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 LT |
10 | #include <linux/errno.h> |
11 | #include <linux/signal.h> | |
1da177e4 | 12 | #include <linux/personality.h> |
7dfb7103 | 13 | #include <linux/freezer.h> |
33fa9b13 | 14 | #include <linux/uaccess.h> |
733e5e4b | 15 | #include <linux/tracehook.h> |
1da177e4 | 16 | |
ee90dabc | 17 | #include <asm/elf.h> |
1da177e4 LT |
18 | #include <asm/cacheflush.h> |
19 | #include <asm/ucontext.h> | |
1da177e4 | 20 | #include <asm/unistd.h> |
82c6f5a5 | 21 | #include <asm/vfp.h> |
1da177e4 | 22 | |
e00d349e | 23 | #include "signal.h" |
1da177e4 LT |
24 | |
25 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
26 | ||
27 | /* | |
28 | * For ARM syscalls, we encode the syscall number into the instruction. | |
29 | */ | |
ee4cd588 | 30 | #define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)|(__NR_OABI_SYSCALL_BASE)) |
31 | #define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)|(__NR_OABI_SYSCALL_BASE)) | |
ab72b007 | 32 | #define SWI_SYS_RESTART (0xef000000|__NR_restart_syscall|__NR_OABI_SYSCALL_BASE) |
1da177e4 | 33 | |
fcca538b NP |
34 | /* |
35 | * With EABI, the syscall number has to be loaded into r7. | |
36 | */ | |
37 | #define MOV_R7_NR_SIGRETURN (0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE)) | |
38 | #define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE)) | |
39 | ||
1da177e4 LT |
40 | /* |
41 | * For Thumb syscalls, we pass the syscall number via r7. We therefore | |
42 | * need two 16-bit instructions. | |
43 | */ | |
44 | #define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE)) | |
45 | #define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE)) | |
46 | ||
fcca538b NP |
47 | const unsigned long sigreturn_codes[7] = { |
48 | MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN, | |
49 | MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN, | |
1da177e4 LT |
50 | }; |
51 | ||
ab72b007 RK |
52 | /* |
53 | * Either we support OABI only, or we have EABI with the OABI | |
54 | * compat layer enabled. In the later case we don't know if | |
55 | * user space is EABI or not, and if not we must not clobber r7. | |
56 | * Always using the OABI syscall solves that issue and works for | |
57 | * all those cases. | |
58 | */ | |
59 | const unsigned long syscall_restart_code[2] = { | |
60 | SWI_SYS_RESTART, /* swi __NR_restart_syscall */ | |
61 | 0xe49df004, /* ldr pc, [sp], #4 */ | |
62 | }; | |
63 | ||
1da177e4 LT |
64 | /* |
65 | * atomically swap in the new signal mask, and wait for a signal. | |
66 | */ | |
36984265 | 67 | asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask) |
1da177e4 | 68 | { |
1da177e4 LT |
69 | mask &= _BLOCKABLE; |
70 | spin_lock_irq(¤t->sighand->siglock); | |
36984265 | 71 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
72 | siginitset(¤t->blocked, mask); |
73 | recalc_sigpending(); | |
74 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 | 75 | |
36984265 MP |
76 | current->state = TASK_INTERRUPTIBLE; |
77 | schedule(); | |
78 | set_restore_sigmask(); | |
79 | return -ERESTARTNOHAND; | |
1da177e4 LT |
80 | } |
81 | ||
82 | asmlinkage int | |
83 | sys_sigaction(int sig, const struct old_sigaction __user *act, | |
84 | struct old_sigaction __user *oact) | |
85 | { | |
86 | struct k_sigaction new_ka, old_ka; | |
87 | int ret; | |
88 | ||
89 | if (act) { | |
90 | old_sigset_t mask; | |
91 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
92 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
93 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
94 | return -EFAULT; | |
95 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
96 | __get_user(mask, &act->sa_mask); | |
97 | siginitset(&new_ka.sa.sa_mask, mask); | |
