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 <asm/ucontext.h>
29 #include <asm/uaccess.h>
30 #include <asm/lowcore.h>
33 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
38 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
42 __u8 retcode[S390_SYSCALL_SIZE];
47 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
48 __u8 retcode[S390_SYSCALL_SIZE];
54 * Atomically swap in the new signal mask, and wait for a signal.
57 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
60 spin_lock_irq(¤t->sighand->siglock);
61 current->saved_sigmask = current->blocked;
62 siginitset(¤t->blocked, mask);
64 spin_unlock_irq(¤t->sighand->siglock);
66 current->state = TASK_INTERRUPTIBLE;
68 set_thread_flag(TIF_RESTORE_SIGMASK);
70 return -ERESTARTNOHAND;
74 sys_sigaction(int sig, const struct old_sigaction __user *act,
75 struct old_sigaction __user *oact)
77 struct k_sigaction new_ka, old_ka;
82 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
83 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
84 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
85 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
86 __get_user(mask, &act->sa_mask))
88 siginitset(&new_ka.sa.sa_mask, mask);
91 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
94 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
95 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
96 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
97 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
98 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
106 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
108 struct pt_regs *regs = task_pt_regs(current);
109 return do_sigaltstack(uss, uoss, regs->gprs[15]);
114 /* Returns non-zero on fault. */
115 static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
119 save_access_regs(current->thread.acrs);
121 /* Copy a 'clean' PSW mask to the user to avoid leaking
122 information about whether PER is currently on. */
123 user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
124 user_sregs.regs.psw.addr = regs->psw.addr;
125 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
126 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
127 sizeof(sregs->regs.acrs));
129 * We have to store the fp registers to current->thread.fp_regs
130 * to merge them with the emulated registers.
132 save_fp_regs(¤t->thread.fp_regs);
133 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
134 sizeof(s390_fp_regs));
135 return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
138 /* Returns positive number on error */
139 static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
144 /* Alwys make any pending restarted system call return -EINTR */
145 current_thread_info()->restart_block.fn = do_no_restart_syscall;
147 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
150 regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
151 user_sregs.regs.psw.mask);
152 regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
153 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
154 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
155 sizeof(sregs->regs.acrs));
156 restore_access_regs(current->thread.acrs);
158 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
159 sizeof(s390_fp_regs));
160 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
162 restore_fp_regs(¤t->thread.fp_regs);
163 regs->svcnr = 0; /* disable syscall checks */
167 asmlinkage long sys_sigreturn(void)
169 struct pt_regs *regs = task_pt_regs(current);
170 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
173 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
175 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
178 sigdelsetmask(&set, ~_BLOCKABLE);
179 spin_lock_irq(¤t->sighand->siglock);
180 current->blocked = set;
182 spin_unlock_irq(¤t->sighand->siglock);
184 if (restore_sigregs(regs, &frame->sregs))
187 return regs->gprs[2];
190 force_sig(SIGSEGV, current);
194 asmlinkage long sys_rt_sigreturn(void)
196 struct pt_regs *regs = task_pt_regs(current);
197 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
200 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
202 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
205 sigdelsetmask(&set, ~_BLOCKABLE);
206 spin_lock_irq(¤t->sighand->siglock);
207 current->blocked = set;
209 spin_unlock_irq(¤t->sighand->siglock);
211 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
214 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
215 regs->gprs[15]) == -EFAULT)
217 return regs->gprs[2];
220 force_sig(SIGSEGV, current);
225 * Set up a signal frame.
230 * Determine which stack to use..
232 static inline void __user *
233 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
237 /* Default to using normal stack */
240 /* Overflow on alternate signal stack gives SIGSEGV. */
241 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
242 return (void __user *) -1UL;
244 /* This is the X/Open sanctioned signal stack switching. */
245 if (ka->sa.sa_flags & SA_ONSTACK) {
246 if (! sas_ss_flags(sp))
247 sp = current->sas_ss_sp + current->sas_ss_size;
250 /* This is the legacy signal stack switching. */
251 else if (!user_mode(regs) &&
252 !(ka->sa.sa_flags & SA_RESTORER) &&
253 ka->sa.sa_restorer) {
254 sp = (unsigned long) ka->sa.sa_restorer;
257 return (void __user *)((sp - frame_size) & -8ul);
260 static inline int map_signal(int sig)
262 if (current_thread_info()->exec_domain
263 && current_thread_info()->exec_domain->signal_invmap
265 return current_thread_info()->exec_domain->signal_invmap[sig];
270 static int setup_frame(int sig, struct k_sigaction *ka,
271 sigset_t *set, struct pt_regs * regs)
273 sigframe __user *frame;
275 frame = get_sigframe(ka, regs, sizeof(sigframe));
276 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
279 if (frame == (void __user *) -1UL)
282 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
285 if (save_sigregs(regs, &frame->sregs))
287 if (__put_user(&frame->sregs, &frame->sc.sregs))
290 /* Set up to return from userspace. If provided, use a stub
291 already in userspace. */
292 if (ka->sa.sa_flags & SA_RESTORER) {
293 regs->gprs[14] = (unsigned long)
294 ka->sa.sa_restorer | PSW_ADDR_AMODE;
296 regs->gprs[14] = (unsigned long)
297 frame->retcode | PSW_ADDR_AMODE;
298 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
299 (u16 __user *)(frame->retcode)))
303 /* Set up backchain. */
304 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
307 /* Set up registers for signal handler */
308 regs->gprs[15] = (unsigned long) frame;
309 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
311 regs->gprs[2] = map_signal(sig);
312 regs->gprs[3] = (unsigned long) &frame->sc;
314 /* We forgot to include these in the sigcontext.
