2 * Architecture-specific signal handling support.
4 * Copyright (C) 1999-2003 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
7 * Derived from i386 and Alpha versions.
10 #include <linux/config.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
14 #include <linux/ptrace.h>
15 #include <linux/sched.h>
16 #include <linux/signal.h>
17 #include <linux/smp.h>
18 #include <linux/smp_lock.h>
19 #include <linux/stddef.h>
20 #include <linux/tty.h>
21 #include <linux/binfmts.h>
22 #include <linux/unistd.h>
23 #include <linux/wait.h>
26 #include <asm/intrinsics.h>
27 #include <asm/uaccess.h>
29 #include <asm/sigcontext.h>
34 #define STACK_ALIGN 16 /* minimal alignment for stack pointer */
35 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
38 # define PUT_SIGSET(k,u) __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t))
39 # define GET_SIGSET(k,u) __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t))
41 # define PUT_SIGSET(k,u) __put_user((k)->sig[0], &(u)->sig[0])
42 # define GET_SIGSET(k,u) __get_user((k)->sig[0], &(u)->sig[0])
46 ia64_rt_sigsuspend (sigset_t *uset, size_t sigsetsize, struct sigscratch *scr)
50 /* XXX: Don't preclude handling different sized sigset_t's. */
51 if (sigsetsize != sizeof(sigset_t))
54 if (!access_ok(VERIFY_READ, uset, sigsetsize))
57 if (GET_SIGSET(&set, uset))
60 sigdelsetmask(&set, ~_BLOCKABLE);
62 spin_lock_irq(¤t->sighand->siglock);
64 oldset = current->blocked;
65 current->blocked = set;
68 spin_unlock_irq(¤t->sighand->siglock);
71 * The return below usually returns to the signal handler. We need to
72 * pre-set the correct error code here to ensure that the right values
73 * get saved in sigcontext by ia64_do_signal.
79 current->state = TASK_INTERRUPTIBLE;
81 if (ia64_do_signal(&oldset, scr, 1))
87 sys_sigaltstack (const stack_t *uss, stack_t *uoss, long arg2, long arg3, long arg4,
88 long arg5, long arg6, long arg7, long stack)
90 struct pt_regs *pt = (struct pt_regs *) &stack;
92 return do_sigaltstack(uss, uoss, pt->r12);
96 restore_sigcontext (struct sigcontext *sc, struct sigscratch *scr)
98 unsigned long ip, flags, nat, um, cfm;
101 /* Always make any pending restarted system calls return -EINTR */
102 current_thread_info()->restart_block.fn = do_no_restart_syscall;
104 /* restore scratch that always needs gets updated during signal delivery: */
105 err = __get_user(flags, &sc->sc_flags);
106 err |= __get_user(nat, &sc->sc_nat);
107 err |= __get_user(ip, &sc->sc_ip); /* instruction pointer */
108 err |= __get_user(cfm, &sc->sc_cfm);
109 err |= __get_user(um, &sc->sc_um); /* user mask */
110 err |= __get_user(scr->pt.ar_rsc, &sc->sc_ar_rsc);
111 err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat);
112 err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr);
113 err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
114 err |= __get_user(scr->pt.pr, &sc->sc_pr); /* predicates */
115 err |= __get_user(scr->pt.b0, &sc->sc_br[0]); /* b0 (rp) */
116 err |= __get_user(scr->pt.b6, &sc->sc_br[6]); /* b6 */
117 err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */
118 err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8); /* r8-r11 */
119 err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8); /* r12-r13 */
120 err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8); /* r15 */
122 scr->pt.cr_ifs = cfm | (1UL << 63);
124 /* establish new instruction pointer: */
125 scr->pt.cr_iip = ip & ~0x3UL;
126 ia64_psr(&scr->pt)->ri = ip & 0x3;
127 scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM);
129 scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat);
131 if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) {
132 /* Restore most scratch-state only when not in syscall. */
133 err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv); /* ar.ccv */
134 err |= __get_user(scr->pt.b7, &sc->sc_br[7]); /* b7 */
135 err |= __get_user(scr->pt.r14, &sc->sc_gr[14]); /* r14 */
136 err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */
137 err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8); /* r2-r3 */
138 err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8); /* r16-r31 */
141 if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) {
142 struct ia64_psr *psr = ia64_psr(&scr->pt);
144 __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16);
145 psr->mfh = 0; /* drop signal handler's fph contents... */
147 ia64_drop_fpu(current);
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);
158 copy_siginfo_to_user (siginfo_t *to, siginfo_t *from)
160 if (!access_ok(VERIFY_WRITE, to, sizeof(siginfo_t)))
162 if (from->si_code < 0) {
163 if (__copy_to_user(to, from, sizeof(siginfo_t)))
170 * If you change siginfo_t structure, please be sure this code is fixed
171 * accordingly. It should never copy any pad contained in the structure
172 * to avoid security leaks, but must copy the generic 3 ints plus the
173 * relevant union member.
