2 * arch/s390/kernel/signal.c
4 * Copyright (C) IBM Corp. 1999,2006
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
7 * Based on Intel version
9 * Copyright (C) 1991, 1992 Linus Torvalds
11 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
14 #include <linux/sched.h>
16 #include <linux/smp.h>
17 #include <linux/kernel.h>
18 #include <linux/signal.h>
19 #include <linux/errno.h>
20 #include <linux/wait.h>
21 #include <linux/ptrace.h>
22 #include <linux/unistd.h>
23 #include <linux/stddef.h>
24 #include <linux/tty.h>
25 #include <linux/personality.h>
26 #include <linux/binfmts.h>
27 #include <linux/tracehook.h>
28 #include <linux/syscalls.h>
29 #include <linux/compat.h>
30 #include <asm/ucontext.h>
31 #include <asm/uaccess.h>
32 #include <asm/lowcore.h>
33 #include <asm/switch_to.h>
36 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
41 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
45 __u8 retcode[S390_SYSCALL_SIZE];
50 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
51 __u8 retcode[S390_SYSCALL_SIZE];
57 * Atomically swap in the new signal mask, and wait for a signal.
59 SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
62 siginitset(&blocked, mask);
63 return sigsuspend(&blocked);
66 SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
67 struct old_sigaction __user *, oact)
69 struct k_sigaction new_ka, old_ka;
74 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
75 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
76 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
77 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
78 __get_user(mask, &act->sa_mask))
80 siginitset(&new_ka.sa.sa_mask, mask);
83 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
86 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
87 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
88 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
89 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
90 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
97 SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
98 stack_t __user *, uoss)
100 struct pt_regs *regs = task_pt_regs(current);
101 return do_sigaltstack(uss, uoss, regs->gprs[15]);
104 /* Returns non-zero on fault. */
105 static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
109 save_access_regs(current->thread.acrs);
111 /* Copy a 'clean' PSW mask to the user to avoid leaking
112 information about whether PER is currently on. */
113 user_sregs.regs.psw.mask = psw_user_bits |
114 (regs->psw.mask & PSW_MASK_USER);
115 user_sregs.regs.psw.addr = regs->psw.addr;
116 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
117 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
118 sizeof(sregs->regs.acrs));
120 * We have to store the fp registers to current->thread.fp_regs
121 * to merge them with the emulated registers.
123 save_fp_regs(¤t->thread.fp_regs);
124 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
125 sizeof(s390_fp_regs));
126 return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
129 /* Returns positive number on error */
130 static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
135 /* Alwys make any pending restarted system call return -EINTR */
136 current_thread_info()->restart_block.fn = do_no_restart_syscall;
138 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
141 /* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
142 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
143 (user_sregs.regs.psw.mask & PSW_MASK_USER);
144 /* Check for invalid amode */
145 if (regs->psw.mask & PSW_MASK_EA)
146 regs->psw.mask |= PSW_MASK_BA;
147 regs->psw.addr = user_sregs.regs.psw.addr;
148 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
149 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
150 sizeof(sregs->regs.acrs));
151 restore_access_regs(current->thread.acrs);
153 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
154 sizeof(s390_fp_regs));
155 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
157 restore_fp_regs(¤t->thread.fp_regs);
158 clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
162 SYSCALL_DEFINE0(sigreturn)
164 struct pt_regs *regs = task_pt_regs(current);
165 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
168 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
170 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
172 sigdelsetmask(&set, ~_BLOCKABLE);
173 set_current_blocked(&set);
174 if (restore_sigregs(regs, &frame->sregs))
176 return regs->gprs[2];
178 force_sig(SIGSEGV, current);
182 SYSCALL_DEFINE0(rt_sigreturn)
184 struct pt_regs *regs = task_pt_regs(current);
185 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
188 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
190 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
192 sigdelsetmask(&set, ~_BLOCKABLE);
193 set_current_blocked(&set);
194 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
196 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
197 regs->gprs[15]) == -EFAULT)
199 return regs->gprs[2];
201 force_sig(SIGSEGV, current);
206 * Set up a signal frame.
