blob: 77f8b49c788258021819ccaab628e9b92e734f17 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Architecture-specific signal handling support.
3 *
4 * Copyright (C) 1999-2004 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
6 *
7 * Derived from i386 and Alpha versions.
8 */
9
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/errno.h>
11#include <linux/kernel.h>
12#include <linux/mm.h>
13#include <linux/ptrace.h>
14#include <linux/sched.h>
15#include <linux/signal.h>
16#include <linux/smp.h>
17#include <linux/smp_lock.h>
18#include <linux/stddef.h>
19#include <linux/tty.h>
20#include <linux/binfmts.h>
21#include <linux/unistd.h>
22#include <linux/wait.h>
23
24#include <asm/ia32.h>
25#include <asm/intrinsics.h>
26#include <asm/uaccess.h>
27#include <asm/rse.h>
28#include <asm/sigcontext.h>
29
30#include "sigframe.h"
31
32#define DEBUG_SIG 0
33#define STACK_ALIGN 16 /* minimal alignment for stack pointer */
34#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
35
36#if _NSIG_WORDS > 1
37# define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t))
38# define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t))
39#else
40# define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0])
41# define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0])
42#endif
43
44long
45ia64_rt_sigsuspend (sigset_t __user *uset, size_t sigsetsize, struct sigscratch *scr)
46{
47 sigset_t oldset, set;
48
49 /* XXX: Don't preclude handling different sized sigset_t's. */
50 if (sigsetsize != sizeof(sigset_t))
51 return -EINVAL;
52
53 if (!access_ok(VERIFY_READ, uset, sigsetsize))
54 return -EFAULT;
55
56 if (GET_SIGSET(&set, uset))
57 return -EFAULT;
58
59 sigdelsetmask(&set, ~_BLOCKABLE);
60
61 spin_lock_irq(&current->sighand->siglock);
62 {
63 oldset = current->blocked;
64 current->blocked = set;
65 recalc_sigpending();
66 }
67 spin_unlock_irq(&current->sighand->siglock);
68
69 /*
70 * The return below usually returns to the signal handler. We need to
71 * pre-set the correct error code here to ensure that the right values
72 * get saved in sigcontext by ia64_do_signal.
73 */
74 scr->pt.r8 = EINTR;
75 scr->pt.r10 = -1;
76
77 while (1) {
78 current->state = TASK_INTERRUPTIBLE;
79 schedule();
80 if (ia64_do_signal(&oldset, scr, 1))
81 return -EINTR;
82 }
83}
84
85asmlinkage long
86sys_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, long arg2,
87 long arg3, long arg4, long arg5, long arg6, long arg7,
88 struct pt_regs regs)
89{
90 return do_sigaltstack(uss, uoss, regs.r12);
91}
92
93static long
94restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr)
95{
Matthew Chapman4ea78722005-06-21 16:19:20 -070096 unsigned long ip, flags, nat, um, cfm, rsc;
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 long err;
98
99 /* Always make any pending restarted system calls return -EINTR */
100 current_thread_info()->restart_block.fn = do_no_restart_syscall;
101
102 /* restore scratch that always needs gets updated during signal delivery: */
103 err = __get_user(flags, &sc->sc_flags);
104 err |= __get_user(nat, &sc->sc_nat);
105 err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */
106 err |= __get_user(cfm, &sc->sc_cfm);
107 err |= __get_user(um, &sc->sc_um); /* user mask */
Matthew Chapman4ea78722005-06-21 16:19:20 -0700108 err |= __get_user(rsc, &sc->sc_ar_rsc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat);
110 err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr);
111 err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
112 err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */
113 err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */
114 err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */
115 err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */
116 err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */
117 err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8); /* r12-r13 */
118 err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8); /* r15 */
119
120 scr->pt.cr_ifs = cfm | (1UL << 63);
Matthew Chapman4ea78722005-06-21 16:19:20 -0700121 scr->pt.ar_rsc = rsc | (3 << 2); /* force PL3 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
123 /* establish new instruction pointer: */
124 scr->pt.cr_iip = ip & ~0x3UL;
125 ia64_psr(&scr->pt)->ri = ip & 0x3;