98 | } | |
99 | ||
100 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
101 | ||
102 | if (!ret && oact) { | |
103 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
104 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
105 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
106 | return -EFAULT; | |
107 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
108 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
109 | } | |
110 | ||
111 | return ret; | |
112 | } | |
113 | ||
3bec6ded | 114 | #ifdef CONFIG_CRUNCH |
65a5053b | 115 | static int preserve_crunch_context(struct crunch_sigframe __user *frame) |
3bec6ded LB |
116 | { |
117 | char kbuf[sizeof(*frame) + 8]; | |
118 | struct crunch_sigframe *kframe; | |
119 | ||
120 | /* the crunch context must be 64 bit aligned */ | |
121 | kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
122 | kframe->magic = CRUNCH_MAGIC; | |
123 | kframe->size = CRUNCH_STORAGE_SIZE; | |
124 | crunch_task_copy(current_thread_info(), &kframe->storage); | |
125 | return __copy_to_user(frame, kframe, sizeof(*frame)); | |
126 | } | |
127 | ||
65a5053b | 128 | static int restore_crunch_context(struct crunch_sigframe __user *frame) |
3bec6ded LB |
129 | { |
130 | char kbuf[sizeof(*frame) + 8]; | |
131 | struct crunch_sigframe *kframe; | |
132 | ||
133 | /* the crunch context must be 64 bit aligned */ | |
134 | kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
135 | if (__copy_from_user(kframe, frame, sizeof(*frame))) | |
136 | return -1; | |
137 | if (kframe->magic != CRUNCH_MAGIC || | |
138 | kframe->size != CRUNCH_STORAGE_SIZE) | |
139 | return -1; | |
140 | crunch_task_restore(current_thread_info(), &kframe->storage); | |
141 | return 0; | |
142 | } | |
143 | #endif | |
144 | ||
1da177e4 LT |
145 | #ifdef CONFIG_IWMMXT |
146 | ||
1da177e4 LT |
147 | static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) |
148 | { | |
69b04754 HD |
149 | char kbuf[sizeof(*frame) + 8]; |
150 | struct iwmmxt_sigframe *kframe; | |
1da177e4 LT |
151 | |
152 | /* the iWMMXt context must be 64 bit aligned */ | |
69b04754 | 153 | kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); |
85fe0681 DJ |
154 | kframe->magic = IWMMXT_MAGIC; |
155 | kframe->size = IWMMXT_STORAGE_SIZE; | |
69b04754 HD |
156 | iwmmxt_task_copy(current_thread_info(), &kframe->storage); |
157 | return __copy_to_user(frame, kframe, sizeof(*frame)); | |
1da177e4 LT |
158 | } |
159 | ||
160 | static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) | |
161 | { | |
69b04754 HD |
162 | char kbuf[sizeof(*frame) + 8]; |
163 | struct iwmmxt_sigframe *kframe; | |
164 | ||
165 | /* the iWMMXt context must be 64 bit aligned */ | |
166 | kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); | |
167 | if (__copy_from_user(kframe, frame, sizeof(*frame))) | |
168 | return -1; | |
85fe0681 DJ |
169 | if (kframe->magic != IWMMXT_MAGIC || |
170 | kframe->size != IWMMXT_STORAGE_SIZE) | |
69b04754 HD |
171 | return -1; |
172 | iwmmxt_task_restore(current_thread_info(), &kframe->storage); | |
173 | return 0; | |
1da177e4 LT |
174 | } |
175 | ||
176 | #endif | |
177 | ||
82c6f5a5 ID |
178 | #ifdef CONFIG_VFP |
179 | ||
180 | static int preserve_vfp_context(struct vfp_sigframe __user *frame) | |
181 | { | |
182 | struct thread_info *thread = current_thread_info(); | |
183 | struct vfp_hard_struct *h = &thread->vfpstate.hard; | |
184 | const unsigned long magic = VFP_MAGIC; | |
185 | const unsigned long size = VFP_STORAGE_SIZE; | |
186 | int err = 0; | |
187 | ||
188 | vfp_sync_hwstate(thread); | |
189 | __put_user_error(magic, &frame->magic, err); | |
190 | __put_user_error(size, &frame->size, err); | |
191 | ||
192 | /* | |
