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1da177e4 LT |
1 | /* |
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 | ||
1da177e4 LT |
10 | #include <linux/errno.h> |
11 | #include <linux/kernel.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/ptrace.h> | |
f14488cc | 14 | #include <linux/tracehook.h> |
1da177e4 LT |
15 | #include <linux/sched.h> |
16 | #include <linux/signal.h> | |
17 | #include <linux/smp.h> | |
1da177e4 LT |
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 | ||
1da177e4 LT |
24 | #include <asm/intrinsics.h> |
25 | #include <asm/uaccess.h> | |
26 | #include <asm/rse.h> | |
27 | #include <asm/sigcontext.h> | |
28 | ||
29 | #include "sigframe.h" | |
30 | ||
31 | #define DEBUG_SIG 0 | |
32 | #define STACK_ALIGN 16 /* minimal alignment for stack pointer */ | |
1da177e4 LT |
33 | |
34 | #if _NSIG_WORDS > 1 | |
35 | # define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t)) | |
36 | # define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t)) | |
37 | #else | |
38 | # define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0]) | |
39 | # define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0]) | |
40 | #endif | |
41 | ||
1da177e4 LT |
42 | asmlinkage long |
43 | sys_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, long arg2, | |
44 | long arg3, long arg4, long arg5, long arg6, long arg7, | |
45 | struct pt_regs regs) | |
46 | { | |
47 | return do_sigaltstack(uss, uoss, regs.r12); | |
48 | } | |
49 | ||
50 | static long | |
51 | restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr) | |
52 | { | |
4ea78729 | 53 | unsigned long ip, flags, nat, um, cfm, rsc; |
1da177e4 LT |
54 | long err; |
55 | ||
56 | /* Always make any pending restarted system calls return -EINTR */ | |
57 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
58 | ||
59 | /* restore scratch that always needs gets updated during signal delivery: */ | |
60 | err = __get_user(flags, &sc->sc_flags); | |
61 | err |= __get_user(nat, &sc->sc_nat); | |
62 | err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */ | |
63 | err |= __get_user(cfm, &sc->sc_cfm); | |
64 | err |= __get_user(um, &sc->sc_um); /* user mask */ | |
4ea78729 | 65 | err |= __get_user(rsc, &sc->sc_ar_rsc); |
1da177e4 LT |
66 | err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat); |
67 | err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); | |
68 | err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); | |
69 | err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */ | |
70 | err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ | |
71 | err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ | |
72 | err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */ | |
73 | err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */ | |
74 | err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8); /* r12-r13 */ | |
75 | err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8); /* r15 */ | |
76 | ||
77 | scr->pt.cr_ifs = cfm | (1UL << 63); | |
4ea78729 | 78 | scr->pt.ar_rsc = rsc | (3 << 2); /* force PL3 */ |
1da177e4 LT |
79 | |
80 | /* establish new instruction pointer: */ | |
81 | scr->pt.cr_iip = ip & ~0x3UL; | |
82 | ia64_psr(&scr->pt)->ri = ip & 0x3; | |
83 | scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM); | |
84 | ||
85 | scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat); | |
86 | ||
87 | if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { | |
88 | /* Restore most scratch-state only when not in syscall. */ | |
89 | err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ | |
90 | err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ | |
91 | err |= __get_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ | |
92 | err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */ | |
93 | err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8); /* r2-r3 */ | |
94 | err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */ | |
95 | } | |
96 | ||
97 | if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) { | |
98 | struct ia64_psr *psr = ia64_psr(&scr->pt); | |
99 | ||
b9ab117c | 100 | err |= __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16); |
1da177e4 | 101 | psr->mfh = 0; /* drop signal handler's fph contents... */ |
2ba3e3e6 | 102 | preempt_disable(); |
