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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/s390/kernel/signal.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/s390/kernel/signal.c')
-rw-r--r--arch/s390/kernel/signal.c527
1 files changed, 527 insertions, 0 deletions
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
new file mode 100644
index 000000000000..610c1d03e975
--- /dev/null
+++ b/arch/s390/kernel/signal.c
@@ -0,0 +1,527 @@
1/*
2 * arch/s390/kernel/signal.c
3 *
4 * S390 version
5 * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
7 *
8 * Based on Intel version
9 *
10 * Copyright (C) 1991, 1992 Linus Torvalds
11 *
12 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
13 */
14
15#include <linux/config.h>
16#include <linux/sched.h>
17#include <linux/mm.h>
18#include <linux/smp.h>
19#include <linux/smp_lock.h>
20#include <linux/kernel.h>
21#include <linux/signal.h>
22#include <linux/errno.h>
23#include <linux/wait.h>
24#include <linux/ptrace.h>
25#include <linux/unistd.h>
26#include <linux/stddef.h>
27#include <linux/tty.h>
28#include <linux/personality.h>
29#include <linux/binfmts.h>
30#include <asm/ucontext.h>
31#include <asm/uaccess.h>
32#include <asm/lowcore.h>
33
34#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
35
36
37typedef struct
38{
39 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
40 struct sigcontext sc;
41 _sigregs sregs;
42 int signo;
43 __u8 retcode[S390_SYSCALL_SIZE];
44} sigframe;
45
46typedef struct
47{
48 __u8 callee_used_stack[__SIGNAL_FRAMESIZE];
49 __u8 retcode[S390_SYSCALL_SIZE];
50 struct siginfo info;
51 struct ucontext uc;
52} rt_sigframe;
53
54int do_signal(struct pt_regs *regs, sigset_t *oldset);
55
56/*
57 * Atomically swap in the new signal mask, and wait for a signal.
58 */
59asmlinkage int
60sys_sigsuspend(struct pt_regs * regs, int history0, int history1,
61 old_sigset_t mask)
62{
63 sigset_t saveset;
64
65 mask &= _BLOCKABLE;
66 spin_lock_irq(&current->sighand->siglock);
67 saveset = current->blocked;
68 siginitset(&current->blocked, mask);
69 recalc_sigpending();
70 spin_unlock_irq(&current->sighand->siglock);
71 regs->gprs[2] = -EINTR;
72
73 while (1) {
74 set_current_state(TASK_INTERRUPTIBLE);
75 schedule();
76 if (do_signal(regs, &saveset))
77 return -EINTR;
78 }
79}
80
81asmlinkage long
82sys_rt_sigsuspend(struct pt_regs *regs, sigset_t __user *unewset,
83 size_t sigsetsize)
84{
85 sigset_t saveset, newset;
86
87 /* XXX: Don't preclude handling different sized sigset_t's. */
88 if (sigsetsize != sizeof(sigset_t))
89 return -EINVAL;
90
91 if (copy_from_user(&newset, unewset, sizeof(newset)))
92 return -EFAULT;
93 sigdelsetmask(&newset, ~_BLOCKABLE);
94
95 spin_lock_irq(&current->sighand->siglock);
96 saveset = current->blocked;
97 current->blocked = newset;
98 recalc_sigpending();
99 spin_unlock_irq(&current->sighand->siglock);
100 regs->gprs[2] = -EINTR;
101
102 while (1) {
103 set_current_state(TASK_INTERRUPTIBLE);
104 schedule();
105 if (do_signal(regs, &saveset))
106 return -EINTR;
107 }
108}
109
110asmlinkage long
111sys_sigaction(int sig, const struct old_sigaction __user *act,
112 struct old_sigaction __user *oact)
113{
114 struct k_sigaction new_ka, old_ka;
115 int ret;
116
117 if (act) {
118 old_sigset_t mask;
119 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
120 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
121 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
122 return -EFAULT;
123 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
124 __get_user(mask, &act->sa_mask);
125 siginitset(&new_ka.sa.sa_mask, mask);
126 }
127
128 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
129
130 if (!ret && oact) {
131 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
132 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
133 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
134 return -EFAULT;
135 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
136 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
137 }
138
139 return ret;
140}
141
142asmlinkage long
143sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
144 struct pt_regs *regs)
145{
146 return do_sigaltstack(uss, uoss, regs->gprs[15]);
147}
148
149
150
151/* Returns non-zero on fault. */
152static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
153{
154 unsigned long old_mask = regs->psw.mask;
155 int err;
156
157 save_access_regs(current->thread.acrs);
158
159 /* Copy a 'clean' PSW mask to the user to avoid leaking
160 information about whether PER is currently on. */
161 regs->psw.mask = PSW_MASK_MERGE(PSW_USER_BITS, regs->psw.mask);
162 err = __copy_to_user(&sregs->regs.psw, &regs->psw,
163 sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));
164 regs->psw.mask = old_mask;
165 if (err != 0)
166 return err;
167 err = __copy_to_user(&sregs->regs.acrs, current->thread.acrs,
168 sizeof(sregs->regs.acrs));
169 if (err != 0)
170 return err;
171 /*
172 * We have to store the fp registers to current->thread.fp_regs
173 * to merge them with the emulated registers.
