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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 | static long |
43 | restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr) | |
44 | { | |
4ea78729 | 45 | unsigned long ip, flags, nat, um, cfm, rsc; |
1da177e4 LT |
46 | long err; |
47 | ||
48 | /* Always make any pending restarted system calls return -EINTR */ | |
f56141e3 | 49 | current->restart_block.fn = do_no_restart_syscall; |
1da177e4 LT |
50 | |
51 | /* restore scratch that always needs gets updated during signal delivery: */ | |
52 | err = __get_user(flags, &sc->sc_flags); | |
53 | err |= __get_user(nat, &sc->sc_nat); | |
54 | err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */ | |
55 | err |= __get_user(cfm, &sc->sc_cfm); | |
56 | err |= __get_user(um, &sc->sc_um); /* user mask */ | |
4ea78729 | 57 | err |= __get_user(rsc, &sc->sc_ar_rsc); |
1da177e4 LT |
58 | err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat); |
59 | err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); | |
60 | err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); | |
61 | err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */ | |
62 | err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ | |
63 | err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ | |
64 | err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */ | |
65 | err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */ | |
66 | err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8); /* r12-r13 */ | |
67 | err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8); /* r15 */ | |
68 | ||
69 | scr->pt.cr_ifs = cfm | (1UL << 63); | |
4ea78729 | 70 | scr->pt.ar_rsc = rsc | (3 << 2); /* force PL3 */ |
1da177e4 LT |
71 | |
72 | /* establish new instruction pointer: */ | |
73 | scr->pt.cr_iip = ip & ~0x3UL; | |
74 | ia64_psr(&scr->pt)->ri = ip & 0x3; | |
75 | scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM); | |
76 | ||
77 | scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat); | |
78 | ||
79 | if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { | |
80 | /* Restore most scratch-state only when not in syscall. */ | |
81 | err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ | |
82 | err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ | |
83 | err |= __get_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ | |
84 | err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */ | |
85 | err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8); /* r2-r3 */ | |
86 | err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */ | |
87 | } | |
88 | ||
89 | if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) { | |
90 | struct ia64_psr *psr = ia64_psr(&scr->pt); | |
91 | ||
b9ab117c | 92 | err |= __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16); |
1da177e4 | 93 | psr->mfh = 0; /* drop signal handler's fph contents... */ |
2ba3e3e6 | 94 | preempt_disable(); |
1da177e4 LT |
95 | if (psr->dfh) |
96 | ia64_drop_fpu(current); | |
97 | else { | |
98 | /* We already own the local fph, otherwise psr->dfh wouldn't be 0. */ | |
99 | __ia64_load_fpu(current->thread.fph); | |
100 | ia64_set_local_fpu_owner(current); | |
101 | } | |
2ba3e3e6 | 102 | preempt_enable(); |
1da177e4 LT |
103 | } |
104 | return err; | |
105 | } | |
106 | ||
107 | int | |
ce395960 | 108 | copy_siginfo_to_user (siginfo_t __user *to, const siginfo_t *from) |
1da177e4 LT |
109 | { |
110 | if (!access_ok(VERIFY_WRITE, to, sizeof(siginfo_t))) | |
111 | return -EFAULT; | |
112 | if (from->si_code < 0) { | |
113 | if (__copy_to_user(to, from, sizeof(siginfo_t))) | |
114 | return -EFAULT; | |
115 | return 0; | |
116 | } else { | |
117 | int err; | |
118 | ||
119 | /* | |
120 | * If you change siginfo_t structure, please be sure this code is fixed | |
121 | * accordingly. It should never copy any pad contained in the structure | |
122 | * to avoid security leaks, but must copy the generic 3 ints plus the | |
123 | * relevant union member. | |
124 | */ | |
