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f864d2f8 G |
1 | /* |
2 | * linux/arch/unicore32/kernel/signal.c | |
3 | * | |
4 | * Code specific to PKUnity SoC and UniCore ISA | |
5 | * | |
6 | * Copyright (C) 2001-2010 GUAN Xue-tao | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | #include <linux/errno.h> | |
13 | #include <linux/signal.h> | |
14 | #include <linux/personality.h> | |
15 | #include <linux/freezer.h> | |
16 | #include <linux/uaccess.h> | |
17 | #include <linux/tracehook.h> | |
18 | #include <linux/elf.h> | |
19 | #include <linux/unistd.h> | |
20 | ||
21 | #include <asm/cacheflush.h> | |
22 | #include <asm/ucontext.h> | |
23 | ||
24 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
25 | ||
26 | /* | |
27 | * For UniCore syscalls, we encode the syscall number into the instruction. | |
28 | */ | |
29 | #define SWI_SYS_SIGRETURN (0xff000000) /* error number for new abi */ | |
30 | #define SWI_SYS_RT_SIGRETURN (0xff000000 | (__NR_rt_sigreturn)) | |
31 | #define SWI_SYS_RESTART (0xff000000 | (__NR_restart_syscall)) | |
32 | ||
33 | #define KERN_SIGRETURN_CODE (KUSER_VECPAGE_BASE + 0x00000500) | |
34 | #define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes)) | |
35 | ||
36 | const unsigned long sigreturn_codes[3] = { | |
37 | SWI_SYS_SIGRETURN, SWI_SYS_RT_SIGRETURN, | |
38 | }; | |
39 | ||
40 | const unsigned long syscall_restart_code[2] = { | |
41 | SWI_SYS_RESTART, /* swi __NR_restart_syscall */ | |
42 | 0x69efc004, /* ldr pc, [sp], #4 */ | |
43 | }; | |
44 | ||
45 | /* | |
46 | * Do a signal return; undo the signal stack. These are aligned to 64-bit. | |
47 | */ | |
48 | struct sigframe { | |
49 | struct ucontext uc; | |
50 | unsigned long retcode[2]; | |
51 | }; | |
52 | ||
53 | struct rt_sigframe { | |
54 | struct siginfo info; | |
55 | struct sigframe sig; | |
56 | }; | |
57 | ||
58 | static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) | |
59 | { | |
60 | sigset_t set; | |
61 | int err; | |
62 | ||
63 | err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); | |
64 | if (err == 0) { | |
65 | sigdelsetmask(&set, ~_BLOCKABLE); | |
7037bd80 | 66 | set_current_blocked(&set); |
f864d2f8 G |
67 | } |
68 | ||
69 | err |= __get_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00); | |
70 | err |= __get_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01); | |
71 | err |= __get_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02); | |
72 | err |= __get_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03); | |
73 | err |= __get_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04); | |
74 | err |= __get_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05); | |
75 | err |= __get_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06); | |
76 | err |= __get_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07); | |
77 | err |= __get_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08); | |
78 | err |= __get_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09); | |
79 | err |= __get_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10); | |
80 | err |= __get_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11); | |
81 | err |= __get_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12); | |
82 | err |= __get_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13); | |
83 | err |= __get_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14); | |
84 | err |= __get_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15); | |
85 | err |= __get_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16); | |
86 | err |= __get_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17); | |
87 | err |= __get_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18); | |
88 | err |= __get_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19); | |
89 | err |= __get_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20); | |
90 | err |= __get_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21); | |
91 | err |= __get_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22); | |
92 | err |= __get_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23); | |
93 | err |= __get_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24); | |
94 | err |= __get_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25); | |
95 | err |= __get_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26); | |
96 | err |= __get_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp); | |
97 | err |= __get_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip); | |
