Commit | Line | Data |
---|---|---|
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); | |
49209590 | 90 | set_current_blocked(&set); |
5f97f7f9 HS |
91 | |
92 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) | |
93 | goto badframe; | |
94 | ||
7c1b90a1 MK |
95 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
96 | goto badframe; | |
97 | ||
5f97f7f9 HS |
98 | pr_debug("Context restored: pc = %08lx, lr = %08lx, sp = %08lx\n", |
99 | regs->pc, regs->lr, regs->sp); | |
100 | ||
101 | return regs->r12; | |
102 | ||
103 | badframe: | |
104 | force_sig(SIGSEGV, current); | |
105 | return 0; | |
106 | } | |
107 | ||
108 | static int | |
109 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) | |
110 | { | |
111 | int err = 0; | |
112 | ||
113 | #define COPY(x) err |= __put_user(regs->x, &sc->x) | |
114 | COPY(sr); | |
115 | COPY(pc); | |
116 | COPY(lr); | |
117 | COPY(sp); | |
118 | COPY(r12); | |
119 | COPY(r11); | |
120 | COPY(r10); | |
121 | COPY(r9); | |
122 | COPY(r8); | |
123 | COPY(r7); | |
124 | COPY(r6); | |
125 | COPY(r5); | |
126 | COPY(r4); | |
127 | COPY(r3); | |
128 | COPY(r2); | |
129 | COPY(r1); | |
130 | COPY(r0); | |
131 | #undef COPY | |
132 | ||
133 | return err; | |
134 | } | |
135 | ||
136 | static inline void __user * | |
137 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) | |
138 | { | |
139 | unsigned long sp = regs->sp; | |
140 | ||
141 | if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) | |
142 | sp = current->sas_ss_sp + current->sas_ss_size; | |
143 | ||
144 | return (void __user *)((sp - framesize) & ~3); | |
145 | } | |
146 | ||
147 | static int | |
148 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
149 | sigset_t *set, struct pt_regs *regs) | |
150 | { | |
151 | struct rt_sigframe __user *frame; | |
152 | int err = 0; | |
153 | ||
154 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
155 | err = -EFAULT; | |
156 | if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame))) | |
157 | goto out; | |
158 | ||
159 | /* | |
160 | * Set up the return code: | |
161 | * | |
162 | * mov r8, __NR_rt_sigreturn | |
163 | * scall | |
164 | * | |
165 | * Note: This will blow up since we're using a non-executable | |
166 | * stack. Better use SA_RESTORER. | |
167 | */ | |
168 | #if __NR_rt_sigreturn > 127 | |
169 | # error __NR_rt_sigreturn must be < 127 to fit in a short mov | |
170 | #endif | |
171 | err = __put_user(0x3008d733 | (__NR_rt_sigreturn << 20), | |
172 | &frame->retcode); | |
173 | ||
174 | err |= copy_siginfo_to_user(&frame->info, info); | |
175 | ||
176 | /* Set up the ucontext */ | |
177 | err |= __put_user(0, &frame->uc.uc_flags); | |
178 | err |= __put_user(NULL, &frame->uc.uc_link); | |
179 | err |= __put_user((void __user *)current->sas_ss_sp, | |
180 | &frame->uc.uc_stack.ss_sp); | |
181 | err |= __put_user(sas_ss_flags(regs->sp), | |
182 | &frame->uc.uc_stack.ss_flags); | |
183 | err |= __put_user(current->sas_ss_size, | |
184 | &frame->uc.uc_stack.ss_size); | |
185 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs); | |
186 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
187 | ||
188 | if (err) | |
189 | goto out; | |
190 | ||
191 | regs->r12 = sig; | |
192 | regs->r11 = (unsigned long) &frame->info; | |
193 | regs->r10 = (unsigned long) &frame->uc; | |
194 | regs->sp = (unsigned long) frame; | |
195 | if (ka->sa.sa_flags & SA_RESTORER) | |
196 | regs->lr = (unsigned long)ka->sa.sa_restorer; | |
197 | else { | |
198 | printk(KERN_NOTICE "[%s:%d] did not set SA_RESTORER\n", | |
199 | current->comm, current->pid); | |
200 | regs->lr = (unsigned long) &frame->retcode; | |
201 | } | |
202 | ||
203 | pr_debug("SIG deliver [%s:%d]: sig=%d sp=0x%lx pc=0x%lx->0x%p lr=0x%lx\n", | |
204 | current->comm, current->pid, sig, regs->sp, | |