175 err = __put_user(from->si_signo, &to->si_signo);
176 err |= __put_user(from->si_errno, &to->si_errno);
177 err |= __put_user((short)from->si_code, &to->si_code);
178 switch (from->si_code >> 16) {
179 case __SI_FAULT >> 16:
180 err |= __put_user(from->si_flags, &to->si_flags);
181 err |= __put_user(from->si_isr, &to->si_isr);
182 case __SI_POLL >> 16:
183 err |= __put_user(from->si_addr, &to->si_addr);
184 err |= __put_user(from->si_imm, &to->si_imm);
186 case __SI_TIMER >> 16:
187 err |= __put_user(from->si_tid, &to->si_tid);
188 err |= __put_user(from->si_overrun, &to->si_overrun);
189 err |= __put_user(from->si_ptr, &to->si_ptr);
191 case __SI_RT >> 16: /* Not generated by the kernel as of now. */
192 case __SI_MESGQ >> 16:
193 err |= __put_user(from->si_uid, &to->si_uid);
194 err |= __put_user(from->si_pid, &to->si_pid);
195 err |= __put_user(from->si_ptr, &to->si_ptr);
197 case __SI_CHLD >> 16:
198 err |= __put_user(from->si_utime, &to->si_utime);
199 err |= __put_user(from->si_stime, &to->si_stime);
200 err |= __put_user(from->si_status, &to->si_status);
202 err |= __put_user(from->si_uid, &to->si_uid);
203 err |= __put_user(from->si_pid, &to->si_pid);
211 ia64_rt_sigreturn (struct sigscratch *scr)
213 extern char ia64_strace_leave_kernel, ia64_leave_kernel;
214 struct sigcontext *sc;
219 sc = &((struct sigframe *) (scr->pt.r12 + 16))->sc;
222 * When we return to the previously executing context, r8 and r10 have already
223 * been setup the way we want them. Indeed, if the signal wasn't delivered while
224 * in a system call, we must not touch r8 or r10 as otherwise user-level state
225 * could be corrupted.
227 retval = (long) &ia64_leave_kernel;
228 if (test_thread_flag(TIF_SYSCALL_TRACE))
230 * strace expects to be notified after sigreturn returns even though the
231 * context to which we return may not be in the middle of a syscall.
232 * Thus, the return-value that strace displays for sigreturn is
235 retval = (long) &ia64_strace_leave_kernel;
237 if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
240 if (GET_SIGSET(&set, &sc->sc_mask))
243 sigdelsetmask(&set, ~_BLOCKABLE);
245 spin_lock_irq(¤t->sighand->siglock);
247 current->blocked = set;
250 spin_unlock_irq(¤t->sighand->siglock);
252 if (restore_sigcontext(sc, scr))
256 printk("SIG return (%s:%d): sp=%lx ip=%lx\n",
257 current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip);
260 * It is more difficult to avoid calling this function than to
261 * call it and ignore errors.
263 do_sigaltstack(&sc->sc_stack, 0, scr->pt.r12);
267 si.si_signo = SIGSEGV;
269 si.si_code = SI_KERNEL;
270 si.si_pid = current->pid;
271 si.si_uid = current->uid;
273 force_sig_info(SIGSEGV, &si, current);
278 * This does just the minimum required setup of sigcontext.
