1 /*
2 * linux/arch/m32r/kernel/signal.c
3 *
4 * Copyright (c) 2003 Hitoshi Yamamoto
5 *
6 * Taken from i386 version.
7 * Copyright (C) 1991, 1992 Linus Torvalds
8 *
9 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
10 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
11 */
12
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/smp.h>
16 #include <linux/kernel.h>
17 #include <linux/signal.h>
18 #include <linux/errno.h>
19 #include <linux/wait.h>
20 #include <linux/unistd.h>
21 #include <linux/stddef.h>
22 #include <linux/personality.h>
23 #include <linux/freezer.h>
24 #include <linux/tracehook.h>
25 #include <asm/cacheflush.h>
26 #include <asm/ucontext.h>
27 #include <asm/uaccess.h>
28
29 #define DEBUG_SIG 0
30
31 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
32
33 asmlinkage int
sys_sigaltstack(const stack_t __user * uss,stack_t __user * uoss,unsigned long r2,unsigned long r3,unsigned long r4,unsigned long r5,unsigned long r6,struct pt_regs * regs)34 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
35 unsigned long r2, unsigned long r3, unsigned long r4,
36 unsigned long r5, unsigned long r6, struct pt_regs *regs)
37 {
38 return do_sigaltstack(uss, uoss, regs->spu);
39 }
40
41
42 /*
43 * Do a signal return; undo the signal stack.
44 */
45
46 struct rt_sigframe
47 {
48 int sig;
49 struct siginfo __user *pinfo;
50 void __user *puc;
51 struct siginfo info;
52 struct ucontext uc;
53 // struct _fpstate fpstate;
54 };
55
56 static int
restore_sigcontext(struct pt_regs * regs,struct sigcontext __user * sc,int * r0_p)57 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
58 int *r0_p)
59 {
60 unsigned int err = 0;
61
62 /* Always make any pending restarted system calls return -EINTR */
63 current_thread_info()->restart_block.fn = do_no_restart_syscall;
64
65 #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
66 COPY(r4);
67 COPY(r5);
68 COPY(r6);
69 COPY(pt_regs);
70 /* COPY(r0); Skip r0 */
71 COPY(r1);
72 COPY(r2);
73 COPY(r3);
74 COPY(r7);
75 COPY(r8);
76 COPY(r9);
77 COPY(r10);
78 COPY(r11);
79 COPY(r12);
80 COPY(acc0h);
81 COPY(acc0l);
82 COPY(acc1h); /* ISA_DSP_LEVEL2 only */
83 COPY(acc1l); /* ISA_DSP_LEVEL2 only */
84 COPY(psw);
85 COPY(bpc);
86 COPY(bbpsw);
87 COPY(bbpc);
88 COPY(spu);
89 COPY(fp);
90 COPY(lr);
91 COPY(spi);
92 #undef COPY
93
94 regs->syscall_nr = -1; /* disable syscall checks */
95 err |= __get_user(*r0_p, &sc->sc_r0);
96
97 return err;
98 }
99
100 asmlinkage int
sys_rt_sigreturn(unsigned long r0,unsigned long r1,unsigned long r2,unsigned long r3,unsigned long r4,unsigned long r5,unsigned long r6,struct pt_regs * regs)101 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
102 unsigned long r2, unsigned long r3, unsigned long r4,
103 unsigned long r5, unsigned long r6, struct pt_regs *regs)
104 {
105 struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
106 sigset_t set;
107 int result;
108
109 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
110 goto badframe;
111 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
112 goto badframe;
113
114 sigdelsetmask(&set, ~_BLOCKABLE);
115 spin_lock_irq(¤t->sighand->siglock);
116 current->blocked = set;
117 recalc_sigpending();
118 spin_unlock_irq(¤t->sighand->siglock);
119
120 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
121 goto badframe;
122
123 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
124 goto badframe;
125
126 return result;
127
128 badframe:
129 force_sig(SIGSEGV, current);
130 return 0;
131 }
132
133 /*
134 * Set up a signal frame.
