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1/*
2 * arch/s390/kernel/compat_signal.c
3 *
4 * Copyright (C) IBM Corp. 2000,2006
5 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
6 * Gerhard Tonn (ton@de.ibm.com)
7 *
8 * Copyright (C) 1991, 1992 Linus Torvalds
9 *
10 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
11 */
12
13#include <linux/compat.h>
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 <asm/ucontext.h>
28#include <asm/uaccess.h>
29#include <asm/lowcore.h>
30#include "compat_linux.h"
31#include "compat_ptrace.h"
32#include "entry.h"
33
34#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
35
36typedef struct
37{
38 __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
39 struct sigcontext32 sc;
40 _sigregs32 sregs;
41 int signo;
42 __u32 gprs_high[NUM_GPRS];
43 __u8 retcode[S390_SYSCALL_SIZE];
44} sigframe32;
45
46typedef struct
47{
48 __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
49 __u8 retcode[S390_SYSCALL_SIZE];
50 compat_siginfo_t info;
51 struct ucontext32 uc;
52 __u32 gprs_high[NUM_GPRS];
53} rt_sigframe32;
54
55int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
56{
57 int err;
58
59 if (!access_ok (VERIFY_WRITE, to, sizeof(compat_siginfo_t)))
60 return -EFAULT;
61
62 /* If you change siginfo_t structure, please be sure
63 this code is fixed accordingly.
64 It should never copy any pad contained in the structure
65 to avoid security leaks, but must copy the generic
66 3 ints plus the relevant union member.
67 This routine must convert siginfo from 64bit to 32bit as well
68 at the same time. */
69 err = __put_user(from->si_signo, &to->si_signo);
70 err |= __put_user(from->si_errno, &to->si_errno);
71 err |= __put_user((short)from->si_code, &to->si_code);
72 if (from->si_code < 0)
73 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
74 else {
75 switch (from->si_code >> 16) {
76 case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
77 case __SI_MESGQ >> 16:
78 err |= __put_user(from->si_int, &to->si_int);
79 /* fallthrough */
80 case __SI_KILL >> 16:
81 err |= __put_user(from->si_pid, &to->si_pid);
82 err |= __put_user(from->si_uid, &to->si_uid);
83 break;
84 case __SI_CHLD >> 16:
85 err |= __put_user(from->si_pid, &to->si_pid);
86 err |= __put_user(from->si_uid, &to->si_uid);
87 err |= __put_user(from->si_utime, &to->si_utime);
88 err |= __put_user(from->si_stime, &to->si_stime);
89 err |= __put_user(from->si_status, &to->si_status);
90 break;
91 case __SI_FAULT >> 16:
92 err |= __put_user((unsigned long) from->si_addr,
93 &to->si_addr);
94 break;
95 case __SI_POLL >> 16:
96 err |= __put_user(from->si_band, &to->si_band);
97 err |= __put_user(from->si_fd, &to->si_fd);
98 break;
99 case __SI_TIMER >> 16:
100 err |= __put_user(from->si_tid, &to->si_tid);
101 err |= __put_user(from->si_overrun, &to->si_overrun);
102 err |= __put_user(from->si_int, &to->si_int);
103 break;
104 default:
105 break;
106 }
107 }
108 return err;
109}
110
111int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
112{
113 int err;
114 u32 tmp;
115
116 if (!access_ok (VERIFY_READ, from, sizeof(compat_siginfo_t)))
117 return -EFAULT;
118
119 err = __get_user(to->si_signo, &from->si_signo);
120 err |= __get_user(to->si_errno, &from->si_errno);
121 err |= __get_user(to->si_code, &from->si_code);
122
123 if (to->si_code < 0)
124 err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
125 else {
126 switch (to->si_code >> 16) {
127 case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
128 case __SI_MESGQ >> 16:
129 err |= __get_user(to->si_int, &from->si_int);
130 /* fallthrough */
131 case __SI_KILL >> 16:
132 err |= __get_user(to->si_pid, &from->si_pid);
133 err |= __get_user(to->si_uid, &from->si_uid);
134 break;
135 case __SI_CHLD >> 16:
136 err |= __get_user(to->si_pid, &from->si_pid);
137 err |= __get_user(to->si_uid, &from->si_uid);
138 err |= __get_user(to->si_utime, &from->si_utime);
139 err |= __get_user(to->si_stime, &from->si_stime);
140 err |= __get_user(to->si_status, &from->si_status);
141 break;
142 case __SI_FAULT >> 16:
143 err |= __get_user(tmp, &from->si_addr);
144 to->si_addr = (void __user *)(u64) (tmp & PSW32_ADDR_INSN);
145 break;
146 case __SI_POLL >> 16:
147 err |= __get_user(to->si_band, &from->si_band);
148 err |= __get_user(to->si_fd, &from->si_fd);
149 break;
150 case __SI_TIMER >> 16:
