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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> | |
f864d2f8 G |
15 | #include <linux/uaccess.h> |
16 | #include <linux/tracehook.h> | |
17 | #include <linux/elf.h> | |
18 | #include <linux/unistd.h> | |
19 | ||
20 | #include <asm/cacheflush.h> | |
21 | #include <asm/ucontext.h> | |
22 | ||
f864d2f8 G |
23 | /* |
24 | * For UniCore syscalls, we encode the syscall number into the instruction. | |
25 | */ | |
26 | #define SWI_SYS_SIGRETURN (0xff000000) /* error number for new abi */ | |
27 | #define SWI_SYS_RT_SIGRETURN (0xff000000 | (__NR_rt_sigreturn)) | |
28 | #define SWI_SYS_RESTART (0xff000000 | (__NR_restart_syscall)) | |
29 | ||
30 | #define KERN_SIGRETURN_CODE (KUSER_VECPAGE_BASE + 0x00000500) | |
31 | #define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes)) | |
32 | ||
33 | const unsigned long sigreturn_codes[3] = { | |
34 | SWI_SYS_SIGRETURN, SWI_SYS_RT_SIGRETURN, | |
35 | }; | |
36 | ||
37 | const unsigned long syscall_restart_code[2] = { | |
38 | SWI_SYS_RESTART, /* swi __NR_restart_syscall */ | |
39 | 0x69efc004, /* ldr pc, [sp], #4 */ | |
40 | }; | |
41 | ||
42 | /* | |
43 | * Do a signal return; undo the signal stack. These are aligned to 64-bit. | |
44 | */ | |
45 | struct sigframe { | |
46 | struct ucontext uc; | |
47 | unsigned long retcode[2]; | |
48 | }; | |
49 | ||
50 | struct rt_sigframe { | |
51 | struct siginfo info; | |
52 | struct sigframe sig; | |
53 | }; | |
54 | ||
55 | static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) | |
56 | { | |
57 | sigset_t set; | |
58 | int err; | |
59 | ||
60 | err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); | |
77097ae5 | 61 | if (err == 0) |
7037bd80 | 62 | set_current_blocked(&set); |
f864d2f8 G |
63 | |
64 | err |= __get_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00); | |
65 | err |= __get_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01); | |
66 | err |= __get_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02); | |
67 | err |= __get_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03); | |
68 | err |= __get_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04); | |
69 | err |= __get_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05); | |
70 | err |= __get_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06); | |
71 | err |= __get_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07); | |
72 | err |= __get_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08); | |
73 | err |= __get_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09); | |
74 | err |= __get_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10); | |
75 | err |= __get_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11); | |
76 | err |= __get_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12); | |
77 | err |= __get_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13); | |
78 | err |= __get_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14); | |
79 | err |= __get_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15); | |
80 | err |= __get_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16); | |
81 | err |= __get_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17); | |
82 | err |= __get_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18); | |
83 | err |= __get_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19); | |
84 | err |= __get_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20); | |
85 | err |= __get_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21); | |
86 | err |= __get_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22); | |
87 | err |= __get_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23); | |
88 | err |= __get_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24); | |
89 | err |= __get_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25); | |
90 | err |= __get_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26); | |
91 | err |= __get_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp); | |
92 | err |= __get_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip); | |
93 | err |= __get_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp); | |
94 | err |= __get_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr); | |
95 | err |= __get_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc); | |
