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>
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.
56 SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
59 siginitset(&blocked, mask);
60 return sigsuspend(&blocked);
63 SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
64 struct old_sigaction __user *, oact)
66 struct k_sigaction new_ka, old_ka;
71 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
72 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
73 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
74 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
75 __get_user(mask, &act->sa_mask))
77 siginitset(&new_ka.sa.sa_mask, mask);
80 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
83 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
84 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
85 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
86 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
87 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
94 SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
95 stack_t __user *, uoss)
97 struct pt_regs *regs = task_pt_regs(current);
98 return do_sigaltstack(uss, uoss, regs->gprs[15]);
101 /* Returns non-zero on fault. */
102 static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
106 save_access_regs(current->thread.acrs);
108 /* Copy a 'clean' PSW mask to the user to avoid leaking
109 information about whether PER is currently on. */
110 user_sregs.regs.psw.mask = psw_user_bits |
111 (regs->psw.mask & PSW_MASK_USER);
112 user_sregs.regs.psw.addr = regs->psw.addr;
113 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
114 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
115 sizeof(sregs->regs.acrs));
117 * We have to store the fp registers to current->thread.fp_regs
118 * to merge them with the emulated registers.
120 save_fp_regs(¤t->thread.fp_regs);
121 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
122 sizeof(s390_fp_regs));
123 return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
126 /* Returns positive number on error */
127 static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
132 /* Alwys make any pending restarted system call return -EINTR */
133 current_thread_info()->restart_block.fn = do_no_restart_syscall;
135 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
138 /* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
139 regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
140 (user_sregs.regs.psw.mask & PSW_MASK_USER);
141 /* Check for invalid amode */
142 if (regs->psw.mask & PSW_MASK_EA)
143 regs->psw.mask |= PSW_MASK_BA;
144 regs->psw.addr = user_sregs.regs.psw.addr;
145 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
146 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
147 sizeof(sregs->regs.acrs));
148 restore_access_regs(current->thread.acrs);
150 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
151 sizeof(s390_fp_regs));
152 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
154 restore_fp_regs(¤t->thread.fp_regs);
155 clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
159 SYSCALL_DEFINE0(sigreturn)
161 struct pt_regs *regs = task_pt_regs(current);
162 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
165 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
167 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
169 set_current_blocked(&set);
170 if (restore_sigregs(regs, &frame->sregs))
172 return regs->gprs[2];
174 force_sig(SIGSEGV, current);
178 SYSCALL_DEFINE0(rt_sigreturn)
180 struct pt_regs *regs = task_pt_regs(current);
181 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
184 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
186 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
188 set_current_blocked(&set);
189 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
191 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
192 regs->gprs[15]) == -EFAULT)
194 return regs->gprs[2];
196 force_sig(SIGSEGV, current);
201 * Set up a signal frame.
206 * Determine which stack to use..
208 static inline void __user *
209 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
213 /* Default to using normal stack */
216 /* Overflow on alternate signal stack gives SIGSEGV. */
217 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
218 return (void __user *) -1UL;
220 /* This is the X/Open sanctioned signal stack switching. */
221 if (ka->sa.sa_flags & SA_ONSTACK) {
222 if (! sas_ss_flags(sp))
223 sp = current->sas_ss_sp + current->sas_ss_size;
226 return (void __user *)((sp - frame_size) & -8ul);
229 static inline int map_signal(int sig)
231 if (current_thread_info()->exec_domain
232 && current_thread_info()->exec_domain->signal_invmap
234 return current_thread_info()->exec_domain->signal_invmap[sig];
239 static int setup_frame(int sig, struct k_sigaction *ka,
240 sigset_t *set, struct pt_regs * regs)
242 sigframe __user *frame;
244 frame = get_sigframe(ka, regs, sizeof(sigframe));
245 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
248 if (frame == (void __user *) -1UL)
251 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
254 if (save_sigregs(regs, &frame->sregs))
256 if (__put_user(&frame->sregs, &frame->sc.sregs))
259 /* Set up to return from userspace. If provided, use a stub
260 already in userspace. */
261 if (ka->sa.sa_flags & SA_RESTORER) {
262 regs->gprs[14] = (unsigned long)
263 ka->sa.sa_restorer | PSW_ADDR_AMODE;
265 regs->gprs[14] = (unsigned long)
266 frame->retcode | PSW_ADDR_AMODE;
267 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
268 (u16 __user *)(frame->retcode)))
272 /* Set up backchain. */
273 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
276 /* Set up registers for signal handler */
277 regs->gprs[15] = (unsigned long) frame;
278 regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
279 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
281 regs->gprs[2] = map_signal(sig);
282 regs->gprs[3] = (unsigned long) &frame->sc;
284 /* We forgot to include these in the sigcontext.