151 err |= __get_user(to->si_tid, &from->si_tid);
152 err |= __get_user(to->si_overrun, &from->si_overrun);
153 err |= __get_user(to->si_int, &from->si_int);
154 break;
155 default:
156 break;
157 }
158 }
159 return err;
160}
161
162asmlinkage long
163sys32_sigaction(int sig, const struct old_sigaction32 __user *act,
164 struct old_sigaction32 __user *oact)
165{
166 struct k_sigaction new_ka, old_ka;
167 unsigned long sa_handler, sa_restorer;
168 int ret;
169
170 if (act) {
171 compat_old_sigset_t mask;
172 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
173 __get_user(sa_handler, &act->sa_handler) ||
174 __get_user(sa_restorer, &act->sa_restorer) ||
175 __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
176 __get_user(mask, &act->sa_mask))
177 return -EFAULT;
178 new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
179 new_ka.sa.sa_restorer = (void (*)(void)) sa_restorer;
180 siginitset(&new_ka.sa.sa_mask, mask);
181 }
182
183 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
184
185 if (!ret && oact) {
186 sa_handler = (unsigned long) old_ka.sa.sa_handler;
187 sa_restorer = (unsigned long) old_ka.sa.sa_restorer;
188 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
189 __put_user(sa_handler, &oact->sa_handler) ||
190 __put_user(sa_restorer, &oact->sa_restorer) ||
191 __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
192 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
193 return -EFAULT;
194 }
195
196 return ret;
197}
198
199asmlinkage long
200sys32_rt_sigaction(int sig, const struct sigaction32 __user *act,
201 struct sigaction32 __user *oact, size_t sigsetsize)
202{
203 struct k_sigaction new_ka, old_ka;
204 unsigned long sa_handler;
205 int ret;
206 compat_sigset_t set32;
207
208 /* XXX: Don't preclude handling different sized sigset_t's. */
209 if (sigsetsize != sizeof(compat_sigset_t))
210 return -EINVAL;
211
212 if (act) {
213 ret = get_user(sa_handler, &act->sa_handler);
214 ret |= __copy_from_user(&set32, &act->sa_mask,
215 sizeof(compat_sigset_t));
216 switch (_NSIG_WORDS) {
217 case 4: new_ka.sa.sa_mask.sig[3] = set32.sig[6]
218 | (((long)set32.sig[7]) << 32);
219 case 3: new_ka.sa.sa_mask.sig[2] = set32.sig[4]
220 | (((long)set32.sig[5]) << 32);
221 case 2: new_ka.sa.sa_mask.sig[1] = set32.sig[2]
222 | (((long)set32.sig[3]) << 32);
223 case 1: new_ka.sa.sa_mask.sig[0] = set32.sig[0]
224 | (((long)set32.sig[1]) << 32);
225 }
226 ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
227
228 if (ret)
229 return -EFAULT;
230 new_ka.sa.sa_handler = (__sighandler_t) sa_handler;
231 }
232
233 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
234
235 if (!ret && oact) {
236 switch (_NSIG_WORDS) {
237 case 4:
238 set32.sig[7] = (old_ka.sa.sa_mask.sig[3] >> 32);
239 set32.sig[6] = old_ka.sa.sa_mask.sig[3];
240 case 3:
241 set32.sig[5] = (old_ka.sa.sa_mask.sig[2] >> 32);
242 set32.sig[4] = old_ka.sa.sa_mask.sig[2];
243 case 2:
244 set32.sig[3] = (old_ka.sa.sa_mask.sig[1] >> 32);
245 set32.sig[2] = old_ka.sa.sa_mask.sig[1];
246 case 1:
247 set32.sig[1] = (old_ka.sa.sa_mask.sig[0] >> 32);
248 set32.sig[0] = old_ka.sa.sa_mask.sig[0];
249 }
250 ret = put_user((unsigned long)old_ka.sa.sa_handler, &oact->sa_handler);
251 ret |= __copy_to_user(&oact->sa_mask, &set32,
252 sizeof(compat_sigset_t));
253 ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
254 }
255
256 return ret;
257}
258
259asmlinkage long
260sys32_sigaltstack(const stack_t32 __user *uss, stack_t32 __user *uoss)
261{
262 struct pt_regs *regs = task_pt_regs(current);
263 stack_t kss, koss;
264 unsigned long ss_sp;
265 int ret, err = 0;
266 mm_segment_t old_fs = get_fs();
267
268 if (uss) {
269 if (!access_ok(VERIFY_READ, uss, sizeof(*uss)))
270 return -EFAULT;
271 err |= __get_user(ss_sp, &uss->ss_sp);
272 err |= __get_user(kss.ss_size, &uss->ss_size);
273 err |= __get_user(kss.ss_flags, &uss->ss_flags);
274 if (err)
275 return -EFAULT;
276 kss.ss_sp = (void __user *) ss_sp;
277 }
278
279 set_fs (KERNEL_DS);
280 ret = do_sigaltstack((stack_t __force __user *) (uss ? &kss : NULL),
281 (stack_t __force __user *) (uoss ? &koss : NULL),
282 regs->gprs[15]);
283 set_fs (old_fs);
284
285 if (!ret && uoss) {
286 if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss)))
287 return -EFAULT;
288 ss_sp = (unsigned long) koss.ss_sp;
289 err |= __put_user(ss_sp, &uoss->ss_sp);