211 * Determine which stack to use..
213 static inline void __user *
214 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
218 /* Default to using normal stack */
221 /* Overflow on alternate signal stack gives SIGSEGV. */
222 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
223 return (void __user *) -1UL;
225 /* This is the X/Open sanctioned signal stack switching. */
226 if (ka->sa.sa_flags & SA_ONSTACK) {
227 if (! sas_ss_flags(sp))
228 sp = current->sas_ss_sp + current->sas_ss_size;
231 return (void __user *)((sp - frame_size) & -8ul);
234 static inline int map_signal(int sig)
236 if (current_thread_info()->exec_domain
237 && current_thread_info()->exec_domain->signal_invmap
239 return current_thread_info()->exec_domain->signal_invmap[sig];
244 static int setup_frame(int sig, struct k_sigaction *ka,
245 sigset_t *set, struct pt_regs * regs)
247 sigframe __user *frame;
249 frame = get_sigframe(ka, regs, sizeof(sigframe));
250 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
253 if (frame == (void __user *) -1UL)
256 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
259 if (save_sigregs(regs, &frame->sregs))
261 if (__put_user(&frame->sregs, &frame->sc.sregs))
264 /* Set up to return from userspace. If provided, use a stub
265 already in userspace. */
266 if (ka->sa.sa_flags & SA_RESTORER) {
267 regs->gprs[14] = (unsigned long)
268 ka->sa.sa_restorer | PSW_ADDR_AMODE;
270 regs->gprs[14] = (unsigned long)
271 frame->retcode | PSW_ADDR_AMODE;
272 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
273 (u16 __user *)(frame->retcode)))
277 /* Set up backchain. */
278 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
281 /* Set up registers for signal handler */
282 regs->gprs[15] = (unsigned long) frame;
283 regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
284 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
286 regs->gprs[2] = map_signal(sig);
287 regs->gprs[3] = (unsigned long) &frame->sc;
289 /* We forgot to include these in the sigcontext.
290 To avoid breaking binary compatibility, they are passed as args. */
291 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
292 sig == SIGTRAP || sig == SIGFPE) {
293 /* set extra registers only for synchronous signals */
294 regs->gprs[4] = regs->int_code & 127;
295 regs->gprs[5] = regs->int_parm_long;
296 regs->gprs[6] = task_thread_info(current)->last_break;
299 /* Place signal number on stack to allow backtrace from handler. */
300 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
305 force_sigsegv(sig, current);
309 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
310 sigset_t *set, struct pt_regs * regs)
313 rt_sigframe __user *frame;
315 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
316 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
319 if (frame == (void __user *) -1UL)
322 if (copy_siginfo_to_user(&frame->info, info))
325 /* Create the ucontext. */
326 err |= __put_user(0, &frame->uc.uc_flags);
327 err |= __put_user(NULL, &frame->uc.uc_link);
328 err |= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
329 err |= __put_user(sas_ss_flags(regs->gprs[15]),
330 &frame->uc.uc_stack.ss_flags);
331 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
332 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
333 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
337 /* Set up to return from userspace. If provided, use a stub
338 already in userspace. */
339 if (ka->sa.sa_flags & SA_RESTORER) {
340 regs->gprs[14] = (unsigned long)
341 ka->sa.sa_restorer | PSW_ADDR_AMODE;
343 regs->gprs[14] = (unsigned long)
344 frame->retcode | PSW_ADDR_AMODE;
345 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
346 (u16 __user *)(frame->retcode)))
350 /* Set up backchain. */
351 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
354 /* Set up registers for signal handler */
355 regs->gprs[15] = (unsigned long) frame;
356 regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
357 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
359 regs->gprs[2] = map_signal(sig);
360 regs->gprs[3] = (unsigned long) &frame->info;
361 regs->gprs[4] = (unsigned long) &frame->uc;
362 regs->gprs[5] = task_thread_info(current)->last_break;
366 force_sigsegv(sig, current);
370 static int handle_signal(unsigned long sig, struct k_sigaction *ka,
371 siginfo_t *info, sigset_t *oldset,
372 struct pt_regs *regs)
376 /* Set up the stack frame */
377 if (ka->sa.sa_flags & SA_SIGINFO)
378 ret = setup_rt_frame(sig, ka, info, oldset, regs);
380 ret = setup_frame(sig, ka, oldset, regs);
383 block_sigmask(ka, sig);
388 * Note that 'init' is a special process: it doesn't get signals it doesn't
389 * want to handle. Thus you cannot kill init even with a SIGKILL even by
392 * Note that we go through the signals twice: once to check the signals that
393 * the kernel can handle, and then we build all the user-level signal handling
394 * stack-frames in one go after that.