193 | * Copy the floating point registers. There can be unused | |
194 | * registers see asm/hwcap.h for details. | |
195 | */ | |
196 | err |= __copy_to_user(&frame->ufp.fpregs, &h->fpregs, | |
197 | sizeof(h->fpregs)); | |
198 | /* | |
199 | * Copy the status and control register. | |
200 | */ | |
201 | __put_user_error(h->fpscr, &frame->ufp.fpscr, err); | |
202 | ||
203 | /* | |
204 | * Copy the exception registers. | |
205 | */ | |
206 | __put_user_error(h->fpexc, &frame->ufp_exc.fpexc, err); | |
207 | __put_user_error(h->fpinst, &frame->ufp_exc.fpinst, err); | |
208 | __put_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err); | |
209 | ||
210 | return err ? -EFAULT : 0; | |
211 | } | |
212 | ||
213 | static int restore_vfp_context(struct vfp_sigframe __user *frame) | |
214 | { | |
215 | struct thread_info *thread = current_thread_info(); | |
216 | struct vfp_hard_struct *h = &thread->vfpstate.hard; | |
217 | unsigned long magic; | |
218 | unsigned long size; | |
219 | unsigned long fpexc; | |
220 | int err = 0; | |
221 | ||
222 | __get_user_error(magic, &frame->magic, err); | |
223 | __get_user_error(size, &frame->size, err); | |
224 | ||
225 | if (err) | |
226 | return -EFAULT; | |
227 | if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE) | |
228 | return -EINVAL; | |
229 | ||
230 | /* | |
231 | * Copy the floating point registers. There can be unused | |
232 | * registers see asm/hwcap.h for details. | |
233 | */ | |
234 | err |= __copy_from_user(&h->fpregs, &frame->ufp.fpregs, | |
235 | sizeof(h->fpregs)); | |
236 | /* | |
237 | * Copy the status and control register. | |
238 | */ | |
239 | __get_user_error(h->fpscr, &frame->ufp.fpscr, err); | |
240 | ||
241 | /* | |
242 | * Sanitise and restore the exception registers. | |
243 | */ | |
244 | __get_user_error(fpexc, &frame->ufp_exc.fpexc, err); | |
245 | /* Ensure the VFP is enabled. */ | |
246 | fpexc |= FPEXC_EN; | |
247 | /* Ensure FPINST2 is invalid and the exception flag is cleared. */ | |
248 | fpexc &= ~(FPEXC_EX | FPEXC_FP2V); | |
249 | h->fpexc = fpexc; | |
250 | ||
251 | __get_user_error(h->fpinst, &frame->ufp_exc.fpinst, err); | |
252 | __get_user_error(h->fpinst2, &frame->ufp_exc.fpinst2, err); | |
253 | ||
254 | if (!err) | |
255 | vfp_flush_hwstate(thread); | |
256 | ||
257 | return err ? -EFAULT : 0; | |
258 | } | |
259 | ||
260 | #endif | |
261 | ||
1da177e4 LT |
262 | /* |
263 | * Do a signal return; undo the signal stack. These are aligned to 64-bit. | |
264 | */ | |
265 | struct sigframe { | |
7d4fdc19 | 266 | struct ucontext uc; |
fcca538b | 267 | unsigned long retcode[2]; |
1da177e4 LT |
268 | }; |
269 | ||
270 | struct rt_sigframe { | |
1da177e4 | 271 | struct siginfo info; |
cb3504e8 | 272 | struct sigframe sig; |
1da177e4 LT |
273 | }; |
274 | ||
68071484 | 275 | static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) |
1da177e4 | 276 | { |
85fe0681 | 277 | struct aux_sigframe __user *aux; |
68071484 RK |
278 | sigset_t set; |
279 | int err; | |
280 | ||
281 | err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); | |
282 | if (err == 0) { | |
283 | sigdelsetmask(&set, ~_BLOCKABLE); | |
284 | spin_lock_irq(¤t->sighand->siglock); | |
285 | current->blocked = set; | |
286 | recalc_sigpending(); | |
287 | spin_unlock_irq(¤t->sighand->siglock); | |
288 | } | |
1da177e4 | 289 | |
68071484 RK |
290 | __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); |
291 | __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); | |
292 | __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); | |
293 | __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); | |
294 | __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); | |
