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1/*
2 * Copyright IBM Corp. 1999, 2006
3 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
4 *
5 * Based on Intel version
6 *
7 * Copyright (C) 1991, 1992 Linus Torvalds
8 *
9 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
10 */
11
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/smp.h>
15#include <linux/kernel.h>
16#include <linux/signal.h>
17#include <linux/errno.h>
18#include <linux/wait.h>
19#include <linux/ptrace.h>
20#include <linux/unistd.h>
21#include <linux/stddef.h>
22#include <linux/tty.h>
23#include <linux/personality.h>
24#include <linux/binfmts.h>
25#include <linux/tracehook.h>
26#include <linux/syscalls.h>
27#include <linux/compat.h>
28#include <asm/ucontext.h>
29#include <linux/uaccess.h>
30#include <asm/lowcore.h>
31#include <asm/switch_to.h>
32#include "entry.h"
33
34/*
35 * Layout of an old-style signal-frame:
36 * -----------------------------------------
37 * | save area (_SIGNAL_FRAMESIZE) |
38 * -----------------------------------------
39 * | struct sigcontext |
40 * | oldmask |
41 * | _sigregs * |
42 * -----------------------------------------
43 * | _sigregs with |
44 * | _s390_regs_common |
45 * | _s390_fp_regs |
46 * -----------------------------------------
47 * | int signo |
48 * -----------------------------------------
49 * | _sigregs_ext with |
50 * | gprs_high 64 byte (opt) |
51 * | vxrs_low 128 byte (opt) |
52 * | vxrs_high 256 byte (opt) |
53 * | reserved 128 byte (opt) |
54 * -----------------------------------------
55 * | __u16 svc_insn |
56 * -----------------------------------------
57 * The svc_insn entry with the sigreturn system call opcode does not
58 * have a fixed position and moves if gprs_high or vxrs exist.
59 * Future extensions will be added to _sigregs_ext.
60 */
61struct sigframe
62{
63 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
64 struct sigcontext sc;
65 _sigregs sregs;
66 int signo;
67 _sigregs_ext sregs_ext;
68 __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */
69};
70
71/*
72 * Layout of an rt signal-frame:
73 * -----------------------------------------
74 * | save area (_SIGNAL_FRAMESIZE) |
75 * -----------------------------------------
76 * | svc __NR_rt_sigreturn 2 byte |
77 * -----------------------------------------
78 * | struct siginfo |
79 * -----------------------------------------
80 * | struct ucontext_extended with |
81 * | unsigned long uc_flags |
82 * | struct ucontext *uc_link |
83 * | stack_t uc_stack |
84 * | _sigregs uc_mcontext with |
85 * | _s390_regs_common |
86 * | _s390_fp_regs |
87 * | sigset_t uc_sigmask |
88 * | _sigregs_ext uc_mcontext_ext |
89 * | gprs_high 64 byte (opt) |
90 * | vxrs_low 128 byte (opt) |
91 * | vxrs_high 256 byte (opt)|
92 * | reserved 128 byte (opt) |
93 * -----------------------------------------
94 * Future extensions will be added to _sigregs_ext.
95 */
96struct rt_sigframe
97{
98 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
99 __u16 svc_insn;
100 struct siginfo info;
101 struct ucontext_extended uc;
102};
103
104/* Store registers needed to create the signal frame */
105static void store_sigregs(void)
106{
107 save_access_regs(current->thread.acrs);
108 save_fpu_regs();
109}
110
111/* Load registers after signal return */
112static void load_sigregs(void)
113{
114 restore_access_regs(current->thread.acrs);
115}
116
117/* Returns non-zero on fault. */
118static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
119{
120 _sigregs user_sregs;
121
122 /* Copy a 'clean' PSW mask to the user to avoid leaking
123 information about whether PER is currently on. */
124 user_sregs.regs.psw.mask = PSW_USER_BITS |
125 (regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
126 user_sregs.regs.psw.addr = regs->psw.addr;
127 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
128 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
129 sizeof(user_sregs.regs.acrs));
130 fpregs_store(&user_sregs.fpregs, ¤t->thread.fpu);
131 if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs)))
132 return -EFAULT;
133 return 0;
134}
135
136static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
137{
138 _sigregs user_sregs;
139
140 /* Alwys make any pending restarted system call return -EINTR */
141 current->restart_block.fn = do_no_restart_syscall;
142
143 if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs)))
144 return -EFAULT;
145
146 if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI))
147 return -EINVAL;
148