125 | err = __put_user(from->si_signo, &to->si_signo); | |
126 | err |= __put_user(from->si_errno, &to->si_errno); | |
127 | err |= __put_user((short)from->si_code, &to->si_code); | |
128 | switch (from->si_code >> 16) { | |
129 | case __SI_FAULT >> 16: | |
130 | err |= __put_user(from->si_flags, &to->si_flags); | |
131 | err |= __put_user(from->si_isr, &to->si_isr); | |
132 | case __SI_POLL >> 16: | |
133 | err |= __put_user(from->si_addr, &to->si_addr); | |
134 | err |= __put_user(from->si_imm, &to->si_imm); | |
135 | break; | |
136 | case __SI_TIMER >> 16: | |
137 | err |= __put_user(from->si_tid, &to->si_tid); | |
138 | err |= __put_user(from->si_overrun, &to->si_overrun); | |
139 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
140 | break; | |
141 | case __SI_RT >> 16: /* Not generated by the kernel as of now. */ | |
142 | case __SI_MESGQ >> 16: | |
143 | err |= __put_user(from->si_uid, &to->si_uid); | |
144 | err |= __put_user(from->si_pid, &to->si_pid); | |
145 | err |= __put_user(from->si_ptr, &to->si_ptr); | |
146 | break; | |
147 | case __SI_CHLD >> 16: | |
148 | err |= __put_user(from->si_utime, &to->si_utime); | |
149 | err |= __put_user(from->si_stime, &to->si_stime); | |
150 | err |= __put_user(from->si_status, &to->si_status); | |
151 | default: | |
152 | err |= __put_user(from->si_uid, &to->si_uid); | |
153 | err |= __put_user(from->si_pid, &to->si_pid); | |
154 | break; | |
155 | } | |
156 | return err; | |
157 | } | |
158 | } | |
159 | ||
160 | long | |
161 | ia64_rt_sigreturn (struct sigscratch *scr) | |
162 | { | |
163 | extern char ia64_strace_leave_kernel, ia64_leave_kernel; | |
164 | struct sigcontext __user *sc; | |
165 | struct siginfo si; | |
166 | sigset_t set; | |
167 | long retval; | |
168 | ||
169 | sc = &((struct sigframe __user *) (scr->pt.r12 + 16))->sc; | |
170 | ||
171 | /* | |
172 | * When we return to the previously executing context, r8 and r10 have already | |
173 | * been setup the way we want them. Indeed, if the signal wasn't delivered while | |
174 | * in a system call, we must not touch r8 or r10 as otherwise user-level state | |
175 | * could be corrupted. | |
176 | */ | |
177 | retval = (long) &ia64_leave_kernel; | |
446b8831 DW |
178 | if (test_thread_flag(TIF_SYSCALL_TRACE) |
179 | || test_thread_flag(TIF_SYSCALL_AUDIT)) | |
1da177e4 LT |
180 | /* |
181 | * strace expects to be notified after sigreturn returns even though the | |
182 | * context to which we return may not be in the middle of a syscall. | |
183 | * Thus, the return-value that strace displays for sigreturn is | |
184 | * meaningless. | |
185 | */ | |
186 | retval = (long) &ia64_strace_leave_kernel; | |
187 | ||
188 | if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) | |
189 | goto give_sigsegv; | |
190 | ||
191 | if (GET_SIGSET(&set, &sc->sc_mask)) | |
192 | goto give_sigsegv; | |
193 | ||
7a076e4f | 194 | set_current_blocked(&set); |
1da177e4 LT |
195 | |
196 | if (restore_sigcontext(sc, scr)) | |
197 | goto give_sigsegv; | |
198 | ||
199 | #if DEBUG_SIG | |
200 | printk("SIG return (%s:%d): sp=%lx ip=%lx\n", | |
201 | current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip); | |
202 | #endif | |
e8d9ef09 AV |
203 | if (restore_altstack(&sc->sc_stack)) |
204 | goto give_sigsegv; | |
1da177e4 LT |
205 | return retval; |
206 | ||
207 | give_sigsegv: | |
208 | si.si_signo = SIGSEGV; | |
209 | si.si_errno = 0; | |
210 | si.si_code = SI_KERNEL; | |
b488893a | 211 | si.si_pid = task_pid_vnr(current); |
6c1ee033 | 212 | si.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 LT |
213 | si.si_addr = sc; |
214 | force_sig_info(SIGSEGV, &si, current); | |
215 | return retval; | |
216 | } | |
217 | ||
218 | /* | |
219 | * This does just the minimum required setup of sigcontext. | |
220 | * Specifically, it only installs data that is either not knowable at | |
221 | * the user-level or that gets modified before execution in the | |
222 | * trampoline starts. Everything else is done at the user-level. | |
223 | */ | |
224 | static long | |