295 | __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); | |
296 | __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); | |
297 | __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); | |
298 | __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); | |
299 | __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); | |
300 | __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); | |
301 | __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); | |
302 | __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); | |
303 | __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); | |
304 | __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); | |
305 | __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); | |
306 | __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); | |
1da177e4 LT |
307 | |
308 | err |= !valid_user_regs(regs); | |
309 | ||
85fe0681 | 310 | aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; |
3bec6ded LB |
311 | #ifdef CONFIG_CRUNCH |
312 | if (err == 0) | |
313 | err |= restore_crunch_context(&aux->crunch); | |
314 | #endif | |
1da177e4 LT |
315 | #ifdef CONFIG_IWMMXT |
316 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
317 | err |= restore_iwmmxt_context(&aux->iwmmxt); | |
318 | #endif | |
319 | #ifdef CONFIG_VFP | |
82c6f5a5 ID |
320 | if (err == 0) |
321 | err |= restore_vfp_context(&aux->vfp); | |
1da177e4 LT |
322 | #endif |
323 | ||
324 | return err; | |
325 | } | |
326 | ||
327 | asmlinkage int sys_sigreturn(struct pt_regs *regs) | |
328 | { | |
329 | struct sigframe __user *frame; | |
1da177e4 LT |
330 | |
331 | /* Always make any pending restarted system calls return -EINTR */ | |
332 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
333 | ||
334 | /* | |
335 | * Since we stacked the signal on a 64-bit boundary, | |
336 | * then 'sp' should be word aligned here. If it's | |
337 | * not, then the user is trying to mess with us. | |
338 | */ | |
339 | if (regs->ARM_sp & 7) | |
340 | goto badframe; | |
341 | ||
342 | frame = (struct sigframe __user *)regs->ARM_sp; | |
343 | ||
344 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
345 | goto badframe; | |
1da177e4 | 346 | |
68071484 | 347 | if (restore_sigframe(regs, frame)) |
1da177e4 LT |
348 | goto badframe; |
349 | ||
1da177e4 LT |
350 | return regs->ARM_r0; |
351 | ||
352 | badframe: | |
353 | force_sig(SIGSEGV, current); | |
354 | return 0; | |
355 | } | |
356 | ||
357 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) | |
358 | { | |
359 | struct rt_sigframe __user *frame; | |
1da177e4 LT |
360 | |
361 | /* Always make any pending restarted system calls return -EINTR */ | |
362 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
363 | ||
364 | /* | |
365 | * Since we stacked the signal on a 64-bit boundary, | |
366 | * then 'sp' should be word aligned here. If it's | |
367 | * not, then the user is trying to mess with us. | |
368 | */ | |
369 | if (regs->ARM_sp & 7) | |
370 | goto badframe; | |
371 | ||
372 | frame = (struct rt_sigframe __user *)regs->ARM_sp; | |
373 | ||
374 | if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) | |
375 | goto badframe; | |
1da177e4 | 376 | |
68071484 | 377 | if (restore_sigframe(regs, &frame->sig)) |
1da177e4 LT |
378 | goto badframe; |
379 | ||
cb3504e8 | 380 | if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT) |
1da177e4 LT |
381 | goto badframe; |
382 | ||
1da177e4 LT |
383 | return regs->ARM_r0; |
384 | ||
385 | badframe: | |
386 | force_sig(SIGSEGV, current); | |
387 | return 0; | |
388 | } | |
389 | ||
390 | static int | |
aca6ca10 | 391 | setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set) |
1da177e4 | 392 | { |
85fe0681 | 393 | struct aux_sigframe __user *aux; |
