Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 1999, 2006
4 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
5 *
6 * Based on Intel version
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/sched.h>
14#include <linux/sched/task_stack.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 <linux/uaccess.h>
32#include <asm/lowcore.h>
33#include <asm/switch_to.h>
34#include "entry.h"
35
36/*
37 * Layout of an old-style signal-frame:
38 * -----------------------------------------
39 * | save area (_SIGNAL_FRAMESIZE) |
40 * -----------------------------------------
41 * | struct sigcontext |
42 * | oldmask |
43 * | _sigregs * |
44 * -----------------------------------------
45 * | _sigregs with |
46 * | _s390_regs_common |
47 * | _s390_fp_regs |
48 * -----------------------------------------
49 * | int signo |
50 * -----------------------------------------
51 * | _sigregs_ext with |
52 * | gprs_high 64 byte (opt) |
53 * | vxrs_low 128 byte (opt) |
54 * | vxrs_high 256 byte (opt) |
55 * | reserved 128 byte (opt) |
56 * -----------------------------------------
57 * | __u16 svc_insn |
58 * -----------------------------------------
59 * The svc_insn entry with the sigreturn system call opcode does not
60 * have a fixed position and moves if gprs_high or vxrs exist.
61 * Future extensions will be added to _sigregs_ext.
62 */
63struct sigframe
64{
65 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
66 struct sigcontext sc;
67 _sigregs sregs;
68 int signo;
69 _sigregs_ext sregs_ext;
70 __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */
71};
72
73/*
74 * Layout of an rt signal-frame:
75 * -----------------------------------------
76 * | save area (_SIGNAL_FRAMESIZE) |
77 * -----------------------------------------
78 * | svc __NR_rt_sigreturn 2 byte |
79 * -----------------------------------------
80 * | struct siginfo |
81 * -----------------------------------------
82 * | struct ucontext_extended with |
83 * | unsigned long uc_flags |
84 * | struct ucontext *uc_link |
85 * | stack_t uc_stack |
86 * | _sigregs uc_mcontext with |
87 * | _s390_regs_common |
88 * | _s390_fp_regs |
89 * | sigset_t uc_sigmask |
90 * | _sigregs_ext uc_mcontext_ext |
91 * | gprs_high 64 byte (opt) |
92 * | vxrs_low 128 byte (opt) |
93 * | vxrs_high 256 byte (opt)|
94 * | reserved 128 byte (opt) |
95 * -----------------------------------------
96 * Future extensions will be added to _sigregs_ext.
97 */
98struct rt_sigframe
99{
100 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
101 __u16 svc_insn;
102 struct siginfo info;
103 struct ucontext_extended uc;
104};
105
106/* Store registers needed to create the signal frame */
107static void store_sigregs(void)
108{
109 save_access_regs(current->thread.acrs);
110 save_fpu_regs();
111}
112
113/* Load registers after signal return */
114static void load_sigregs(void)
115{
116 restore_access_regs(current->thread.acrs);
117}
118
119/* Returns non-zero on fault. */
120static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
121{
122 _sigregs user_sregs;
123
124 /* Copy a 'clean' PSW mask to the user to avoid leaking
125 information about whether PER is currently on. */
126 user_sregs.regs.psw.mask = PSW_USER_BITS |
127 (regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
128 user_sregs.regs.psw.addr = regs->psw.addr;
129 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
130 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
131 sizeof(user_sregs.regs.acrs));
132 fpregs_store(&user_sregs.fpregs, ¤t->thread.fpu);
133 if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs)))
134 return -EFAULT;
135 return 0;
136}
137
138static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
139{
140 _sigregs user_sregs;
141
142 /* Alwys make any pending restarted system call return -EINTR */
143 current->restart_block.fn = do_no_restart_syscall;
144
145 if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs)))
146 return -EFAULT;
147
148 if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI))
149 return -EINVAL;
150
151 /* Test the floating-point-control word. */
152 if (test_fp_ctl(user_sregs.fpregs.fpc))
153 return -EINVAL;
154
155 /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
156 regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