290 err |= __put_user(koss.ss_size, &uoss->ss_size);
291 err |= __put_user(koss.ss_flags, &uoss->ss_flags);
292 if (err)
293 return -EFAULT;
294 }
295 return ret;
296}
297
298static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
299{
300 _s390_regs_common32 regs32;
301 int err, i;
302
303 regs32.psw.mask = PSW32_MASK_MERGE(psw32_user_bits,
304 (__u32)(regs->psw.mask >> 32));
305 regs32.psw.addr = PSW32_ADDR_AMODE31 | (__u32) regs->psw.addr;
306 for (i = 0; i < NUM_GPRS; i++)
307 regs32.gprs[i] = (__u32) regs->gprs[i];
308 save_access_regs(current->thread.acrs);
309 memcpy(regs32.acrs, current->thread.acrs, sizeof(regs32.acrs));
310 err = __copy_to_user(&sregs->regs, ®s32, sizeof(regs32));
311 if (err)
312 return err;
313 save_fp_regs(¤t->thread.fp_regs);
314 /* s390_fp_regs and _s390_fp_regs32 are the same ! */
315 return __copy_to_user(&sregs->fpregs, ¤t->thread.fp_regs,
316 sizeof(_s390_fp_regs32));
317}
318
319static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
320{
321 _s390_regs_common32 regs32;
322 int err, i;
323
324 /* Alwys make any pending restarted system call return -EINTR */
325 current_thread_info()->restart_block.fn = do_no_restart_syscall;
326
327 err = __copy_from_user(®s32, &sregs->regs, sizeof(regs32));
328 if (err)
329 return err;
330 regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
331 (__u64)regs32.psw.mask << 32);
332 regs->psw.addr = (__u64)(regs32.psw.addr & PSW32_ADDR_INSN);
333 for (i = 0; i < NUM_GPRS; i++)
334 regs->gprs[i] = (__u64) regs32.gprs[i];
335 memcpy(current->thread.acrs, regs32.acrs, sizeof(current->thread.acrs));
336 restore_access_regs(current->thread.acrs);
337
338 err = __copy_from_user(¤t->thread.fp_regs, &sregs->fpregs,
339 sizeof(_s390_fp_regs32));
340 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
341 if (err)
342 return err;
343
344 restore_fp_regs(¤t->thread.fp_regs);
345 regs->svcnr = 0; /* disable syscall checks */
346 return 0;
347}
348
349static int save_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs)
350{
351 __u32 gprs_high[NUM_GPRS];
352 int i;
353
354 for (i = 0; i < NUM_GPRS; i++)
355 gprs_high[i] = regs->gprs[i] >> 32;
356
357 return __copy_to_user(uregs, &gprs_high, sizeof(gprs_high));
358}
359
360static int restore_sigregs_gprs_high(struct pt_regs *regs, __u32 __user *uregs)
361{
362 __u32 gprs_high[NUM_GPRS];
363 int err, i;
364
365 err = __copy_from_user(&gprs_high, uregs, sizeof(gprs_high));
366 if (err)
367 return err;
368 for (i = 0; i < NUM_GPRS; i++)
369 *(__u32 *)®s->gprs[i] = gprs_high[i];
370 return 0;
371}
372
373asmlinkage long sys32_sigreturn(void)
374{
375 struct pt_regs *regs = task_pt_regs(current);
376 sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
377 sigset_t set;
378
379 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
380 goto badframe;
381 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
382 goto badframe;
383 sigdelsetmask(&set, ~_BLOCKABLE);
384 set_current_blocked(&set);
385 if (restore_sigregs32(regs, &frame->sregs))
386 goto badframe;
387 if (restore_sigregs_gprs_high(regs, frame->gprs_high))
388 goto badframe;
389 return regs->gprs[2];
390badframe:
391 force_sig(SIGSEGV, current);
392 return 0;
393}
394
395asmlinkage long sys32_rt_sigreturn(void)
396{
397 struct pt_regs *regs = task_pt_regs(current);
398 rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
399 sigset_t set;
400 stack_t st;
401 __u32 ss_sp;
402 int err;
403 mm_segment_t old_fs = get_fs();
404
405 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
406 goto badframe;
407 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
408 goto badframe;
409 sigdelsetmask(&set, ~_BLOCKABLE);
410 set_current_blocked(&set);
411 if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
412 goto badframe;
413 if (restore_sigregs_gprs_high(regs, frame->gprs_high))
414 goto badframe;
415 err = __get_user(ss_sp, &frame->uc.uc_stack.ss_sp);
416 st.ss_sp = compat_ptr(ss_sp);
417 err |= __get_user(st.ss_size, &frame->uc.uc_stack.ss_size);
418 err |= __get_user(st.ss_flags, &frame->uc.uc_stack.ss_flags);
419 if (err)
420 goto badframe;
421 set_fs (KERNEL_DS);
422 do_sigaltstack((stack_t __force __user *)&st, NULL, regs->gprs[15]);
423 set_fs (old_fs);
424 return regs->gprs[2];
425badframe:
426 force_sig(SIGSEGV, current);
427 return 0;
428}
429
430/*
431 * Set up a signal frame.