1da177e4 LT |
394 | int err = 0; |
395 | ||
aca6ca10 RK |
396 | __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); |
397 | __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); | |
398 | __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); | |
399 | __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); | |
400 | __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); | |
401 | __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); | |
402 | __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); | |
403 | __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); | |
404 | __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); | |
405 | __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); | |
406 | __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); | |
407 | __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); | |
408 | __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); | |
409 | __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); | |
410 | __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); | |
411 | __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); | |
412 | __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); | |
413 | ||
414 | __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err); | |
415 | __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err); | |
416 | __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err); | |
417 | __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err); | |
418 | ||
419 | err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); | |
1da177e4 | 420 | |
85fe0681 | 421 | aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; |
3bec6ded LB |
422 | #ifdef CONFIG_CRUNCH |
423 | if (err == 0) | |
424 | err |= preserve_crunch_context(&aux->crunch); | |
425 | #endif | |
1da177e4 LT |
426 | #ifdef CONFIG_IWMMXT |
427 | if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) | |
428 | err |= preserve_iwmmxt_context(&aux->iwmmxt); | |
429 | #endif | |
430 | #ifdef CONFIG_VFP | |
82c6f5a5 ID |
431 | if (err == 0) |
432 | err |= preserve_vfp_context(&aux->vfp); | |
1da177e4 | 433 | #endif |
85fe0681 | 434 | __put_user_error(0, &aux->end_magic, err); |
1da177e4 LT |
435 | |
436 | return err; | |
437 | } | |
438 | ||
439 | static inline void __user * | |
440 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) | |
441 | { | |
442 | unsigned long sp = regs->ARM_sp; | |
443 | void __user *frame; | |
444 | ||
445 | /* | |
446 | * This is the X/Open sanctioned signal stack switching. | |
447 | */ | |
448 | if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) | |
449 | sp = current->sas_ss_sp + current->sas_ss_size; | |
450 | ||
451 | /* | |
452 | * ATPCS B01 mandates 8-byte alignment | |
453 | */ | |
454 | frame = (void __user *)((sp - framesize) & ~7); | |
455 | ||
456 | /* | |
457 | * Check that we can actually write to the signal frame. | |
458 | */ | |
459 | if (!access_ok(VERIFY_WRITE, frame, framesize)) | |
460 | frame = NULL; | |
461 | ||
462 | return frame; | |
463 | } | |
464 | ||
465 | static int | |
466 | setup_return(struct pt_regs *regs, struct k_sigaction *ka, | |
467 | unsigned long __user *rc, void __user *frame, int usig) | |
468 | { | |
469 | unsigned long handler = (unsigned long)ka->sa.sa_handler; | |
470 | unsigned long retcode; | |
471 | int thumb = 0; | |
53399053 RK |
472 | unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT); |
473 | ||
474 | cpsr |= PSR_ENDSTATE; | |
1da177e4 LT |
475 | |
476 | /* | |
477 | * Maybe we need to deliver a 32-bit signal to a 26-bit task. | |
478 | */ | |
479 | if (ka->sa.sa_flags & SA_THIRTYTWO) | |
480 | cpsr = (cpsr & ~MODE_MASK) | USR_MODE; | |