1da177e4 LT |
103 | if (psr->dfh) |
104 | ia64_drop_fpu(current); | |
105 | else { | |
106 | /* We already own the local fph, otherwise psr->dfh wouldn't be 0. */ | |
107 | __ia64_load_fpu(current->thread.fph); | |
108 | ia64_set_local_fpu_owner(current); | |
109 | } | |
2ba3e3e6 | 110 | preempt_enable(); |
1da177e4 LT |
111 | } |
112 | return err; | |
113 | } | |
114 | ||
115 | int | |
116 | copy_siginfo_to_user (siginfo_t __user *to, siginfo_t *from) | |
117 | { | |
118 | if (!access_ok(VERIFY_WRITE, to, sizeof(siginfo_t))) | |
119 | return -EFAULT; | |
120 | if (from->si_code < 0) { | |
121 | if (__copy_to_user(to, from, sizeof(siginfo_t))) | |
122 | return -EFAULT; | |
123 | return 0; | |
124 | } else { | |
125 | int err; | |
126 | ||
127 | /* | |
128 | * If you change siginfo_t structure, please be sure this code is fixed | |
129 | * accordingly. It should never copy any pad contained in the structure | |
130 | * to avoid security leaks, but must copy the generic 3 ints plus the | |
131 | * relevant union member. | |
132 | */ | |
133 | err = __put_user(from->si_signo, &to->si_signo); | |
134 | err |= __put_user(from->si_errno, &to->si_errno); | |
135 | err |= __put_user((short)from->si_code, &to->si_code); | |
136 | switch (from->si_code >> 16) { | |
137 | case __SI_FAULT >> 16: | |
138 | err |= __put_user(from->si_flags, &to->si_flags); | |
139 | err |= __put_user(from->si_isr, &to->si_isr); | |
140 | case __SI_POLL >> 16: | |
141 | err |= __put_user(from->si_addr, &to->si_addr); | |
142 | err |= __put_user(from->si_imm, &to->si_imm); | |
143 | break; | |
144 | case __SI_TIMER >> 16: | |
145 | err |= __put_user(from->si_tid, &to->si_tid); | |
146 | err |= __put_user(from->si_overrun, &to->si_overrun); | |
147 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
148 | break; | |
149 | case __SI_RT >> 16: /* Not generated by the kernel as of now. */ | |
150 | case __SI_MESGQ >> 16: | |
151 | err |= __put_user(from->si_uid, &to->si_uid); | |
152 | err |= __put_user(from->si_pid, &to->si_pid); | |
153 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
154 | break; | |
155 | case __SI_CHLD >> 16: | |
156 | err |= __put_user(from->si_utime, &to->si_utime); | |
157 | err |= __put_user(from->si_stime, &to->si_stime); | |
158 | err |= __put_user(from->si_status, &to->si_status); | |
159 | default: | |
160 | err |= __put_user(from->si_uid, &to->si_uid); | |
161 | err |= __put_user(from->si_pid, &to->si_pid); | |
162 | break; | |
163 | } | |
164 | return err; | |
165 | } | |
166 | } | |
167 | ||
168 | long | |
169 | ia64_rt_sigreturn (struct sigscratch *scr) | |
170 | { | |
171 | extern char ia64_strace_leave_kernel, ia64_leave_kernel; | |
172 | struct sigcontext __user *sc; | |
173 | struct siginfo si; | |
174 | sigset_t set; | |
175 | long retval; | |
176 | ||
177 | sc = &((struct sigframe __user *) (scr->pt.r12 + 16))->sc; | |
178 | ||
179 | /* | |
180 | * When we return to the previously executing context, r8 and r10 have already | |
181 | * been setup the way we want them. Indeed, if the signal wasn't delivered while | |
182 | * in a system call, we must not touch r8 or r10 as otherwise user-level state | |
183 | * could be corrupted. | |
184 | */ | |
185 | retval = (long) &ia64_leave_kernel; | |
446b8831 DW |
186 | if (test_thread_flag(TIF_SYSCALL_TRACE) |
187 | || test_thread_flag(TIF_SYSCALL_AUDIT)) | |
1da177e4 LT |
188 | /* |
189 | * strace expects to be notified after sigreturn returns even though the | |
190 | * context to which we return may not be in the middle of a syscall. | |
191 | * Thus, the return-value that strace displays for sigreturn is | |
192 | * meaningless. | |
193 | */ | |
194 | retval = (long) &ia64_strace_leave_kernel; | |
195 | ||
196 | if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) | |
197 | goto give_sigsegv; | |
198 | ||
199 | if (GET_SIGSET(&set, &sc->sc_mask)) | |
200 | goto give_sigsegv; | |
201 | ||
7a076e4f | 202 | set_current_blocked(&set); |
1da177e4 LT |
203 | |
204 | if (restore_sigcontext(sc, scr)) | |
205 | goto give_sigsegv; | |
206 | ||
207 | #if DEBUG_SIG | |
208 | printk("SIG return (%s:%d): sp=%lx ip=%lx\n", | |
209 | current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip); | |
210 | #endif | |
211 | /* | |