96 | err |= __get_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr); | |
97 | ||
98 | err |= !valid_user_regs(regs); | |
99 | ||
100 | return err; | |
101 | } | |
102 | ||
103 | asmlinkage int __sys_rt_sigreturn(struct pt_regs *regs) | |
104 | { | |
105 | struct rt_sigframe __user *frame; | |
106 | ||
107 | /* Always make any pending restarted system calls return -EINTR */ | |
108 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
109 | ||
110 | /* | |
111 | * Since we stacked the signal on a 64-bit boundary, | |
112 | * then 'sp' should be word aligned here. If it's | |
113 | * not, then the user is trying to mess with us. | |
114 | */ | |
115 | if (regs->UCreg_sp & 7) | |
116 | goto badframe; | |
117 | ||
118 | frame = (struct rt_sigframe __user *)regs->UCreg_sp; | |
119 | ||
120 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
121 | goto badframe; | |
122 | ||
123 | if (restore_sigframe(regs, &frame->sig)) | |
124 | goto badframe; | |
125 | ||
50b3c9e3 | 126 | if (restore_altstack(&frame->sig.uc.uc_stack)) |
f864d2f8 G |
127 | goto badframe; |
128 | ||
129 | return regs->UCreg_00; | |
130 | ||
131 | badframe: | |
132 | force_sig(SIGSEGV, current); | |
133 | return 0; | |
134 | } | |
135 | ||
136 | static int setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, | |
137 | sigset_t *set) | |
138 | { | |
139 | int err = 0; | |
140 | ||
141 | err |= __put_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00); | |
142 | err |= __put_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01); | |
143 | err |= __put_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02); | |
144 | err |= __put_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03); | |
145 | err |= __put_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04); | |
146 | err |= __put_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05); | |
147 | err |= __put_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06); | |
148 | err |= __put_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07); | |
149 | err |= __put_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08); | |
150 | err |= __put_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09); | |
151 | err |= __put_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10); | |
152 | err |= __put_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11); | |
153 | err |= __put_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12); | |
154 | err |= __put_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13); | |
155 | err |= __put_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14); | |
156 | err |= __put_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15); | |
157 | err |= __put_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16); | |
158 | err |= __put_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17); | |
159 | err |= __put_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18); | |
160 | err |= __put_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19); | |
161 | err |= __put_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20); | |
162 | err |= __put_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21); | |
163 | err |= __put_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22); | |
164 | err |= __put_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23); | |
165 | err |= __put_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24); | |
166 | err |= __put_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25); | |
167 | err |= __put_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26); | |
168 | err |= __put_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp); | |
169 | err |= __put_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip); | |
170 | err |= __put_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp); | |
171 | err |= __put_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr); | |
172 | err |= __put_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc); | |
173 | err |= __put_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr); | |
174 | ||
175 | err |= __put_user(current->thread.trap_no, | |
176 | &sf->uc.uc_mcontext.trap_no); | |
177 | err |= __put_user(current->thread.error_code, | |
178 | &sf->uc.uc_mcontext.error_code); | |
179 | err |= __put_user(current->thread.address, | |
180 | &sf->uc.uc_mcontext.fault_address); | |