135 */
136
137 static int
setup_sigcontext(struct sigcontext __user * sc,struct pt_regs * regs,unsigned long mask)138 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
139 unsigned long mask)
140 {
141 int err = 0;
142
143 #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
144 COPY(r4);
145 COPY(r5);
146 COPY(r6);
147 COPY(pt_regs);
148 COPY(r0);
149 COPY(r1);
150 COPY(r2);
151 COPY(r3);
152 COPY(r7);
153 COPY(r8);
154 COPY(r9);
155 COPY(r10);
156 COPY(r11);
157 COPY(r12);
158 COPY(acc0h);
159 COPY(acc0l);
160 COPY(acc1h); /* ISA_DSP_LEVEL2 only */
161 COPY(acc1l); /* ISA_DSP_LEVEL2 only */
162 COPY(psw);
163 COPY(bpc);
164 COPY(bbpsw);
165 COPY(bbpc);
166 COPY(spu);
167 COPY(fp);
168 COPY(lr);
169 COPY(spi);
170 #undef COPY
171
172 err |= __put_user(mask, &sc->oldmask);
173
174 return err;
175 }
176
177 /*
178 * Determine which stack to use..
179 */
180 static inline void __user *
get_sigframe(struct k_sigaction * ka,unsigned long sp,size_t frame_size)181 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
182 {
183 /* This is the X/Open sanctioned signal stack switching. */
184 if (ka->sa.sa_flags & SA_ONSTACK) {
185 if (sas_ss_flags(sp) == 0)
186 sp = current->sas_ss_sp + current->sas_ss_size;
187 }
188
189 return (void __user *)((sp - frame_size) & -8ul);
190 }
191
setup_rt_frame(int sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * set,struct pt_regs * regs)192 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
193 sigset_t *set, struct pt_regs *regs)
194 {
195 struct rt_sigframe __user *frame;
196 int err = 0;
197 int signal;
198
199 frame = get_sigframe(ka, regs->spu, sizeof(*frame));
200
201 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
202 goto give_sigsegv;
203
204 signal = current_thread_info()->exec_domain
205 && current_thread_info()->exec_domain->signal_invmap
206 && sig < 32
207 ? current_thread_info()->exec_domain->signal_invmap[sig]
208 : sig;
209
210 err |= __put_user(signal, &frame->sig);
211 if (err)
212 goto give_sigsegv;
213
214 err |= __put_user(&frame->info, &frame->pinfo);
215 err |= __put_user(&frame->uc, &frame->puc);
216 err |= copy_siginfo_to_user(&frame->info, info);
217 if (err)
218 goto give_sigsegv;
219
220 /* Create the ucontext. */
221 err |= __put_user(0, &frame->uc.uc_flags);
222 err |= __put_user(0, &frame->uc.uc_link);
223 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
224 err |= __put_user(sas_ss_flags(regs->spu),
225 &frame->uc.uc_stack.ss_flags);
226 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
227 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
228 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
229 if (err)
230 goto give_sigsegv;
231
232 /* Set up to return from userspace. */
233 regs->lr = (unsigned long)ka->sa.sa_restorer;
234
235 /* Set up registers for signal handler */
236 regs->spu = (unsigned long)frame;
237 regs->r0 = signal; /* Arg for signal handler */
238 regs->r1 = (unsigned long)&frame->info;
239 regs->r2 = (unsigned long)&frame->uc;
240 regs->bpc = (unsigned long)ka->sa.sa_handler;
241
242 set_fs(USER_DS);
243
244 #if DEBUG_SIG
245 printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
246 current->comm, current->pid, frame, regs->pc);
247 #endif
248
249 return 0;
250
251 give_sigsegv:
252 force_sigsegv(sig, current);
253 return -EFAULT;
254 }
255
prev_insn(struct pt_regs * regs)256 static int prev_insn(struct pt_regs *regs)
257 {
258 u16 inst;
259 if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
260 return -EFAULT;
261 if ((inst & 0xfff0) == 0x10f0) /* trap ? */
262 regs->bpc -= 2;
263 else
264 regs->bpc -= 4;
265 regs->syscall_nr = -1;
266 return 0;
267 }
268
269 /*
270 * OK, we're invoking a handler
