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>
35 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
40 __u8 callee_used_stack
[__SIGNAL_FRAMESIZE
];
44 __u8 retcode
[S390_SYSCALL_SIZE
];
49 __u8 callee_used_stack
[__SIGNAL_FRAMESIZE
];
50 __u8 retcode
[S390_SYSCALL_SIZE
];
56 * Atomically swap in the new signal mask, and wait for a signal.
58 SYSCALL_DEFINE3(sigsuspend
, int, history0
, int, history1
, old_sigset_t
, mask
)
62 current
->saved_sigmask
= current
->blocked
;
64 siginitset(&blocked
, mask
);
65 set_current_blocked(&blocked
);
66 set_current_state(TASK_INTERRUPTIBLE
);
68 set_restore_sigmask();
69 return -ERESTARTNOHAND
;
72 SYSCALL_DEFINE3(sigaction
, int, sig
, const struct old_sigaction __user
*, act
,
73 struct old_sigaction __user
*, oact
)
75 struct k_sigaction new_ka
, old_ka
;
80 if (!access_ok(VERIFY_READ
, act
, sizeof(*act
)) ||
81 __get_user(new_ka
.sa
.sa_handler
, &act
->sa_handler
) ||
82 __get_user(new_ka
.sa
.sa_restorer
, &act
->sa_restorer
) ||
83 __get_user(new_ka
.sa
.sa_flags
, &act
->sa_flags
) ||
84 __get_user(mask
, &act
->sa_mask
))
86 siginitset(&new_ka
.sa
.sa_mask
, mask
);
89 ret
= do_sigaction(sig
, act
? &new_ka
: NULL
, oact
? &old_ka
: NULL
);
92 if (!access_ok(VERIFY_WRITE
, oact
, sizeof(*oact
)) ||
93 __put_user(old_ka
.sa
.sa_handler
, &oact
->sa_handler
) ||
94 __put_user(old_ka
.sa
.sa_restorer
, &oact
->sa_restorer
) ||
95 __put_user(old_ka
.sa
.sa_flags
, &oact
->sa_flags
) ||
96 __put_user(old_ka
.sa
.sa_mask
.sig
[0], &oact
->sa_mask
))
103 SYSCALL_DEFINE2(sigaltstack
, const stack_t __user
*, uss
,
104 stack_t __user
*, uoss
)
106 struct pt_regs
*regs
= task_pt_regs(current
);
107 return do_sigaltstack(uss
, uoss
, regs
->gprs
[15]);
110 /* Returns non-zero on fault. */
111 static int save_sigregs(struct pt_regs
*regs
, _sigregs __user
*sregs
)
115 save_access_regs(current
->thread
.acrs
);
117 /* Copy a 'clean' PSW mask to the user to avoid leaking
118 information about whether PER is currently on. */
119 user_sregs
.regs
.psw
.mask
= PSW_MASK_MERGE(psw_user_bits
, regs
->psw
.mask
);
120 user_sregs
.regs
.psw
.addr
= regs
->psw
.addr
;
121 memcpy(&user_sregs
.regs
.gprs
, ®s
->gprs
, sizeof(sregs
->regs
.gprs
));
122 memcpy(&user_sregs
.regs
.acrs
, current
->thread
.acrs
,
123 sizeof(sregs
->regs
.acrs
));
125 * We have to store the fp registers to current->thread.fp_regs
126 * to merge them with the emulated registers.