149 /* Test the floating-point-control word. */
150 if (test_fp_ctl(user_sregs.fpregs.fpc))
151 return -EINVAL;
152
153 /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
154 regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
155 (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
156 /* Check for invalid user address space control. */
157 if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
158 regs->psw.mask = PSW_ASC_PRIMARY |
159 (regs->psw.mask & ~PSW_MASK_ASC);
160 /* Check for invalid amode */
161 if (regs->psw.mask & PSW_MASK_EA)
162 regs->psw.mask |= PSW_MASK_BA;
163 regs->psw.addr = user_sregs.regs.psw.addr;
164 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
165 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
166 sizeof(current->thread.acrs));
167
168 fpregs_load(&user_sregs.fpregs, ¤t->thread.fpu);
169
170 clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
171 return 0;
172}
173
174/* Returns non-zero on fault. */
175static int save_sigregs_ext(struct pt_regs *regs,
176 _sigregs_ext __user *sregs_ext)
177{
178 __u64 vxrs[__NUM_VXRS_LOW];
179 int i;
180
181 /* Save vector registers to signal stack */
182 if (MACHINE_HAS_VX) {
183 for (i = 0; i < __NUM_VXRS_LOW; i++)
184 vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
185 if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
186 sizeof(sregs_ext->vxrs_low)) ||
187 __copy_to_user(&sregs_ext->vxrs_high,
188 current->thread.fpu.vxrs + __NUM_VXRS_LOW,
189 sizeof(sregs_ext->vxrs_high)))
190 return -EFAULT;
191 }
192 return 0;
193}
194
195static int restore_sigregs_ext(struct pt_regs *regs,
196 _sigregs_ext __user *sregs_ext)
197{
198 __u64 vxrs[__NUM_VXRS_LOW];
199 int i;
200
201 /* Restore vector registers from signal stack */
202 if (MACHINE_HAS_VX) {
203 if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
204 sizeof(sregs_ext->vxrs_low)) ||
205 __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
206 &sregs_ext->vxrs_high,
207 sizeof(sregs_ext->vxrs_high)))
208 return -EFAULT;
209 for (i = 0; i < __NUM_VXRS_LOW; i++)
210 *((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
211 }
212 return 0;
213}
214
215SYSCALL_DEFINE0(sigreturn)
216{
217 struct pt_regs *regs = task_pt_regs(current);
218 struct sigframe __user *frame =
219 (struct sigframe __user *) regs->gprs[15];
220 sigset_t set;
221
222 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
223 goto badframe;
224 set_current_blocked(&set);
225 save_fpu_regs();
226 if (restore_sigregs(regs, &frame->sregs))
227 goto badframe;
228 if (restore_sigregs_ext(regs, &frame->sregs_ext))
229 goto badframe;
230 load_sigregs();
231 return regs->gprs[2];
232badframe:
233 force_sig(SIGSEGV, current);
234 return 0;
235}
236
237SYSCALL_DEFINE0(rt_sigreturn)
238{
239 struct pt_regs *regs = task_pt_regs(current);
240 struct rt_sigframe __user *frame =
241 (struct rt_sigframe __user *)regs->gprs[15];
242 sigset_t set;
243
244 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
245 goto badframe;
246 set_current_blocked(&set);
247 if (restore_altstack(&frame->uc.uc_stack))
248 goto badframe;
249 save_fpu_regs();
250 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
251 goto badframe;
252 if (restore_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
253 goto badframe;
254 load_sigregs();
255 return regs->gprs[2];
256badframe:
257 force_sig(SIGSEGV, current);
258 return 0;
259}
260
261/*
262 * Determine which stack to use..
263 */
264static inline void __user *
265get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
266{
267 unsigned long sp;
268
269 /* Default to using normal stack */
270 sp = regs->gprs[15];
271
272 /* Overflow on alternate signal stack gives SIGSEGV. */
273 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
274 return (void __user *) -1UL;
275
276 /* This is the X/Open sanctioned signal stack switching. */
277 if (ka->sa.sa_flags & SA_ONSTACK) {
278 if (! sas_ss_flags(sp))
279 sp = current->sas_ss_sp + current->sas_ss_size;
280 }
281
282 return (void __user *)((sp - frame_size) & -8ul);
283}
284
285static int setup_frame(int sig, struct k_sigaction *ka,
286 sigset_t *set, struct pt_regs * regs)
287{
288 struct sigframe __user *frame;
289 struct sigcontext sc;
290 unsigned long restorer;
291 size_t frame_size;
292
293 /*
294 * gprs_high are only present for a 31-bit task running on
295 * a 64-bit kernel (see compat_signal.c) but the space for
296 * gprs_high need to be allocated if vector registers are
297 * included in the signal frame on a 31-bit system.