212 | * It is more difficult to avoid calling this function than to | |
213 | * call it and ignore errors. | |
214 | */ | |
215 | do_sigaltstack(&sc->sc_stack, NULL, scr->pt.r12); | |
216 | return retval; | |
217 | ||
218 | give_sigsegv: | |
219 | si.si_signo = SIGSEGV; | |
220 | si.si_errno = 0; | |
221 | si.si_code = SI_KERNEL; | |
b488893a | 222 | si.si_pid = task_pid_vnr(current); |
6c1ee033 | 223 | si.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 LT |
224 | si.si_addr = sc; |
225 | force_sig_info(SIGSEGV, &si, current); | |
226 | return retval; | |
227 | } | |
228 | ||
229 | /* | |
230 | * This does just the minimum required setup of sigcontext. | |
231 | * Specifically, it only installs data that is either not knowable at | |
232 | * the user-level or that gets modified before execution in the | |
233 | * trampoline starts. Everything else is done at the user-level. | |
234 | */ | |
235 | static long | |
236 | setup_sigcontext (struct sigcontext __user *sc, sigset_t *mask, struct sigscratch *scr) | |
237 | { | |
238 | unsigned long flags = 0, ifs, cfm, nat; | |
b9ab117c | 239 | long err = 0; |
1da177e4 LT |
240 | |
241 | ifs = scr->pt.cr_ifs; | |
242 | ||
243 | if (on_sig_stack((unsigned long) sc)) | |
244 | flags |= IA64_SC_FLAG_ONSTACK; | |
245 | if ((ifs & (1UL << 63)) == 0) | |
246 | /* if cr_ifs doesn't have the valid bit set, we got here through a syscall */ | |
247 | flags |= IA64_SC_FLAG_IN_SYSCALL; | |
248 | cfm = ifs & ((1UL << 38) - 1); | |
249 | ia64_flush_fph(current); | |
250 | if ((current->thread.flags & IA64_THREAD_FPH_VALID)) { | |
251 | flags |= IA64_SC_FLAG_FPH_VALID; | |
b9ab117c | 252 | err = __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16); |
1da177e4 LT |
253 | } |
254 | ||
255 | nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat); | |
256 | ||
b9ab117c | 257 | err |= __put_user(flags, &sc->sc_flags); |
1da177e4 LT |
258 | err |= __put_user(nat, &sc->sc_nat); |
259 | err |= PUT_SIGSET(mask, &sc->sc_mask); | |
260 | err |= __put_user(cfm, &sc->sc_cfm); | |
261 | err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um); | |
262 | err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc); | |
263 | err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */ | |
264 | err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */ | |
265 | err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); | |
266 | err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */ | |
267 | err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ | |
268 | err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ | |
269 | err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 8); /* r1 */ | |
270 | err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */ | |
271 | err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 2*8); /* r12-r13 */ | |
272 | err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8); /* r15 */ | |
273 | err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip); | |
274 | ||
2018df76 | 275 | if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { |
1da177e4 LT |
276 | /* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */ |
277 | err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ | |
278 | err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ | |
279 | err |= __put_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ | |
280 | err |= __copy_to_user(&sc->sc_ar25, &scr->pt.ar_csd, 2*8); /* ar.csd & ar.ssd */ | |
281 | err |= __copy_to_user(&sc->sc_gr[2], &scr->pt.r2, 2*8); /* r2-r3 */ | |
282 | err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */ | |
283 | } | |
284 | return err; | |
285 | } | |
286 | ||
287 | /* | |
288 | * Check whether the register-backing store is already on the signal stack. | |
289 | */ | |
290 | static inline int | |
291 | rbs_on_sig_stack (unsigned long bsp) | |
292 | { | |
293 | return (bsp - current->sas_ss_sp < current->sas_ss_size); | |
294 | } | |
295 | ||
296 | static long | |
297 | force_sigsegv_info (int sig, void __user *addr) | |
298 | { | |
299 | unsigned long flags; | |
300 | struct siginfo si; | |
301 | ||
302 | if (sig == SIGSEGV) { | |
303 | /* | |
304 | * Acquiring siglock around the sa_handler-update is almost | |
305 | * certainly overkill, but this isn't a | |
306 | * performance-critical path and I'd rather play it safe | |