128 save_fp_regs(¤t
->thread
.fp_regs
);
129 memcpy(&user_sregs
.fpregs
, ¤t
->thread
.fp_regs
,
130 sizeof(s390_fp_regs
));
131 return __copy_to_user(sregs
, &user_sregs
, sizeof(_sigregs
));
134 /* Returns positive number on error */
135 static int restore_sigregs(struct pt_regs
*regs
, _sigregs __user
*sregs
)
140 /* Alwys make any pending restarted system call return -EINTR */
141 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
143 err
= __copy_from_user(&user_sregs
, sregs
, sizeof(_sigregs
));
146 regs
->psw
.mask
= PSW_MASK_MERGE(regs
->psw
.mask
,
147 user_sregs
.regs
.psw
.mask
);
148 regs
->psw
.addr
= PSW_ADDR_AMODE
| user_sregs
.regs
.psw
.addr
;
149 memcpy(®s
->gprs
, &user_sregs
.regs
.gprs
, sizeof(sregs
->regs
.gprs
));
150 memcpy(¤t
->thread
.acrs
, &user_sregs
.regs
.acrs
,
151 sizeof(sregs
->regs
.acrs
));
152 restore_access_regs(current
->thread
.acrs
);
154 memcpy(¤t
->thread
.fp_regs
, &user_sregs
.fpregs
,
155 sizeof(s390_fp_regs
));
156 current
->thread
.fp_regs
.fpc
&= FPC_VALID_MASK
;
158 restore_fp_regs(¤t
->thread
.fp_regs
);
159 regs
->svcnr
= 0; /* disable syscall checks */
163 SYSCALL_DEFINE0(sigreturn
)
165 struct pt_regs
*regs
= task_pt_regs(current
);
166 sigframe __user
*frame
= (sigframe __user
*)regs
->gprs
[15];
169 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
171 if (__copy_from_user(&set
.sig
, &frame
->sc
.oldmask
, _SIGMASK_COPY_SIZE
))
173 sigdelsetmask(&set
, ~_BLOCKABLE
);
174 set_current_blocked(&set
);
175 if (restore_sigregs(regs
, &frame
->sregs
))
177 return regs
->gprs
[2];
179 force_sig(SIGSEGV
, current
);
183 SYSCALL_DEFINE0(rt_sigreturn
)
185 struct pt_regs
*regs
= task_pt_regs(current
);
186 rt_sigframe __user
*frame
= (rt_sigframe __user
*)regs
->gprs
[15];
189 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
191 if (__copy_from_user(&set
.sig
, &frame
->uc
.uc_sigmask
, sizeof(set
)))
193 sigdelsetmask(&set
, ~_BLOCKABLE
);
194 set_current_blocked(&set
);
195 if (restore_sigregs(regs
, &frame
->uc
.uc_mcontext
))
197 if (do_sigaltstack(&frame
->uc
.uc_stack
, NULL
,
198 regs
->gprs
[15]) == -EFAULT
)
200 return regs
->gprs
[2];
202 force_sig(SIGSEGV
, current
);
207 * Set up a signal frame.
212 * Determine which stack to use..
214 static inline void __user
*
215 get_sigframe(struct k_sigaction
*ka
, struct pt_regs
* regs
, size_t frame_size
)
219 /* Default to using normal stack */
222 /* Overflow on alternate signal stack gives SIGSEGV. */
223 if (on_sig_stack(sp
) && !on_sig_stack((sp
- frame_size
) & -8UL))
224 return (void __user
*) -1UL;
226 /* This is the X/Open sanctioned signal stack switching. */
227 if (ka
->sa
.sa_flags
& SA_ONSTACK
) {
228 if (! sas_ss_flags(sp
))
229 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
232 /* This is the legacy signal stack switching. */
233 else if (!user_mode(regs
) &&
234 !(ka
->sa
.sa_flags
& SA_RESTORER
) &&
235 ka
->sa
.sa_restorer
) {
236 sp
= (unsigned long) ka
->sa
.sa_restorer
;
239 return (void __user
*)((sp
- frame_size
) & -8ul);
242 static inline int map_signal(int sig
)
244 if (current_thread_info()->exec_domain
245 && current_thread_info()->exec_domain
->signal_invmap
247 return current_thread_info()->exec_domain
->signal_invmap
[sig
];
252 static int setup_frame(int sig
, struct k_sigaction
*ka
,
253 sigset_t
*set
, struct pt_regs
* regs
)
255 sigframe __user
*frame
;
257 frame
= get_sigframe(ka
, regs
, sizeof(sigframe
));
258 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(sigframe
)))
261 if (frame
== (void __user
*) -1UL)
264 if (__copy_to_user(&frame
->sc
.oldmask
, &set
->sig
, _SIGMASK_COPY_SIZE
))
267 if (save_sigregs(regs
, &frame
->sregs
))
269 if (__put_user(&frame
->sregs
, &frame
->sc
.sregs
))
272 /* Set up to return from userspace. If provided, use a stub
273 already in userspace. */
274 if (ka
->sa
.sa_flags
& SA_RESTORER
) {
275 regs
->gprs
[14] = (unsigned long)
276 ka
->sa
.sa_restorer
| PSW_ADDR_AMODE
;
278 regs
->gprs
[14] = (unsigned long)
279 frame
->retcode
| PSW_ADDR_AMODE
;
280 if (__put_user(S390_SYSCALL_OPCODE
| __NR_sigreturn
,
281 (u16 __user
*)(frame
->retcode
)))
285 /* Set up backchain. */
286 if (__put_user(regs
->gprs
[15], (addr_t __user
*) frame
))
289 /* Set up registers for signal handler */
290 regs
->gprs
[15] = (unsigned long) frame
;
291 regs
->psw
.addr
= (unsigned long) ka
->sa
.sa_handler
| PSW_ADDR_AMODE
;
293 regs
->gprs
[2] = map_signal(sig
);
294 regs
->gprs
[3] = (unsigned long) &frame
->sc
;
296 /* We forgot to include these in the sigcontext.