225 | setup_sigcontext (struct sigcontext __user *sc, sigset_t *mask, struct sigscratch *scr) | |
226 | { | |
227 | unsigned long flags = 0, ifs, cfm, nat; | |
b9ab117c | 228 | long err = 0; |
1da177e4 LT |
229 | |
230 | ifs = scr->pt.cr_ifs; | |
231 | ||
232 | if (on_sig_stack((unsigned long) sc)) | |
233 | flags |= IA64_SC_FLAG_ONSTACK; | |
234 | if ((ifs & (1UL << 63)) == 0) | |
235 | /* if cr_ifs doesn't have the valid bit set, we got here through a syscall */ | |
236 | flags |= IA64_SC_FLAG_IN_SYSCALL; | |
237 | cfm = ifs & ((1UL << 38) - 1); | |
238 | ia64_flush_fph(current); | |
239 | if ((current->thread.flags & IA64_THREAD_FPH_VALID)) { | |
240 | flags |= IA64_SC_FLAG_FPH_VALID; | |
b9ab117c | 241 | err = __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16); |
1da177e4 LT |
242 | } |
243 | ||
244 | nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat); | |
245 | ||
b9ab117c | 246 | err |= __put_user(flags, &sc->sc_flags); |
1da177e4 LT |
247 | err |= __put_user(nat, &sc->sc_nat); |
248 | err |= PUT_SIGSET(mask, &sc->sc_mask); | |
249 | err |= __put_user(cfm, &sc->sc_cfm); | |
250 | err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um); | |
251 | err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc); | |
252 | err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat); /* ar.unat */ | |
253 | err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr); /* ar.fpsr */ | |
254 | err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs); | |
255 | err |= __put_user(scr->pt.pr, &sc->sc_pr); /* predicates */ | |
256 | err |= __put_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */ | |
257 | err |= __put_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */ | |
258 | err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 8); /* r1 */ | |
259 | err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8); /* r8-r11 */ | |
260 | err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 2*8); /* r12-r13 */ | |
261 | err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8); /* r15 */ | |
262 | err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip); | |
263 | ||
2018df76 | 264 | if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) { |
1da177e4 LT |
265 | /* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */ |
266 | err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */ | |
267 | err |= __put_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */ | |
268 | err |= __put_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */ | |
269 | err |= __copy_to_user(&sc->sc_ar25, &scr->pt.ar_csd, 2*8); /* ar.csd & ar.ssd */ | |
270 | err |= __copy_to_user(&sc->sc_gr[2], &scr->pt.r2, 2*8); /* r2-r3 */ | |
271 | err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8); /* r16-r31 */ | |
272 | } | |
273 | return err; | |
274 | } | |
275 | ||
276 | /* | |
277 | * Check whether the register-backing store is already on the signal stack. | |
278 | */ | |
279 | static inline int | |
280 | rbs_on_sig_stack (unsigned long bsp) | |
281 | { | |
282 | return (bsp - current->sas_ss_sp < current->sas_ss_size); | |
283 | } | |
284 | ||
285 | static long | |
286 | force_sigsegv_info (int sig, void __user *addr) | |
287 | { | |
288 | unsigned long flags; | |
289 | struct siginfo si; | |
290 | ||
291 | if (sig == SIGSEGV) { | |
292 | /* | |
293 | * Acquiring siglock around the sa_handler-update is almost | |
294 | * certainly overkill, but this isn't a | |
295 | * performance-critical path and I'd rather play it safe | |
296 | * here than having to debug a nasty race if and when | |
297 | * something changes in kernel/signal.c that would make it | |
298 | * no longer safe to modify sa_handler without holding the | |
299 | * lock. | |
300 | */ | |
301 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
302 | current->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; | |
303 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
304 | } | |
305 | si.si_signo = SIGSEGV; | |
306 | si.si_errno = 0; | |
307 | si.si_code = SI_KERNEL; | |