432 */
433
434
435/*
436 * Determine which stack to use..
437 */
438static inline void __user *
439get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
440{
441 unsigned long sp;
442
443 /* Default to using normal stack */
444 sp = (unsigned long) A(regs->gprs[15]);
445
446 /* Overflow on alternate signal stack gives SIGSEGV. */
447 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
448 return (void __user *) -1UL;
449
450 /* This is the X/Open sanctioned signal stack switching. */
451 if (ka->sa.sa_flags & SA_ONSTACK) {
452 if (! sas_ss_flags(sp))
453 sp = current->sas_ss_sp + current->sas_ss_size;
454 }
455
456 /* This is the legacy signal stack switching. */
457 else if (!user_mode(regs) &&
458 !(ka->sa.sa_flags & SA_RESTORER) &&
459 ka->sa.sa_restorer) {
460 sp = (unsigned long) ka->sa.sa_restorer;
461 }
462
463 return (void __user *)((sp - frame_size) & -8ul);
464}
465
466static inline int map_signal(int sig)
467{
468 if (current_thread_info()->exec_domain
469 && current_thread_info()->exec_domain->signal_invmap
470 && sig < 32)
471 return current_thread_info()->exec_domain->signal_invmap[sig];
472 else
473 return sig;
474}
475
476static int setup_frame32(int sig, struct k_sigaction *ka,
477 sigset_t *set, struct pt_regs * regs)
478{
479 sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(sigframe32));
480 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe32)))
481 goto give_sigsegv;
482
483 if (frame == (void __user *) -1UL)
484 goto give_sigsegv;
485
486 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE32))
487 goto give_sigsegv;
488
489 if (save_sigregs32(regs, &frame->sregs))
490 goto give_sigsegv;
491 if (save_sigregs_gprs_high(regs, frame->gprs_high))
492 goto give_sigsegv;
493 if (__put_user((unsigned long) &frame->sregs, &frame->sc.sregs))
494 goto give_sigsegv;
495
496 /* Set up to return from userspace. If provided, use a stub
497 already in userspace. */
498 if (ka->sa.sa_flags & SA_RESTORER) {
499 regs->gprs[14] = (__u64) ka->sa.sa_restorer;
500 } else {
501 regs->gprs[14] = (__u64) frame->retcode;
502 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
503 (u16 __user *)(frame->retcode)))
504 goto give_sigsegv;
505 }
506
507 /* Set up backchain. */
508 if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
509 goto give_sigsegv;
510
511 /* Set up registers for signal handler */
512 regs->gprs[15] = (__u64) frame;
513 regs->psw.addr = (__u64) ka->sa.sa_handler;
514
515 regs->gprs[2] = map_signal(sig);
516 regs->gprs[3] = (__u64) &frame->sc;
517
518 /* We forgot to include these in the sigcontext.
519 To avoid breaking binary compatibility, they are passed as args. */
520 regs->gprs[4] = current->thread.trap_no;
521 regs->gprs[5] = current->thread.prot_addr;
522
523 /* Place signal number on stack to allow backtrace from handler. */
524 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
525 goto give_sigsegv;
526 return 0;
527
528give_sigsegv:
529 force_sigsegv(sig, current);
530 return -EFAULT;
531}
532
533static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
534 sigset_t *set, struct pt_regs * regs)
535{
536 int err = 0;
537 rt_sigframe32 __user *frame = get_sigframe(ka, regs, sizeof(rt_sigframe32));
538 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe32)))
539 goto give_sigsegv;
540
541 if (frame == (void __user *) -1UL)
542 goto give_sigsegv;
543
544 if (copy_siginfo_to_user32(&frame->info, info))
545 goto give_sigsegv;
546
547 /* Create the ucontext. */
548 err |= __put_user(UC_EXTENDED, &frame->uc.uc_flags);
549 err |= __put_user(0, &frame->uc.uc_link);
550 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
551 err |= __put_user(sas_ss_flags(regs->gprs[15]),
552 &frame->uc.uc_stack.ss_flags);
553 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
554 err |= save_sigregs32(regs, &frame->uc.uc_mcontext);
555 err |= save_sigregs_gprs_high(regs, frame->gprs_high);
556 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
557 if (err)
558 goto give_sigsegv;
559
560 /* Set up to return from userspace. If provided, use a stub
561 already in userspace. */
562 if (ka->sa.sa_flags & SA_RESTORER) {
563 regs->gprs[14] = (__u64) ka->sa.sa_restorer;
564 } else {