98 | err |= __get_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp); | |
99 | err |= __get_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr); | |
100 | err |= __get_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc); | |
101 | err |= __get_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr); | |
102 | ||
103 | err |= !valid_user_regs(regs); | |
104 | ||
105 | return err; | |
106 | } | |
107 | ||
108 | asmlinkage int __sys_rt_sigreturn(struct pt_regs *regs) | |
109 | { | |
110 | struct rt_sigframe __user *frame; | |
111 | ||
112 | /* Always make any pending restarted system calls return -EINTR */ | |
113 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
114 | ||
115 | /* | |
116 | * Since we stacked the signal on a 64-bit boundary, | |
117 | * then 'sp' should be word aligned here. If it's | |
118 | * not, then the user is trying to mess with us. | |
119 | */ | |
120 | if (regs->UCreg_sp & 7) | |
121 | goto badframe; | |
122 | ||
123 | frame = (struct rt_sigframe __user *)regs->UCreg_sp; | |
124 | ||
125 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
126 | goto badframe; | |
127 | ||
128 | if (restore_sigframe(regs, &frame->sig)) | |
129 | goto badframe; | |
130 | ||
131 | if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->UCreg_sp) | |
132 | == -EFAULT) | |
133 | goto badframe; | |
134 | ||
135 | return regs->UCreg_00; | |
136 | ||
137 | badframe: | |
138 | force_sig(SIGSEGV, current); | |
139 | return 0; | |
140 | } | |
141 | ||
142 | static int setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, | |
143 | sigset_t *set) | |
144 | { | |
145 | int err = 0; | |
146 | ||
147 | err |= __put_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00); | |
148 | err |= __put_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01); | |
149 | err |= __put_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02); | |
150 | err |= __put_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03); | |
151 | err |= __put_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04); | |
152 | err |= __put_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05); | |
153 | err |= __put_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06); | |
154 | err |= __put_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07); | |
155 | err |= __put_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08); | |
156 | err |= __put_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09); | |
157 | err |= __put_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10); | |
158 | err |= __put_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11); | |
159 | err |= __put_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12); | |
160 | err |= __put_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13); | |
161 | err |= __put_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14); | |
162 | err |= __put_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15); | |
163 | err |= __put_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16); | |
164 | err |= __put_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17); | |
165 | err |= __put_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18); | |
166 | err |= __put_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19); | |
167 | err |= __put_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20); | |
168 | err |= __put_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21); | |
169 | err |= __put_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22); | |
170 | err |= __put_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23); | |
171 | err |= __put_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24); | |
172 | err |= __put_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25); | |
173 | err |= __put_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26); | |
174 | err |= __put_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp); | |
175 | err |= __put_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip); | |
176 | err |= __put_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp); | |
177 | err |= __put_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr); | |
178 | err |= __put_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc); | |
179 | err |= __put_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr); | |
180 | ||
181 | err |= __put_user(current->thread.trap_no, | |
182 | &sf->uc.uc_mcontext.trap_no); | |
183 | err |= __put_user(current->thread.error_code, | |
184 | &sf->uc.uc_mcontext.error_code); | |