205 | regs->pc, ka->sa.sa_handler, regs->lr); | |
206 | ||
207 | regs->pc = (unsigned long) ka->sa.sa_handler; | |
208 | ||
209 | out: | |
210 | return err; | |
211 | } | |
212 | ||
288ddad5 | 213 | static inline void setup_syscall_restart(struct pt_regs *regs) |
5f97f7f9 HS |
214 | { |
215 | if (regs->r12 == -ERESTART_RESTARTBLOCK) | |
216 | regs->r8 = __NR_restart_syscall; | |
217 | else | |
218 | regs->r12 = regs->r12_orig; | |
219 | regs->pc -= 2; | |
220 | } | |
221 | ||
222 | static inline void | |
223 | handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, | |
224 | sigset_t *oldset, struct pt_regs *regs, int syscall) | |
225 | { | |
226 | int ret; | |
227 | ||
228 | /* | |
229 | * Set up the stack frame | |
230 | */ | |
231 | ret = setup_rt_frame(sig, ka, info, oldset, regs); | |
232 | ||
233 | /* | |
234 | * Check that the resulting registers are sane | |
235 | */ | |
236 | ret |= !valid_user_regs(regs); | |
237 | ||
e1b1fd79 MF |
238 | if (ret != 0) { |
239 | force_sigsegv(sig, current); | |
240 | return; | |
241 | } | |
242 | ||
5f97f7f9 | 243 | /* |
e1b1fd79 | 244 | * Block the signal if we were successful. |
5f97f7f9 | 245 | */ |
54bbf3e3 | 246 | block_sigmask(ka, sig); |
5f97f7f9 HS |
247 | } |
248 | ||
249 | /* | |
250 | * Note that 'init' is a special process: it doesn't get signals it | |
251 | * doesn't want to handle. Thus you cannot kill init even with a | |
252 | * SIGKILL even by mistake. | |
253 | */ | |
254 | int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall) | |
255 | { | |
256 | siginfo_t info; | |
257 | int signr; | |
258 | struct k_sigaction ka; | |
259 | ||
260 | /* | |
261 | * We want the common case to go fast, which is why we may in | |
262 | * certain cases get here from kernel mode. Just return | |
263 | * without doing anything if so. | |
264 | */ | |
265 | if (!user_mode(regs)) | |
266 | return 0; | |
267 | ||
5f97f7f9 HS |
268 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
269 | oldset = ¤t->saved_sigmask; | |
270 | else if (!oldset) | |
271 | oldset = ¤t->blocked; | |
272 | ||
273 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
5f97f7f9 HS |
274 | if (syscall) { |
275 | switch (regs->r12) { | |
276 | case -ERESTART_RESTARTBLOCK: | |
277 | case -ERESTARTNOHAND: | |
278 | if (signr > 0) { | |
279 | regs->r12 = -EINTR; | |
280 | break; | |
281 | } | |
282 | /* fall through */ | |
283 | case -ERESTARTSYS: | |
284 | if (signr > 0 && !(ka.sa.sa_flags & SA_RESTART)) { | |
285 | regs->r12 = -EINTR; | |
286 | break; | |
287 | } | |
288 | /* fall through */ | |
289 | case -ERESTARTNOINTR: | |
288ddad5 | 290 | setup_syscall_restart(regs); |
5f97f7f9 HS |
291 | } |
292 | } | |
293 | ||
294 | if (signr == 0) { | |
295 | /* No signal to deliver -- put the saved sigmask back */ | |
296 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { | |
297 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
298 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
299 | } | |
300 | return 0; | |
301 | } | |
302 | ||
303 | handle_signal(signr, &ka, &info, oldset, regs, syscall); | |
304 | return 1; | |
305 | } | |
306 | ||
307 | asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti) | |
308 | { | |
309 | int syscall = 0; | |
310 | ||
311 | if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR) | |
312 | syscall = 1; | |
313 | ||
314 | if (ti->flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) | |
315 | do_signal(regs, ¤t->blocked, syscall); | |
d0420c83 DH |
316 | |
317 | if (ti->flags & _TIF_NOTIFY_RESUME) { | |
318 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
319 | tracehook_notify_resume(regs); | |
ee18d64c DH |
320 | if (current->replacement_session_keyring) |
321 | key_replace_session_keyring(); | |
d0420c83 | 322 | } |
5f97f7f9 | 323 | } |