 626 | |
17ef3295 | 627 | addr = page_address(page); |
a5510daa | 628 | |
17ef3295 RK |
629 | /* Give the signal return code some randomness */ |
630 | offset = 0x200 + (get_random_int() & 0x7fc); | |
631 | signal_return_offset = offset; | |
a5510daa | 632 | |
17ef3295 RK |
633 | /* |
634 | * Copy signal return handlers into the vector page, and | |
635 | * set sigreturn to be a pointer to these. | |
636 | */ | |
637 | memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes)); | |
a5510daa | 638 | |
17ef3295 RK |
639 | ptr = (unsigned long)addr + offset; |
640 | flush_icache_range(ptr, ptr + sizeof(sigreturn_codes)); | |
a5510daa | 641 | |
17ef3295 | 642 | return page; |
a5510daa | 643 | } |