Loading...
1/*
2 * arch/s390/kernel/signal.c
3 *
4 * Copyright (C) IBM Corp. 1999,2006
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
6 *
7 * Based on Intel version
8 *
9 * Copyright (C) 1991, 1992 Linus Torvalds
10 *
11 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
12 */
13
14#include <linux/sched.h>
15#include <linux/mm.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 "entry.h"
34
35#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
36
37
38typedef struct
39{
40 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
41 struct sigcontext sc;
42 _sigregs sregs;
43 int signo;
44 __u8 retcode[S390_SYSCALL_SIZE];
45} sigframe;
46
47typedef struct
48{
49 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
50 __u8 retcode[S390_SYSCALL_SIZE];
51 struct siginfo info;
52 struct ucontext uc;
53} rt_sigframe;
54
55/*
56 * Atomically swap in the new signal mask, and wait for a signal.
57 */
58SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
59{
60 sigset_t blocked;
61
62 current->saved_sigmask = current->blocked;
63 mask &= _BLOCKABLE;
64 siginitset(&blocked, mask);
65 set_current_blocked(&blocked);
66 set_current_state(TASK_INTERRUPTIBLE);
67 schedule();
68 set_restore_sigmask();
69 return -ERESTARTNOHAND;
70}
71
72SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
73 struct old_sigaction __user *, oact)
74{
75 struct k_sigaction new_ka, old_ka;
76 int ret;
77
78 if (act) {
79 old_sigset_t mask;
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))
85 return -EFAULT;
86 siginitset(&new_ka.sa.sa_mask, mask);
87 }
88
89 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
90
91 if (!ret && oact) {
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))
97 return -EFAULT;
98 }
99
100 return ret;
101}
102
103SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
104 stack_t __user *, uoss)
105{
106 struct pt_regs *regs = task_pt_regs(current);
107 return do_sigaltstack(uss, uoss, regs->gprs[15]);
108}
109
110/* Returns non-zero on fault. */
111static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
112{
113 _sigregs user_sregs;
114
115 save_access_regs(current->thread.acrs);
116
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));
124 /*
125 * We have to store the fp registers to current->thread.fp_regs
126 * to merge them with the emulated registers.
127 */
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));
132}
133
134/* Returns positive number on error */
135static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
136{
137 int err;
138 _sigregs user_sregs;
139
140 /* Alwys make any pending restarted system call return -EINTR */
141 current_thread_info()->restart_block.fn = do_no_restart_syscall;
142
143 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
144 if (err)
145 return err;
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);
153
154 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
155 sizeof(s390_fp_regs));
156 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
157
158 restore_fp_regs(¤t->thread.fp_regs);
159 regs->svcnr = 0; /* disable syscall checks */
160 return 0;
161}
162
163SYSCALL_DEFINE0(sigreturn)
164{
165 struct pt_regs *regs = task_pt_regs(current);
166 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
167 sigset_t set;
168
169 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
170 goto badframe;
171 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
172 goto badframe;
173 sigdelsetmask(&set, ~_BLOCKABLE);
174 set_current_blocked(&set);
175 if (restore_sigregs(regs, &frame->sregs))
176 goto badframe;
177 return regs->gprs[2];
178badframe:
179 force_sig(SIGSEGV, current);
180 return 0;
181}
182
183SYSCALL_DEFINE0(rt_sigreturn)
184{
185 struct pt_regs *regs = task_pt_regs(current);
186 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
187 sigset_t set;
188
189 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
190 goto badframe;
191 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
192 goto badframe;
193 sigdelsetmask(&set, ~_BLOCKABLE);
194 set_current_blocked(&set);
195 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
196 goto badframe;
197 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
198 regs->gprs[15]) == -EFAULT)
199 goto badframe;
200 return regs->gprs[2];
201badframe:
202 force_sig(SIGSEGV, current);
203 return 0;
204}
205
206/*
207 * Set up a signal frame.
208 */
209
210
211/*
212 * Determine which stack to use..