315 To avoid breaking binary compatibility, they are passed as args. */
316 regs->gprs[4] = current->thread.trap_no;
317 regs->gprs[5] = current->thread.prot_addr;
319 /* Place signal number on stack to allow backtrace from handler. */
320 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
325 force_sigsegv(sig, current);
329 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
330 sigset_t *set, struct pt_regs * regs)
333 rt_sigframe __user *frame;
335 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
336 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
339 if (frame == (void __user *) -1UL)
342 if (copy_siginfo_to_user(&frame->info, info))
345 /* Create the ucontext. */
346 err |= __put_user(0, &frame->uc.uc_flags);
347 err |= __put_user(NULL, &frame->uc.uc_link);
348 err |= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
349 err |= __put_user(sas_ss_flags(regs->gprs[15]),
350 &frame->uc.uc_stack.ss_flags);
351 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
352 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
353 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
357 /* Set up to return from userspace. If provided, use a stub
358 already in userspace. */
359 if (ka->sa.sa_flags & SA_RESTORER) {
360 regs->gprs[14] = (unsigned long)
361 ka->sa.sa_restorer | PSW_ADDR_AMODE;
363 regs->gprs[14] = (unsigned long)
364 frame->retcode | PSW_ADDR_AMODE;
365 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
366 (u16 __user *)(frame->retcode)))
370 /* Set up backchain. */
371 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
374 /* Set up registers for signal handler */
375 regs->gprs[15] = (unsigned long) frame;
376 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
378 regs->gprs[2] = map_signal(sig);
379 regs->gprs[3] = (unsigned long) &frame->info;
380 regs->gprs[4] = (unsigned long) &frame->uc;
384 force_sigsegv(sig, current);
389 * OK, we're invoking a handler
393 handle_signal(unsigned long sig, struct k_sigaction *ka,
394 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
398 /* Set up the stack frame */
399 if (ka->sa.sa_flags & SA_SIGINFO)
400 ret = setup_rt_frame(sig, ka, info, oldset, regs);
402 ret = setup_frame(sig, ka, oldset, regs);
405 spin_lock_irq(¤t->sighand->siglock);
406 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
407 if (!(ka->sa.sa_flags & SA_NODEFER))
408 sigaddset(¤t->blocked,sig);
410 spin_unlock_irq(¤t->sighand->siglock);
417 * Note that 'init' is a special process: it doesn't get signals it doesn't
418 * want to handle. Thus you cannot kill init even with a SIGKILL even by
421 * Note that we go through the signals twice: once to check the signals that
422 * the kernel can handle, and then we build all the user-level signal handling
423 * stack-frames in one go after that.
425 void do_signal(struct pt_regs *regs)
427 unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
430 struct k_sigaction ka;
434 * We want the common case to go fast, which
435 * is why we may in certain cases get here from
436 * kernel mode. Just return without doing anything
439 if (!user_mode(regs))
442 if (test_thread_flag(TIF_RESTORE_SIGMASK))
443 oldset = ¤t->saved_sigmask;
445 oldset = ¤t->blocked;
447 /* Are we from a system call? */
449 continue_addr = regs->psw.addr;
450 restart_addr = continue_addr - regs->ilc;
451 retval = regs->gprs[2];
453 /* Prepare for system call restart. We do this here so that a
454 debugger will see the already changed PSW. */
456 case -ERESTARTNOHAND:
458 case -ERESTARTNOINTR:
459 regs->gprs[2] = regs->orig_gpr2;
460 regs->psw.addr = restart_addr;
462 case -ERESTART_RESTARTBLOCK:
463 regs->gprs[2] = -EINTR;
465 regs->svcnr = 0; /* Don't deal with this again. */
468 /* Get signal to deliver. When running under ptrace, at this point
469 the debugger may change all our registers ... */
470 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
472 /* Depending on the signal settings we may need to revert the
473 decision to restart the system call. */
474 if (signr > 0 && regs->psw.addr == restart_addr) {
475 if (retval == -ERESTARTNOHAND
476 || (retval == -ERESTARTSYS
477 && !(current->sighand->action[signr-1].sa.sa_flags
479 regs->gprs[2] = -EINTR;
480 regs->psw.addr = continue_addr;
485 /* Whee! Actually deliver the signal. */
488 if (test_thread_flag(TIF_31BIT)) {
489 ret = handle_signal32(signr, &ka, &info, oldset, regs);
493 ret = handle_signal(signr, &ka, &info, oldset, regs);
496 * A signal was successfully delivered; the saved
497 * sigmask will have been stored in the signal frame,
498 * and will be restored by sigreturn, so we can simply
499 * clear the TIF_RESTORE_SIGMASK flag.
501 if (test_thread_flag(TIF_RESTORE_SIGMASK))
502 clear_thread_flag(TIF_RESTORE_SIGMASK);
505 * If we would have taken a single-step trap
506 * for a normal instruction, act like we took
507 * one for the handler setup.
509 if (current->thread.per_info.single_step)
510 set_thread_flag(TIF_SINGLE_STEP);
513 * Let tracing know that we've done the handler setup.
515 tracehook_signal_handler(signr, &info, &ka, regs,
516 test_thread_flag(TIF_SINGLE_STEP));
522 * If there's no signal to deliver, we just put the saved sigmask back.
524 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
525 clear_thread_flag(TIF_RESTORE_SIGMASK);
526 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
529 /* Restart a different system call. */
530 if (retval == -ERESTART_RESTARTBLOCK
531 && regs->psw.addr == continue_addr) {
532 regs->gprs[2] = __NR_restart_syscall;
533 set_thread_flag(TIF_RESTART_SVC);
537 void do_notify_resume(struct pt_regs *regs)
539 clear_thread_flag(TIF_NOTIFY_RESUME);
540 tracehook_notify_resume(regs);