181 | err |= __put_user(set->sig[0], &sf->uc.uc_mcontext.oldmask); | |
182 | ||
183 | err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); | |
184 | ||
185 | return err; | |
186 | } | |
187 | ||
188 | static inline void __user *get_sigframe(struct k_sigaction *ka, | |
189 | struct pt_regs *regs, int framesize) | |
190 | { | |
191 | unsigned long sp = regs->UCreg_sp; | |
192 | void __user *frame; | |
193 | ||
194 | /* | |
195 | * This is the X/Open sanctioned signal stack switching. | |
196 | */ | |
197 | if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) | |
198 | sp = current->sas_ss_sp + current->sas_ss_size; | |
199 | ||
200 | /* | |
201 | * ATPCS B01 mandates 8-byte alignment | |
202 | */ | |
203 | frame = (void __user *)((sp - framesize) & ~7); | |
204 | ||
205 | /* | |
206 | * Check that we can actually write to the signal frame. | |
207 | */ | |
208 | if (!access_ok(VERIFY_WRITE, frame, framesize)) | |
209 | frame = NULL; | |
210 | ||
211 | return frame; | |
212 | } | |
213 | ||
214 | static int setup_return(struct pt_regs *regs, struct k_sigaction *ka, | |
215 | unsigned long __user *rc, void __user *frame, int usig) | |
216 | { | |
217 | unsigned long handler = (unsigned long)ka->sa.sa_handler; | |
218 | unsigned long retcode; | |
219 | unsigned long asr = regs->UCreg_asr & ~PSR_f; | |
220 | ||
221 | unsigned int idx = 0; | |
222 | ||
223 | if (ka->sa.sa_flags & SA_SIGINFO) | |
224 | idx += 1; | |
225 | ||
226 | if (__put_user(sigreturn_codes[idx], rc) || | |
227 | __put_user(sigreturn_codes[idx+1], rc+1)) | |
228 | return 1; | |
229 | ||
230 | retcode = KERN_SIGRETURN_CODE + (idx << 2); | |
231 | ||
232 | regs->UCreg_00 = usig; | |
233 | regs->UCreg_sp = (unsigned long)frame; | |
234 | regs->UCreg_lr = retcode; | |
235 | regs->UCreg_pc = handler; | |
236 | regs->UCreg_asr = asr; | |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
241 | static int setup_frame(int usig, struct k_sigaction *ka, | |
242 | sigset_t *set, struct pt_regs *regs) | |
243 | { | |
244 | struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); | |
245 | int err = 0; | |
246 | ||
247 | if (!frame) | |
248 | return 1; | |
249 | ||
250 | /* | |
251 | * Set uc.uc_flags to a value which sc.trap_no would never have. | |
252 | */ | |
253 | err |= __put_user(0x5ac3c35a, &frame->uc.uc_flags); | |
254 | ||
255 | err |= setup_sigframe(frame, regs, set); | |
256 | if (err == 0) | |
257 | err |= setup_return(regs, ka, frame->retcode, frame, usig); | |
258 | ||
259 | return err; | |
260 | } | |
261 | ||
262 | static int setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, | |
263 | sigset_t *set, struct pt_regs *regs) | |
264 | { | |
265 | struct rt_sigframe __user *frame = | |
266 | get_sigframe(ka, regs, sizeof(*frame)); | |
f864d2f8 G |
267 | int err = 0; |
268 | ||
269 | if (!frame) | |
270 | return 1; | |
271 | ||
272 | err |= copy_siginfo_to_user(&frame->info, info); | |
273 | ||
274 | err |= __put_user(0, &frame->sig.uc.uc_flags); | |
275 | err |= __put_user(NULL, &frame->sig.uc.uc_link); | |
50b3c9e3 | 276 | err |= __save_altstack(&frame->sig.uc.uc_stack, regs->UCreg_sp); |
f864d2f8 G |
277 | err |= setup_sigframe(&frame->sig, regs, set); |
278 | if (err == 0) | |
279 | err |= setup_return(regs, ka, frame->sig.retcode, frame, usig); | |
280 | ||
281 | if (err == 0) { | |
282 | /* | |
283 | * For realtime signals we must also set the second and third | |
284 | * arguments for the signal handler. | |
285 | */ | |
286 | regs->UCreg_01 = (unsigned long)&frame->info; | |
287 | regs->UCreg_02 = (unsigned long)&frame->sig.uc; | |
288 | } | |
289 | ||
290 | return err; | |
291 | } | |
292 | ||
293 | static inline void setup_syscall_restart(struct pt_regs *regs) | |
294 | { | |
295 | regs->UCreg_00 = regs->UCreg_ORIG_00; | |
296 | regs->UCreg_pc -= 4; | |
297 | } | |
298 | ||
299 | /* | |
300 | * OK, we're invoking a handler | |
301 | */ | |
a610d6e6 | 302 | static void handle_signal(unsigned long sig, struct k_sigaction *ka, |
b7f9a11a | 303 | siginfo_t *info, struct pt_regs *regs, int syscall) |
f864d2f8 G |
304 | { |
305 | struct thread_info *thread = current_thread_info(); | |
306 | struct task_struct *tsk = current; | |
b7f9a11a | 307 | sigset_t *oldset = sigmask_to_save(); |
f864d2f8 G |
308 | int usig = sig; |
309 | int ret; | |
310 | ||
311 | /* | |