157 (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
158 /* Check for invalid user address space control. */
159 if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
160 regs->psw.mask = PSW_ASC_PRIMARY |
161 (regs->psw.mask & ~PSW_MASK_ASC);
162 /* Check for invalid amode */
163 if (regs->psw.mask & PSW_MASK_EA)
164 regs->psw.mask |= PSW_MASK_BA;
165 regs->psw.addr = user_sregs.regs.psw.addr;
166 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
167 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
168 sizeof(current->thread.acrs));
169
170 fpregs_load(&user_sregs.fpregs, ¤t->thread.fpu);
171
172 clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
173 return 0;
174}
175
176/* Returns non-zero on fault. */
177static int save_sigregs_ext(struct pt_regs *regs,
178 _sigregs_ext __user *sregs_ext)
179{
180 __u64 vxrs[__NUM_VXRS_LOW];
181 int i;
182
183 /* Save vector registers to signal stack */
184 if (MACHINE_HAS_VX) {
185 for (i = 0; i < __NUM_VXRS_LOW; i++)
186 vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
187 if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
188 sizeof(sregs_ext->vxrs_low)) ||
189 __copy_to_user(&sregs_ext->vxrs_high,
190 current->thread.fpu.vxrs + __NUM_VXRS_LOW,
191 sizeof(sregs_ext->vxrs_high)))
192 return -EFAULT;
193 }
194 return 0;
195}
196
197static int restore_sigregs_ext(struct pt_regs *regs,
198 _sigregs_ext __user *sregs_ext)
199{
200 __u64 vxrs[__NUM_VXRS_LOW];
201 int i;
202
203 /* Restore vector registers from signal stack */
204 if (MACHINE_HAS_VX) {
205 if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
206 sizeof(sregs_ext->vxrs_low)) ||
207 __copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
208 &sregs_ext->vxrs_high,
209 sizeof(sregs_ext->vxrs_high)))
210 return -EFAULT;
211 for (i = 0; i < __NUM_VXRS_LOW; i++)
212 *((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
213 }
214 return 0;
215}
216
217SYSCALL_DEFINE0(sigreturn)
218{
219 struct pt_regs *regs = task_pt_regs(current);
220 struct sigframe __user *frame =
221 (struct sigframe __user *) regs->gprs[15];
222 sigset_t set;
223
224 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
225 goto badframe;
226 set_current_blocked(&set);
227 save_fpu_regs();
228 if (restore_sigregs(regs, &frame->sregs))
229 goto badframe;
230 if (restore_sigregs_ext(regs, &frame->sregs_ext))
231 goto badframe;
232 load_sigregs();
233 return regs->gprs[2];
234badframe:
235 force_sig(SIGSEGV, current);
236 return 0;
237}
238
239SYSCALL_DEFINE0(rt_sigreturn)
240{
241 struct pt_regs *regs = task_pt_regs(current);
242 struct rt_sigframe __user *frame =
243 (struct rt_sigframe __user *)regs->gprs[15];
244 sigset_t set;
245
246 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
247 goto badframe;
248 set_current_blocked(&set);
249 if (restore_altstack(&frame->uc.uc_stack))
250 goto badframe;
251 save_fpu_regs();
252 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
253 goto badframe;
254 if (restore_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
255 goto badframe;
256 load_sigregs();
257 return regs->gprs[2];
258badframe:
259 force_sig(SIGSEGV, current);
260 return 0;
261}
262
263/*
264 * Determine which stack to use..
265 */
266static inline void __user *
267get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
268{
269 unsigned long sp;
270
271 /* Default to using normal stack */
272 sp = regs->gprs[15];
273
274 /* Overflow on alternate signal stack gives SIGSEGV. */
275 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
276 return (void __user *) -1UL;
277
278 /* This is the X/Open sanctioned signal stack switching. */
279 if (ka->sa.sa_flags & SA_ONSTACK) {
280 if (! sas_ss_flags(sp))
281 sp = current->sas_ss_sp + current->sas_ss_size;
282 }
283
284 return (void __user *)((sp - frame_size) & -8ul);
285}
286
287static int setup_frame(int sig, struct k_sigaction *ka,
288 sigset_t *set, struct pt_regs * regs)
289{
290 struct sigframe __user *frame;
291 struct sigcontext sc;
292 unsigned long restorer;
293 size_t frame_size;
294
295 /*
296 * gprs_high are only present for a 31-bit task running on
297 * a 64-bit kernel (see compat_signal.c) but the space for
298 * gprs_high need to be allocated if vector registers are
299 * included in the signal frame on a 31-bit system.