297 To avoid breaking binary compatibility, they are passed as args. */
298 regs
->gprs
[4] = current
->thread
.trap_no
;
299 regs
->gprs
[5] = current
->thread
.prot_addr
;
300 regs
->gprs
[6] = task_thread_info(current
)->last_break
;
302 /* Place signal number on stack to allow backtrace from handler. */
303 if (__put_user(regs
->gprs
[2], (int __user
*) &frame
->signo
))
308 force_sigsegv(sig
, current
);
312 static int setup_rt_frame(int sig
, struct k_sigaction
*ka
, siginfo_t
*info
,
313 sigset_t
*set
, struct pt_regs
* regs
)
316 rt_sigframe __user
*frame
;
318 frame
= get_sigframe(ka
, regs
, sizeof(rt_sigframe
));
319 if (!access_ok(VERIFY_WRITE
, frame
, sizeof(rt_sigframe
)))
322 if (frame
== (void __user
*) -1UL)
325 if (copy_siginfo_to_user(&frame
->info
, info
))
328 /* Create the ucontext. */
329 err
|= __put_user(0, &frame
->uc
.uc_flags
);
330 err
|= __put_user(NULL
, &frame
->uc
.uc_link
);
331 err
|= __put_user((void __user
*)current
->sas_ss_sp
, &frame
->uc
.uc_stack
.ss_sp
);
332 err
|= __put_user(sas_ss_flags(regs
->gprs
[15]),
333 &frame
->uc
.uc_stack
.ss_flags
);
334 err
|= __put_user(current
->sas_ss_size
, &frame
->uc
.uc_stack
.ss_size
);
335 err
|= save_sigregs(regs
, &frame
->uc
.uc_mcontext
);
336 err
|= __copy_to_user(&frame
->uc
.uc_sigmask
, set
, sizeof(*set
));
340 /* Set up to return from userspace. If provided, use a stub
341 already in userspace. */
342 if (ka
->sa
.sa_flags
& SA_RESTORER
) {
343 regs
->gprs
[14] = (unsigned long)
344 ka
->sa
.sa_restorer
| PSW_ADDR_AMODE
;
346 regs
->gprs
[14] = (unsigned long)
347 frame
->retcode
| PSW_ADDR_AMODE
;
348 if (__put_user(S390_SYSCALL_OPCODE
| __NR_rt_sigreturn
,
349 (u16 __user
*)(frame
->retcode
)))
353 /* Set up backchain. */
354 if (__put_user(regs
->gprs
[15], (addr_t __user
*) frame
))
357 /* Set up registers for signal handler */
358 regs
->gprs
[15] = (unsigned long) frame
;
359 regs
->psw
.addr
= (unsigned long) ka
->sa
.sa_handler
| PSW_ADDR_AMODE
;
361 regs
->gprs
[2] = map_signal(sig
);
362 regs
->gprs
[3] = (unsigned long) &frame
->info
;
363 regs
->gprs
[4] = (unsigned long) &frame
->uc
;
364 regs
->gprs
[5] = task_thread_info(current
)->last_break
;
368 force_sigsegv(sig
, current
);
372 static int handle_signal(unsigned long sig
, struct k_sigaction
*ka
,
373 siginfo_t
*info
, sigset_t
*oldset
,
374 struct pt_regs
*regs
)
378 /* Set up the stack frame */
379 if (ka
->sa
.sa_flags
& SA_SIGINFO
)
380 ret
= setup_rt_frame(sig
, ka
, info
, oldset
, regs
);
382 ret
= setup_frame(sig
, ka
, oldset
, regs
);
385 block_sigmask(ka
, sig
);
390 * Note that 'init' is a special process: it doesn't get signals it doesn't
391 * want to handle. Thus you cannot kill init even with a SIGKILL even by
394 * Note that we go through the signals twice: once to check the signals that
395 * the kernel can handle, and then we build all the user-level signal handling
396 * stack-frames in one go after that.
