2 * linux/arch/cris/kernel/signal.c
4 * Based on arch/i386/kernel/signal.c by
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson *
8 * Ideas also taken from arch/arm.
10 * Copyright (C) 2000, 2001 Axis Communications AB
12 * Authors: Bjorn Wesen (bjornw@axis.com)
16 #include <linux/sched.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>
28 #include <asm/processor.h>
29 #include <asm/ucontext.h>
30 #include <asm/uaccess.h>
34 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
36 /* a syscall in Linux/CRIS is a break 13 instruction which is 2 bytes */
37 /* manipulate regs so that upon return, it will be re-executed */
39 /* We rely on that pc points to the instruction after "break 13", so the
40 * library must never do strange things like putting it in a delay slot.
42 #define RESTART_CRIS_SYS(regs) regs->r10 = regs->orig_r10; regs->irp -= 2;
44 int do_signal(int canrestart, sigset_t *oldset, struct pt_regs *regs);
47 * Atomically swap in the new signal mask, and wait for a signal. Define
48 * dummy arguments to be able to reach the regs argument. (Note that this
49 * arrangement relies on old_sigset_t occupying one register.)
52 sys_sigsuspend(old_sigset_t mask, long r11, long r12, long r13, long mof,
53 long srp, struct pt_regs *regs)
58 spin_lock_irq(¤t->sighand->siglock);
59 saveset = current->blocked;
60 siginitset(¤t->blocked, mask);
62 spin_unlock_irq(¤t->sighand->siglock);
66 current->state = TASK_INTERRUPTIBLE;
68 if (do_signal(0, &saveset, regs))
69 /* We will get here twice: once to call the signal
70 handler, then again to return from the
71 sigsuspend system call. When calling the
72 signal handler, R10 holds the signal number as
73 set through do_signal. The sigsuspend call
74 will return with the restored value set above;
80 /* Define dummy arguments to be able to reach the regs argument. (Note that
81 * this arrangement relies on size_t occupying one register.)
84 sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize, long r12, long r13,
85 long mof, long srp, struct pt_regs *regs)
87 sigset_t saveset, newset;
89 /* XXX: Don't preclude handling different sized sigset_t's. */
90 if (sigsetsize != sizeof(sigset_t))
93 if (copy_from_user(&newset, unewset, sizeof(newset)))
95 sigdelsetmask(&newset, ~_BLOCKABLE);
97 spin_lock_irq(¤t->sighand->siglock);
98 saveset = current->blocked;
99 current->blocked = newset;
101 spin_unlock_irq(¤t->sighand->siglock);
105 current->state = TASK_INTERRUPTIBLE;
107 if (do_signal(0, &saveset, regs))
108 /* We will get here twice: once to call the signal
109 handler, then again to return from the
110 sigsuspend system call. When calling the
111 signal handler, R10 holds the signal number as
112 set through do_signal. The sigsuspend call
113 will return with the restored value set above;
120 sys_sigaction(int sig, const struct old_sigaction __user *act,
121 struct old_sigaction *oact)
123 struct k_sigaction new_ka, old_ka;
128 if (verify_area(VERIFY_READ, act, sizeof(*act)) ||
129 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
130 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
132 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
133 __get_user(mask, &act->sa_mask);
134 siginitset(&new_ka.sa.sa_mask, mask);
137 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
140 if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) ||
141 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
142 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
144 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
145 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
152 sys_sigaltstack(const stack_t *uss, stack_t __user *uoss)
154 return do_sigaltstack(uss, uoss, rdusp());
159 * Do a signal return; undo the signal stack.
163 struct sigcontext sc;
164 unsigned long extramask[_NSIG_WORDS-1];
165 unsigned char retcode[8]; /* trampoline code */
169 struct siginfo *pinfo;
173 unsigned char retcode[8]; /* trampoline code */
178 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
180 unsigned int err = 0;
181 unsigned long old_usp;
183 /* restore the regs from &sc->regs (same as sc, since regs is first)
184 * (sc is already checked for VERIFY_READ since the sigframe was
185 * checked in sys_sigreturn previously)
188 if (__copy_from_user(regs, sc, sizeof(struct pt_regs)))
191 /* make sure the U-flag is set so user-mode cannot fool us */
193 regs->dccr |= 1 << 8;
195 /* restore the old USP as it was before we stacked the sc etc.
196 * (we cannot just pop the sigcontext since we aligned the sp and
197 * stuff after pushing it)
200 err |= __get_user(old_usp, &sc->usp);
204 /* TODO: the other ports use regs->orig_XX to disable syscall checks
205 * after this completes, but we don't use that mechanism. maybe we can
215 /* Define dummy arguments to be able to reach the regs argument. */
217 asmlinkage int sys_sigreturn(long r10, long r11, long r12, long r13, long mof,
218 long srp, struct pt_regs *regs)
220 struct sigframe __user *frame = (struct sigframe *)rdusp();
224 * Since we stacked the signal on a dword boundary,
225 * then frame should be dword aligned here. If it's
226 * not, then the user is trying to mess with us.