300 */
301 frame_size = sizeof(*frame) - sizeof(frame->sregs_ext);
302 if (MACHINE_HAS_VX)
303 frame_size += sizeof(frame->sregs_ext);
304 frame = get_sigframe(ka, regs, frame_size);
305 if (frame == (void __user *) -1UL)
306 return -EFAULT;
307
308 /* Set up backchain. */
309 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
310 return -EFAULT;
311
312 /* Create struct sigcontext on the signal stack */
313 memcpy(&sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE);
314 sc.sregs = (_sigregs __user __force *) &frame->sregs;
315 if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc)))
316 return -EFAULT;
317
318 /* Store registers needed to create the signal frame */
319 store_sigregs();
320
321 /* Create _sigregs on the signal stack */
322 if (save_sigregs(regs, &frame->sregs))
323 return -EFAULT;
324
325 /* Place signal number on stack to allow backtrace from handler. */
326 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
327 return -EFAULT;
328
329 /* Create _sigregs_ext on the signal stack */
330 if (save_sigregs_ext(regs, &frame->sregs_ext))
331 return -EFAULT;
332
333 /* Set up to return from userspace. If provided, use a stub
334 already in userspace. */
335 if (ka->sa.sa_flags & SA_RESTORER) {
336 restorer = (unsigned long) ka->sa.sa_restorer;
337 } else {
338 /* Signal frame without vector registers are short ! */
339 __u16 __user *svc = (void __user *) frame + frame_size - 2;
340 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
341 return -EFAULT;
342 restorer = (unsigned long) svc;
343 }
344
345 /* Set up registers for signal handler */
346 regs->gprs[14] = restorer;
347 regs->gprs[15] = (unsigned long) frame;
348 /* Force default amode and default user address space control. */
349 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
350 (PSW_USER_BITS & PSW_MASK_ASC) |
351 (regs->psw.mask & ~PSW_MASK_ASC);
352 regs->psw.addr = (unsigned long) ka->sa.sa_handler;
353
354 regs->gprs[2] = sig;
355 regs->gprs[3] = (unsigned long) &frame->sc;
356
357 /* We forgot to include these in the sigcontext.
358 To avoid breaking binary compatibility, they are passed as args. */
359 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
360 sig == SIGTRAP || sig == SIGFPE) {
361 /* set extra registers only for synchronous signals */
362 regs->gprs[4] = regs->int_code & 127;
363 regs->gprs[5] = regs->int_parm_long;
364 regs->gprs[6] = current->thread.last_break;
365 }
366 return 0;
367}
368
369static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
370 struct pt_regs *regs)
371{
372 struct rt_sigframe __user *frame;
373 unsigned long uc_flags, restorer;
374 size_t frame_size;
375
376 frame_size = sizeof(struct rt_sigframe) - sizeof(_sigregs_ext);
377 /*
378 * gprs_high are only present for a 31-bit task running on
379 * a 64-bit kernel (see compat_signal.c) but the space for
380 * gprs_high need to be allocated if vector registers are
381 * included in the signal frame on a 31-bit system.