185 | err |= __put_user(current->thread.address, | |
186 | &sf->uc.uc_mcontext.fault_address); | |
187 | err |= __put_user(set->sig[0], &sf->uc.uc_mcontext.oldmask); | |
188 | ||
189 | err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); | |
190 | ||
191 | return err; | |
192 | } | |
193 | ||
194 | static inline void __user *get_sigframe(struct k_sigaction *ka, | |
195 | struct pt_regs *regs, int framesize) | |
196 | { | |
197 | unsigned long sp = regs->UCreg_sp; | |
198 | void __user *frame; | |
199 | ||
200 | /* | |
201 | * This is the X/Open sanctioned signal stack switching. | |
202 | */ | |
203 | if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) | |
204 | sp = current->sas_ss_sp + current->sas_ss_size; | |
205 | ||
206 | /* | |
207 | * ATPCS B01 mandates 8-byte alignment | |
208 | */ | |
209 | frame = (void __user *)((sp - framesize) & ~7); | |
210 | ||
211 | /* | |
212 | * Check that we can actually write to the signal frame. | |
213 | */ | |
214 | if (!access_ok(VERIFY_WRITE, frame, framesize)) | |
215 | frame = NULL; | |
216 | ||
217 | return frame; | |
218 | } | |
219 | ||
220 | static int setup_return(struct pt_regs *regs, struct k_sigaction *ka, | |
221 | unsigned long __user *rc, void __user *frame, int usig) | |
222 | { | |
223 | unsigned long handler = (unsigned long)ka->sa.sa_handler; | |
224 | unsigned long retcode; | |
225 | unsigned long asr = regs->UCreg_asr & ~PSR_f; | |
226 | ||
227 | unsigned int idx = 0; | |
228 | ||
229 | if (ka->sa.sa_flags & SA_SIGINFO) | |
230 | idx += 1; | |
231 | ||
232 | if (__put_user(sigreturn_codes[idx], rc) || | |
233 | __put_user(sigreturn_codes[idx+1], rc+1)) | |
234 | return 1; | |
235 | ||
236 | retcode = KERN_SIGRETURN_CODE + (idx << 2); | |
237 | ||
238 | regs->UCreg_00 = usig; | |
239 | regs->UCreg_sp = (unsigned long)frame; | |
240 | regs->UCreg_lr = retcode; | |
241 | regs->UCreg_pc = handler; | |
242 | regs->UCreg_asr = asr; | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
247 | static int setup_frame(int usig, struct k_sigaction *ka, | |
248 | sigset_t *set, struct pt_regs *regs) | |
249 | { | |
250 | struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
251 | int err = 0; | |
252 | ||
253 | if (!frame) | |
254 | return 1; | |
255 | ||
256 | /* | |
257 | * Set uc.uc_flags to a value which sc.trap_no would never have. | |
258 | */ | |
259 | err |= __put_user(0x5ac3c35a, &frame->uc.uc_flags); | |
260 | ||
261 | err |= setup_sigframe(frame, regs, set); | |
262 | if (err == 0) | |
263 | err |= setup_return(regs, ka, frame->retcode, frame, usig); | |
264 | ||
265 | return err; | |
266 | } | |
267 | ||
268 | static int setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, | |
269 | sigset_t *set, struct pt_regs *regs) | |
270 | { | |
271 | struct rt_sigframe __user *frame = | |
272 | get_sigframe(ka, regs, sizeof(*frame)); | |
273 | stack_t stack; | |
274 | int err = 0; | |
275 | ||
276 | if (!frame) | |
277 | return 1; | |
278 | ||
279 | err |= copy_siginfo_to_user(&frame->info, info); | |
280 | ||
281 | err |= __put_user(0, &frame->sig.uc.uc_flags); | |
282 | err |= __put_user(NULL, &frame->sig.uc.uc_link); | |
283 | ||
284 | memset(&stack, 0, sizeof(stack)); | |
285 | stack.ss_sp = (void __user *)current->sas_ss_sp; | |
286 | stack.ss_flags = sas_ss_flags(regs->UCreg_sp); | |
287 | stack.ss_size = current->sas_ss_size; | |
288 | err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack)); | |
289 | ||
290 | err |= setup_sigframe(&frame->sig, regs, set); | |
291 | if (err == 0) | |
292 | err |= setup_return(regs, ka, frame->sig.retcode, frame, usig); | |
293 | ||
294 | if (err == 0) { | |
295 | /* | |
296 | * For realtime signals we must also set the second and third | |
297 | * arguments for the signal handler. | |
298 | */ | |
299 | regs->UCreg_01 = (unsigned long)&frame->info; | |
300 | regs->UCreg_02 = (unsigned long)&frame->sig.uc; | |
301 | } | |
302 | ||
303 | return err; | |
304 | } | |
305 | ||
306 | static inline void setup_syscall_restart(struct pt_regs *regs) | |
307 | { | |
308 | regs->UCreg_00 = regs->UCreg_ORIG_00; | |
309 | regs->UCreg_pc -= 4; | |
310 | } | |
311 | ||
312 | /* | |
313 | * OK, we're invoking a handler | |
314 | */ | |
a610d6e6 | 315 | static void handle_signal(unsigned long sig, struct k_sigaction *ka, |
b7f9a11a | 316 | siginfo_t *info, struct pt_regs *regs, int syscall) |
f864d2f8 G |
317 | { |
318 | struct thread_info *thread = current_thread_info(); | |
319 | struct task_struct *tsk = current; | |