285 To avoid breaking binary compatibility, they are passed as args. */
286 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
287 sig == SIGTRAP || sig == SIGFPE) {
288 /* set extra registers only for synchronous signals */
289 regs->gprs[4] = regs->int_code & 127;
290 regs->gprs[5] = regs->int_parm_long;
291 regs->gprs[6] = task_thread_info(current)->last_break;
294 /* Place signal number on stack to allow backtrace from handler. */
295 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
300 force_sigsegv(sig, current);
304 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
305 sigset_t *set, struct pt_regs * regs)
308 rt_sigframe __user *frame;
310 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
311 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
314 if (frame == (void __user *) -1UL)
317 if (copy_siginfo_to_user(&frame->info, info))
320 /* Create the ucontext. */
321 err |= __put_user(0, &frame->uc.uc_flags);
322 err |= __put_user(NULL, &frame->uc.uc_link);
323 err |= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
324 err |= __put_user(sas_ss_flags(regs->gprs[15]),
325 &frame->uc.uc_stack.ss_flags);
326 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
327 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
328 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
332 /* Set up to return from userspace. If provided, use a stub
333 already in userspace. */
334 if (ka->sa.sa_flags & SA_RESTORER) {
335 regs->gprs[14] = (unsigned long)
336 ka->sa.sa_restorer | PSW_ADDR_AMODE;
338 regs->gprs[14] = (unsigned long)
339 frame->retcode | PSW_ADDR_AMODE;
340 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
341 (u16 __user *)(frame->retcode)))
345 /* Set up backchain. */
346 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
349 /* Set up registers for signal handler */
350 regs->gprs[15] = (unsigned long) frame;
351 regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
352 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
354 regs->gprs[2] = map_signal(sig);
355 regs->gprs[3] = (unsigned long) &frame->info;
356 regs->gprs[4] = (unsigned long) &frame->uc;
357 regs->gprs[5] = task_thread_info(current)->last_break;
361 force_sigsegv(sig, current);
365 static void handle_signal(unsigned long sig, struct k_sigaction *ka,
366 siginfo_t *info, sigset_t *oldset,
367 struct pt_regs *regs)
371 /* Set up the stack frame */
372 if (ka->sa.sa_flags & SA_SIGINFO)
373 ret = setup_rt_frame(sig, ka, info, oldset, regs);
375 ret = setup_frame(sig, ka, oldset, regs);
378 signal_delivered(sig, info, ka, regs,
379 test_thread_flag(TIF_SINGLE_STEP));
383 * Note that 'init' is a special process: it doesn't get signals it doesn't
384 * want to handle. Thus you cannot kill init even with a SIGKILL even by
387 * Note that we go through the signals twice: once to check the signals that
388 * the kernel can handle, and then we build all the user-level signal handling
389 * stack-frames in one go after that.
391 void do_signal(struct pt_regs *regs)
395 struct k_sigaction ka;
396 sigset_t *oldset = sigmask_to_save();
399 * Get signal to deliver. When running under ptrace, at this point
400 * the debugger may change all our registers, including the system
403 current_thread_info()->system_call =
404 test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
405 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
408 /* Whee! Actually deliver the signal. */
409 if (current_thread_info()->system_call) {
410 regs->int_code = current_thread_info()->system_call;
411 /* Check for system call restarting. */
412 switch (regs->gprs[2]) {
413 case -ERESTART_RESTARTBLOCK:
414 case -ERESTARTNOHAND:
415 regs->gprs[2] = -EINTR;
418 if (!(ka.sa.sa_flags & SA_RESTART)) {
419 regs->gprs[2] = -EINTR;
423 case -ERESTARTNOINTR:
424 regs->gprs[2] = regs->orig_gpr2;
426 __rewind_psw(regs->psw,
427 regs->int_code >> 16);
431 /* No longer in a system call */
432 clear_thread_flag(TIF_SYSCALL);
434 if (is_compat_task())
435 handle_signal32(signr, &ka, &info, oldset, regs);
437 handle_signal(signr, &ka, &info, oldset, regs);
441 /* No handlers present - check for system call restart */
442 clear_thread_flag(TIF_SYSCALL);
443 if (current_thread_info()->system_call) {
444 regs->int_code = current_thread_info()->system_call;
445 switch (regs->gprs[2]) {
446 case -ERESTART_RESTARTBLOCK:
447 /* Restart with sys_restart_syscall */
448 regs->int_code = __NR_restart_syscall;
450 case -ERESTARTNOHAND:
452 case -ERESTARTNOINTR:
453 /* Restart system call with magic TIF bit. */
454 regs->gprs[2] = regs->orig_gpr2;
455 set_thread_flag(TIF_SYSCALL);
461 * If there's no signal to deliver, we just put the saved sigmask back.
463 restore_saved_sigmask();
466 void do_notify_resume(struct pt_regs *regs)
468 clear_thread_flag(TIF_NOTIFY_RESUME);
469 tracehook_notify_resume(regs);