213 */
214static inline void __user *
215get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
216{
217 unsigned long sp;
218
219 /* Default to using normal stack */
220 sp = regs->gprs[15];
221
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;
225
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;
230 }
231
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;
237 }
238
239 return (void __user *)((sp - frame_size) & -8ul);
240}
241
242static inline int map_signal(int sig)
243{
244 if (current_thread_info()->exec_domain
245 && current_thread_info()->exec_domain->signal_invmap
246 && sig < 32)
247 return current_thread_info()->exec_domain->signal_invmap[sig];
248 else
249 return sig;
250}
251
252static int setup_frame(int sig, struct k_sigaction *ka,
253 sigset_t *set, struct pt_regs * regs)
254{
255 sigframe __user *frame;
256
257 frame = get_sigframe(ka, regs, sizeof(sigframe));
258 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
259 goto give_sigsegv;
260
261 if (frame == (void __user *) -1UL)
262 goto give_sigsegv;
263
264 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
265 goto give_sigsegv;
266
267 if (save_sigregs(regs, &frame->sregs))
268 goto give_sigsegv;
269 if (__put_user(&frame->sregs, &frame->sc.sregs))
270 goto give_sigsegv;
271
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;
277 } else {
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)))
282 goto give_sigsegv;
283 }
284
285 /* Set up backchain. */
286 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
287 goto give_sigsegv;
288
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;
292
293 regs->gprs[2] = map_signal(sig);
294 regs->gprs[3] = (unsigned long) &frame->sc;
295
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;
301
302 /* Place signal number on stack to allow backtrace from handler. */
303 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
304 goto give_sigsegv;
305 return 0;
306
307give_sigsegv:
308 force_sigsegv(sig, current);
309 return -EFAULT;
310}
311
312static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
313 sigset_t *set, struct pt_regs * regs)
314{
315 int err = 0;
316 rt_sigframe __user *frame;
317
318 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
319 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
320 goto give_sigsegv;
321
322 if (frame == (void __user *) -1UL)
323 goto give_sigsegv;
324
325 if (copy_siginfo_to_user(&frame->info, info))
326 goto give_sigsegv;
327
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));
337 if (err)
338 goto give_sigsegv;
339
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;
345 } else {
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)))
350 goto give_sigsegv;
351 }
352
353 /* Set up backchain. */
354 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
355 goto give_sigsegv;
356
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;
360
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;
365 return 0;
366
367give_sigsegv:
368 force_sigsegv(sig, current);
369 return -EFAULT;
370}
371
372static int handle_signal(unsigned long sig, struct k_sigaction *ka,
373 siginfo_t *info, sigset_t *oldset,
374 struct pt_regs *regs)
375{
376 sigset_t blocked;
377 int ret;
378
379 /* Set up the stack frame */
380 if (ka->sa.sa_flags & SA_SIGINFO)
381 ret = setup_rt_frame(sig, ka, info, oldset, regs);
382 else
383 ret = setup_frame(sig, ka, oldset, regs);
384 if (ret)
385 return ret;
386 sigorsets(&blocked, ¤t->blocked, &ka->sa.sa_mask);
387 if (!(ka->sa.sa_flags & SA_NODEFER))
388 sigaddset(&blocked, sig);
389 set_current_blocked(&blocked);
390 return 0;
391}
392
393/*
394 * Note that 'init' is a special process: it doesn't get signals it doesn't
395 * want to handle. Thus you cannot kill init even with a SIGKILL even by
396 * mistake.
397 *
398 * Note that we go through the signals twice: once to check the signals that
399 * the kernel can handle, and then we build all the user-level signal handling
400 * stack-frames in one go after that.
401 */
402void do_signal(struct pt_regs *regs)
403{
404 unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
405 siginfo_t info;
406 int signr;
407 struct k_sigaction ka;
408 sigset_t *oldset;
409
410 /*
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
414 * if so.
