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)
63 current->saved_sigmask = current->blocked;
65 siginitset(&blocked, mask);
66 set_current_blocked(&blocked);
67 set_current_state(TASK_INTERRUPTIBLE);
69 set_restore_sigmask();
70 return -ERESTARTNOHAND;
73 SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
74 struct old_sigaction __user *, oact)
76 struct k_sigaction new_ka, old_ka;
81 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
82 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
83 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
84 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
85 __get_user(mask, &act->sa_mask))
87 siginitset(&new_ka.sa.sa_mask, mask);
90 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
93 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
94 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
95 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
96 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
97 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
104 SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
105 stack_t __user *, uoss)
107 struct pt_regs *regs = task_pt_regs(current);
108 return do_sigaltstack(uss, uoss, regs->gprs[15]);
111 /* Returns non-zero on fault. */
112 static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
116 save_access_regs(current->thread.acrs);
118 /* Copy a 'clean' PSW mask to the user to avoid leaking
119 information about whether PER is currently on. */
120 user_sregs.regs.psw.mask = psw_user_bits |
121 (regs->psw.mask & PSW_MASK_USER);
122 user_sregs.regs.psw.addr = regs->psw.addr;
123 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
124 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
125 sizeof(sregs->regs.acrs));
127 * We have to store the fp registers to current->thread.fp_regs
128 * to merge them with the emulated registers.
130 save_fp_regs(¤t->thread.fp_regs);
131 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
132 sizeof(s390_fp_regs));
133 return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
136 /* Returns positive number on error */
137 static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
142 /* Alwys make any pending restarted system call return -EINTR */
143 current_thread_info()->restart_block.fn = do_no_restart_syscall;
145 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
148 /* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
149 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
150 (user_sregs.regs.psw.mask & PSW_MASK_USER);
151 /* Check for invalid amode */
152 if (regs->psw.mask & PSW_MASK_EA)
153 regs->psw.mask |= PSW_MASK_BA;
154 regs->psw.addr = user_sregs.regs.psw.addr;
155 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
156 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
157 sizeof(sregs->regs.acrs));
158 restore_access_regs(current->thread.acrs);
160 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
161 sizeof(s390_fp_regs));
162 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
164 restore_fp_regs(¤t->thread.fp_regs);
165 clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
169 SYSCALL_DEFINE0(sigreturn)
171 struct pt_regs *regs = task_pt_regs(current);
172 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
175 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
177 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
179 sigdelsetmask(&set, ~_BLOCKABLE);
180 set_current_blocked(&set);
181 if (restore_sigregs(regs, &frame->sregs))
183 return regs->gprs[2];
185 force_sig(SIGSEGV, current);
189 SYSCALL_DEFINE0(rt_sigreturn)
191 struct pt_regs *regs = task_pt_regs(current);
192 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
195 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
197 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
199 sigdelsetmask(&set, ~_BLOCKABLE);
200 set_current_blocked(&set);
201 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
203 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
204 regs->gprs[15]) == -EFAULT)
206 return regs->gprs[2];
208 force_sig(SIGSEGV, current);
213 * Set up a signal frame.
218 * Determine which stack to use..
220 static inline void __user *
221 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
225 /* Default to using normal stack */
228 /* Overflow on alternate signal stack gives SIGSEGV. */
229 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
230 return (void __user *) -1UL;
232 /* This is the X/Open sanctioned signal stack switching. */
233 if (ka->sa.sa_flags & SA_ONSTACK) {
234 if (! sas_ss_flags(sp))
235 sp = current->sas_ss_sp + current->sas_ss_size;
238 /* This is the legacy signal stack switching. */
239 else if (!user_mode(regs) &&
240 !(ka->sa.sa_flags & SA_RESTORER) &&
241 ka->sa.sa_restorer) {
242 sp = (unsigned long) ka->sa.sa_restorer;
245 return (void __user *)((sp - frame_size) & -8ul);
248 static inline int map_signal(int sig)
250 if (current_thread_info()->exec_domain
251 && current_thread_info()->exec_domain->signal_invmap
253 return current_thread_info()->exec_domain->signal_invmap[sig];
258 static int setup_frame(int sig, struct k_sigaction *ka,
259 sigset_t *set, struct pt_regs * regs)
261 sigframe __user *frame;
263 frame = get_sigframe(ka, regs, sizeof(sigframe));
264 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
267 if (frame == (void __user *) -1UL)
270 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
273 if (save_sigregs(regs, &frame->sregs))
275 if (__put_user(&frame->sregs, &frame->sc.sregs))
278 /* Set up to return from userspace. If provided, use a stub
279 already in userspace. */
280 if (ka->sa.sa_flags & SA_RESTORER) {
281 regs->gprs[14] = (unsigned long)
282 ka->sa.sa_restorer | PSW_ADDR_AMODE;
284 regs->gprs[14] = (unsigned long)
285 frame->retcode | PSW_ADDR_AMODE;
286 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
287 (u16 __user *)(frame->retcode)))
291 /* Set up backchain. */
292 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
295 /* Set up registers for signal handler */
296 regs->gprs[15] = (unsigned long) frame;
297 regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
298 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
300 regs->gprs[2] = map_signal(sig);
301 regs->gprs[3] = (unsigned long) &frame->sc;
303 /* We forgot to include these in the sigcontext.