481 | ||
482 | #ifdef CONFIG_ARM_THUMB | |
483 | if (elf_hwcap & HWCAP_THUMB) { | |
484 | /* | |
485 | * The LSB of the handler determines if we're going to | |
486 | * be using THUMB or ARM mode for this signal handler. | |
487 | */ | |
488 | thumb = handler & 1; | |
489 | ||
d71e1352 | 490 | if (thumb) { |
1da177e4 | 491 | cpsr |= PSR_T_BIT; |
d71e1352 CM |
492 | #if __LINUX_ARM_ARCH__ >= 7 |
493 | /* clear the If-Then Thumb-2 execution state */ | |
494 | cpsr &= ~PSR_IT_MASK; | |
495 | #endif | |
496 | } else | |
1da177e4 LT |
497 | cpsr &= ~PSR_T_BIT; |
498 | } | |
499 | #endif | |
500 | ||
501 | if (ka->sa.sa_flags & SA_RESTORER) { | |
502 | retcode = (unsigned long)ka->sa.sa_restorer; | |
503 | } else { | |
fcca538b | 504 | unsigned int idx = thumb << 1; |
1da177e4 LT |
505 | |
506 | if (ka->sa.sa_flags & SA_SIGINFO) | |
fcca538b | 507 | idx += 3; |
1da177e4 | 508 | |
fcca538b NP |
509 | if (__put_user(sigreturn_codes[idx], rc) || |
510 | __put_user(sigreturn_codes[idx+1], rc+1)) | |
1da177e4 LT |
511 | return 1; |
512 | ||
e00d349e RK |
513 | if (cpsr & MODE32_BIT) { |
514 | /* | |
515 | * 32-bit code can use the new high-page | |
516 | * signal return code support. | |
517 | */ | |
518 | retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb; | |
519 | } else { | |
520 | /* | |
521 | * Ensure that the instruction cache sees | |
522 | * the return code written onto the stack. | |
523 | */ | |
524 | flush_icache_range((unsigned long)rc, | |
fcca538b | 525 | (unsigned long)(rc + 2)); |
e00d349e RK |
526 | |
527 | retcode = ((unsigned long)rc) + thumb; | |
528 | } | |
1da177e4 LT |
529 | } |
530 | ||
531 | regs->ARM_r0 = usig; | |
532 | regs->ARM_sp = (unsigned long)frame; | |
533 | regs->ARM_lr = retcode; | |
534 | regs->ARM_pc = handler; | |
535 | regs->ARM_cpsr = cpsr; | |
536 | ||
537 | return 0; | |
538 | } | |
539 | ||
540 | static int | |
541 | setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) | |
542 | { | |
543 | struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
544 | int err = 0; | |
545 | ||
546 | if (!frame) | |
547 | return 1; | |
548 | ||
ca195cfe RK |
549 | /* |
550 | * Set uc.uc_flags to a value which sc.trap_no would never have. | |
551 | */ | |
552 | __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err); | |
1da177e4 | 553 | |
aca6ca10 | 554 | err |= setup_sigframe(frame, regs, set); |
1da177e4 | 555 | if (err == 0) |
fcca538b | 556 | err = setup_return(regs, ka, frame->retcode, frame, usig); |
1da177e4 LT |
557 | |
558 | return err; | |
559 | } | |
560 | ||
561 | static int | |
562 | setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, | |
563 | sigset_t *set, struct pt_regs *regs) | |
564 | { | |
565 | struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
566 | stack_t stack; | |
567 | int err = 0; | |
568 | ||
569 | if (!frame) | |
570 | return 1; | |
571 | ||
1da177e4 LT |
572 | err |= copy_siginfo_to_user(&frame->info, info); |
573 | ||
cb3504e8 RK |
574 | __put_user_error(0, &frame->sig.uc.uc_flags, err); |
575 | __put_user_error(NULL, &frame->sig.uc.uc_link, err); | |
1da177e4 LT |
576 | |
577 | memset(&stack, 0, sizeof(stack)); | |
578 | stack.ss_sp = (void __user *)current->sas_ss_sp; | |
579 | stack.ss_flags = sas_ss_flags(regs->ARM_sp); | |
580 | stack.ss_size = current->sas_ss_size; | |
cb3504e8 | 581 | err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack)); |
1da177e4 | 582 | |
aca6ca10 | 583 | err |= setup_sigframe(&frame->sig, regs, set); |
1da177e4 | 584 | if (err == 0) |
cb3504e8 | 585 | err = setup_return(regs, ka, frame->sig.retcode, frame, usig); |
1da177e4 LT |
586 | |
587 | if (err == 0) { | |
588 | /* | |
589 | * For realtime signals we must also set the second and third | |