228 if (((long)frame) & 3)
231 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
233 if (__get_user(set.sig[0], &frame->sc.oldmask)
235 && __copy_from_user(&set.sig[1], frame->extramask,
236 sizeof(frame->extramask))))
239 sigdelsetmask(&set, ~_BLOCKABLE);
240 spin_lock_irq(¤t->sighand->siglock);
241 current->blocked = set;
243 spin_unlock_irq(¤t->sighand->siglock);
245 if (restore_sigcontext(regs, &frame->sc))
248 /* TODO: SIGTRAP when single-stepping as in arm ? */
253 force_sig(SIGSEGV, current);
257 /* Define dummy arguments to be able to reach the regs argument. */
259 asmlinkage int sys_rt_sigreturn(long r10, long r11, long r12, long r13,
260 long mof, long srp, struct pt_regs *regs)
262 struct rt_sigframe __user *frame = (struct rt_sigframe *)rdusp();
267 * Since we stacked the signal on a dword boundary,
268 * then frame should be dword aligned here. If it's
269 * not, then the user is trying to mess with us.
271 if (((long)frame) & 3)
274 if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
276 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
279 sigdelsetmask(&set, ~_BLOCKABLE);
280 spin_lock_irq(¤t->sighand->siglock);
281 current->blocked = set;
283 spin_unlock_irq(¤t->sighand->siglock);
285 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
288 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
290 /* It is more difficult to avoid calling this function than to
291 call it and ignore errors. */
292 do_sigaltstack(&st, NULL, rdusp());
297 force_sig(SIGSEGV, current);
302 * Set up a signal frame.
306 setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, unsigned long mask)
309 unsigned long usp = rdusp();
311 /* copy the regs. they are first in sc so we can use sc directly */
313 err |= __copy_to_user(sc, regs, sizeof(struct pt_regs));
315 /* Set the frametype to CRIS_FRAME_NORMAL for the execution of
316 the signal handler. The frametype will be restored to its previous
317 value in restore_sigcontext. */
318 regs->frametype = CRIS_FRAME_NORMAL;
320 /* then some other stuff */
322 err |= __put_user(mask, &sc->oldmask);
324 err |= __put_user(usp, &sc->usp);
329 /* figure out where we want to put the new signal frame - usually on the stack */
331 static inline void __user *
332 get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
334 unsigned long sp = rdusp();
336 /* This is the X/Open sanctioned signal stack switching. */
337 if (ka->sa.sa_flags & SA_ONSTACK) {
338 if (! on_sig_stack(sp))
339 sp = current->sas_ss_sp + current->sas_ss_size;
342 /* make sure the frame is dword-aligned */
346 return (void __user*)(sp - frame_size);
349 /* grab and setup a signal frame.
351 * basically we stack a lot of state info, and arrange for the
352 * user-mode program to return to the kernel using either a
353 * trampoline which performs the syscall sigreturn, or a provided
354 * user-mode trampoline.
357 static void setup_frame(int sig, struct k_sigaction *ka,
358 sigset_t *set, struct pt_regs * regs)
360 struct sigframe __user *frame;
361 unsigned long return_ip;
364 frame = get_sigframe(ka, regs, sizeof(*frame));
366 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
369 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
373 if (_NSIG_WORDS > 1) {
374 err |= __copy_to_user(frame->extramask, &set->sig[1],
375 sizeof(frame->extramask));
380 /* Set up to return from userspace. If provided, use a stub
381 already in userspace. */
382 if (ka->sa.sa_flags & SA_RESTORER) {
383 return_ip = (unsigned long)ka->sa.sa_restorer;
385 /* trampoline - the desired return ip is the retcode itself */
386 return_ip = (unsigned long)&frame->retcode;
387 /* This is movu.w __NR_sigreturn, r9; break 13; */
388 err |= __put_user(0x9c5f, (short *)(frame->retcode+0));
389 err |= __put_user(__NR_sigreturn, (short *)(frame->retcode+2));
390 err |= __put_user(0xe93d, (short *)(frame->retcode+4));
396 /* Set up registers for signal handler */
398 regs->irp = (unsigned long) ka->sa.sa_handler; /* what we enter NOW */
399 regs->srp = return_ip; /* what we enter LATER */
400 regs->r10 = sig; /* first argument is signo */
402 /* actually move the usp to reflect the stacked frame */
404 wrusp((unsigned long)frame);
410 ka->sa.sa_handler = SIG_DFL;
411 force_sig(SIGSEGV, current);
414 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
415 sigset_t *set, struct pt_regs * regs)