382 */
383 uc_flags = 0;
384 if (MACHINE_HAS_VX) {
385 frame_size += sizeof(_sigregs_ext);
386 uc_flags |= UC_VXRS;
387 }
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], (addr_t __user *) frame))
394 return -EFAULT;
395
396 /* Set up to return from userspace. If provided, use a stub
397 already in userspace. */
398 if (ksig->ka.sa.sa_flags & SA_RESTORER) {
399 restorer = (unsigned long) ksig->ka.sa.sa_restorer;
400 } else {
401 __u16 __user *svc = &frame->svc_insn;
402 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
403 return -EFAULT;
404 restorer = (unsigned long) svc;
405 }
406
407 /* Create siginfo on the signal stack */
408 if (copy_siginfo_to_user(&frame->info, &ksig->info))
409 return -EFAULT;
410
411 /* Store registers needed to create the signal frame */
412 store_sigregs();
413
414 /* Create ucontext on the signal stack. */
415 if (__put_user(uc_flags, &frame->uc.uc_flags) ||
416 __put_user(NULL, &frame->uc.uc_link) ||
417 __save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
418 save_sigregs(regs, &frame->uc.uc_mcontext) ||
419 __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)) ||
420 save_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
421 return -EFAULT;
422
423 /* Set up registers for signal handler */
424 regs->gprs[14] = restorer;
425 regs->gprs[15] = (unsigned long) frame;
426 /* Force default amode and default user address space control. */
427 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
428 (PSW_USER_BITS & PSW_MASK_ASC) |
429 (regs->psw.mask & ~PSW_MASK_ASC);
430 regs->psw.addr = (unsigned long) ksig->ka.sa.sa_handler;
431
432 regs->gprs[2] = ksig->sig;
433 regs->gprs[3] = (unsigned long) &frame->info;
434 regs->gprs[4] = (unsigned long) &frame->uc;
435 regs->gprs[5] = current->thread.last_break;
436 return 0;
437}
438
439static void handle_signal(struct ksignal *ksig, sigset_t *oldset,
440 struct pt_regs *regs)
441{
442 int ret;
443
444 /* Set up the stack frame */
445 if (ksig->ka.sa.sa_flags & SA_SIGINFO)
446 ret = setup_rt_frame(ksig, oldset, regs);
447 else
448 ret = setup_frame(ksig->sig, &ksig->ka, oldset, regs);
449
450 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
451}
452
453/*
454 * Note that 'init' is a special process: it doesn't get signals it doesn't
455 * want to handle. Thus you cannot kill init even with a SIGKILL even by
456 * mistake.
457 *
458 * Note that we go through the signals twice: once to check the signals that
459 * the kernel can handle, and then we build all the user-level signal handling
460 * stack-frames in one go after that.
461 */
462void do_signal(struct pt_regs *regs)
463{
464 struct ksignal ksig;
465 sigset_t *oldset = sigmask_to_save();
466
467 /*
468 * Get signal to deliver. When running under ptrace, at this point
469 * the debugger may change all our registers, including the system
470 * call information.
471 */
472 current->thread.system_call =
473 test_pt_regs_flag(regs, PIF_SYSCALL) ? regs->int_code : 0;
474
475 if (get_signal(&ksig)) {
476 /* Whee! Actually deliver the signal. */
477 if (current->thread.system_call) {
478 regs->int_code = current->thread.system_call;
479 /* Check for system call restarting. */
480 switch (regs->gprs[2]) {
481 case -ERESTART_RESTARTBLOCK:
482 case -ERESTARTNOHAND:
483 regs->gprs[2] = -EINTR;
484 break;
485 case -ERESTARTSYS:
486 if (!(ksig.ka.sa.sa_flags & SA_RESTART)) {
487 regs->gprs[2] = -EINTR;
488 break;
489 }
490 /* fallthrough */
491 case -ERESTARTNOINTR:
492 regs->gprs[2] = regs->orig_gpr2;
493 regs->psw.addr =
494 __rewind_psw(regs->psw,
495 regs->int_code >> 16);
496 break;
497 }
498 }
499 /* No longer in a system call */
500 clear_pt_regs_flag(regs, PIF_SYSCALL);
501
502 if (is_compat_task())
503 handle_signal32(&ksig, oldset, regs);
504 else
505 handle_signal(&ksig, oldset, regs);
506 return;
507 }
508
509 /* No handlers present - check for system call restart */
510 clear_pt_regs_flag(regs, PIF_SYSCALL);
511 if (current->thread.system_call) {
512 regs->int_code = current->thread.system_call;
513 switch (regs->gprs[2]) {
514 case -ERESTART_RESTARTBLOCK:
515 /* Restart with sys_restart_syscall */
516 regs->int_code = __NR_restart_syscall;
517 /* fallthrough */
518 case -ERESTARTNOHAND:
519 case -ERESTARTSYS:
520 case -ERESTARTNOINTR:
521 /* Restart system call with magic TIF bit. */
522 regs->gprs[2] = regs->orig_gpr2;
523 set_pt_regs_flag(regs, PIF_SYSCALL);
524 if (test_thread_flag(TIF_SINGLE_STEP))
525 clear_pt_regs_flag(regs, PIF_PER_TRAP);
526 break;
527 }
528 }
529
530 /*
531 * If there's no signal to deliver, we just put the saved sigmask back.