307 | * here than having to debug a nasty race if and when | |
308 | * something changes in kernel/signal.c that would make it | |
309 | * no longer safe to modify sa_handler without holding the | |
310 | * lock. | |
311 | */ | |
312 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
313 | current->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; | |
314 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
315 | } | |
316 | si.si_signo = SIGSEGV; | |
317 | si.si_errno = 0; | |
318 | si.si_code = SI_KERNEL; | |
b488893a | 319 | si.si_pid = task_pid_vnr(current); |
6c1ee033 | 320 | si.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 LT |
321 | si.si_addr = addr; |
322 | force_sig_info(SIGSEGV, &si, current); | |
323 | return 0; | |
324 | } | |
325 | ||
326 | static long | |
327 | setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, | |
328 | struct sigscratch *scr) | |
329 | { | |
330 | extern char __kernel_sigtramp[]; | |
cf20d1ea | 331 | unsigned long tramp_addr, new_rbs = 0, new_sp; |
1da177e4 LT |
332 | struct sigframe __user *frame; |
333 | long err; | |
334 | ||
cf20d1ea | 335 | new_sp = scr->pt.r12; |
1da177e4 | 336 | tramp_addr = (unsigned long) __kernel_sigtramp; |
d7a6c68a SW |
337 | if (ka->sa.sa_flags & SA_ONSTACK) { |
338 | int onstack = sas_ss_flags(new_sp); | |
339 | ||
340 | if (onstack == 0) { | |
341 | new_sp = current->sas_ss_sp + current->sas_ss_size; | |
342 | /* | |
343 | * We need to check for the register stack being on the | |
344 | * signal stack separately, because it's switched | |
345 | * separately (memory stack is switched in the kernel, | |
346 | * register stack is switched in the signal trampoline). | |
347 | */ | |
348 | if (!rbs_on_sig_stack(scr->pt.ar_bspstore)) | |
349 | new_rbs = ALIGN(current->sas_ss_sp, | |
350 | sizeof(long)); | |
351 | } else if (onstack == SS_ONSTACK) { | |
352 | unsigned long check_sp; | |
353 | ||
354 | /* | |
355 | * If we are on the alternate signal stack and would | |
356 | * overflow it, don't. Return an always-bogus address | |
357 | * instead so we will die with SIGSEGV. | |
358 | */ | |
359 | check_sp = (new_sp - sizeof(*frame)) & -STACK_ALIGN; | |
360 | if (!likely(on_sig_stack(check_sp))) | |
361 | return force_sigsegv_info(sig, (void __user *) | |
362 | check_sp); | |
363 | } | |
1da177e4 | 364 | } |
cf20d1ea | 365 | frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN); |
1da177e4 LT |
366 | |
367 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
368 | return force_sigsegv_info(sig, frame); | |
369 | ||
370 | err = __put_user(sig, &frame->arg0); | |
371 | err |= __put_user(&frame->info, &frame->arg1); | |
372 | err |= __put_user(&frame->sc, &frame->arg2); | |
373 | err |= __put_user(new_rbs, &frame->sc.sc_rbs_base); | |
374 | err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */ | |
375 | err |= __put_user(ka->sa.sa_handler, &frame->handler); | |
376 | ||
377 | err |= copy_siginfo_to_user(&frame->info, info); | |
378 | ||
379 | err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp); | |
380 | err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size); | |
381 | err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags); | |
382 | err |= setup_sigcontext(&frame->sc, set, scr); | |
383 | ||
384 | if (unlikely(err)) | |
385 | return force_sigsegv_info(sig, frame); | |
386 | ||
387 | scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */ | |
388 | scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */ | |
389 | scr->pt.cr_iip = tramp_addr; | |
390 | ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */ | |
391 | ia64_psr(&scr->pt)->be = 0; /* force little-endian byte-order */ | |
392 | /* | |
393 | * Force the interruption function mask to zero. This has no effect when a | |
394 | * system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is | |
395 | * ignored), but it has the desirable effect of making it possible to deliver a | |
396 | * signal with an incomplete register frame (which happens when a mandatory RSE | |
397 | * load faults). Furthermore, it has no negative effect on the getting the user's | |
398 | * dirty partition preserved, because that's governed by scr->pt.loadrs. | |
399 | */ | |
400 | scr->pt.cr_ifs = (1UL << 63); | |
401 | ||