174 */
175 save_fp_regs(&current->thread.fp_regs);
176 return __copy_to_user(&sregs->fpregs, &current->thread.fp_regs,
177 sizeof(s390_fp_regs));
178}
179
180/* Returns positive number on error */
181static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
182{
183 unsigned long old_mask = regs->psw.mask;
184 int err;
185
186 /* Alwys make any pending restarted system call return -EINTR */
187 current_thread_info()->restart_block.fn = do_no_restart_syscall;
188
189 err = __copy_from_user(&regs->psw, &sregs->regs.psw,
190 sizeof(sregs->regs.psw)+sizeof(sregs->regs.gprs));
191 regs->psw.mask = PSW_MASK_MERGE(old_mask, regs->psw.mask);
192 regs->psw.addr |= PSW_ADDR_AMODE;
193 if (err)
194 return err;
195 err = __copy_from_user(&current->thread.acrs, &sregs->regs.acrs,
196 sizeof(sregs->regs.acrs));
197 if (err)
198 return err;
199 restore_access_regs(current->thread.acrs);
200
201 err = __copy_from_user(&current->thread.fp_regs, &sregs->fpregs,
202 sizeof(s390_fp_regs));
203 current->thread.fp_regs.fpc &= FPC_VALID_MASK;
204 if (err)
205 return err;
206
207 restore_fp_regs(&current->thread.fp_regs);
208 regs->trap = -1; /* disable syscall checks */
209 return 0;
210}
211
212asmlinkage long sys_sigreturn(struct pt_regs *regs)
213{
214 sigframe __user *frame = (sigframe __user *)regs->gprs[15];
215 sigset_t set;
216
217 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
218 goto badframe;
219 if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
220 goto badframe;
221
222 sigdelsetmask(&set, ~_BLOCKABLE);
223 spin_lock_irq(&current->sighand->siglock);
224 current->blocked = set;
225 recalc_sigpending();
226 spin_unlock_irq(&current->sighand->siglock);
227
228 if (restore_sigregs(regs, &frame->sregs))
229 goto badframe;
230
231 return regs->gprs[2];
232
233badframe:
234 force_sig(SIGSEGV, current);
235 return 0;
236}
237
238asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
239{
240 rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
241 sigset_t set;
242
243 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
244 goto badframe;
245 if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
246 goto badframe;
247
248 sigdelsetmask(&set, ~_BLOCKABLE);
249 spin_lock_irq(&current->sighand->siglock);
250 current->blocked = set;
251 recalc_sigpending();
252 spin_unlock_irq(&current->sighand->siglock);
253
254 if (restore_sigregs(regs, &frame->uc.uc_mcontext))
255 goto badframe;
256
257 /* It is more difficult to avoid calling this function than to
258 call it and ignore errors. */
259 do_sigaltstack(&frame->uc.uc_stack, NULL, regs->gprs[15]);
260 return regs->gprs[2];
261
262badframe:
263 force_sig(SIGSEGV, current);
264 return 0;
265}
266
267/*
268 * Set up a signal frame.
269 */
270
271
272/*
273 * Determine which stack to use..