532 */
533 restore_saved_sigmask();
534}
535
536void do_notify_resume(struct pt_regs *regs)
537{
538 clear_thread_flag(TIF_NOTIFY_RESUME);
539 tracehook_notify_resume(regs);
540}
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 <asm/uaccess.h>
30#include <asm/lowcore.h>
31#include <asm/switch_to.h>
32#include "entry.h"
33
34typedef struct
35{
36 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
37 struct sigcontext sc;
38 _sigregs sregs;
39 int signo;
40 __u8 retcode[S390_SYSCALL_SIZE];
41} sigframe;
42
43typedef struct
44{
45 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
46 __u8 retcode[S390_SYSCALL_SIZE];
47 struct siginfo info;
48 struct ucontext uc;
49} rt_sigframe;
50
51/* Returns non-zero on fault. */
52static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
53{
54 _sigregs user_sregs;
55
56 save_access_regs(current->thread.acrs);
57
58 /* Copy a 'clean' PSW mask to the user to avoid leaking
59 information about whether PER is currently on. */
60 user_sregs.regs.psw.mask = PSW_USER_BITS |
61 (regs->psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
62 user_sregs.regs.psw.addr = regs->psw.addr;
63 memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
64 memcpy(&user_sregs.regs.acrs, current->thread.acrs,
65 sizeof(user_sregs.regs.acrs));
66 /*
67 * We have to store the fp registers to current->thread.fp_regs
68 * to merge them with the emulated registers.
69 */
70 save_fp_ctl(¤t->thread.fp_regs.fpc);
71 save_fp_regs(current->thread.fp_regs.fprs);
72 memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
73 sizeof(user_sregs.fpregs));
74 if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs)))
75 return -EFAULT;
76 return 0;
77}
78
79static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
80{
81 _sigregs user_sregs;
82
83 /* Alwys make any pending restarted system call return -EINTR */
84 current_thread_info()->restart_block.fn = do_no_restart_syscall;
85
86 if (__copy_from_user(&user_sregs, sregs, sizeof(user_sregs)))
87 return -EFAULT;
88
89 if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI))
90 return -EINVAL;
91
92 /* Loading the floating-point-control word can fail. Do that first. */
93 if (restore_fp_ctl(&user_sregs.fpregs.fpc))
94 return -EINVAL;
95
96 /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
97 regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
98 (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
99 /* Check for invalid user address space control. */
100 if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
101 regs->psw.mask = PSW_ASC_PRIMARY |
102 (regs->psw.mask & ~PSW_MASK_ASC);
103 /* Check for invalid amode */
104 if (regs->psw.mask & PSW_MASK_EA)
105 regs->psw.mask |= PSW_MASK_BA;
106 regs->psw.addr = user_sregs.regs.psw.addr;
107 memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
108 memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
109 sizeof(current->thread.acrs));
110 restore_access_regs(current->thread.acrs);
111
112 memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
113 sizeof(current->thread.fp_regs));
114
115 restore_fp_regs(current->thread.fp_regs.fprs);
116 clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
117 return 0;
118}
119
120SYSCALL_DEFINE0(sigreturn)
121{
122 struct pt_regs *regs = task_pt_regs(current);
123 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
124 sigset_t set;
125
126 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
127 goto badframe;
128 set_current_blocked(&set);
129 if (restore_sigregs(regs, &frame->sregs))
130 goto badframe;
131 return regs->gprs[2];
132badframe:
133 force_sig(SIGSEGV, current);
134 return 0;
135}
136
137SYSCALL_DEFINE0(rt_sigreturn)
138{
139 struct pt_regs *regs = task_pt_regs(current);
140 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
141 sigset_t set;
142
143 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
144 goto badframe;
145 set_current_blocked(&set);
146 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
147 goto badframe;
148 if (restore_altstack(&frame->uc.uc_stack))
149 goto badframe;
150 return regs->gprs[2];
151badframe:
152 force_sig(SIGSEGV, current);
153 return 0;
154}
155
156/*
157 * Set up a signal frame.
158 */
159
160
161/*
162 * Determine which stack to use..
