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5f97f7f9 HS |
1 | /* |
2 | * Copyright (C) 2004-2006 Atmel Corporation | |
3 | * | |
4 | * Based on linux/arch/sh/kernel/signal.c | |
5 | * Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima | |
6 | * Copyright (C) 1991, 1992 Linus Torvalds | |
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 | ||
13 | #include <linux/sched.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/ptrace.h> | |
17 | #include <linux/unistd.h> | |
7dfb7103 | 18 | #include <linux/freezer.h> |
733e5e4b | 19 | #include <linux/tracehook.h> |
5f97f7f9 HS |
20 | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/ucontext.h> | |
c80ce2d5 | 23 | #include <asm/syscalls.h> |
5f97f7f9 HS |
24 | |
25 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
26 | ||
27 | asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, | |
28 | struct pt_regs *regs) | |
29 | { | |
30 | return do_sigaltstack(uss, uoss, regs->sp); | |
31 | } | |
32 | ||
33 | struct rt_sigframe | |
34 | { | |
35 | struct siginfo info; | |
36 | struct ucontext uc; | |
37 | unsigned long retcode; | |
38 | }; | |
39 | ||
40 | static int | |
41 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) | |
42 | { | |
43 | int err = 0; | |
44 | ||
45 | #define COPY(x) err |= __get_user(regs->x, &sc->x) | |
46 | COPY(sr); | |
47 | COPY(pc); | |
48 | COPY(lr); | |
49 | COPY(sp); | |
50 | COPY(r12); | |
51 | COPY(r11); | |
52 | COPY(r10); | |
53 | COPY(r9); | |
54 | COPY(r8); | |
55 | COPY(r7); | |
56 | COPY(r6); | |
57 | COPY(r5); | |
58 | COPY(r4); | |
59 | COPY(r3); | |
60 | COPY(r2); | |
61 | COPY(r1); | |
62 | COPY(r0); | |
63 | #undef COPY | |
64 | ||
65 | /* | |
66 | * Don't allow anyone to pretend they're running in supervisor | |
67 | * mode or something... | |
68 | */ | |
69 | err |= !valid_user_regs(regs); | |
70 | ||
71 | return err; | |
72 | } | |
73 | ||
74 | ||
75 | asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) | |
76 | { | |
77 | struct rt_sigframe __user *frame; | |
78 | sigset_t set; | |
79 | ||
80 | frame = (struct rt_sigframe __user *)regs->sp; | |
81 | pr_debug("SIG return: frame = %p\n", frame); | |
82 | ||
83 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
84 | goto badframe; | |
85 | ||
86 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
87 | goto badframe; | |
88 | ||
89 | sigdelsetmask(&set, ~_BLOCKABLE); | |
90 | spin_lock_irq(¤t->sighand->siglock); | |
91 | current->blocked = set; | |
92 | recalc_sigpending(); | |
93 | spin_unlock_irq(¤t->sighand->siglock); | |
94 | ||
95 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) | |
96 | goto badframe; | |
97 | ||
7c1b90a1 MK |
98 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
99 | goto badframe; | |
100 | ||
5f97f7f9 HS |
101 | pr_debug("Context restored: pc = %08lx, lr = %08lx, sp = %08lx\n", |
102 | regs->pc, regs->lr, regs->sp); | |
103 | ||
104 | return regs->r12; | |
105 | ||
106 | badframe: | |
107 | force_sig(SIGSEGV, current); | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static int | |
112 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) | |
113 | { | |
114 | int err = 0; | |
115 | ||
116 | #define COPY(x) err |= __put_user(regs->x, &sc->x) | |
117 | COPY(sr); | |
118 | COPY(pc); | |
119 | COPY(lr); | |
120 | COPY(sp); | |
121 | COPY(r12); | |
122 | COPY(r11); | |
123 | COPY(r10); | |
124 | COPY(r9); | |
125 | COPY(r8); | |