126 scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM);
127
128 scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat);
129
130 if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) {
131 /* Restore most scratch-state only when not in syscall. */
132 err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */
133 err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */
134 err |= __get_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */
135 err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */
136 err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8); /* r2-r3 */
137 err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */
138 }
139
140 if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) {
141 struct ia64_psr *psr = ia64_psr(&scr->pt);
142
143 __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16);
144 psr->mfh = 0; /* drop signal handler's fph contents... */
Keith Owens2ba3e3e2005-06-30 22:53:00 -0700145 preempt_disable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 if (psr->dfh)
147 ia64_drop_fpu(current);
148 else {
149 /* We already own the local fph, otherwise psr->dfh wouldn't be 0. */
150 __ia64_load_fpu(current->thread.fph);
151 ia64_set_local_fpu_owner(current);
152 }
Keith Owens2ba3e3e2005-06-30 22:53:00 -0700153 preempt_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 }
155 return err;
156}
157
158int
159copy_siginfo_to_user (siginfo_t __user *to, siginfo_t *from)
160{
161 if (!access_ok(VERIFY_WRITE, to, sizeof(siginfo_t)))
162 return -EFAULT;
163 if (from->si_code < 0) {
164 if (__copy_to_user(to, from, sizeof(siginfo_t)))
165 return -EFAULT;
166 return 0;
167 } else {
168 int err;
169
170 /*
171 * If you change siginfo_t structure, please be sure this code is fixed
172 * accordingly. It should never copy any pad contained in the structure
173 * to avoid security leaks, but must copy the generic 3 ints plus the
174 * relevant union member.
175 */
176 err = __put_user(from->si_signo, &to->si_signo);
177 err |= __put_user(from->si_errno, &to->si_errno);
178 err |= __put_user((short)from->si_code, &to->si_code);
179 switch (from->si_code >> 16) {
180 case __SI_FAULT >> 16:
181 err |= __put_user(from->si_flags, &to->si_flags);
182 err |= __put_user(from->si_isr, &to->si_isr);
183 case __SI_POLL >> 16:
184 err |= __put_user(from->si_addr, &to->si_addr);
185 err |= __put_user(from->si_imm, &to->si_imm);
186 break;
187 case __SI_TIMER >> 16:
188 err |= __put_user(from->si_tid, &to->si_tid);
189 err |= __put_user(from->si_overrun, &to->si_overrun);
190 err |= __put_user(from->si_ptr, &to->si_ptr);
191 break;
192 case __SI_RT >> 16: /* Not generated by the kernel as of now. */
193 case __SI_MESGQ >> 16:
194 err |= __put_user(from->si_uid, &to->si_uid);
195 err |= __put_user(from->si_pid, &to->si_pid);
196 err |= __put_user(from->si_ptr, &to->si_ptr);
197 break;
198 case __SI_CHLD >> 16:
199 err |= __put_user(from->si_utime, &to->si_utime);
200 err |= __put_user(from->si_stime, &to->si_stime);
201 err |= __put_user(from->si_status, &to->si_status);
202 default:
203 err |= __put_user(from->si_uid, &to->si_uid);
204 err |= __put_user(from->si_pid, &to->si_pid);
205 break;
206 }
207 return err;
208 }
209}
210
211long
212ia64_rt_sigreturn (struct sigscratch *scr)
213{
214 extern char ia64_strace_leave_kernel, ia64_leave_kernel;
215 struct sigcontext __user *sc;
216 struct siginfo si;
217 sigset_t set;
218 long retval;
219
220 sc = &((struct sigframe __user *) (scr->pt.r12 + 16))->sc;
221
222 /*
223 * When we return to the previously executing context, r8 and r10 have already
224 * been setup the way we want them. Indeed, if the signal wasn't delivered while
225 * in a system call, we must not touch r8 or r10 as otherwise user-level state
226 * could be corrupted.
227 */
228 retval = (long) &ia64_leave_kernel;
David Woodhouse446b8832005-04-05 17:47:00 -0700229 if (test_thread_flag(TIF_SYSCALL_TRACE)
230 || test_thread_flag(TIF_SYSCALL_AUDIT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 /*
232 * strace expects to be notified after sigreturn returns even though the
233 * context to which we return may not be in the middle of a syscall.
234 * Thus, the return-value that strace displays for sigreturn is
235 * meaningless.