415 */
416 if (!user_mode(regs))
417 return;
418
419 if (test_thread_flag(TIF_RESTORE_SIGMASK))
420 oldset = ¤t->saved_sigmask;
421 else
422 oldset = ¤t->blocked;
423
424 /* Are we from a system call? */
425 if (regs->svcnr) {
426 continue_addr = regs->psw.addr;
427 restart_addr = continue_addr - regs->ilc;
428 retval = regs->gprs[2];
429
430 /* Prepare for system call restart. We do this here so that a
431 debugger will see the already changed PSW. */
432 switch (retval) {
433 case -ERESTARTNOHAND:
434 case -ERESTARTSYS:
435 case -ERESTARTNOINTR:
436 regs->gprs[2] = regs->orig_gpr2;
437 regs->psw.addr = restart_addr;
438 break;
439 case -ERESTART_RESTARTBLOCK:
440 regs->gprs[2] = -EINTR;
441 }
442 regs->svcnr = 0; /* Don't deal with this again. */
443 }
444
445 /* Get signal to deliver. When running under ptrace, at this point
446 the debugger may change all our registers ... */
447 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
448
449 /* Depending on the signal settings we may need to revert the
450 decision to restart the system call. */
451 if (signr > 0 && regs->psw.addr == restart_addr) {
452 if (retval == -ERESTARTNOHAND
453 || (retval == -ERESTARTSYS
454 && !(current->sighand->action[signr-1].sa.sa_flags
455 & SA_RESTART))) {
456 regs->gprs[2] = -EINTR;
457 regs->psw.addr = continue_addr;
458 }
459 }
460
461 if (signr > 0) {
462 /* Whee! Actually deliver the signal. */
463 int ret;
464#ifdef CONFIG_COMPAT
465 if (is_compat_task()) {
466 ret = handle_signal32(signr, &ka, &info, oldset, regs);
467 }
468 else
469#endif
470 ret = handle_signal(signr, &ka, &info, oldset, regs);
471 if (!ret) {
472 /*
473 * A signal was successfully delivered; the saved
474 * sigmask will have been stored in the signal frame,
475 * and will be restored by sigreturn, so we can simply
476 * clear the TIF_RESTORE_SIGMASK flag.
477 */
478 if (test_thread_flag(TIF_RESTORE_SIGMASK))
479 clear_thread_flag(TIF_RESTORE_SIGMASK);
480
481 /*
482 * Let tracing know that we've done the handler setup.
483 */
484 tracehook_signal_handler(signr, &info, &ka, regs,
485 test_thread_flag(TIF_SINGLE_STEP));
486 }
487 return;
488 }
489
490 /*
491 * If there's no signal to deliver, we just put the saved sigmask back.
492 */
493 if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
494 clear_thread_flag(TIF_RESTORE_SIGMASK);
495 sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
496 }
497
498 /* Restart a different system call. */
499 if (retval == -ERESTART_RESTARTBLOCK
500 && regs->psw.addr == continue_addr) {
501 regs->gprs[2] = __NR_restart_syscall;
502 set_thread_flag(TIF_RESTART_SVC);
503 }
504}
505
506void do_notify_resume(struct pt_regs *regs)
507{
508 clear_thread_flag(TIF_NOTIFY_RESUME);
509 tracehook_notify_resume(regs);
510 if (current->replacement_session_keyring)
511 key_replace_session_keyring();
512}
1/*
2 * arch/s390/kernel/signal.c
3 *
4 * Copyright (C) IBM Corp. 1999,2006
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
6 *
7 * Based on Intel version
8 *
9 * Copyright (C) 1991, 1992 Linus Torvalds
10 *
11 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
12 */
13
14#include <linux/sched.h>
15#include <linux/mm.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>
34#include "entry.h"
35
36typedef struct
37{
38 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
39 struct sigcontext sc;
40 _sigregs sregs;
41 int signo;
42 __u8 retcode[S390_SYSCALL_SIZE];
43} sigframe;
44
45typedef struct
46{
47 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
48 __u8 retcode[S390_SYSCALL_SIZE];
49 struct siginfo info;
50 struct ucontext uc;
51} rt_sigframe;
52
53/*
54 * Atomically swap in the new signal mask, and wait for a signal.