565 regs->gprs[14] = (__u64) frame->retcode;
566 err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
567 (u16 __user *)(frame->retcode));
568 }
569
570 /* Set up backchain. */
571 if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
572 goto give_sigsegv;
573
574 /* Set up registers for signal handler */
575 regs->gprs[15] = (__u64) frame;
576 regs->psw.addr = (__u64) ka->sa.sa_handler;
577
578 regs->gprs[2] = map_signal(sig);
579 regs->gprs[3] = (__u64) &frame->info;
580 regs->gprs[4] = (__u64) &frame->uc;
581 return 0;
582
583give_sigsegv:
584 force_sigsegv(sig, current);
585 return -EFAULT;
586}
587
588/*
589 * OK, we're invoking a handler
590 */
591
592int handle_signal32(unsigned long sig, struct k_sigaction *ka,
593 siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
594{
595 sigset_t blocked;
596 int ret;
597
598 /* Set up the stack frame */
599 if (ka->sa.sa_flags & SA_SIGINFO)
600 ret = setup_rt_frame32(sig, ka, info, oldset, regs);
601 else
602 ret = setup_frame32(sig, ka, oldset, regs);
603 if (ret)
604 return ret;
605 sigorsets(&blocked, ¤t->blocked, &ka->sa.sa_mask);
606 if (!(ka->sa.sa_flags & SA_NODEFER))
607 sigaddset(&blocked, sig);
608 set_current_blocked(&blocked);
609 return 0;
610}
611
1/*
2 * Copyright IBM Corp. 2000, 2006
3 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
4 * Gerhard Tonn (ton@de.ibm.com)
5 *
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 *
8 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
9 */
10
11#include <linux/compat.h>
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 <asm/ucontext.h>
26#include <asm/uaccess.h>
27#include <asm/lowcore.h>
28#include <asm/switch_to.h>
29#include "compat_linux.h"
30#include "compat_ptrace.h"
31#include "entry.h"
32
33typedef struct
34{
35 __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
36 struct sigcontext32 sc;
37 _sigregs32 sregs;
38 int signo;
39 _sigregs_ext32 sregs_ext;
40 __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */
41} sigframe32;
42
43typedef struct
44{
45 __u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
46 __u16 svc_insn;
47 compat_siginfo_t info;
48 struct ucontext32 uc;
49} rt_sigframe32;
50
51static inline void sigset_to_sigset32(unsigned long *set64,
52 compat_sigset_word *set32)
53{
54 set32[0] = (compat_sigset_word) set64[0];
55 set32[1] = (compat_sigset_word)(set64[0] >> 32);
56}
57
58static inline void sigset32_to_sigset(compat_sigset_word *set32,
59 unsigned long *set64)
60{
61 set64[0] = (unsigned long) set32[0] | ((unsigned long) set32[1] << 32);
62}
63
64int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
65{
66 int err;
67
68 /* If you change siginfo_t structure, please be sure
69 this code is fixed accordingly.
70 It should never copy any pad contained in the structure
71 to avoid security leaks, but must copy the generic
72 3 ints plus the relevant union member.
73 This routine must convert siginfo from 64bit to 32bit as well
74 at the same time. */
75 err = __put_user(from->si_signo, &to->si_signo);
76 err |= __put_user(from->si_errno, &to->si_errno);
77 err |= __put_user((short)from->si_code, &to->si_code);
78 if (from->si_code < 0)
79 err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
80 else {
81 switch (from->si_code >> 16) {
82 case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
83 case __SI_MESGQ >> 16:
84 err |= __put_user(from->si_int, &to->si_int);
85 /* fallthrough */
86 case __SI_KILL >> 16:
87 err |= __put_user(from->si_pid, &to->si_pid);
88 err |= __put_user(from->si_uid, &to->si_uid);
89 break;
90 case __SI_CHLD >> 16:
91 err |= __put_user(from->si_pid, &to->si_pid);
92 err |= __put_user(from->si_uid, &to->si_uid);
93 err |= __put_user(from->si_utime, &to->si_utime);
94 err |= __put_user(from->si_stime, &to->si_stime);
95 err |= __put_user(from->si_status, &to->si_status);
96 break;
97 case __SI_FAULT >> 16:
98 err |= __put_user((unsigned long) from->si_addr,
99 &to->si_addr);
100 break;
101 case __SI_POLL >> 16:
102 err |= __put_user(from->si_band, &to->si_band);
103 err |= __put_user(from->si_fd, &to->si_fd);
104 break;
105 case __SI_TIMER >> 16:
106 err |= __put_user(from->si_tid, &to->si_tid);
107 err |= __put_user(from->si_overrun, &to->si_overrun);