298 */
299 frame_size = sizeof(*frame) - sizeof(frame->sregs_ext);
300 if (MACHINE_HAS_VX)
301 frame_size += sizeof(frame->sregs_ext);
302 frame = get_sigframe(ka, regs, frame_size);
303 if (frame == (void __user *) -1UL)
304 return -EFAULT;
305
306 /* Set up backchain. */
307 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
308 return -EFAULT;
309
310 /* Create struct sigcontext on the signal stack */
311 memcpy(&sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE);
312 sc.sregs = (_sigregs __user __force *) &frame->sregs;
313 if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc)))
314 return -EFAULT;
315
316 /* Store registers needed to create the signal frame */
317 store_sigregs();
318
319 /* Create _sigregs on the signal stack */
320 if (save_sigregs(regs, &frame->sregs))
321 return -EFAULT;
322
323 /* Place signal number on stack to allow backtrace from handler. */
324 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
325 return -EFAULT;
326
327 /* Create _sigregs_ext on the signal stack */
328 if (save_sigregs_ext(regs, &frame->sregs_ext))
329 return -EFAULT;
330
331 /* Set up to return from userspace. If provided, use a stub
332 already in userspace. */
333 if (ka->sa.sa_flags & SA_RESTORER) {
334 restorer = (unsigned long) ka->sa.sa_restorer;
335 } else {
336 /* Signal frame without vector registers are short ! */
337 __u16 __user *svc = (void __user *) frame + frame_size - 2;
338 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
339 return -EFAULT;
340 restorer = (unsigned long) svc;
341 }
342
343 /* Set up registers for signal handler */
344 regs->gprs[14] = restorer;
345 regs->gprs[15] = (unsigned long) frame;
346 /* Force default amode and default user address space control. */
347 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
348 (PSW_USER_BITS & PSW_MASK_ASC) |
349 (regs->psw.mask & ~PSW_MASK_ASC);
350 regs->psw.addr = (unsigned long) ka->sa.sa_handler;
351
352 regs->gprs[2] = sig;
353 regs->gprs[3] = (unsigned long) &frame->sc;
354
355 /* We forgot to include these in the sigcontext.
356 To avoid breaking binary compatibility, they are passed as args. */
357 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
358 sig == SIGTRAP || sig == SIGFPE) {
359 /* set extra registers only for synchronous signals */
360 regs->gprs[4] = regs->int_code & 127;
361 regs->gprs[5] = regs->int_parm_long;
362 regs->gprs[6] = current->thread.last_break;
363 }
364 return 0;
365}
366
367static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
368 struct pt_regs *regs)
369{
370 struct rt_sigframe __user *frame;
371 unsigned long uc_flags, restorer;
372 size_t frame_size;
373
374 frame_size = sizeof(struct rt_sigframe) - sizeof(_sigregs_ext);
375 /*
376 * gprs_high are only present for a 31-bit task running on
377 * a 64-bit kernel (see compat_signal.c) but the space for
378 * gprs_high need to be allocated if vector registers are
379 * included in the signal frame on a 31-bit system.