236 */
237 retval = (long) &ia64_strace_leave_kernel;
238
239 if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
240 goto give_sigsegv;
241
242 if (GET_SIGSET(&set, &sc->sc_mask))
243 goto give_sigsegv;
244
245 sigdelsetmask(&set, ~_BLOCKABLE);
246
247 spin_lock_irq(&current->sighand->siglock);
248 {
249 current->blocked = set;
250 recalc_sigpending();
251 }
252 spin_unlock_irq(&current->sighand->siglock);
253
254 if (restore_sigcontext(sc, scr))
255 goto give_sigsegv;
256
257#if DEBUG_SIG
258 printk("SIG return (%s:%d): sp=%lx ip=%lx\n",
259 current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip);
260#endif
261 /*
262 * It is more difficult to avoid calling this function than to
263 * call it and ignore errors.
264 */
265 do_sigaltstack(&sc->sc_stack, NULL, scr->pt.r12);
266 return retval;
267
268 give_sigsegv:
269 si.si_signo = SIGSEGV;
270 si.si_errno = 0;
271 si.si_code = SI_KERNEL;
272 si.si_pid = current->pid;
273 si.si_uid = current->uid;
274 si.si_addr = sc;
275 force_sig_info(SIGSEGV, &si, current);
276 return retval;
277}
278
279/*
280 * This does just the minimum required setup of sigcontext.
281 * Specifically, it only installs data that is either not knowable at
282 * the user-level or that gets modified before execution in the
283 * trampoline starts. Everything else is done at the user-level.
284 */
285static long
286setup_sigcontext (struct sigcontext __user *sc, sigset_t *mask, struct sigscratch *scr)
287{
288 unsigned long flags = 0, ifs, cfm, nat;
289 long err;
290
291 ifs = scr->pt.cr_ifs;
292
293 if (on_sig_stack((unsigned long) sc))
294 flags |= IA64_SC_FLAG_ONSTACK;
295 if ((ifs & (1UL << 63)) == 0)
296 /* if cr_ifs doesn't have the valid bit set, we got here through a syscall */
297 flags |= IA64_SC_FLAG_IN_SYSCALL;
298 cfm = ifs & ((1UL << 38) - 1);
299 ia64_flush_fph(current);
300 if ((current->thread.flags & IA64_THREAD_FPH_VALID)) {
301 flags |= IA64_SC_FLAG_FPH_VALID;
302 __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16);
303 }
304
305 nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat);
306
307 err = __put_user(flags, &sc->sc_flags);
308 err |= __put_user(nat, &sc->sc_nat);
309 err |= PUT_SIGSET(mask, &sc->sc_mask);
310 err |= __put_user(cfm, &sc->sc_cfm);
311 err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um);
312 err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc);
313 err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */
314 err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */
315 err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
316 err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */
317 err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */
318 err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */
319 err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 8); /* r1 */
320 err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */
321 err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 2*8); /* r12-r13 */
322 err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8); /* r15 */
323 err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip);
324
325 if (flags & IA64_SC_FLAG_IN_SYSCALL) {
326 /* Clear scratch registers if the signal interrupted a system call. */
327 err |= __put_user(0, &sc->sc_ar_ccv); /* ar.ccv */
328 err |= __put_user(0, &sc->sc_br[7]); /* b7 */
329 err |= __put_user(0, &sc->sc_gr[14]); /* r14 */
330 err |= __clear_user(&sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */
331 err |= __clear_user(&sc->sc_gr[2], 2*8); /* r2-r3 */
332 err |= __clear_user(&sc->sc_gr[16], 16*8); /* r16-r31 */
333 } else {
334 /* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */
335 err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */
336 err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */
337 err |= __put_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */
338 err |= __copy_to_user(&sc->sc_ar25, &scr->pt.ar_csd, 2*8); /* ar.csd & ar.ssd */
339 err |= __copy_to_user(&sc->sc_gr[2], &scr->pt.r2, 2*8); /* r2-r3 */
340 err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */
341 }
342 return err;
343}
344
345/*
346 * Check whether the register-backing store is already on the signal stack.