108 err |= __put_user(from->si_int, &to->si_int);
109 break;
110 default:
111 break;
112 }
113 }
114 return err ? -EFAULT : 0;
115}
116
117int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
118{
119 int err;
120 u32 tmp;
121
122 err = __get_user(to->si_signo, &from->si_signo);
123 err |= __get_user(to->si_errno, &from->si_errno);
124 err |= __get_user(to->si_code, &from->si_code);
125
126 if (to->si_code < 0)
127 err |= __copy_from_user(&to->_sifields._pad, &from->_sifields._pad, SI_PAD_SIZE);
128 else {
129 switch (to->si_code >> 16) {
130 case __SI_RT >> 16: /* This is not generated by the kernel as of now. */
131 case __SI_MESGQ >> 16:
132 err |= __get_user(to->si_int, &from->si_int);
133 /* fallthrough */
134 case __SI_KILL >> 16:
135 err |= __get_user(to->si_pid, &from->si_pid);
136 err |= __get_user(to->si_uid, &from->si_uid);
137 break;
138 case __SI_CHLD >> 16:
139 err |= __get_user(to->si_pid, &from->si_pid);
140 err |= __get_user(to->si_uid, &from->si_uid);
141 err |= __get_user(to->si_utime, &from->si_utime);
142 err |= __get_user(to->si_stime, &from->si_stime);
143 err |= __get_user(to->si_status, &from->si_status);
144 break;
145 case __SI_FAULT >> 16:
146 err |= __get_user(tmp, &from->si_addr);
147 to->si_addr = (void __force __user *)
148 (u64) (tmp & PSW32_ADDR_INSN);
149 break;
150 case __SI_POLL >> 16:
151 err |= __get_user(to->si_band, &from->si_band);
152 err |= __get_user(to->si_fd, &from->si_fd);
153 break;
154 case __SI_TIMER >> 16:
155 err |= __get_user(to->si_tid, &from->si_tid);
156 err |= __get_user(to->si_overrun, &from->si_overrun);
157 err |= __get_user(to->si_int, &from->si_int);
158 break;
159 default:
160 break;
161 }
162 }
163 return err ? -EFAULT : 0;
164}
165
166/* Store registers needed to create the signal frame */
167static void store_sigregs(void)
168{
169 save_access_regs(current->thread.acrs);
170 save_fpu_regs();
171}
172
173/* Load registers after signal return */
174static void load_sigregs(void)
175{
176 restore_access_regs(current->thread.acrs);
177}
178
179static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
180{
181 _sigregs32 user_sregs;
182 int i;
183
184 user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32);
185 user_sregs.regs.psw.mask &= PSW32_MASK_USER | PSW32_MASK_RI;
186 user_sregs.regs.psw.mask |= PSW32_USER_BITS;
187 user_sregs.regs.psw.addr = (__u32) regs->psw.addr |
188 (__u32)(regs->psw.mask & PSW_MASK_BA);
189 for (i = 0; i < NUM_GPRS; i++)
190 user_sregs.regs.gprs[i] = (__u32) regs->gprs[i];
191 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
192 sizeof(user_sregs.regs.acrs));
193 fpregs_store((_s390_fp_regs *) &user_sregs.fpregs, ¤t->thread.fpu);
194 if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32)))
195 return -EFAULT;
196 return 0;
197}
198
199static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
200{
201 _sigregs32 user_sregs;
202 int i;
203
204 /* Alwys make any pending restarted system call return -EINTR */
205 current->restart_block.fn = do_no_restart_syscall;
206
207 if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs)))
208 return -EFAULT;
209
210 if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI))
211 return -EINVAL;
212
213 /* Test the floating-point-control word. */
214 if (test_fp_ctl(user_sregs.fpregs.fpc))
215 return -EINVAL;
216
217 /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
218 regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
219 (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 |
220 (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 |
221 (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);
222 /* Check for invalid user address space control. */
223 if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
224 regs->psw.mask = PSW_ASC_PRIMARY |
225 (regs->psw.mask & ~PSW_MASK_ASC);
226 regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN);
227 for (i = 0; i < NUM_GPRS; i++)
228 regs->gprs[i] = (__u64) user_sregs.regs.gprs[i];
229 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
230 sizeof(current->thread.acrs));
231 fpregs_load((_s390_fp_regs *) &user_sregs.fpregs, ¤t->thread.fpu);
232
233 clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