279 * Specifically, it only installs data that is either not knowable at
280 * the user-level or that gets modified before execution in the
281 * trampoline starts. Everything else is done at the user-level.
284 setup_sigcontext (struct sigcontext *sc, sigset_t *mask, struct sigscratch *scr)
286 unsigned long flags = 0, ifs, cfm, nat;
289 ifs = scr->pt.cr_ifs;
291 if (on_sig_stack((unsigned long) sc))
292 flags |= IA64_SC_FLAG_ONSTACK;
293 if ((ifs & (1UL << 63)) == 0) {
294 /* if cr_ifs isn't valid, we got here through a syscall */
295 flags |= IA64_SC_FLAG_IN_SYSCALL;
296 cfm = scr->ar_pfs & ((1UL << 38) - 1);
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);
305 nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat);
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);
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 */
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(&scr->pt.ar_csd, &sc->sc_ar25, 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 */
346 * Check whether the register-backing store is already on the signal stack.
349 rbs_on_sig_stack (unsigned long bsp)
351 return (bsp - current->sas_ss_sp < current->sas_ss_size);
355 setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set,
356 struct sigscratch *scr)
358 extern char __kernel_sigtramp[];
359 unsigned long tramp_addr, new_rbs = 0;
360 struct sigframe *frame;
364 frame = (void *) scr->pt.r12;
365 tramp_addr = (unsigned long) __kernel_sigtramp;
366 if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags((unsigned long) frame) == 0) {
367 frame = (void *) ((current->sas_ss_sp + current->sas_ss_size)
368 & ~(STACK_ALIGN - 1));
370 * We need to check for the register stack being on the signal stack
371 * separately, because it's switched separately (memory stack is switched
372 * in the kernel, register stack is switched in the signal trampoline).
374 if (!rbs_on_sig_stack(scr->pt.ar_bspstore))
375 new_rbs = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1);
377 frame = (void *) frame - ((sizeof(*frame) + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1));
379 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
382 err = __put_user(sig, &frame->arg0);
383 err |= __put_user(&frame->info, &frame->arg1);
384 err |= __put_user(&frame->sc, &frame->arg2);
385 err |= __put_user(new_rbs, &frame->sc.sc_rbs_base);
386 err |= __put_user(0, &frame->sc.sc_loadrs); /* initialize to zero */
387 err |= __put_user(ka->sa.sa_handler, &frame->handler);
389 err |= copy_siginfo_to_user(&frame->info, info);
391 err |= __put_user(current->sas_ss_sp, &frame->sc.sc_stack.ss_sp);
392 err |= __put_user(current->sas_ss_size, &frame->sc.sc_stack.ss_size);
393 err |= __put_user(sas_ss_flags(scr->pt.r12), &frame->sc.sc_stack.ss_flags);
394 err |= setup_sigcontext(&frame->sc, set, scr);
399 scr->pt.r12 = (unsigned long) frame - 16; /* new stack pointer */
400 scr->pt.ar_fpsr = FPSR_DEFAULT; /* reset fpsr for signal handler */
401 scr->pt.cr_iip = tramp_addr;
402 ia64_psr(&scr->pt)->ri = 0; /* start executing in first slot */
403 ia64_psr(&scr->pt)->be = 0; /* force little-endian byte-order */
405 * Force the interruption function mask to zero. This has no effect when a
406 * system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is
407 * ignored), but it has the desirable effect of making it possible to deliver a
408 * signal with an incomplete register frame (which happens when a mandatory RSE
409 * load faults). Furthermore, it has no negative effect on the getting the user's
410 * dirty partition preserved, because that's governed by scr->pt.loadrs.
412 scr->pt.cr_ifs = (1UL << 63);
415 * Note: this affects only the NaT bits of the scratch regs (the ones saved in
416 * pt_regs), which is exactly what we want.