b7f9a11a | 320 | sigset_t *oldset = sigmask_to_save(); |
f864d2f8 G |
321 | int usig = sig; |
322 | int ret; | |
323 | ||
324 | /* | |
325 | * If we were from a system call, check for system call restarting... | |
326 | */ | |
327 | if (syscall) { | |
328 | switch (regs->UCreg_00) { | |
329 | case -ERESTART_RESTARTBLOCK: | |
330 | case -ERESTARTNOHAND: | |
331 | regs->UCreg_00 = -EINTR; | |
332 | break; | |
333 | case -ERESTARTSYS: | |
334 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
335 | regs->UCreg_00 = -EINTR; | |
336 | break; | |
337 | } | |
338 | /* fallthrough */ | |
339 | case -ERESTARTNOINTR: | |
340 | setup_syscall_restart(regs); | |
341 | } | |
342 | } | |
343 | ||
344 | /* | |
345 | * translate the signal | |
346 | */ | |
347 | if (usig < 32 && thread->exec_domain | |
348 | && thread->exec_domain->signal_invmap) | |
349 | usig = thread->exec_domain->signal_invmap[usig]; | |
350 | ||
351 | /* | |
352 | * Set up the stack frame | |
353 | */ | |
354 | if (ka->sa.sa_flags & SA_SIGINFO) | |
355 | ret = setup_rt_frame(usig, ka, info, oldset, regs); | |
356 | else | |
357 | ret = setup_frame(usig, ka, oldset, regs); | |
358 | ||
359 | /* | |
360 | * Check that the resulting registers are actually sane. | |
361 | */ | |
362 | ret |= !valid_user_regs(regs); | |
363 | ||
364 | if (ret != 0) { | |
365 | force_sigsegv(sig, tsk); | |
a610d6e6 | 366 | return; |
f864d2f8 G |
367 | } |
368 | ||
369 | /* | |
370 | * Block the signal if we were successful. | |
371 | */ | |
9ae36796 | 372 | block_sigmask(ka, sig); |
f864d2f8 G |
373 | } |
374 | ||
375 | /* | |
376 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
377 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
378 | * mistake. | |
379 | * | |
380 | * Note that we go through the signals twice: once to check the signals that | |
381 | * the kernel can handle, and then we build all the user-level signal handling | |
382 | * stack-frames in one go after that. | |
383 | */ | |
384 | static void do_signal(struct pt_regs *regs, int syscall) | |
385 | { | |
386 | struct k_sigaction ka; | |
387 | siginfo_t info; | |
388 | int signr; | |
389 | ||
390 | /* | |
391 | * We want the common case to go fast, which | |
392 | * is why we may in certain cases get here from | |
393 | * kernel mode. Just return without doing anything | |
394 | * if so. | |
395 | */ | |
396 | if (!user_mode(regs)) | |
397 | return; | |
398 | ||
f864d2f8 G |
399 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
400 | if (signr > 0) { | |
a610d6e6 | 401 | handle_signal(signr, &ka, &info, regs, syscall); |
f864d2f8 G |
402 | return; |
403 | } | |
404 | ||
f864d2f8 G |
405 | /* |
406 | * No signal to deliver to the process - restart the syscall. | |
407 | */ | |
408 | if (syscall) { | |
409 | if (regs->UCreg_00 == -ERESTART_RESTARTBLOCK) { | |
410 | u32 __user *usp; | |
411 | ||
412 | regs->UCreg_sp -= 4; | |
413 | usp = (u32 __user *)regs->UCreg_sp; | |
414 | ||
415 | if (put_user(regs->UCreg_pc, usp) == 0) { | |
416 | regs->UCreg_pc = KERN_RESTART_CODE; | |
417 | } else { | |
418 | regs->UCreg_sp += 4; | |
419 | force_sigsegv(0, current); | |
420 | } | |
421 | } | |
422 | if (regs->UCreg_00 == -ERESTARTNOHAND || | |
423 | regs->UCreg_00 == -ERESTARTSYS || | |
424 | regs->UCreg_00 == -ERESTARTNOINTR) { | |
425 | setup_syscall_restart(regs); | |
426 | } | |
f864d2f8 | 427 | } |
415d04d0 AV |
428 | /* If there's no signal to deliver, we just put the saved |
429 | * sigmask back. | |
430 | */ | |
51a7b448 | 431 | restore_saved_sigmask(); |
f864d2f8 G |
432 | } |
433 | ||
434 | asmlinkage void do_notify_resume(struct pt_regs *regs, | |
435 | unsigned int thread_flags, int syscall) | |
436 | { | |
437 | if (thread_flags & _TIF_SIGPENDING) | |
438 | do_signal(regs, syscall); | |
439 | ||
440 | if (thread_flags & _TIF_NOTIFY_RESUME) { | |
441 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
442 | tracehook_notify_resume(regs); | |
f864d2f8 G |
443 | } |
444 | } | |
445 | ||
446 | /* | |
447 | * Copy signal return handlers into the vector page, and | |
448 | * set sigreturn to be a pointer to these. | |
449 | */ | |
450 | void __init early_signal_init(void) | |
451 | { | |
452 | memcpy((void *)kuser_vecpage_to_vectors(KERN_SIGRETURN_CODE), | |
453 | sigreturn_codes, sizeof(sigreturn_codes)); | |
454 | memcpy((void *)kuser_vecpage_to_vectors(KERN_RESTART_CODE), | |
455 | syscall_restart_code, sizeof(syscall_restart_code)); | |
456 | /* Need not to flush icache, since early_trap_init will do it last. */ | |
457 | } |