271 */
272
273 static int
handle_signal(unsigned long sig,struct k_sigaction * ka,siginfo_t * info,sigset_t * oldset,struct pt_regs * regs)274 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
275 sigset_t *oldset, struct pt_regs *regs)
276 {
277 /* Are we from a system call? */
278 if (regs->syscall_nr >= 0) {
279 /* If so, check system call restarting.. */
280 switch (regs->r0) {
281 case -ERESTART_RESTARTBLOCK:
282 case -ERESTARTNOHAND:
283 regs->r0 = -EINTR;
284 break;
285
286 case -ERESTARTSYS:
287 if (!(ka->sa.sa_flags & SA_RESTART)) {
288 regs->r0 = -EINTR;
289 break;
290 }
291 /* fallthrough */
292 case -ERESTARTNOINTR:
293 regs->r0 = regs->orig_r0;
294 if (prev_insn(regs) < 0)
295 return -EFAULT;
296 }
297 }
298
299 /* Set up the stack frame */
300 if (setup_rt_frame(sig, ka, info, oldset, regs))
301 return -EFAULT;
302
303 spin_lock_irq(¤t->sighand->siglock);
304 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
305 if (!(ka->sa.sa_flags & SA_NODEFER))
306 sigaddset(¤t->blocked,sig);
307 recalc_sigpending();
308 spin_unlock_irq(¤t->sighand->siglock);
309 return 0;
310 }
311
312 /*
313 * Note that 'init' is a special process: it doesn't get signals it doesn't
314 * want to handle. Thus you cannot kill init even with a SIGKILL even by
315 * mistake.
316 */
do_signal(struct pt_regs * regs)317 static void do_signal(struct pt_regs *regs)
318 {
319 siginfo_t info;
320 int signr;
321 struct k_sigaction ka;
322 sigset_t *oldset;
323
324 /*
325 * We want the common case to go fast, which
326 * is why we may in certain cases get here from
327 * kernel mode. Just return without doing anything
328 * if so.
329 */
330 if (!user_mode(regs))
331 return;
332
333 if (try_to_freeze())
334 goto no_signal;
335
336 if (test_thread_flag(TIF_RESTORE_SIGMASK))
337 oldset = ¤t->saved_sigmask;
338 else
339 oldset = ¤t->blocked;
340
341 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
342 if (signr > 0) {
343 /* Re-enable any watchpoints before delivering the
344 * signal to user space. The processor register will
345 * have been cleared if the watchpoint triggered
346 * inside the kernel.
347 */
348
349 /* Whee! Actually deliver the signal. */
350 if (handle_signal(signr, &ka, &info, oldset, regs) == 0)
351 clear_thread_flag(TIF_RESTORE_SIGMASK);
352
353 return;
354 }
355
356 no_signal:
357 /* Did we come from a system call? */
358 if (regs->syscall_nr >= 0) {
359 /* Restart the system call - no handlers present */
360 if (regs->r0 == -ERESTARTNOHAND ||
361 regs->r0 == -ERESTARTSYS ||
362 regs->r0 == -ERESTARTNOINTR) {
363 regs->r0 = regs->orig_r0;
364 prev_insn(regs);
365 } else if (regs->r0 == -ERESTART_RESTARTBLOCK){
366 regs->r0 = regs->orig_r0;
367 regs->r7 = __NR_restart_syscall;
368 prev_insn(regs);
369 }
370 }
371 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
372 clear_thread_flag(TIF_RESTORE_SIGMASK);
373 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
374 }
375 }
376
377 /*
378 * notification of userspace execution resumption
379 * - triggered by current->work.notify_resume
380 */
do_notify_resume(struct pt_regs * regs,__u32 thread_info_flags)381 void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
382 {
383 /* Pending single-step? */
384 if (thread_info_flags & _TIF_SINGLESTEP)
385 clear_thread_flag(TIF_SINGLESTEP);
386
387 /* deal with pending signal delivery */
388 if (thread_info_flags & _TIF_SIGPENDING)
389 do_signal(regs);
390
391 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
392 clear_thread_flag(TIF_NOTIFY_RESUME);
393 tracehook_notify_resume(regs);
394 if (current->replacement_session_keyring)
395 key_replace_session_keyring();
396 }
397
398 clear_thread_flag(TIF_IRET);
399 }
400