380 */
381 uc_flags = 0;
382 if (MACHINE_HAS_VX) {
383 frame_size += sizeof(_sigregs_ext);
384 uc_flags |= UC_VXRS;
385 }
386 frame = get_sigframe(&ksig->ka, regs, frame_size);
387 if (frame == (void __user *) -1UL)
388 return -EFAULT;
389
390 /* Set up backchain. */
391 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
392 return -EFAULT;
393
394 /* Set up to return from userspace. If provided, use a stub
395 already in userspace. */
396 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
397 restorer = (unsigned long) ksig->ka.sa.sa_restorer;
398 } else {
399 __u16 __user *svc = &frame->svc_insn;
400 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
401 return -EFAULT;
402 restorer = (unsigned long) svc;
403 }
404
405 /* Create siginfo on the signal stack */
406 if (copy_siginfo_to_user(&frame->info, &ksig->info))
407 return -EFAULT;
408
409 /* Store registers needed to create the signal frame */
410 store_sigregs();
411
412 /* Create ucontext on the signal stack. */
413 if (__put_user(uc_flags, &frame->uc.uc_flags) ||
414 __put_user(NULL, &frame->uc.uc_link) ||
415 __save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
416 save_sigregs(regs, &frame->uc.uc_mcontext) ||
417 __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)) ||
418 save_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
419 return -EFAULT;
420
421 /* Set up registers for signal handler */
422 regs->gprs[14] = restorer;
423 regs->gprs[15] = (unsigned long) frame;
424 /* Force default amode and default user address space control. */
425 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
426 (PSW_USER_BITS & PSW_MASK_ASC) |
427 (regs->psw.mask & ~PSW_MASK_ASC);
428 regs->psw.addr = (unsigned long) ksig->ka.sa.sa_handler;
429
430 regs->gprs[2] = ksig->sig;
431 regs->gprs[3] = (unsigned long) &frame->info;
432 regs->gprs[4] = (unsigned long) &frame->uc;
433 regs->gprs[5] = current->thread.last_break;
434 return 0;
435}
436
437static void handle_signal(struct ksignal *ksig, sigset_t *oldset,
438 struct pt_regs *regs)
439{
440 int ret;
441
442 /* Set up the stack frame */
443 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
444 ret = setup_rt_frame(ksig, oldset, regs);
445 else
446 ret = setup_frame(ksig->sig, &ksig->ka, oldset, regs);
447
448 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
449}
450
451/*
452 * Note that 'init' is a special process: it doesn't get signals it doesn't
453 * want to handle. Thus you cannot kill init even with a SIGKILL even by
454 * mistake.
455 *
456 * Note that we go through the signals twice: once to check the signals that
457 * the kernel can handle, and then we build all the user-level signal handling
458 * stack-frames in one go after that.
459 */
460void do_signal(struct pt_regs *regs)
461{
462 struct ksignal ksig;
463 sigset_t *oldset = sigmask_to_save();
464
465 /*
466 * Get signal to deliver. When running under ptrace, at this point
467 * the debugger may change all our registers, including the system
468 * call information.
469 */
470 current->thread.system_call =
471 test_pt_regs_flag(regs, PIF_SYSCALL) ? regs->int_code : 0;
472
473 if (get_signal(&ksig)) {
474 /* Whee! Actually deliver the signal. */
475 if (current->thread.system_call) {
476 regs->int_code = current->thread.system_call;
477 /* Check for system call restarting. */
478 switch (regs->gprs[2]) {
479 case -ERESTART_RESTARTBLOCK:
480 case -ERESTARTNOHAND:
481 regs->gprs[2] = -EINTR;
482 break;
483 case -ERESTARTSYS:
484 if (!(ksig.ka.sa.sa_flags & SA_RESTART)) {
485 regs->gprs[2] = -EINTR;
486 break;
487 }
488 /* fallthrough */
489 case -ERESTARTNOINTR:
490 regs->gprs[2] = regs->orig_gpr2;
491 regs->psw.addr =
492 __rewind_psw(regs->psw,
493 regs->int_code >> 16);
494 break;
495 }
496 }
497 /* No longer in a system call */
498 clear_pt_regs_flag(regs, PIF_SYSCALL);
499
500 if (is_compat_task())
501 handle_signal32(&ksig, oldset, regs);
502 else
503 handle_signal(&ksig, oldset, regs);
504 return;
505 }
506
507 /* No handlers present - check for system call restart */
508 clear_pt_regs_flag(regs, PIF_SYSCALL);
509 if (current->thread.system_call) {
510 regs->int_code = current->thread.system_call;
511 switch (regs->gprs[2]) {
512 case -ERESTART_RESTARTBLOCK:
513 /* Restart with sys_restart_syscall */
514 regs->int_code = __NR_restart_syscall;
515 /* fallthrough */
516 case -ERESTARTNOHAND:
517 case -ERESTARTSYS:
518 case -ERESTARTNOINTR:
519 /* Restart system call with magic TIF bit. */
520 regs->gprs[2] = regs->orig_gpr2;
521 set_pt_regs_flag(regs, PIF_SYSCALL);
522 if (test_thread_flag(TIF_SINGLE_STEP))
523 clear_pt_regs_flag(regs, PIF_PER_TRAP);
524 break;
525 }
526 }
527
528 /*
529 * If there's no signal to deliver, we just put the saved sigmask back.
530 */
531 restore_saved_sigmask();
532}
533
534void do_notify_resume(struct pt_regs *regs)
535{
536 clear_thread_flag(TIF_NOTIFY_RESUME);
537 tracehook_notify_resume(regs);
538}
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}