234 return 0;
235}
236
237static int save_sigregs_ext32(struct pt_regs *regs,
238 _sigregs_ext32 __user *sregs_ext)
239{
240 __u32 gprs_high[NUM_GPRS];
241 __u64 vxrs[__NUM_VXRS_LOW];
242 int i;
243
244 /* Save high gprs to signal stack */
245 for (i = 0; i < NUM_GPRS; i++)
246 gprs_high[i] = regs->gprs[i] >> 32;
247 if (__copy_to_user(&sregs_ext->gprs_high, &gprs_high,
248 sizeof(sregs_ext->gprs_high)))
249 return -EFAULT;
250
251 /* Save vector registers to signal stack */
252 if (MACHINE_HAS_VX) {
253 for (i = 0; i < __NUM_VXRS_LOW; i++)
254 vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
255 if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
256 sizeof(sregs_ext->vxrs_low)) ||
257 __copy_to_user(&sregs_ext->vxrs_high,
258 current->thread.fpu.vxrs + __NUM_VXRS_LOW,
259 sizeof(sregs_ext->vxrs_high)))
260 return -EFAULT;
261 }
262 return 0;
263}
264
265static int restore_sigregs_ext32(struct pt_regs *regs,
266 _sigregs_ext32 __user *sregs_ext)
267{
268 __u32 gprs_high[NUM_GPRS];
269 __u64 vxrs[__NUM_VXRS_LOW];
270 int i;
271
272 /* Restore high gprs from signal stack */
273 if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high,
274 sizeof(sregs_ext->gprs_high)))
275 return -EFAULT;
276 for (i = 0; i < NUM_GPRS; i++)
277 *(__u32 *)®s->gprs[i] = gprs_high[i];
278
279 /* Restore vector registers from signal stack */
280 if (MACHINE_HAS_VX) {
281 if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
282 sizeof(sregs_ext->vxrs_low)) ||
283 __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
284 &sregs_ext->vxrs_high,
285 sizeof(sregs_ext->vxrs_high)))
286 return -EFAULT;
287 for (i = 0; i < __NUM_VXRS_LOW; i++)
288 *((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
289 }
290 return 0;
291}
292
293COMPAT_SYSCALL_DEFINE0(sigreturn)
294{
295 struct pt_regs *regs = task_pt_regs(current);
296 sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
297 compat_sigset_t cset;
298 sigset_t set;
299
300 if (__copy_from_user(&cset.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE32))
301 goto badframe;
302 sigset32_to_sigset(cset.sig, set.sig);
303 set_current_blocked(&set);
304 save_fpu_regs();
305 if (restore_sigregs32(regs, &frame->sregs))
306 goto badframe;
307 if (restore_sigregs_ext32(regs, &frame->sregs_ext))
308 goto badframe;
309 load_sigregs();
310 return regs->gprs[2];
311badframe:
312 force_sig(SIGSEGV, current);
313 return 0;
314}
315
316COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
317{
318 struct pt_regs *regs = task_pt_regs(current);
319 rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
320 compat_sigset_t cset;
321 sigset_t set;
322
323 if (__copy_from_user(&cset, &frame->uc.uc_sigmask, sizeof(cset)))
324 goto badframe;
325 sigset32_to_sigset(cset.sig, set.sig);
326 set_current_blocked(&set);
327 if (compat_restore_altstack(&frame->uc.uc_stack))
328 goto badframe;
329 save_fpu_regs();
330 if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
331 goto badframe;
332 if (restore_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
333 goto badframe;
334 load_sigregs();
335 return regs->gprs[2];
336badframe:
337 force_sig(SIGSEGV, current);
338 return 0;
339}
340
341/*
342 * Set up a signal frame.
343 */
344
345
346/*
347 * Determine which stack to use..
348 */
349static inline void __user *
350get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
351{
352 unsigned long sp;
353
354 /* Default to using normal stack */
355 sp = (unsigned long) A(regs->gprs[15]);
356
357 /* Overflow on alternate signal stack gives SIGSEGV. */
358 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
359 return (void __user *) -1UL;
360
361 /* This is the X/Open sanctioned signal stack switching. */
362 if (ka->sa.sa_flags & SA_ONSTACK) {
363 if (! sas_ss_flags(sp))
364 sp = current->sas_ss_sp + current->sas_ss_size;
365 }
366
367 return (void __user *)((sp - frame_size) & -8ul);
368}
369
370static int setup_frame32(struct ksignal *ksig, sigset_t *set,
371 struct pt_regs *regs)
372{
373 int sig = ksig->sig;
374 sigframe32 __user *frame;
375 struct sigcontext32 sc;
376 unsigned long restorer;
377 size_t frame_size;
378
379 /*
380 * gprs_high are always present for 31-bit compat tasks.