55 */
56SYSCALL_DEFINE3(sigsuspend, int, history0, int, history1, old_sigset_t, mask)
57{
58 sigset_t blocked;
59 siginitset(&blocked, mask);
60 return sigsuspend(&blocked);
61}
62
63SYSCALL_DEFINE3(sigaction, int, sig, const struct old_sigaction __user *, act,
64 struct old_sigaction __user *, oact)
65{
66 struct k_sigaction new_ka, old_ka;
67 int ret;
68
69 if (act) {
70 old_sigset_t mask;
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))
76 return -EFAULT;
77 siginitset(&new_ka.sa.sa_mask, mask);
78 }
79
80 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
81
82 if (!ret && oact) {
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))
88 return -EFAULT;
89 }
90
91 return ret;
92}
93
94SYSCALL_DEFINE2(sigaltstack, const stack_t __user *, uss,
95 stack_t __user *, uoss)
96{
97 struct pt_regs *regs = task_pt_regs(current);
98 return do_sigaltstack(uss, uoss, regs->gprs[15]);
99}
100
101/* Returns non-zero on fault. */
102static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
103{
104 _sigregs user_sregs;
105
106 save_access_regs(current->thread.acrs);
107
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));
116 /*
117 * We have to store the fp registers to current->thread.fp_regs
118 * to merge them with the emulated registers.
119 */
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));
124}
125
126/* Returns positive number on error */
127static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
128{
129 int err;
130 _sigregs user_sregs;
131
132 /* Alwys make any pending restarted system call return -EINTR */
133 current_thread_info()->restart_block.fn = do_no_restart_syscall;
134
135 err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
136 if (err)
137 return err;
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);
149
150 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
151 sizeof(s390_fp_regs));
152 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
153
154 restore_fp_regs(¤t->thread.fp_regs);
155 clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
156 return 0;
157}
158
159SYSCALL_DEFINE0(sigreturn)
160{
161 struct pt_regs *regs = task_pt_regs(current);
162 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
163 sigset_t set;
164
165 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
166 goto badframe;
167 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
168 goto badframe;
169 set_current_blocked(&set);
170 if (restore_sigregs(regs, &frame->sregs))
171 goto badframe;
172 return regs->gprs[2];
173badframe:
174 force_sig(SIGSEGV, current);
175 return 0;
176}
177
178SYSCALL_DEFINE0(rt_sigreturn)
179{
180 struct pt_regs *regs = task_pt_regs(current);
181 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
182 sigset_t set;
183
184 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
185 goto badframe;
186 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
187 goto badframe;
188 set_current_blocked(&set);
189 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
190 goto badframe;
191 if (do_sigaltstack(&frame->uc.uc_stack, NULL,
192 regs->gprs[15]) == -EFAULT)
193 goto badframe;
194 return regs->gprs[2];
195badframe:
196 force_sig(SIGSEGV, current);
197 return 0;
198}
199
200/*
201 * Set up a signal frame.
202 */
203
204
205/*
206 * Determine which stack to use..