304 To avoid breaking binary compatibility, they are passed as args. */
305 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
306 sig == SIGTRAP || sig == SIGFPE) {
307 /* set extra registers only for synchronous signals */
308 regs->gprs[4] = regs->int_code & 127;
309 regs->gprs[5] = regs->int_parm_long;
310 regs->gprs[6] = task_thread_info(current)->last_break;
313 /* Place signal number on stack to allow backtrace from handler. */
314 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
319 force_sigsegv(sig, current);
323 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
324 sigset_t *set, struct pt_regs * regs)
327 rt_sigframe __user *frame;
329 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
330 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
333 if (frame == (void __user *) -1UL)
336 if (copy_siginfo_to_user(&frame->info, info))
339 /* Create the ucontext. */
340 err |= __put_user(0, &frame->uc.uc_flags);
341 err |= __put_user(NULL, &frame->uc.uc_link);
342 err |= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
343 err |= __put_user(sas_ss_flags(regs->gprs[15]),
344 &frame->uc.uc_stack.ss_flags);
345 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
346 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
347 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
351 /* Set up to return from userspace. If provided, use a stub
352 already in userspace. */
353 if (ka->sa.sa_flags & SA_RESTORER) {
354 regs->gprs[14] = (unsigned long)
355 ka->sa.sa_restorer | PSW_ADDR_AMODE;
357 regs->gprs[14] = (unsigned long)
358 frame->retcode | PSW_ADDR_AMODE;
359 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
360 (u16 __user *)(frame->retcode)))
364 /* Set up backchain. */
365 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
368 /* Set up registers for signal handler */
369 regs->gprs[15] = (unsigned long) frame;
370 regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
371 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
373 regs->gprs[2] = map_signal(sig);
374 regs->gprs[3] = (unsigned long) &frame->info;
375 regs->gprs[4] = (unsigned long) &frame->uc;
376 regs->gprs[5] = task_thread_info(current)->last_break;
380 force_sigsegv(sig, current);
384 static int handle_signal(unsigned long sig, struct k_sigaction *ka,
385 siginfo_t *info, sigset_t *oldset,
386 struct pt_regs *regs)
390 /* Set up the stack frame */
391 if (ka->sa.sa_flags & SA_SIGINFO)
392 ret = setup_rt_frame(sig, ka, info, oldset, regs);
394 ret = setup_frame(sig, ka, oldset, regs);
397 block_sigmask(ka, sig);
402 * Note that 'init' is a special process: it doesn't get signals it doesn't
403 * want to handle. Thus you cannot kill init even with a SIGKILL even by
406 * Note that we go through the signals twice: once to check the signals that
407 * the kernel can handle, and then we build all the user-level signal handling
408 * stack-frames in one go after that.
410 void do_signal(struct pt_regs *regs)
414 struct k_sigaction ka;
418 * We want the common case to go fast, which
419 * is why we may in certain cases get here from
420 * kernel mode. Just return without doing anything
423 if (!user_mode(regs))
426 if (test_thread_flag(TIF_RESTORE_SIGMASK))
427 oldset = ¤t->saved_sigmask;
429 oldset = ¤t->blocked;
432 * Get signal to deliver. When running under ptrace, at this point
433 * the debugger may change all our registers, including the system
436 current_thread_info()->system_call =
437 test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
438 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
441 /* Whee! Actually deliver the signal. */
442 if (current_thread_info()->system_call) {
443 regs->int_code = current_thread_info()->system_call;
444 /* Check for system call restarting. */
445 switch (regs->gprs[2]) {
446 case -ERESTART_RESTARTBLOCK:
447 case -ERESTARTNOHAND:
448 regs->gprs[2] = -EINTR;
451 if (!(ka.sa.sa_flags & SA_RESTART)) {
452 regs->gprs[2] = -EINTR;
456 case -ERESTARTNOINTR:
457 regs->gprs[2] = regs->orig_gpr2;
459 __rewind_psw(regs->psw,
460 regs->int_code >> 16);
464 /* No longer in a system call */
465 clear_thread_flag(TIF_SYSCALL);
467 if ((is_compat_task() ?
468 handle_signal32(signr, &ka, &info, oldset, regs) :
469 handle_signal(signr, &ka, &info, oldset, regs)) == 0) {
471 * A signal was successfully delivered; the saved
472 * sigmask will have been stored in the signal frame,
473 * and will be restored by sigreturn, so we can simply
474 * clear the TIF_RESTORE_SIGMASK flag.
476 if (test_thread_flag(TIF_RESTORE_SIGMASK))
477 clear_thread_flag(TIF_RESTORE_SIGMASK);
480 * Let tracing know that we've done the handler setup.
482 tracehook_signal_handler(signr, &info, &ka, regs,
483 test_thread_flag(TIF_SINGLE_STEP));
488 /* No handlers present - check for system call restart */
489 clear_thread_flag(TIF_SYSCALL);
490 if (current_thread_info()->system_call) {
491 regs->int_code = current_thread_info()->system_call;
492 switch (regs->gprs[2]) {
493 case -ERESTART_RESTARTBLOCK:
494 /* Restart with sys_restart_syscall */
495 regs->int_code = __NR_restart_syscall;
497 case -ERESTARTNOHAND:
499 case -ERESTARTNOINTR:
500 /* Restart system call with magic TIF bit. */
501 regs->gprs[2] = regs->orig_gpr2;
502 set_thread_flag(TIF_SYSCALL);
508 * If there's no signal to deliver, we just put the saved sigmask back.
510 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
511 clear_thread_flag(TIF_RESTORE_SIGMASK);
512 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
516 void do_notify_resume(struct pt_regs *regs)
518 clear_thread_flag(TIF_NOTIFY_RESUME);
519 tracehook_notify_resume(regs);
520 if (current->replacement_session_keyring)
521 key_replace_session_keyring();