418 scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */
421 printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n",
422 current->comm, current->pid, sig, scr->pt.r12, frame->sc.sc_ip, frame->handler);
428 ka->sa.sa_handler = SIG_DFL;
429 si.si_signo = SIGSEGV;
431 si.si_code = SI_KERNEL;
432 si.si_pid = current->pid;
433 si.si_uid = current->uid;
435 force_sig_info(SIGSEGV, &si, current);
440 handle_signal (unsigned long sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *oldset,
441 struct sigscratch *scr)
443 if (IS_IA32_PROCESS(&scr->pt)) {
444 /* send signal to IA-32 process */
445 if (!ia32_setup_frame1(sig, ka, info, oldset, &scr->pt))
448 /* send signal to IA-64 process */
449 if (!setup_frame(sig, ka, info, oldset, scr))
452 if (ka->sa.sa_flags & SA_ONESHOT)
453 ka->sa.sa_handler = SIG_DFL;
455 if (!(ka->sa.sa_flags & SA_NODEFER)) {
456 spin_lock_irq(¤t->sighand->siglock);
458 sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask);
459 sigaddset(¤t->blocked, sig);
462 spin_unlock_irq(¤t->sighand->siglock);
468 * Note that `init' is a special process: it doesn't get signals it doesn't want to
469 * handle. Thus you cannot kill init even with a SIGKILL even by mistake.
472 ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall)
474 struct k_sigaction *ka;
476 long restart = in_syscall;
477 long errno = scr->pt.r8;
478 # define ERR_CODE(c) (IS_IA32_PROCESS(&scr->pt) ? -(c) : (c))
481 * In the ia64_leave_kernel code path, we want the common case to go fast, which
482 * is why we may in certain cases get here from kernel mode. Just return without
483 * doing anything if so.
485 if (!user_mode(&scr->pt))
489 oldset = ¤t->blocked;
492 * This only loops in the rare cases of handle_signal() failing, in which case we
493 * need to push through a forced SIGSEGV.
496 int signr = get_signal_to_deliver(&info, &scr->pt, NULL);
499 * get_signal_to_deliver() may have run a debugger (via notify_parent())
500 * and the debugger may have modified the state (e.g., to arrange for an
501 * inferior call), thus it's important to check for restarting _after_
502 * get_signal_to_deliver().
504 if (IS_IA32_PROCESS(&scr->pt)) {
511 } else if ((long) scr->pt.r10 != -1)
513 * A system calls has to be restarted only if one of the error codes
514 * ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned. If r10
515 * isn't -1 then r8 doesn't hold an error code and we don't need to
516 * restart the syscall, so we can clear the "restart" flag here.
523 ka = ¤t->sighand->action[signr - 1];
525 if (unlikely(restart)) {
527 case ERESTART_RESTARTBLOCK:
529 scr->pt.r8 = ERR_CODE(EINTR);
530 /* note: scr->pt.r10 is already -1 */
534 if ((ka->sa.sa_flags & SA_RESTART) == 0) {
535 scr->pt.r8 = ERR_CODE(EINTR);
536 /* note: scr->pt.r10 is already -1 */
540 if (IS_IA32_PROCESS(&scr->pt)) {
541 scr->pt.r8 = scr->pt.r1;
544 ia64_decrement_ip(&scr->pt);
545 restart = 0; /* don't restart twice if handle_signal() fails... */
550 * Whee! Actually deliver the signal. If the delivery failed, we need to
551 * continue to iterate in this loop so we can deliver the SIGSEGV...
553 if (handle_signal(signr, ka, &info, oldset, scr))
557 /* Did we come from a system call? */
559 /* Restart the system call - no handlers present */
560 if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR
561 || errno == ERESTART_RESTARTBLOCK)
563 if (IS_IA32_PROCESS(&scr->pt)) {
564 scr->pt.r8 = scr->pt.r1;
566 if (errno == ERESTART_RESTARTBLOCK)
567 scr->pt.r8 = 0; /* x86 version of __NR_restart_syscall */
570 * Note: the syscall number is in r15 which is saved in
571 * pt_regs so all we need to do here is adjust ip so that
572 * the "break" instruction gets re-executed.
574 ia64_decrement_ip(&scr->pt);
575 if (errno == ERESTART_RESTARTBLOCK)
576 scr->pt.r15 = __NR_restart_syscall;