207 */
208static inline void __user *
209get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
210{
211 unsigned long sp;
212
213 /* Default to using normal stack */
214 sp = regs->gprs[15];
215
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;
219
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;
224 }
225
226 return (void __user *)((sp - frame_size) & -8ul);
227}
228
229static inline int map_signal(int sig)
230{
231 if (current_thread_info()->exec_domain
232 && current_thread_info()->exec_domain->signal_invmap
233 && sig < 32)
234 return current_thread_info()->exec_domain->signal_invmap[sig];
235 else
236 return sig;
237}
238
239static int setup_frame(int sig, struct k_sigaction *ka,
240 sigset_t *set, struct pt_regs * regs)
241{
242 sigframe __user *frame;
243
244 frame = get_sigframe(ka, regs, sizeof(sigframe));
245 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
246 goto give_sigsegv;
247
248 if (frame == (void __user *) -1UL)
249 goto give_sigsegv;
250
251 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
252 goto give_sigsegv;
253
254 if (save_sigregs(regs, &frame->sregs))
255 goto give_sigsegv;
256 if (__put_user(&frame->sregs, &frame->sc.sregs))
257 goto give_sigsegv;
258
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;
264 } else {
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)))
269 goto give_sigsegv;
270 }
271
272 /* Set up backchain. */
273 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
274 goto give_sigsegv;
275
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;
280
281 regs->gprs[2] = map_signal(sig);
282 regs->gprs[3] = (unsigned long) &frame->sc;
283
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;
292 }
293
294 /* Place signal number on stack to allow backtrace from handler. */
295 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
296 goto give_sigsegv;
297 return 0;
298
299give_sigsegv:
300 force_sigsegv(sig, current);
301 return -EFAULT;
302}
303
304static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
305 sigset_t *set, struct pt_regs * regs)
306{
307 int err = 0;
308 rt_sigframe __user *frame;
309
310 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
311 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
312 goto give_sigsegv;
313
314 if (frame == (void __user *) -1UL)
315 goto give_sigsegv;
316
317 if (copy_siginfo_to_user(&frame->info, info))
318 goto give_sigsegv;
319
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));
329 if (err)
330 goto give_sigsegv;
331
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;
337 } else {
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)))
342 goto give_sigsegv;
343 }
344
345 /* Set up backchain. */
346 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
347 goto give_sigsegv;
348
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;
353
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;
358 return 0;
359
360give_sigsegv:
361 force_sigsegv(sig, current);
362 return -EFAULT;
363}
364
365static void handle_signal(unsigned long sig, struct k_sigaction *ka,
366 siginfo_t *info, sigset_t *oldset,
367 struct pt_regs *regs)
368{
369 int ret;
370
371 /* Set up the stack frame */
372 if (ka->sa.sa_flags & SA_SIGINFO)
373 ret = setup_rt_frame(sig, ka, info, oldset, regs);
374 else
375 ret = setup_frame(sig, ka, oldset, regs);
376 if (ret)
377 return;
378 signal_delivered(sig, info, ka, regs,
379 test_thread_flag(TIF_SINGLE_STEP));
380}
381
382/*
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
385 * mistake.
386 *
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.
390 */
391void do_signal(struct pt_regs *regs)
392{
393 siginfo_t info;
394 int signr;
395 struct k_sigaction ka;
396 sigset_t *oldset = sigmask_to_save();
397
398 /*
399 * Get signal to deliver. When running under ptrace, at this point
400 * the debugger may change all our registers, including the system
401 * call information.
402 */
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);
406
407 if (signr > 0) {
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;
416 break;
417 case -ERESTARTSYS:
418 if (!(ka.sa.sa_flags & SA_RESTART)) {
419 regs->gprs[2] = -EINTR;
420 break;
421 }
422 /* fallthrough */
423 case -ERESTARTNOINTR:
424 regs->gprs[2] = regs->orig_gpr2;
425 regs->psw.addr =
426 __rewind_psw(regs->psw,
427 regs->int_code >> 16);
428 break;
429 }
430 }
431 /* No longer in a system call */
432 clear_thread_flag(TIF_SYSCALL);
433
434 if (is_compat_task())
435 handle_signal32(signr, &ka, &info, oldset, regs);
436 else
437 handle_signal(signr, &ka, &info, oldset, regs);
438 return;
439 }
440
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;
449 /* fallthrough */
450 case -ERESTARTNOHAND:
451 case -ERESTARTSYS:
452 case -ERESTARTNOINTR:
453 /* Restart system call with magic TIF bit. */
454 regs->gprs[2] = regs->orig_gpr2;
455 set_thread_flag(TIF_SYSCALL);
456 break;
457 }
458 }
459
460 /*
461 * If there's no signal to deliver, we just put the saved sigmask back.
462 */
463 restore_saved_sigmask();
464}
465
466void do_notify_resume(struct pt_regs *regs)
467{
468 clear_thread_flag(TIF_NOTIFY_RESUME);
469 tracehook_notify_resume(regs);
470}