163 */
164static inline void __user *
165get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
166{
167 unsigned long sp;
168
169 /* Default to using normal stack */
170 sp = regs->gprs[15];
171
172 /* Overflow on alternate signal stack gives SIGSEGV. */
173 if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
174 return (void __user *) -1UL;
175
176 /* This is the X/Open sanctioned signal stack switching. */
177 if (ka->sa.sa_flags & SA_ONSTACK) {
178 if (! sas_ss_flags(sp))
179 sp = current->sas_ss_sp + current->sas_ss_size;
180 }
181
182 return (void __user *)((sp - frame_size) & -8ul);
183}
184
185static inline int map_signal(int sig)
186{
187 if (current_thread_info()->exec_domain
188 && current_thread_info()->exec_domain->signal_invmap
189 && sig < 32)
190 return current_thread_info()->exec_domain->signal_invmap[sig];
191 else
192 return sig;
193}
194
195static int setup_frame(int sig, struct k_sigaction *ka,
196 sigset_t *set, struct pt_regs * regs)
197{
198 sigframe __user *frame;
199
200 frame = get_sigframe(ka, regs, sizeof(sigframe));
201
202 if (frame == (void __user *) -1UL)
203 goto give_sigsegv;
204
205 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
206 goto give_sigsegv;
207
208 if (save_sigregs(regs, &frame->sregs))
209 goto give_sigsegv;
210 if (__put_user(&frame->sregs, &frame->sc.sregs))
211 goto give_sigsegv;
212
213 /* Set up to return from userspace. If provided, use a stub
214 already in userspace. */
215 if (ka->sa.sa_flags & SA_RESTORER) {
216 regs->gprs[14] = (unsigned long)
217 ka->sa.sa_restorer | PSW_ADDR_AMODE;
218 } else {
219 regs->gprs[14] = (unsigned long)
220 frame->retcode | PSW_ADDR_AMODE;
221 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
222 (u16 __user *)(frame->retcode)))
223 goto give_sigsegv;
224 }
225
226 /* Set up backchain. */
227 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
228 goto give_sigsegv;
229
230 /* Set up registers for signal handler */
231 regs->gprs[15] = (unsigned long) frame;
232 /* Force default amode and default user address space control. */
233 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
234 (PSW_USER_BITS & PSW_MASK_ASC) |
235 (regs->psw.mask & ~PSW_MASK_ASC);
236 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
237
238 regs->gprs[2] = map_signal(sig);
239 regs->gprs[3] = (unsigned long) &frame->sc;
240
241 /* We forgot to include these in the sigcontext.
242 To avoid breaking binary compatibility, they are passed as args. */
243 if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
244 sig == SIGTRAP || sig == SIGFPE) {
245 /* set extra registers only for synchronous signals */
246 regs->gprs[4] = regs->int_code & 127;
247 regs->gprs[5] = regs->int_parm_long;
248 regs->gprs[6] = task_thread_info(current)->last_break;
249 }
250
251 /* Place signal number on stack to allow backtrace from handler. */
252 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
253 goto give_sigsegv;
254 return 0;
255
256give_sigsegv:
257 force_sigsegv(sig, current);
258 return -EFAULT;
259}
260
261static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
262 sigset_t *set, struct pt_regs * regs)
263{
264 int err = 0;
265 rt_sigframe __user *frame;
266
267 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
268
269 if (frame == (void __user *) -1UL)
270 goto give_sigsegv;
271
272 if (copy_siginfo_to_user(&frame->info, info))
273 goto give_sigsegv;
274
275 /* Create the ucontext. */
276 err |= __put_user(0, &frame->uc.uc_flags);
277 err |= __put_user(NULL, &frame->uc.uc_link);
278 err |= __save_altstack(&frame->uc.uc_stack, regs->gprs[15]);
279 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
280 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
281 if (err)
282 goto give_sigsegv;
283
284 /* Set up to return from userspace. If provided, use a stub
285 already in userspace. */
286 if (ka->sa.sa_flags & SA_RESTORER) {
287 regs->gprs[14] = (unsigned long)
288 ka->sa.sa_restorer | PSW_ADDR_AMODE;
289 } else {
290 regs->gprs[14] = (unsigned long)
291 frame->retcode | PSW_ADDR_AMODE;