402 | /* | |
403 | * Note: this affects only the NaT bits of the scratch regs (the ones saved in | |
404 | * pt_regs), which is exactly what we want. | |
405 | */ | |
406 | scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */ | |
407 | ||
408 | #if DEBUG_SIG | |
409 | printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n", | |
410 | current->comm, current->pid, sig, scr->pt.r12, frame->sc.sc_ip, frame->handler); | |
411 | #endif | |
412 | return 1; | |
413 | } | |
414 | ||
415 | static long | |
b7f9a11a | 416 | handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, |
1da177e4 LT |
417 | struct sigscratch *scr) |
418 | { | |
b7f9a11a | 419 | if (!setup_frame(sig, ka, info, sigmask_to_save(), scr)) |
32974ad4 | 420 | return 0; |
1da177e4 | 421 | |
efee984c | 422 | signal_delivered(sig, info, ka, &scr->pt, |
f14488cc SL |
423 | test_thread_flag(TIF_SINGLESTEP)); |
424 | ||
1da177e4 LT |
425 | return 1; |
426 | } | |
427 | ||
428 | /* | |
429 | * Note that `init' is a special process: it doesn't get signals it doesn't want to | |
430 | * handle. Thus you cannot kill init even with a SIGKILL even by mistake. | |
431 | */ | |
4a177cbf AD |
432 | void |
433 | ia64_do_signal (struct sigscratch *scr, long in_syscall) | |
1da177e4 LT |
434 | { |
435 | struct k_sigaction ka; | |
436 | siginfo_t info; | |
437 | long restart = in_syscall; | |
438 | long errno = scr->pt.r8; | |
1da177e4 | 439 | |
1da177e4 LT |
440 | /* |
441 | * This only loops in the rare cases of handle_signal() failing, in which case we | |
442 | * need to push through a forced SIGSEGV. | |
443 | */ | |
444 | while (1) { | |
445 | int signr = get_signal_to_deliver(&info, &ka, &scr->pt, NULL); | |
446 | ||
447 | /* | |
448 | * get_signal_to_deliver() may have run a debugger (via notify_parent()) | |
449 | * and the debugger may have modified the state (e.g., to arrange for an | |
450 | * inferior call), thus it's important to check for restarting _after_ | |
451 | * get_signal_to_deliver(). | |
452 | */ | |
32974ad4 | 453 | if ((long) scr->pt.r10 != -1) |
1da177e4 LT |
454 | /* |
455 | * A system calls has to be restarted only if one of the error codes | |
456 | * ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10 | |
457 | * isn't -1 then r8 doesn't hold an error code and we don't need to | |
458 | * restart the syscall, so we can clear the "restart" flag here. | |
459 | */ | |
460 | restart = 0; | |
461 | ||
462 | if (signr <= 0) | |
463 | break; | |
464 | ||
465 | if (unlikely(restart)) { | |
466 | switch (errno) { | |
467 | case ERESTART_RESTARTBLOCK: | |
468 | case ERESTARTNOHAND: | |
32974ad4 | 469 | scr->pt.r8 = EINTR; |
1da177e4 LT |
470 | /* note: scr->pt.r10 is already -1 */ |
471 | break; | |
472 | ||
473 | case ERESTARTSYS: | |
474 | if ((ka.sa.sa_flags & SA_RESTART) == 0) { | |
32974ad4 | 475 | scr->pt.r8 = EINTR; |
1da177e4 LT |
476 | /* note: scr->pt.r10 is already -1 */ |
477 | break; | |
478 | } | |
479 | case ERESTARTNOINTR: | |
32974ad4 | 480 | ia64_decrement_ip(&scr->pt); |
1da177e4 LT |
481 | restart = 0; /* don't restart twice if handle_signal() fails... */ |
482 | } | |
483 | } | |
484 | ||
485 | /* | |
486 | * Whee! Actually deliver the signal. If the delivery failed, we need to | |
487 | * continue to iterate in this loop so we can deliver the SIGSEGV... | |
488 | */ | |
a610d6e6 | 489 | if (handle_signal(signr, &ka, &info, scr)) |
4a177cbf | 490 | return; |
1da177e4 LT |
491 | } |
492 | ||
493 | /* Did we come from a system call? */ | |
494 | if (restart) { | |
495 | /* Restart the system call - no handlers present */ | |
496 | if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR | |
497 | || errno == ERESTART_RESTARTBLOCK) | |
498 | { | |
32974ad4 TL |
499 | /* |
500 | * Note: the syscall number is in r15 which is saved in | |
501 | * pt_regs so all we need to do here is adjust ip so that | |
502 | * the "break" instruction gets re-executed. | |
503 | */ | |
504 | ia64_decrement_ip(&scr->pt); | |
505 | if (errno == ERESTART_RESTARTBLOCK) | |
506 | scr->pt.r15 = __NR_restart_syscall; | |
1da177e4 LT |
507 | } |
508 | } | |
4a177cbf AD |
509 | |
510 | /* if there's no signal to deliver, we just put the saved sigmask | |
511 | * back */ | |
51a7b448 | 512 | restore_saved_sigmask(); |
1da177e4 | 513 | } |