396 void do_signal(struct pt_regs *regs)
400 struct k_sigaction ka;
403 if (test_thread_flag(TIF_RESTORE_SIGMASK))
404 oldset = ¤t->saved_sigmask;
406 oldset = ¤t->blocked;
409 * Get signal to deliver. When running under ptrace, at this point
410 * the debugger may change all our registers, including the system
413 current_thread_info()->system_call =
414 test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
415 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
418 /* Whee! Actually deliver the signal. */
419 if (current_thread_info()->system_call) {
420 regs->int_code = current_thread_info()->system_call;
421 /* Check for system call restarting. */
422 switch (regs->gprs[2]) {
423 case -ERESTART_RESTARTBLOCK:
424 case -ERESTARTNOHAND:
425 regs->gprs[2] = -EINTR;
428 if (!(ka.sa.sa_flags & SA_RESTART)) {
429 regs->gprs[2] = -EINTR;
433 case -ERESTARTNOINTR:
434 regs->gprs[2] = regs->orig_gpr2;
436 __rewind_psw(regs->psw,
437 regs->int_code >> 16);
441 /* No longer in a system call */
442 clear_thread_flag(TIF_SYSCALL);
444 if ((is_compat_task() ?
445 handle_signal32(signr, &ka, &info, oldset, regs) :
446 handle_signal(signr, &ka, &info, oldset, regs)) == 0) {
448 * A signal was successfully delivered; the saved
449 * sigmask will have been stored in the signal frame,
450 * and will be restored by sigreturn, so we can simply
451 * clear the TIF_RESTORE_SIGMASK flag.
453 if (test_thread_flag(TIF_RESTORE_SIGMASK))
454 clear_thread_flag(TIF_RESTORE_SIGMASK);
457 * Let tracing know that we've done the handler setup.
459 tracehook_signal_handler(signr, &info, &ka, regs,
460 test_thread_flag(TIF_SINGLE_STEP));
465 /* No handlers present - check for system call restart */
466 clear_thread_flag(TIF_SYSCALL);
467 if (current_thread_info()->system_call) {
468 regs->int_code = current_thread_info()->system_call;
469 switch (regs->gprs[2]) {
470 case -ERESTART_RESTARTBLOCK:
471 /* Restart with sys_restart_syscall */
472 regs->int_code = __NR_restart_syscall;
474 case -ERESTARTNOHAND:
476 case -ERESTARTNOINTR:
477 /* Restart system call with magic TIF bit. */
478 regs->gprs[2] = regs->orig_gpr2;
479 set_thread_flag(TIF_SYSCALL);
485 * If there's no signal to deliver, we just put the saved sigmask back.
487 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
488 clear_thread_flag(TIF_RESTORE_SIGMASK);
489 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
493 void do_notify_resume(struct pt_regs *regs)
495 clear_thread_flag(TIF_NOTIFY_RESUME);
496 tracehook_notify_resume(regs);