347 */
348static inline int
349rbs_on_sig_stack (unsigned long bsp)
350{
351 return (bsp - current->sas_ss_sp < current->sas_ss_size);
352}
353
354static long
355force_sigsegv_info (int sig, void __user *addr)
356{
357 unsigned long flags;
358 struct siginfo si;
359
360 if (sig == SIGSEGV) {
361 /*
362 * Acquiring siglock around the sa_handler-update is almost
363 * certainly overkill, but this isn't a
364 * performance-critical path and I'd rather play it safe
365 * here than having to debug a nasty race if and when
366 * something changes in kernel/signal.c that would make it
367 * no longer safe to modify sa_handler without holding the
368 * lock.
369 */
370 spin_lock_irqsave(&current->sighand->siglock, flags);
371 current->sighand->action[sig - 1].sa.sa_handler = SIG_DFL;
372 spin_unlock_irqrestore(&current->sighand->siglock, flags);
373 }
374 si.si_signo = SIGSEGV;
375 si.si_errno = 0;
376 si.si_code = SI_KERNEL;
377 si.si_pid = current->pid;
378 si.si_uid = current->uid;
379 si.si_addr = addr;
380 force_sig_info(SIGSEGV, &si, current);
381 return 0;
382}
383
384static long
385setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set,
386 struct sigscratch *scr)
387{
388 extern char __kernel_sigtramp[];
David Mosberger-Tangcf20d1e2005-11-02 22:40:19 -0800389 unsigned long tramp_addr, new_rbs = 0, new_sp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 struct sigframe __user *frame;
391 long err;
392
David Mosberger-Tangcf20d1e2005-11-02 22:40:19 -0800393 new_sp = scr->pt.r12;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 tramp_addr = (unsigned long) __kernel_sigtramp;
David Mosberger-Tangcf20d1e2005-11-02 22:40:19 -0800395 if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags(new_sp) == 0) {
396 new_sp = current->sas_ss_sp + current->sas_ss_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 /*
398 * We need to check for the register stack being on the signal stack
399 * separately, because it's switched separately (memory stack is switched
400 * in the kernel, register stack is switched in the signal trampoline).
401 */
402 if (!rbs_on_sig_stack(scr->pt.ar_bspstore))
403 new_rbs = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1);
404 }
David Mosberger-Tangcf20d1e2005-11-02 22:40:19 -0800405 frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406
407 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
408 return force_sigsegv_info(sig, frame);
409
410 err = __put_user(sig, &frame->arg0);
411 err |= __put_user(&frame->info, &frame->arg1);
412 err |= __put_user(&frame->sc, &frame->arg2);
413 err |= __put_user(new_rbs, &frame->sc.sc_rbs_base);
414 err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */
415 err |= __put_user(ka->sa.sa_handler, &frame->handler);
416
417 err |= copy_siginfo_to_user(&frame->info, info);
418
419 err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp);
420 err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size);
421 err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags);
422 err |= setup_sigcontext(&frame->sc, set, scr);
423
424 if (unlikely(err))
425 return force_sigsegv_info(sig, frame);
426
427 scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */
428 scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */
429 scr->pt.cr_iip = tramp_addr;
430 ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */
431 ia64_psr(&scr->pt)->be = 0; /* force little-endian byte-order */
432 /*
433 * Force the interruption function mask to zero. This has no effect when a
434 * system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is
435 * ignored), but it has the desirable effect of making it possible to deliver a
436 * signal with an incomplete register frame (which happens when a mandatory RSE
437 * load faults). Furthermore, it has no negative effect on the getting the user's
438 * dirty partition preserved, because that's governed by scr->pt.loadrs.
439 */
440 scr->pt.cr_ifs = (1UL << 63);
441
442 /*
443 * Note: this affects only the NaT bits of the scratch regs (the ones saved in
444 * pt_regs), which is exactly what we want.
445 */
446 scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */
447
448#if DEBUG_SIG
449 printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n",
450 current->comm, current->pid, sig, scr->pt.r12, frame->sc.sc_ip, frame->handler);
451#endif
452 return 1;
453}
454
455static long
456handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset,
457 struct sigscratch *scr)
458{
459 if (IS_IA32_PROCESS(&scr->pt)) {
460 /* send signal to IA-32 process */
461 if (!ia32_setup_frame1(sig, ka, info, oldset, &scr->pt))
462 return 0;
463 } else
464 /* send signal to IA-64 process */
465 if (!setup_frame(sig, ka, info, oldset, scr))
466 return 0;
467
Steven Rostedt69be8f12005-08-29 11:44:09 -0400468 spin_lock_irq(&current->sighand->siglock);
469 sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
470 if (!(ka->sa.sa_flags & SA_NODEFER))
471 sigaddset(&current->blocked, sig);
472 recalc_sigpending();
473 spin_unlock_irq(&current->sighand->siglock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 return 1;
475}
476
477/*
478 * Note that `init' is a special process: it doesn't get signals it doesn't want to
479 * handle. Thus you cannot kill init even with a SIGKILL even by mistake.