292 if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
293 (u16 __user *)(frame->retcode)))
294 goto give_sigsegv;
295 }
296
297 /* Set up backchain. */
298 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
299 goto give_sigsegv;
300
301 /* Set up registers for signal handler */
302 regs->gprs[15] = (unsigned long) frame;
303 /* Force default amode and default user address space control. */
304 regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
305 (PSW_USER_BITS & PSW_MASK_ASC) |
306 (regs->psw.mask & ~PSW_MASK_ASC);
307 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
308
309 regs->gprs[2] = map_signal(sig);
310 regs->gprs[3] = (unsigned long) &frame->info;
311 regs->gprs[4] = (unsigned long) &frame->uc;
312 regs->gprs[5] = task_thread_info(current)->last_break;
313 return 0;
314
315give_sigsegv:
316 force_sigsegv(sig, current);
317 return -EFAULT;
318}
319
320static void handle_signal(unsigned long sig, struct k_sigaction *ka,
321 siginfo_t *info, sigset_t *oldset,
322 struct pt_regs *regs)
323{
324 int ret;
325
326 /* Set up the stack frame */
327 if (ka->sa.sa_flags & SA_SIGINFO)
328 ret = setup_rt_frame(sig, ka, info, oldset, regs);
329 else
330 ret = setup_frame(sig, ka, oldset, regs);
331 if (ret)
332 return;
333 signal_delivered(sig, info, ka, regs,
334 test_thread_flag(TIF_SINGLE_STEP));
335}
336
337/*
338 * Note that 'init' is a special process: it doesn't get signals it doesn't
339 * want to handle. Thus you cannot kill init even with a SIGKILL even by
340 * mistake.
341 *
342 * Note that we go through the signals twice: once to check the signals that
343 * the kernel can handle, and then we build all the user-level signal handling
344 * stack-frames in one go after that.
345 */
346void do_signal(struct pt_regs *regs)
347{
348 siginfo_t info;
349 int signr;
350 struct k_sigaction ka;
351 sigset_t *oldset = sigmask_to_save();
352
353 /*
354 * Get signal to deliver. When running under ptrace, at this point
355 * the debugger may change all our registers, including the system
356 * call information.
357 */
358 current_thread_info()->system_call =
359 test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
360 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
361
362 if (signr > 0) {
363 /* Whee! Actually deliver the signal. */
364 if (current_thread_info()->system_call) {
365 regs->int_code = current_thread_info()->system_call;
366 /* Check for system call restarting. */
367 switch (regs->gprs[2]) {
368 case -ERESTART_RESTARTBLOCK:
369 case -ERESTARTNOHAND:
370 regs->gprs[2] = -EINTR;
371 break;
372 case -ERESTARTSYS:
373 if (!(ka.sa.sa_flags & SA_RESTART)) {
374 regs->gprs[2] = -EINTR;
375 break;
376 }
377 /* fallthrough */
378 case -ERESTARTNOINTR:
379 regs->gprs[2] = regs->orig_gpr2;
380 regs->psw.addr =
381 __rewind_psw(regs->psw,
382 regs->int_code >> 16);
383 break;
384 }
385 }
386 /* No longer in a system call */
387 clear_thread_flag(TIF_SYSCALL);
388
389 if (is_compat_task())
390 handle_signal32(signr, &ka, &info, oldset, regs);
391 else
392 handle_signal(signr, &ka, &info, oldset, regs);
393 return;
394 }
395
396 /* No handlers present - check for system call restart */
397 clear_thread_flag(TIF_SYSCALL);
398 if (current_thread_info()->system_call) {
399 regs->int_code = current_thread_info()->system_call;
400 switch (regs->gprs[2]) {
401 case -ERESTART_RESTARTBLOCK:
402 /* Restart with sys_restart_syscall */
403 regs->int_code = __NR_restart_syscall;
404 /* fallthrough */
405 case -ERESTARTNOHAND:
406 case -ERESTARTSYS:
407 case -ERESTARTNOINTR:
408 /* Restart system call with magic TIF bit. */
409 regs->gprs[2] = regs->orig_gpr2;
410 set_thread_flag(TIF_SYSCALL);
411 if (test_thread_flag(TIF_SINGLE_STEP))
412 set_thread_flag(TIF_PER_TRAP);
413 break;
414 }
415 }
416
417 /*
418 * If there's no signal to deliver, we just put the saved sigmask back.
419 */
420 restore_saved_sigmask();
421}
422
423void do_notify_resume(struct pt_regs *regs)
424{
425 clear_thread_flag(TIF_NOTIFY_RESUME);
426 tracehook_notify_resume(regs);
427}