417 struct rt_sigframe __user *frame;
418 unsigned long return_ip;
421 frame = get_sigframe(ka, regs, sizeof(*frame));
423 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
426 err |= __put_user(&frame->info, &frame->pinfo);
427 err |= __put_user(&frame->uc, &frame->puc);
428 err |= copy_siginfo_to_user(&frame->info, info);
432 /* Clear all the bits of the ucontext we don't use. */
433 err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
435 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
437 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
442 /* Set up to return from userspace. If provided, use a stub
443 already in userspace. */
444 if (ka->sa.sa_flags & SA_RESTORER) {
445 return_ip = (unsigned long)ka->sa.sa_restorer;
447 /* trampoline - the desired return ip is the retcode itself */
448 return_ip = (unsigned long)&frame->retcode;
449 /* This is movu.w __NR_rt_sigreturn, r9; break 13; */
450 err |= __put_user(0x9c5f, (short *)(frame->retcode+0));
451 err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode+2));
452 err |= __put_user(0xe93d, (short *)(frame->retcode+4));
458 /* TODO what is the current->exec_domain stuff and invmap ? */
460 /* Set up registers for signal handler */
462 regs->irp = (unsigned long) ka->sa.sa_handler; /* what we enter NOW */
463 regs->srp = return_ip; /* what we enter LATER */
464 regs->r10 = sig; /* first argument is signo */
465 regs->r11 = (unsigned long) &frame->info; /* second argument is (siginfo_t *) */
466 regs->r12 = 0; /* third argument is unused */
468 /* actually move the usp to reflect the stacked frame */
470 wrusp((unsigned long)frame);
476 ka->sa.sa_handler = SIG_DFL;
477 force_sig(SIGSEGV, current);
481 * OK, we're invoking a handler
485 handle_signal(int canrestart, unsigned long sig,
486 siginfo_t *info, sigset_t *oldset, struct pt_regs * regs)
488 struct k_sigaction *ka = ¤t->sighand->action[sig-1];
490 /* Are we from a system call? */
492 /* If so, check system call restarting.. */
494 case -ERESTART_RESTARTBLOCK:
495 current_thread_info()->restart_block.fn = do_no_restart_syscall;
496 case -ERESTARTNOHAND:
497 /* ERESTARTNOHAND means that the syscall should only be
498 restarted if there was no handler for the signal, and since
499 we only get here if there is a handler, we don't restart */
504 /* ERESTARTSYS means to restart the syscall if there is no
505 handler or the handler was registered with SA_RESTART */
506 if (!(ka->sa.sa_flags & SA_RESTART)) {
511 case -ERESTARTNOINTR:
512 /* ERESTARTNOINTR means that the syscall should be called again
513 after the signal handler returns. */
514 RESTART_CRIS_SYS(regs);
518 /* Set up the stack frame */
519 if (ka->sa.sa_flags & SA_SIGINFO)
520 setup_rt_frame(sig, ka, info, oldset, regs);
522 setup_frame(sig, ka, oldset, regs);
524 if (ka->sa.sa_flags & SA_ONESHOT)
525 ka->sa.sa_handler = SIG_DFL;
527 if (!(ka->sa.sa_flags & SA_NODEFER)) {
528 spin_lock_irq(¤t->sighand->siglock);
529 sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
530 sigaddset(¤t->blocked,sig);
532 spin_unlock_irq(¤t->sighand->siglock);
537 * Note that 'init' is a special process: it doesn't get signals it doesn't
538 * want to handle. Thus you cannot kill init even with a SIGKILL even by
541 * Also note that the regs structure given here as an argument, is the latest
542 * pushed pt_regs. It may or may not be the same as the first pushed registers
543 * when the initial usermode->kernelmode transition took place. Therefore
544 * we can use user_mode(regs) to see if we came directly from kernel or user
548 int do_signal(int canrestart, sigset_t *oldset, struct pt_regs *regs)
554 * We want the common case to go fast, which
555 * is why we may in certain cases get here from
556 * kernel mode. Just return without doing anything
559 if (!user_mode(regs))
563 oldset = ¤t->blocked;
565 signr = get_signal_to_deliver(&info, regs, NULL);
567 /* Whee! Actually deliver the signal. */
568 handle_signal(canrestart, signr, &info, oldset, regs);
572 /* Did we come from a system call? */
574 /* Restart the system call - no handlers present */
575 if (regs->r10 == -ERESTARTNOHAND ||
576 regs->r10 == -ERESTARTSYS ||
577 regs->r10 == -ERESTARTNOINTR) {
578 RESTART_CRIS_SYS(regs);
580 if (regs->r10 == -ERESTART_RESTARTBLOCK){
581 regs->r10 = __NR_restart_syscall;