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/compat.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_MASK_MERGE(psw_user_bits, regs->psw.mask);
121 user_sregs.regs.psw.addr = regs->psw.addr;
122 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
123 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
124 sizeof(sregs->regs.acrs));
126 * We have to store the fp registers to current->thread.fp_regs
127 * to merge them with the emulated registers.
129 save_fp_regs(¤t->thread.fp_regs);
130 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
131 sizeof(s390_fp_regs));
132 return __copy_to_user(sregs, &user_sregs, sizeof(_sigregs));
135 /* Returns positive number on error */
136 static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
141 /* Alwys make any pending restarted system call return -EINTR */
142 current_thread_info()->restart_block.fn = do_no_restart_syscall;
144 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
147 regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
148 user_sregs.regs.psw.mask);
149 regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
150 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
151 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
152 sizeof(sregs->regs.acrs));
153 restore_access_regs(current->thread.acrs);
155 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
156 sizeof(s390_fp_regs));
157 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
159 restore_fp_regs(¤t->thread.fp_regs);
160 regs->svc_code = 0; /* disable syscall checks */
164 SYSCALL_DEFINE0(sigreturn)
166 struct pt_regs *regs = task_pt_regs(current);
167 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
170 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
172 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
174 sigdelsetmask(&set, ~_BLOCKABLE);
175 set_current_blocked(&set);
176 if (restore_sigregs(regs, &frame->sregs))
178 return regs->gprs[2];
180 force_sig(SIGSEGV, current);
184 SYSCALL_DEFINE0(rt_sigreturn)
186 struct pt_regs *regs = task_pt_regs(current);
187 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
190 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
192 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
194 sigdelsetmask(&set, ~_BLOCKABLE);
195 set_current_blocked(&set);
196 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
198 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
199 regs->gprs[15]) == -EFAULT)
201 return regs->gprs[2];
203 force_sig(SIGSEGV, current);
208 * Set up a signal frame.
213 * Determine which stack to use..
215 static inline void __user *
216 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
220 /* Default to using normal stack */
223 /* Overflow on alternate signal stack gives SIGSEGV. */
224 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
225 return (void __user *) -1UL;
227 /* This is the X/Open sanctioned signal stack switching. */
228 if (ka->sa.sa_flags & SA_ONSTACK) {
229 if (! sas_ss_flags(sp))
230 sp = current->sas_ss_sp + current->sas_ss_size;
233 /* This is the legacy signal stack switching. */
234 else if (!user_mode(regs) &&
235 !(ka->sa.sa_flags & SA_RESTORER) &&
236 ka->sa.sa_restorer) {
237 sp = (unsigned long) ka->sa.sa_restorer;
240 return (void __user *)((sp - frame_size) & -8ul);
243 static inline int map_signal(int sig)
245 if (current_thread_info()->exec_domain
246 && current_thread_info()->exec_domain->signal_invmap
248 return current_thread_info()->exec_domain->signal_invmap[sig];
253 static int setup_frame(int sig, struct k_sigaction *ka,
254 sigset_t *set, struct pt_regs * regs)
256 sigframe __user *frame;
258 frame = get_sigframe(ka, regs, sizeof(sigframe));
259 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
262 if (frame == (void __user *) -1UL)
265 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
268 if (save_sigregs(regs, &frame->sregs))
270 if (__put_user(&frame->sregs, &frame->sc.sregs))
273 /* Set up to return from userspace. If provided, use a stub
274 already in userspace. */
275 if (ka->sa.sa_flags & SA_RESTORER) {
276 regs->gprs[14] = (unsigned long)
277 ka->sa.sa_restorer | PSW_ADDR_AMODE;
279 regs->gprs[14] = (unsigned long)
280 frame->retcode | PSW_ADDR_AMODE;
281 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
282 (u16 __user *)(frame->retcode)))
286 /* Set up backchain. */
287 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
290 /* Set up registers for signal handler */
291 regs->gprs[15] = (unsigned long) frame;
292 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
294 regs->gprs[2] = map_signal(sig);
295 regs->gprs[3] = (unsigned long) &frame->sc;
297 /* We forgot to include these in the sigcontext.