274 */
275static inline void __user *
276get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
277{
278 unsigned long sp;
279
280 /* Default to using normal stack */
281 sp = regs->gprs[15];
282
283 /* This is the X/Open sanctioned signal stack switching. */
284 if (ka->sa.sa_flags & SA_ONSTACK) {
285 if (! sas_ss_flags(sp))
286 sp = current->sas_ss_sp + current->sas_ss_size;
287 }
288
289 /* This is the legacy signal stack switching. */
290 else if (!user_mode(regs) &&
291 !(ka->sa.sa_flags & SA_RESTORER) &&
292 ka->sa.sa_restorer) {
293 sp = (unsigned long) ka->sa.sa_restorer;
294 }
295
296 return (void __user *)((sp - frame_size) & -8ul);
297}
298
299static inline int map_signal(int sig)
300{
301 if (current_thread_info()->exec_domain
302 && current_thread_info()->exec_domain->signal_invmap
303 && sig < 32)
304 return current_thread_info()->exec_domain->signal_invmap[sig];
305 else
306 return sig;
307}
308
309static void setup_frame(int sig, struct k_sigaction *ka,
310 sigset_t *set, struct pt_regs * regs)
311{
312 sigframe __user *frame;
313
314 frame = get_sigframe(ka, regs, sizeof(sigframe));
315 if (!access_ok(VERIFY_WRITE, frame, sizeof(sigframe)))
316 goto give_sigsegv;
317
318 if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
319 goto give_sigsegv;
320
321 if (save_sigregs(regs, &frame->sregs))
322 goto give_sigsegv;
323 if (__put_user(&frame->sregs, &frame->sc.sregs))
324 goto give_sigsegv;
325
326 /* Set up to return from userspace. If provided, use a stub
327 already in userspace. */
328 if (ka->sa.sa_flags & SA_RESTORER) {
329 regs->gprs[14] = (unsigned long)
330 ka->sa.sa_restorer | PSW_ADDR_AMODE;
331 } else {
332 regs->gprs[14] = (unsigned long)
333 frame->retcode | PSW_ADDR_AMODE;
334 if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
335 (u16 __user *)(frame->retcode)))
336 goto give_sigsegv;
337 }
338
339 /* Set up backchain. */
340 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
341 goto give_sigsegv;
342
343 /* Set up registers for signal handler */
344 regs->gprs[15] = (unsigned long) frame;
345 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
346
347 regs->gprs[2] = map_signal(sig);
348 regs->gprs[3] = (unsigned long) &frame->sc;
349
350 /* We forgot to include these in the sigcontext.
351 To avoid breaking binary compatibility, they are passed as args. */
352 regs->gprs[4] = current->thread.trap_no;
353 regs->gprs[5] = current->thread.prot_addr;
354
355 /* Place signal number on stack to allow backtrace from handler. */
356 if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
357 goto give_sigsegv;
358 return;
359
360give_sigsegv:
361 force_sigsegv(sig, current);
362}
363
364static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
365 sigset_t *set, struct pt_regs * regs)
366{
367 int err = 0;
368 rt_sigframe __user *frame;
369
370 frame = get_sigframe(ka, regs, sizeof(rt_sigframe));
371 if (!access_ok(VERIFY_WRITE, frame, sizeof(rt_sigframe)))
372 goto give_sigsegv;
373
374 if (copy_siginfo_to_user(&frame->info, info))
375 goto give_sigsegv;
376
377 /* Create the ucontext. */
378 err |= __put_user(0, &frame->uc.uc_flags);
379 err |= __put_user(0, &frame->uc.uc_link);
380 err |= __put_user((void *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
381 err |= __put_user(sas_ss_flags(regs->gprs[15]),
382 &frame->uc.uc_stack.ss_flags);
383 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
384 err |= save_sigregs(regs, &frame->uc.uc_mcontext);
385 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
386 if (err)
387 goto give_sigsegv;
388
389 /* Set up to return from userspace. If provided, use a stub
390 already in userspace. */
391 if (ka->sa.sa_flags & SA_RESTORER) {
392 regs->gprs[14] = (unsigned long)
393 ka->sa.sa_restorer | PSW_ADDR_AMODE;
394 } else {
395 regs->gprs[14] = (unsigned long)
396 frame->retcode | PSW_ADDR_AMODE;