590 | * arguments for the signal handler. | |
591 | * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06 | |
592 | */ | |
593 | regs->ARM_r1 = (unsigned long)&frame->info; | |
cb3504e8 | 594 | regs->ARM_r2 = (unsigned long)&frame->sig.uc; |
1da177e4 LT |
595 | } |
596 | ||
597 | return err; | |
598 | } | |
599 | ||
1da177e4 LT |
600 | /* |
601 | * OK, we're invoking a handler | |
602 | */ | |
36984265 | 603 | static int |
1da177e4 LT |
604 | handle_signal(unsigned long sig, struct k_sigaction *ka, |
605 | siginfo_t *info, sigset_t *oldset, | |
2af68df0 | 606 | struct pt_regs * regs) |
1da177e4 LT |
607 | { |
608 | struct thread_info *thread = current_thread_info(); | |
609 | struct task_struct *tsk = current; | |
610 | int usig = sig; | |
611 | int ret; | |
612 | ||
1da177e4 LT |
613 | /* |
614 | * translate the signal | |
615 | */ | |
616 | if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) | |
617 | usig = thread->exec_domain->signal_invmap[usig]; | |
618 | ||
619 | /* | |
620 | * Set up the stack frame | |
621 | */ | |
622 | if (ka->sa.sa_flags & SA_SIGINFO) | |
623 | ret = setup_rt_frame(usig, ka, info, oldset, regs); | |
624 | else | |
625 | ret = setup_frame(usig, ka, oldset, regs); | |
626 | ||
627 | /* | |
628 | * Check that the resulting registers are actually sane. | |
629 | */ | |
630 | ret |= !valid_user_regs(regs); | |
631 | ||
69be8f18 | 632 | if (ret != 0) { |
a6c61e9d | 633 | force_sigsegv(sig, tsk); |
36984265 | 634 | return ret; |
1da177e4 LT |
635 | } |
636 | ||
a6c61e9d DJ |
637 | /* |
638 | * Block the signal if we were successful. | |
639 | */ | |
640 | spin_lock_irq(&tsk->sighand->siglock); | |
641 | sigorsets(&tsk->blocked, &tsk->blocked, | |
642 | &ka->sa.sa_mask); | |
643 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
644 | sigaddset(&tsk->blocked, sig); | |
645 | recalc_sigpending(); | |
646 | spin_unlock_irq(&tsk->sighand->siglock); | |
1da177e4 | 647 | |
36984265 | 648 | return 0; |
1da177e4 LT |
649 | } |
650 | ||
651 | /* | |
652 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
653 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
654 | * mistake. | |
655 | * | |
656 | * Note that we go through the signals twice: once to check the signals that | |
657 | * the kernel can handle, and then we build all the user-level signal handling | |
658 | * stack-frames in one go after that. | |
659 | */ | |
36984265 | 660 | static void do_signal(struct pt_regs *regs, int syscall) |
1da177e4 | 661 | { |
2af68df0 | 662 | unsigned int retval = 0, continue_addr = 0, restart_addr = 0; |
1da177e4 LT |
663 | struct k_sigaction ka; |
664 | siginfo_t info; | |
665 | int signr; | |
666 | ||
667 | /* | |
668 | * We want the common case to go fast, which | |
669 | * is why we may in certain cases get here from | |
670 | * kernel mode. Just return without doing anything | |
671 | * if so. | |
672 | */ | |
673 | if (!user_mode(regs)) | |
36984265 | 674 | return; |
1da177e4 | 675 | |
2af68df0 AB |
676 | /* |
677 | * If we were from a system call, check for system call restarting... | |
678 | */ | |
679 | if (syscall) { | |
680 | continue_addr = regs->ARM_pc; | |
681 | restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4); | |
682 | retval = regs->ARM_r0; | |
683 | ||
684 | /* | |
685 | * Prepare for system call restart. We do this here so that a | |
686 | * debugger will see the already changed PSW. | |
687 | */ | |
688 | switch (retval) { | |
689 | case -ERESTARTNOHAND: | |
690 | case -ERESTARTSYS: | |
691 | case -ERESTARTNOINTR: | |
692 | regs->ARM_r0 = regs->ARM_ORIG_r0; | |
693 | regs->ARM_pc = restart_addr; | |
694 | break; | |
695 | case -ERESTART_RESTARTBLOCK: | |