398 void do_signal(struct pt_regs
*regs
)
400 unsigned long retval
= 0, continue_addr
= 0, restart_addr
= 0;
403 struct k_sigaction ka
;
407 * We want the common case to go fast, which
408 * is why we may in certain cases get here from
409 * kernel mode. Just return without doing anything
412 if (!user_mode(regs
))
415 if (test_thread_flag(TIF_RESTORE_SIGMASK
))
416 oldset
= ¤t
->saved_sigmask
;
418 oldset
= ¤t
->blocked
;
420 /* Are we from a system call? */
422 continue_addr
= regs
->psw
.addr
;
423 restart_addr
= continue_addr
- regs
->ilc
;
424 retval
= regs
->gprs
[2];
426 /* Prepare for system call restart. We do this here so that a
427 debugger will see the already changed PSW. */
429 case -ERESTARTNOHAND
:
431 case -ERESTARTNOINTR
:
432 regs
->gprs
[2] = regs
->orig_gpr2
;
433 regs
->psw
.addr
= restart_addr
;
435 case -ERESTART_RESTARTBLOCK
:
436 regs
->gprs
[2] = -EINTR
;
438 regs
->svcnr
= 0; /* Don't deal with this again. */
441 /* Get signal to deliver. When running under ptrace, at this point
442 the debugger may change all our registers ... */
443 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
445 /* Depending on the signal settings we may need to revert the
446 decision to restart the system call. */
447 if (signr
> 0 && regs
->psw
.addr
== restart_addr
) {
448 if (retval
== -ERESTARTNOHAND
449 || (retval
== -ERESTARTSYS
450 && !(current
->sighand
->action
[signr
-1].sa
.sa_flags
452 regs
->gprs
[2] = -EINTR
;
453 regs
->psw
.addr
= continue_addr
;
458 /* Whee! Actually deliver the signal. */
461 if (is_compat_task()) {
462 ret
= handle_signal32(signr
, &ka
, &info
, oldset
, regs
);
466 ret
= handle_signal(signr
, &ka
, &info
, oldset
, regs
);
469 * A signal was successfully delivered; the saved
470 * sigmask will have been stored in the signal frame,
471 * and will be restored by sigreturn, so we can simply
472 * clear the TIF_RESTORE_SIGMASK flag.
474 if (test_thread_flag(TIF_RESTORE_SIGMASK
))
475 clear_thread_flag(TIF_RESTORE_SIGMASK
);
478 * Let tracing know that we've done the handler setup.
480 tracehook_signal_handler(signr
, &info
, &ka
, regs
,
481 test_thread_flag(TIF_SINGLE_STEP
));
487 * If there's no signal to deliver, we just put the saved sigmask back.
489 if (test_thread_flag(TIF_RESTORE_SIGMASK
)) {
490 clear_thread_flag(TIF_RESTORE_SIGMASK
);
491 sigprocmask(SIG_SETMASK
, ¤t
->saved_sigmask
, NULL
);
494 /* Restart a different system call. */
495 if (retval
== -ERESTART_RESTARTBLOCK
496 && regs
->psw
.addr
== continue_addr
) {
497 regs
->gprs
[2] = __NR_restart_syscall
;
498 set_thread_flag(TIF_RESTART_SVC
);
502 void do_notify_resume(struct pt_regs
*regs
)
504 clear_thread_flag(TIF_NOTIFY_RESUME
);
505 tracehook_notify_resume(regs
);
506 if (current
->replacement_session_keyring
)
507 key_replace_session_keyring();