397 err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
398 (u16 __user *)(frame->retcode));
399 }
400
401 /* Set up backchain. */
402 if (__put_user(regs->gprs[15], (addr_t __user *) frame))
403 goto give_sigsegv;
404
405 /* Set up registers for signal handler */
406 regs->gprs[15] = (unsigned long) frame;
407 regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
408
409 regs->gprs[2] = map_signal(sig);
410 regs->gprs[3] = (unsigned long) &frame->info;
411 regs->gprs[4] = (unsigned long) &frame->uc;
412 return;
413
414give_sigsegv:
415 force_sigsegv(sig, current);
416}
417
418/*
419 * OK, we're invoking a handler
420 */
421
422static void
423handle_signal(unsigned long sig, struct k_sigaction *ka,
424 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
425{
426 /* Set up the stack frame */
427 if (ka->sa.sa_flags & SA_SIGINFO)
428 setup_rt_frame(sig, ka, info, oldset, regs);
429 else
430 setup_frame(sig, ka, oldset, regs);
431
432 if (!(ka->sa.sa_flags & SA_NODEFER)) {
433 spin_lock_irq(&current->sighand->siglock);
434 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
435 sigaddset(&current->blocked,sig);
436 recalc_sigpending();
437 spin_unlock_irq(&current->sighand->siglock);
438 }
439}
440
441/*
442 * Note that 'init' is a special process: it doesn't get signals it doesn't
443 * want to handle. Thus you cannot kill init even with a SIGKILL even by
444 * mistake.
445 *
446 * Note that we go through the signals twice: once to check the signals that
447 * the kernel can handle, and then we build all the user-level signal handling
448 * stack-frames in one go after that.
449 */
450int do_signal(struct pt_regs *regs, sigset_t *oldset)
451{
452 unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
453 siginfo_t info;
454 int signr;
455 struct k_sigaction ka;
456
457 /*
458 * We want the common case to go fast, which
459 * is why we may in certain cases get here from
460 * kernel mode. Just return without doing anything
461 * if so.
462 */
463 if (!user_mode(regs))
464 return 1;
465
466 if (!oldset)
467 oldset = &current->blocked;
468
469 /* Are we from a system call? */
470 if (regs->trap == __LC_SVC_OLD_PSW) {
471 continue_addr = regs->psw.addr;
472 restart_addr = continue_addr - regs->ilc;
473 retval = regs->gprs[2];
474
475 /* Prepare for system call restart. We do this here so that a
476 debugger will see the already changed PSW. */
477 if (retval == -ERESTARTNOHAND ||
478 retval == -ERESTARTSYS ||
479 retval == -ERESTARTNOINTR) {
480 regs->gprs[2] = regs->orig_gpr2;
481 regs->psw.addr = restart_addr;
482 } else if (retval == -ERESTART_RESTARTBLOCK) {
483 regs->gprs[2] = -EINTR;
484 }
485 }
486
487 /* Get signal to deliver. When running under ptrace, at this point
488 the debugger may change all our registers ... */
489 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
490
491 /* Depending on the signal settings we may need to revert the
492 decision to restart the system call. */
493 if (signr > 0 && regs->psw.addr == restart_addr) {
494 if (retval == -ERESTARTNOHAND
495 || (retval == -ERESTARTSYS
496 && !(current->sighand->action[signr-1].sa.sa_flags
497 & SA_RESTART))) {
498 regs->gprs[2] = -EINTR;
499 regs->psw.addr = continue_addr;
500 }
501 }
502
503 if (signr > 0) {
504 /* Whee! Actually deliver the signal. */
505#ifdef CONFIG_S390_SUPPORT
506 if (test_thread_flag(TIF_31BIT)) {
507 extern void handle_signal32(unsigned long sig,
508 struct k_sigaction *ka,
509 siginfo_t *info,
510 sigset_t *oldset,
511 struct pt_regs *regs);
512 handle_signal32(signr, &ka, &info, oldset, regs);
513 return 1;
514 }
515#endif
516 handle_signal(signr, &ka, &info, oldset, regs);
517 return 1;
518 }
519
520 /* Restart a different system call. */
521 if (retval == -ERESTART_RESTARTBLOCK
522 && regs->psw.addr == continue_addr) {
523 regs->gprs[2] = __NR_restart_syscall;
524 set_thread_flag(TIF_RESTART_SVC);
525 }
526 return 0;
527}