298 To avoid breaking binary compatibility, they are passed as args. */
299 regs->gprs[4] = current->thread.trap_no;
300 regs->gprs[5] = current->thread.prot_addr;
301 regs->gprs[6] = task_thread_info(current)->last_break;
303 /* Place signal number on stack to allow backtrace from handler. */
304 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
309 force_sigsegv(sig, current);
313 static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
314 sigset_t *set, struct pt_regs * regs)
317 rt_sigframe __user *frame;
319 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
320 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
323 if (frame == (void __user *) -1UL)
326 if (copy_siginfo_to_user(&frame->info, info))
329 /* Create the ucontext. */
330 err |= __put_user(0, &frame->uc.uc_flags);
331 err |= __put_user(NULL, &frame->uc.uc_link);
332 err |= __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
333 err |= __put_user(sas_ss_flags(regs->gprs[15]),
334 &frame->uc.uc_stack.ss_flags);
335 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
336 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
337 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
341 /* Set up to return from userspace. If provided, use a stub
342 already in userspace. */
343 if (ka->sa.sa_flags & SA_RESTORER) {
344 regs->gprs[14] = (unsigned long)
345 ka->sa.sa_restorer | PSW_ADDR_AMODE;
347 regs->gprs[14] = (unsigned long)
348 frame->retcode | PSW_ADDR_AMODE;
349 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
350 (u16 __user *)(frame->retcode)))
354 /* Set up backchain. */
355 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
358 /* Set up registers for signal handler */
359 regs->gprs[15] = (unsigned long) frame;
360 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
362 regs->gprs[2] = map_signal(sig);
363 regs->gprs[3] = (unsigned long) &frame->info;
364 regs->gprs[4] = (unsigned long) &frame->uc;
365 regs->gprs[5] = task_thread_info(current)->last_break;
369 force_sigsegv(sig, current);
373 static int handle_signal(unsigned long sig, struct k_sigaction *ka,
374 siginfo_t *info, sigset_t *oldset,
375 struct pt_regs *regs)
380 /* Set up the stack frame */
381 if (ka->sa.sa_flags & SA_SIGINFO)
382 ret = setup_rt_frame(sig, ka, info, oldset, regs);
384 ret = setup_frame(sig, ka, oldset, regs);
387 sigorsets(&blocked, ¤t->blocked, &ka->sa.sa_mask);
388 if (!(ka->sa.sa_flags & SA_NODEFER))
389 sigaddset(&blocked, sig);
390 set_current_blocked(&blocked);
395 * Note that 'init' is a special process: it doesn't get signals it doesn't
396 * want to handle. Thus you cannot kill init even with a SIGKILL even by
399 * Note that we go through the signals twice: once to check the signals that
400 * the kernel can handle, and then we build all the user-level signal handling
401 * stack-frames in one go after that.
403 void do_signal(struct pt_regs *regs)
407 struct k_sigaction ka;
411 * We want the common case to go fast, which
412 * is why we may in certain cases get here from
413 * kernel mode. Just return without doing anything
416 if (!user_mode(regs))
419 if (test_thread_flag(TIF_RESTORE_SIGMASK))
420 oldset = ¤t->saved_sigmask;
422 oldset = ¤t->blocked;
425 * Get signal to deliver. When running under ptrace, at this point
426 * the debugger may change all our registers, including the system
429 current_thread_info()->system_call = regs->svc_code;
430 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
431 regs->svc_code = current_thread_info()->system_call;
434 /* Whee! Actually deliver the signal. */
435 if (regs->svc_code > 0) {
436 /* Check for system call restarting. */
437 switch (regs->gprs[2]) {
438 case -ERESTART_RESTARTBLOCK:
439 case -ERESTARTNOHAND:
440 regs->gprs[2] = -EINTR;
443 if (!(ka.sa.sa_flags & SA_RESTART)) {
444 regs->gprs[2] = -EINTR;
448 case -ERESTARTNOINTR:
449 regs->gprs[2] = regs->orig_gpr2;
450 regs->psw.addr = regs->psw.addr -
451 (regs->svc_code >> 16);
454 /* No longer in a system call */
458 if ((is_compat_task() ?
459 handle_signal32(signr, &ka, &info, oldset, regs) :
460 handle_signal(signr, &ka, &info, oldset, regs)) == 0) {
462 * A signal was successfully delivered; the saved
463 * sigmask will have been stored in the signal frame,
464 * and will be restored by sigreturn, so we can simply
465 * clear the TIF_RESTORE_SIGMASK flag.
467 if (test_thread_flag(TIF_RESTORE_SIGMASK))
468 clear_thread_flag(TIF_RESTORE_SIGMASK);
471 * Let tracing know that we've done the handler setup.
473 tracehook_signal_handler(signr, &info, &ka, regs,
474 test_thread_flag(TIF_SINGLE_STEP));
479 /* No handlers present - check for system call restart */
480 if (regs->svc_code > 0) {
481 switch (regs->gprs[2]) {
482 case -ERESTART_RESTARTBLOCK:
483 /* Restart with sys_restart_syscall */
484 regs->svc_code = __NR_restart_syscall;
486 case -ERESTARTNOHAND:
488 case -ERESTARTNOINTR:
489 /* Restart system call with magic TIF bit. */
490 regs->gprs[2] = regs->orig_gpr2;
491 set_thread_flag(TIF_RESTART_SVC);
497 * If there's no signal to deliver, we just put the saved sigmask back.
499 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
500 clear_thread_flag(TIF_RESTORE_SIGMASK);
501 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
505 void do_notify_resume(struct pt_regs *regs)
507 clear_thread_flag(TIF_NOTIFY_RESUME);
508 tracehook_notify_resume(regs);
509 if (current->replacement_session_keyring)
510 key_replace_session_keyring();