312 | * If we were from a system call, check for system call restarting... | |
313 | */ | |
314 | if (syscall) { | |
315 | switch (regs->UCreg_00) { | |
316 | case -ERESTART_RESTARTBLOCK: | |
317 | case -ERESTARTNOHAND: | |
318 | regs->UCreg_00 = -EINTR; | |
319 | break; | |
320 | case -ERESTARTSYS: | |
321 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
322 | regs->UCreg_00 = -EINTR; | |
323 | break; | |
324 | } | |
325 | /* fallthrough */ | |
326 | case -ERESTARTNOINTR: | |
327 | setup_syscall_restart(regs); | |
328 | } | |
329 | } | |
330 | ||
331 | /* | |
332 | * translate the signal | |
333 | */ | |
334 | if (usig < 32 && thread->exec_domain | |
335 | && thread->exec_domain->signal_invmap) | |
336 | usig = thread->exec_domain->signal_invmap[usig]; | |
337 | ||
338 | /* | |
339 | * Set up the stack frame | |
340 | */ | |
341 | if (ka->sa.sa_flags & SA_SIGINFO) | |
342 | ret = setup_rt_frame(usig, ka, info, oldset, regs); | |
343 | else | |
344 | ret = setup_frame(usig, ka, oldset, regs); | |
345 | ||
346 | /* | |
347 | * Check that the resulting registers are actually sane. | |
348 | */ | |
349 | ret |= !valid_user_regs(regs); | |
350 | ||
351 | if (ret != 0) { | |
352 | force_sigsegv(sig, tsk); | |
a610d6e6 | 353 | return; |
f864d2f8 G |
354 | } |
355 | ||
efee984c | 356 | signal_delivered(sig, info, ka, regs, 0); |
f864d2f8 G |
357 | } |
358 | ||
359 | /* | |
360 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
361 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
362 | * mistake. | |
363 | * | |
364 | * Note that we go through the signals twice: once to check the signals that | |
365 | * the kernel can handle, and then we build all the user-level signal handling | |
366 | * stack-frames in one go after that. | |
367 | */ | |
368 | static void do_signal(struct pt_regs *regs, int syscall) | |
369 | { | |
370 | struct k_sigaction ka; | |
371 | siginfo_t info; | |
372 | int signr; | |
373 | ||
374 | /* | |
375 | * We want the common case to go fast, which | |
376 | * is why we may in certain cases get here from | |
377 | * kernel mode. Just return without doing anything | |
378 | * if so. | |
379 | */ | |
380 | if (!user_mode(regs)) | |
381 | return; | |
382 | ||
f864d2f8 G |
383 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
384 | if (signr > 0) { | |
a610d6e6 | 385 | handle_signal(signr, &ka, &info, regs, syscall); |
f864d2f8 G |
386 | return; |
387 | } | |
388 | ||
f864d2f8 G |
389 | /* |
390 | * No signal to deliver to the process - restart the syscall. | |
391 | */ | |
392 | if (syscall) { | |
393 | if (regs->UCreg_00 == -ERESTART_RESTARTBLOCK) { | |
394 | u32 __user *usp; | |
395 | ||
396 | regs->UCreg_sp -= 4; | |
397 | usp = (u32 __user *)regs->UCreg_sp; | |
398 | ||
399 | if (put_user(regs->UCreg_pc, usp) == 0) { | |
400 | regs->UCreg_pc = KERN_RESTART_CODE; | |
401 | } else { | |
402 | regs->UCreg_sp += 4; | |
403 | force_sigsegv(0, current); | |
404 | } | |
405 | } | |
406 | if (regs->UCreg_00 == -ERESTARTNOHAND || | |
407 | regs->UCreg_00 == -ERESTARTSYS || | |
408 | regs->UCreg_00 == -ERESTARTNOINTR) { | |
409 | setup_syscall_restart(regs); | |
410 | } | |
f864d2f8 | 411 | } |
415d04d0 AV |
412 | /* If there's no signal to deliver, we just put the saved |
413 | * sigmask back. | |
414 | */ | |
51a7b448 | 415 | restore_saved_sigmask(); |
f864d2f8 G |
416 | } |
417 | ||
418 | asmlinkage void do_notify_resume(struct pt_regs *regs, | |
419 | unsigned int thread_flags, int syscall) | |
420 | { | |
421 | if (thread_flags & _TIF_SIGPENDING) | |
422 | do_signal(regs, syscall); | |
423 | ||
424 | if (thread_flags & _TIF_NOTIFY_RESUME) { | |
425 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
426 | tracehook_notify_resume(regs); | |
f864d2f8 G |
427 | } |
428 | } | |
429 | ||
430 | /* | |
431 | * Copy signal return handlers into the vector page, and | |
432 | * set sigreturn to be a pointer to these. | |
433 | */ | |
434 | void __init early_signal_init(void) | |
435 | { | |
436 | memcpy((void *)kuser_vecpage_to_vectors(KERN_SIGRETURN_CODE), | |
437 | sigreturn_codes, sizeof(sigreturn_codes)); | |
438 | memcpy((void *)kuser_vecpage_to_vectors(KERN_RESTART_CODE), | |
439 | syscall_restart_code, sizeof(syscall_restart_code)); | |
440 | /* Need not to flush icache, since early_trap_init will do it last. */ | |
441 | } |