381 * The space for vector registers is only allocated if
382 * the machine supports it
383 */
384 frame_size = sizeof(*frame) - sizeof(frame->sregs_ext.__reserved);
385 if (!MACHINE_HAS_VX)
386 frame_size -= sizeof(frame->sregs_ext.vxrs_low) +
387 sizeof(frame->sregs_ext.vxrs_high);
388 frame = get_sigframe(&ksig->ka, regs, frame_size);
389 if (frame == (void __user *) -1UL)
390 return -EFAULT;
391
392 /* Set up backchain. */
393 if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
394 return -EFAULT;
395
396 /* Create struct sigcontext32 on the signal stack */
397 sigset_to_sigset32(set->sig, sc.oldmask);
398 sc.sregs = (__u32)(unsigned long __force) &frame->sregs;
399 if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc)))
400 return -EFAULT;
401
402 /* Store registers needed to create the signal frame */
403 store_sigregs();
404
405 /* Create _sigregs32 on the signal stack */
406 if (save_sigregs32(regs, &frame->sregs))
407 return -EFAULT;
408
409 /* Place signal number on stack to allow backtrace from handler. */
410 if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo))
411 return -EFAULT;
412
413 /* Create _sigregs_ext32 on the signal stack */
414 if (save_sigregs_ext32(regs, &frame->sregs_ext))
415 return -EFAULT;
416
417 /* Set up to return from userspace. If provided, use a stub
418 already in userspace. */
419 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
420 restorer = (unsigned long __force)
421 ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
422 } else {
423 /* Signal frames without vectors registers are short ! */
424 __u16 __user *svc = (void __user *) frame + frame_size - 2;
425 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
426 return -EFAULT;
427 restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
428 }
429
430 /* Set up registers for signal handler */
431 regs->gprs[14] = restorer;
432 regs->gprs[15] = (__force __u64) frame;
433 /* Force 31 bit amode and default user address space control. */
434 regs->psw.mask = PSW_MASK_BA |
435 (PSW_USER_BITS & PSW_MASK_ASC) |
436 (regs->psw.mask & ~PSW_MASK_ASC);
437 regs->psw.addr = (__force __u64) ksig->ka.sa.sa_handler;
438
439 regs->gprs[2] = sig;
440 regs->gprs[3] = (__force __u64) &frame->sc;
441
442 /* We forgot to include these in the sigcontext.
443 To avoid breaking binary compatibility, they are passed as args. */
444 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
445 sig == SIGTRAP || sig == SIGFPE) {
446 /* set extra registers only for synchronous signals */
447 regs->gprs[4] = regs->int_code & 127;
448 regs->gprs[5] = regs->int_parm_long;
449 regs->gprs[6] = task_thread_info(current)->last_break;
450 }
451
452 return 0;
453}
454
455static int setup_rt_frame32(struct ksignal *ksig, sigset_t *set,
456 struct pt_regs *regs)
457{
458 compat_sigset_t cset;
459 rt_sigframe32 __user *frame;
460 unsigned long restorer;
461 size_t frame_size;
462 u32 uc_flags;
463
464 frame_size = sizeof(*frame) -
465 sizeof(frame->uc.uc_mcontext_ext.__reserved);
466 /*
467 * gprs_high are always present for 31-bit compat tasks.
468 * The space for vector registers is only allocated if
469 * the machine supports it
470 */
471 uc_flags = UC_GPRS_HIGH;
472 if (MACHINE_HAS_VX) {
473 uc_flags |= UC_VXRS;
474 } else
475 frame_size -= sizeof(frame->uc.uc_mcontext_ext.vxrs_low) +
476 sizeof(frame->uc.uc_mcontext_ext.vxrs_high);
477 frame = get_sigframe(&ksig->ka, regs, frame_size);
478 if (frame == (void __user *) -1UL)
479 return -EFAULT;
480
481 /* Set up backchain. */
482 if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame))
483 return -EFAULT;
484
485 /* Set up to return from userspace. If provided, use a stub
486 already in userspace. */
487 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
488 restorer = (unsigned long __force)
489 ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
490 } else {
491 __u16 __user *svc = &frame->svc_insn;
492 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
493 return -EFAULT;
494 restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
495 }
496
497 /* Create siginfo on the signal stack */
498 if (copy_siginfo_to_user32(&frame->info, &ksig->info))
499 return -EFAULT;
500
501 /* Store registers needed to create the signal frame */
502 store_sigregs();
503
504 /* Create ucontext on the signal stack. */
505 sigset_to_sigset32(set->sig, cset.sig);
506 if (__put_user(uc_flags, &frame->uc.uc_flags) ||
507 __put_user(0, &frame->uc.uc_link) ||
508 __compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
509 save_sigregs32(regs, &frame->uc.uc_mcontext) ||
510 __copy_to_user(&frame->uc.uc_sigmask, &cset, sizeof(cset)) ||
511 save_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
512 return -EFAULT;
513
514 /* Set up registers for signal handler */
515 regs->gprs[14] = restorer;
516 regs->gprs[15] = (__force __u64) frame;
517 /* Force 31 bit amode and default user address space control. */
518 regs->psw.mask = PSW_MASK_BA |
519 (PSW_USER_BITS & PSW_MASK_ASC) |
520 (regs->psw.mask & ~PSW_MASK_ASC);
521 regs->psw.addr = (__u64 __force) ksig->ka.sa.sa_handler;
522
523 regs->gprs[2] = ksig->sig;
524 regs->gprs[3] = (__force __u64) &frame->info;
525 regs->gprs[4] = (__force __u64) &frame->uc;
526 regs->gprs[5] = task_thread_info(current)->last_break;
527 return 0;
528}
529
530/*
531 * OK, we're invoking a handler
532 */
533
534void handle_signal32(struct ksignal *ksig, sigset_t *oldset,
535 struct pt_regs *regs)
536{
537 int ret;
538
539 /* Set up the stack frame */
540 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
541 ret = setup_rt_frame32(ksig, oldset, regs);
542 else
543 ret = setup_frame32(ksig, oldset, regs);
544
545 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
546}
547