126 | COPY(r7); | |
127 | COPY(r6); | |
128 | COPY(r5); | |
129 | COPY(r4); | |
130 | COPY(r3); | |
131 | COPY(r2); | |
132 | COPY(r1); | |
133 | COPY(r0); | |
134 | #undef COPY | |
135 | ||
136 | return err; | |
137 | } | |
138 | ||
139 | static inline void __user * | |
140 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) | |
141 | { | |
142 | unsigned long sp = regs->sp; | |
143 | ||
144 | if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) | |
145 | sp = current->sas_ss_sp + current->sas_ss_size; | |
146 | ||
147 | return (void __user *)((sp - framesize) & ~3); | |
148 | } | |
149 | ||
150 | static int | |
151 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
152 | sigset_t *set, struct pt_regs *regs) | |
153 | { | |
154 | struct rt_sigframe __user *frame; | |
155 | int err = 0; | |
156 | ||
157 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
158 | err = -EFAULT; | |
159 | if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) | |
160 | goto out; | |
161 | ||
162 | /* | |
163 | * Set up the return code: | |
164 | * | |
165 | * mov r8, __NR_rt_sigreturn | |
166 | * scall | |
167 | * | |
168 | * Note: This will blow up since we're using a non-executable | |
169 | * stack. Better use SA_RESTORER. | |
170 | */ | |
171 | #if __NR_rt_sigreturn > 127 | |
172 | # error __NR_rt_sigreturn must be < 127 to fit in a short mov | |
173 | #endif | |
174 | err = __put_user(0x3008d733 | (__NR_rt_sigreturn << 20), | |
175 | &frame->retcode); | |
176 | ||
177 | err |= copy_siginfo_to_user(&frame->info, info); | |
178 | ||
179 | /* Set up the ucontext */ | |
180 | err |= __put_user(0, &frame->uc.uc_flags); | |
181 | err |= __put_user(NULL, &frame->uc.uc_link); | |
182 | err |= __put_user((void __user *)current->sas_ss_sp, | |
183 | &frame->uc.uc_stack.ss_sp); | |
184 | err |= __put_user(sas_ss_flags(regs->sp), | |
185 | &frame->uc.uc_stack.ss_flags); | |
186 | err |= __put_user(current->sas_ss_size, | |
187 | &frame->uc.uc_stack.ss_size); | |
188 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs); | |
189 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
190 | ||
191 | if (err) | |
192 | goto out; | |
193 | ||
194 | regs->r12 = sig; | |
195 | regs->r11 = (unsigned long) &frame->info; | |
196 | regs->r10 = (unsigned long) &frame->uc; | |
197 | regs->sp = (unsigned long) frame; | |
198 | if (ka->sa.sa_flags & SA_RESTORER) | |
199 | regs->lr = (unsigned long)ka->sa.sa_restorer; | |
200 | else { | |
201 | printk(KERN_NOTICE "[%s:%d] did not set SA_RESTORER\n", | |
202 | current->comm, current->pid); | |
203 | regs->lr = (unsigned long) &frame->retcode; | |
204 | } | |
205 | ||
206 | pr_debug("SIG deliver [%s:%d]: sig=%d sp=0x%lx pc=0x%lx->0x%p lr=0x%lx\n", | |
207 | current->comm, current->pid, sig, regs->sp, | |
208 | regs->pc, ka->sa.sa_handler, regs->lr); | |
209 | ||
210 | regs->pc = (unsigned long) ka->sa.sa_handler; | |
211 | ||
212 | out: | |
213 | return err; | |
214 | } | |
215 | ||
288ddad5 | 216 | static inline void setup_syscall_restart(struct pt_regs *regs) |
5f97f7f9 HS |
217 | { |
218 | if (regs->r12 == -ERESTART_RESTARTBLOCK) | |
219 | regs->r8 = __NR_restart_syscall; | |
220 | else | |
221 | regs->r12 = regs->r12_orig; | |
222 | regs->pc -= 2; | |
223 | } | |
224 | ||
225 | static inline void | |
226 | handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, | |