480 */
481long
482ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall)
483{
484 struct k_sigaction ka;
485 siginfo_t info;
486 long restart = in_syscall;
487 long errno = scr->pt.r8;
488# define ERR_CODE(c) (IS_IA32_PROCESS(&scr->pt) ? -(c) : (c))
489
490 /*
491 * In the ia64_leave_kernel code path, we want the common case to go fast, which
492 * is why we may in certain cases get here from kernel mode. Just return without
493 * doing anything if so.
494 */
495 if (!user_mode(&scr->pt))
496 return 0;
497
498 if (!oldset)
499 oldset = &current->blocked;
500
501 /*
502 * This only loops in the rare cases of handle_signal() failing, in which case we
503 * need to push through a forced SIGSEGV.
504 */
505 while (1) {
506 int signr = get_signal_to_deliver(&info, &ka, &scr->pt, NULL);
507
508 /*
509 * get_signal_to_deliver() may have run a debugger (via notify_parent())
510 * and the debugger may have modified the state (e.g., to arrange for an
511 * inferior call), thus it's important to check for restarting _after_
512 * get_signal_to_deliver().
513 */
514 if (IS_IA32_PROCESS(&scr->pt)) {
515 if (in_syscall) {
516 if (errno >= 0)
517 restart = 0;
518 else
519 errno = -errno;
520 }
521 } else if ((long) scr->pt.r10 != -1)
522 /*
523 * A system calls has to be restarted only if one of the error codes
524 * ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10
525 * isn't -1 then r8 doesn't hold an error code and we don't need to
526 * restart the syscall, so we can clear the "restart" flag here.
527 */
528 restart = 0;
529
530 if (signr <= 0)
531 break;
532
533 if (unlikely(restart)) {
534 switch (errno) {
535 case ERESTART_RESTARTBLOCK:
536 case ERESTARTNOHAND:
537 scr->pt.r8 = ERR_CODE(EINTR);
538 /* note: scr->pt.r10 is already -1 */
539 break;
540
541 case ERESTARTSYS:
542 if ((ka.sa.sa_flags & SA_RESTART) == 0) {
543 scr->pt.r8 = ERR_CODE(EINTR);
544 /* note: scr->pt.r10 is already -1 */
545 break;
546 }
547 case ERESTARTNOINTR:
548 if (IS_IA32_PROCESS(&scr->pt)) {
549 scr->pt.r8 = scr->pt.r1;
550 scr->pt.cr_iip -= 2;
551 } else
552 ia64_decrement_ip(&scr->pt);
553 restart = 0; /* don't restart twice if handle_signal() fails... */
554 }
555 }
556
557 /*
558 * Whee! Actually deliver the signal. If the delivery failed, we need to
559 * continue to iterate in this loop so we can deliver the SIGSEGV...
560 */
561 if (handle_signal(signr, &ka, &info, oldset, scr))
562 return 1;
563 }
564
565 /* Did we come from a system call? */
566 if (restart) {
567 /* Restart the system call - no handlers present */
568 if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR
569 || errno == ERESTART_RESTARTBLOCK)
570 {
571 if (IS_IA32_PROCESS(&scr->pt)) {
572 scr->pt.r8 = scr->pt.r1;
573 scr->pt.cr_iip -= 2;
574 if (errno == ERESTART_RESTARTBLOCK)
575 scr->pt.r8 = 0; /* x86 version of __NR_restart_syscall */
576 } else {
577 /*
578 * Note: the syscall number is in r15 which is saved in
579 * pt_regs so all we need to do here is adjust ip so that
580 * the "break" instruction gets re-executed.
581 */
582 ia64_decrement_ip(&scr->pt);
583 if (errno == ERESTART_RESTARTBLOCK)
584 scr->pt.r15 = __NR_restart_syscall;
585 }
586 }
587 }
588 return 0;
589}