b488893a | 308 | si.si_pid = task_pid_vnr(current); |
6c1ee033 | 309 | si.si_uid = from_kuid_munged(current_user_ns(), current_uid()); |
1da177e4 LT |
310 | si.si_addr = addr; |
311 | force_sig_info(SIGSEGV, &si, current); | |
98c20309 | 312 | return 1; |
1da177e4 LT |
313 | } |
314 | ||
315 | static long | |
98c20309 | 316 | setup_frame(struct ksignal *ksig, sigset_t *set, struct sigscratch *scr) |
1da177e4 LT |
317 | { |
318 | extern char __kernel_sigtramp[]; | |
cf20d1ea | 319 | unsigned long tramp_addr, new_rbs = 0, new_sp; |
1da177e4 LT |
320 | struct sigframe __user *frame; |
321 | long err; | |
322 | ||
cf20d1ea | 323 | new_sp = scr->pt.r12; |
1da177e4 | 324 | tramp_addr = (unsigned long) __kernel_sigtramp; |
98c20309 | 325 | if (ksig->ka.sa.sa_flags & SA_ONSTACK) { |
d7a6c68a SW |
326 | int onstack = sas_ss_flags(new_sp); |
327 | ||
328 | if (onstack == 0) { | |
329 | new_sp = current->sas_ss_sp + current->sas_ss_size; | |
330 | /* | |
331 | * We need to check for the register stack being on the | |
332 | * signal stack separately, because it's switched | |
333 | * separately (memory stack is switched in the kernel, | |
334 | * register stack is switched in the signal trampoline). | |
335 | */ | |
336 | if (!rbs_on_sig_stack(scr->pt.ar_bspstore)) | |
337 | new_rbs = ALIGN(current->sas_ss_sp, | |
338 | sizeof(long)); | |
339 | } else if (onstack == SS_ONSTACK) { | |
340 | unsigned long check_sp; | |
341 | ||
342 | /* | |
343 | * If we are on the alternate signal stack and would | |
344 | * overflow it, don't. Return an always-bogus address | |
345 | * instead so we will die with SIGSEGV. | |
346 | */ | |
347 | check_sp = (new_sp - sizeof(*frame)) & -STACK_ALIGN; | |
348 | if (!likely(on_sig_stack(check_sp))) | |
98c20309 | 349 | return force_sigsegv_info(ksig->sig, (void __user *) |
d7a6c68a SW |
350 | check_sp); |
351 | } | |
1da177e4 | 352 | } |
cf20d1ea | 353 | frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN); |
1da177e4 LT |
354 | |
355 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
98c20309 | 356 | return force_sigsegv_info(ksig->sig, frame); |
1da177e4 | 357 | |
98c20309 | 358 | err = __put_user(ksig->sig, &frame->arg0); |
1da177e4 LT |
359 | err |= __put_user(&frame->info, &frame->arg1); |
360 | err |= __put_user(&frame->sc, &frame->arg2); | |
361 | err |= __put_user(new_rbs, &frame->sc.sc_rbs_base); | |
362 | err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */ | |
98c20309 | 363 | err |= __put_user(ksig->ka.sa.sa_handler, &frame->handler); |
1da177e4 | 364 | |
98c20309 | 365 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
1da177e4 | 366 | |
e8d9ef09 | 367 | err |= __save_altstack(&frame->sc.sc_stack, scr->pt.r12); |
1da177e4 LT |
368 | err |= setup_sigcontext(&frame->sc, set, scr); |
369 | ||
370 | if (unlikely(err)) | |
98c20309 | 371 | return force_sigsegv_info(ksig->sig, frame); |
1da177e4 LT |
372 | |
373 | scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */ | |
374 | scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */ | |
375 | scr->pt.cr_iip = tramp_addr; | |
376 | ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */ | |
377 | ia64_psr(&scr->pt)->be = 0; /* force little-endian byte-order */ | |
378 | /* | |
379 | * Force the interruption function mask to zero. This has no effect when a | |
380 | * system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is | |
381 | * ignored), but it has the desirable effect of making it possible to deliver a | |
382 | * signal with an incomplete register frame (which happens when a mandatory RSE | |
383 | * load faults). Furthermore, it has no negative effect on the getting the user's | |
384 | * dirty partition preserved, because that's governed by scr->pt.loadrs. | |
385 | */ | |
386 | scr->pt.cr_ifs = (1UL << 63); | |
387 | ||
388 | /* | |
389 | * Note: this affects only the NaT bits of the scratch regs (the ones saved in | |
390 | * pt_regs), which is exactly what we want. | |
391 | */ | |
392 | scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */ | |
393 | ||
394 | #if DEBUG_SIG | |
395 | printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n", | |
98c20309 | 396 | current->comm, current->pid, ksig->sig, scr->pt.r12, frame->sc.sc_ip, frame->handler); |
1da177e4 | 397 | #endif |
98c20309 | 398 | return 0; |
1da177e4 LT |
399 | } |
400 | ||
401 | static long | |
98c20309 | 402 | handle_signal (struct ksignal *ksig, struct sigscratch *scr) |
1da177e4 | 403 | { |
98c20309 | 404 | int ret = setup_frame(ksig, sigmask_to_save(), scr); |
1da177e4 | 405 | |
98c20309 RW |
406 | if (!ret) |
407 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); | |
f14488cc | 408 | |
98c20309 | 409 | return ret; |
1da177e4 LT |
410 | } |
411 | ||
412 | /* | |
413 | * Note that `init' is a special process: it doesn't get signals it doesn't want to | |
414 | * handle. Thus you cannot kill init even with a SIGKILL even by mistake. | |
415 | */ | |
4a177cbf AD |
416 | void |
417 | ia64_do_signal (struct sigscratch *scr, long in_syscall) | |
1da177e4 | 418 | { |
1da177e4 LT |
419 | long restart = in_syscall; |
420 | long errno = scr->pt.r8; | |
98c20309 | 421 | struct ksignal ksig; |
1da177e4 | 422 | |
1da177e4 LT |
423 | /* |
424 | * This only loops in the rare cases of handle_signal() failing, in which case we | |
425 | * need to push through a forced SIGSEGV. | |
426 | */ | |
427 | while (1) { | |
98c20309 | 428 | get_signal(&ksig); |
1da177e4 LT |
429 | |
430 | /* | |
431 | * get_signal_to_deliver() may have run a debugger (via notify_parent()) | |
432 | * and the debugger may have modified the state (e.g., to arrange for an | |
433 | * inferior call), thus it's important to check for restarting _after_ | |
434 | * get_signal_to_deliver(). | |
435 | */ | |
32974ad4 | 436 | if ((long) scr->pt.r10 != -1) |
1da177e4 LT |
437 | /* |
438 | * A system calls has to be restarted only if one of the error codes | |
439 | * ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10 | |
440 | * isn't -1 then r8 doesn't hold an error code and we don't need to | |
441 | * restart the syscall, so we can clear the "restart" flag here. | |
442 | */ | |
443 | restart = 0; | |
444 | ||
98c20309 | 445 | if (ksig.sig <= 0) |
1da177e4 LT |
446 | break; |
447 | ||
448 | if (unlikely(restart)) { | |
449 | switch (errno) { | |
450 | case ERESTART_RESTARTBLOCK: | |
451 | case ERESTARTNOHAND: | |
32974ad4 | 452 | scr->pt.r8 = EINTR; |
1da177e4 LT |
453 | /* note: scr->pt.r10 is already -1 */ |
454 | break; | |
455 | ||
456 | case ERESTARTSYS: | |
98c20309 | 457 | if ((ksig.ka.sa.sa_flags & SA_RESTART) == 0) { |
32974ad4 | 458 | scr->pt.r8 = EINTR; |
1da177e4 LT |
459 | /* note: scr->pt.r10 is already -1 */ |
460 | break; | |
461 | } | |
462 | case ERESTARTNOINTR: | |
32974ad4 | 463 | ia64_decrement_ip(&scr->pt); |
1da177e4 LT |
464 | restart = 0; /* don't restart twice if handle_signal() fails... */ |
465 | } | |
466 | } | |
467 | ||
468 | /* | |
469 | * Whee! Actually deliver the signal. If the delivery failed, we need to | |
470 | * continue to iterate in this loop so we can deliver the SIGSEGV... | |
471 | */ | |
98c20309 | 472 | if (handle_signal(&ksig, scr)) |
4a177cbf | 473 | return; |
1da177e4 LT |
474 | } |
475 | ||
476 | /* Did we come from a system call? */ | |
477 | if (restart) { | |
478 | /* Restart the system call - no handlers present */ | |
479 | if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR | |
480 | || errno == ERESTART_RESTARTBLOCK) | |
481 | { | |
32974ad4 TL |
482 | /* |
483 | * Note: the syscall number is in r15 which is saved in | |
484 | * pt_regs so all we need to do here is adjust ip so that | |
485 | * the "break" instruction gets re-executed. | |
486 | */ | |
487 | ia64_decrement_ip(&scr->pt); | |
488 | if (errno == ERESTART_RESTARTBLOCK) | |
489 | scr->pt.r15 = __NR_restart_syscall; | |
1da177e4 LT |
490 | } |
491 | } | |
4a177cbf AD |
492 | |
493 | /* if there's no signal to deliver, we just put the saved sigmask | |
494 | * back */ | |
51a7b448 | 495 | restore_saved_sigmask(); |
1da177e4 | 496 | } |