696 | regs->ARM_r0 = -EINTR; | |
697 | break; | |
698 | } | |
699 | } | |
700 | ||
bdb94f3a | 701 | if (try_to_freeze()) |
1da177e4 LT |
702 | goto no_signal; |
703 | ||
2af68df0 AB |
704 | /* |
705 | * Get the signal to deliver. When running under ptrace, at this | |
706 | * point the debugger may change all our registers ... | |
707 | */ | |
1da177e4 LT |
708 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
709 | if (signr > 0) { | |
36984265 MP |
710 | sigset_t *oldset; |
711 | ||
2af68df0 AB |
712 | /* |
713 | * Depending on the signal settings we may need to revert the | |
714 | * decision to restart the system call. But skip this if a | |
715 | * debugger has chosen to restart at a different PC. | |
716 | */ | |
717 | if (regs->ARM_pc == restart_addr) { | |
718 | if (retval == -ERESTARTNOHAND | |
719 | || (retval == -ERESTARTSYS | |
720 | && !(ka.sa.sa_flags & SA_RESTART))) { | |
721 | regs->ARM_r0 = -EINTR; | |
722 | regs->ARM_pc = continue_addr; | |
723 | } | |
724 | } | |
725 | ||
36984265 MP |
726 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
727 | oldset = ¤t->saved_sigmask; | |
728 | else | |
729 | oldset = ¤t->blocked; | |
2af68df0 | 730 | if (handle_signal(signr, &ka, &info, oldset, regs) == 0) { |
36984265 MP |
731 | /* |
732 | * A signal was successfully delivered; the saved | |
733 | * sigmask will have been stored in the signal frame, | |
734 | * and will be restored by sigreturn, so we can simply | |
735 | * clear the TIF_RESTORE_SIGMASK flag. | |
736 | */ | |
737 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) | |
738 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
739 | } | |
36984265 | 740 | return; |
1da177e4 LT |
741 | } |
742 | ||
743 | no_signal: | |
1da177e4 | 744 | if (syscall) { |
2af68df0 AB |
745 | /* |
746 | * Handle restarting a different system call. As above, | |
747 | * if a debugger has chosen to restart at a different PC, | |
748 | * ignore the restart. | |
749 | */ | |
750 | if (retval == -ERESTART_RESTARTBLOCK | |
751 | && regs->ARM_pc == continue_addr) { | |
1da177e4 | 752 | if (thumb_mode(regs)) { |
f606a6ff | 753 | regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE; |
1da177e4 LT |
754 | regs->ARM_pc -= 2; |
755 | } else { | |
f606a6ff NP |
756 | #if defined(CONFIG_AEABI) && !defined(CONFIG_OABI_COMPAT) |
757 | regs->ARM_r7 = __NR_restart_syscall; | |
758 | regs->ARM_pc -= 4; | |
759 | #else | |
1da177e4 LT |
760 | u32 __user *usp; |
761 | ||
ab72b007 | 762 | regs->ARM_sp -= 4; |
1da177e4 LT |
763 | usp = (u32 __user *)regs->ARM_sp; |
764 | ||
3336f4f0 JP |
765 | if (put_user(regs->ARM_pc, usp) == 0) { |
766 | regs->ARM_pc = KERN_RESTART_CODE; | |
767 | } else { | |
768 | regs->ARM_sp += 4; | |
769 | force_sigsegv(0, current); | |
770 | } | |
f606a6ff | 771 | #endif |
1da177e4 LT |
772 | } |
773 | } | |
36984265 MP |
774 | |
775 | /* If there's no signal to deliver, we just put the saved sigmask | |
776 | * back. | |
777 | */ | |
778 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { | |
779 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
780 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
781 | } | |
1da177e4 | 782 | } |
1da177e4 LT |
783 | } |
784 | ||
785 | asmlinkage void | |
786 | do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) | |
787 | { | |
788 | if (thread_flags & _TIF_SIGPENDING) | |
36984265 | 789 | do_signal(regs, syscall); |
d0420c83 DH |
790 | |
791 | if (thread_flags & _TIF_NOTIFY_RESUME) { | |
792 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
793 | tracehook_notify_resume(regs); | |
ee18d64c DH |
794 | if (current->replacement_session_keyring) |
795 | key_replace_session_keyring(); | |
d0420c83 | 796 | } |
1da177e4 | 797 | } |