227 | sigset_t *oldset, struct pt_regs *regs, int syscall) | |
228 | { | |
229 | int ret; | |
230 | ||
231 | /* | |
232 | * Set up the stack frame | |
233 | */ | |
234 | ret = setup_rt_frame(sig, ka, info, oldset, regs); | |
235 | ||
236 | /* | |
237 | * Check that the resulting registers are sane | |
238 | */ | |
239 | ret |= !valid_user_regs(regs); | |
240 | ||
241 | /* | |
242 | * Block the signal if we were unsuccessful. | |
243 | */ | |
244 | if (ret != 0 || !(ka->sa.sa_flags & SA_NODEFER)) { | |
245 | spin_lock_irq(¤t->sighand->siglock); | |
246 | sigorsets(¤t->blocked, ¤t->blocked, | |
247 | &ka->sa.sa_mask); | |
248 | sigaddset(¤t->blocked, sig); | |
249 | recalc_sigpending(); | |
250 | spin_unlock_irq(¤t->sighand->siglock); | |
251 | } | |
252 | ||
253 | if (ret == 0) | |
254 | return; | |
255 | ||
256 | force_sigsegv(sig, current); | |
257 | } | |
258 | ||
259 | /* | |
260 | * Note that 'init' is a special process: it doesn't get signals it | |
261 | * doesn't want to handle. Thus you cannot kill init even with a | |
262 | * SIGKILL even by mistake. | |
263 | */ | |
264 | int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall) | |
265 | { | |
266 | siginfo_t info; | |
267 | int signr; | |
268 | struct k_sigaction ka; | |
269 | ||
270 | /* | |
271 | * We want the common case to go fast, which is why we may in | |
272 | * certain cases get here from kernel mode. Just return | |
273 | * without doing anything if so. | |
274 | */ | |
275 | if (!user_mode(regs)) | |
276 | return 0; | |
277 | ||
5f97f7f9 HS |
278 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
279 | oldset = ¤t->saved_sigmask; | |
280 | else if (!oldset) | |
281 | oldset = ¤t->blocked; | |
282 | ||
283 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
5f97f7f9 HS |
284 | if (syscall) { |
285 | switch (regs->r12) { | |
286 | case -ERESTART_RESTARTBLOCK: | |
287 | case -ERESTARTNOHAND: | |
288 | if (signr > 0) { | |
289 | regs->r12 = -EINTR; | |
290 | break; | |
291 | } | |
292 | /* fall through */ | |
293 | case -ERESTARTSYS: | |
294 | if (signr > 0 && !(ka.sa.sa_flags & SA_RESTART)) { | |
295 | regs->r12 = -EINTR; | |
296 | break; | |
297 | } | |
298 | /* fall through */ | |
299 | case -ERESTARTNOINTR: | |
288ddad5 | 300 | setup_syscall_restart(regs); |
5f97f7f9 HS |
301 | } |
302 | } | |
303 | ||
304 | if (signr == 0) { | |
305 | /* No signal to deliver -- put the saved sigmask back */ | |
306 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { | |
307 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
308 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
309 | } | |
310 | return 0; | |
311 | } | |
312 | ||
313 | handle_signal(signr, &ka, &info, oldset, regs, syscall); | |
314 | return 1; | |
315 | } | |
316 | ||
317 | asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti) | |
318 | { | |
319 | int syscall = 0; | |
320 | ||
321 | if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR) | |
322 | syscall = 1; | |
323 | ||
324 | if (ti->flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) | |
325 | do_signal(regs, ¤t->blocked, syscall); | |
d0420c83 DH |
326 | |
327 | if (ti->flags & _TIF_NOTIFY_RESUME) { | |
328 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
329 | tracehook_notify_resume(regs); | |
ee18d64c DH |
330 | if (current->replacement_session_keyring) |
331 | key_replace_session_keyring(); | |
d0420c83 | 332 | } |
5f97f7f9 | 333 | } |