a6029d1c8c
We need to define set_restore_sigmask() in order to get pselect and ppoll. Also, the setup_frame function can not be used when __NR_sigreturn is not defined. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michal Simek <monstr@monstr.eu>
469 lines
12 KiB
C
469 lines
12 KiB
C
/*
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* Signal handling
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*
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* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2008-2009 PetaLogix
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* Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au>
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* Copyright (C) 2001 NEC Corporation
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* Copyright (C) 2001 Miles Bader <miles@gnu.org>
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* Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima
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* Copyright (C) 1991,1992 Linus Torvalds
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*
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* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
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*
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* This file was was derived from the sh version, arch/sh/kernel/signal.c
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file COPYING in the main directory of this
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* archive for more details.
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*/
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/unistd.h>
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#include <linux/stddef.h>
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#include <linux/personality.h>
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#include <linux/percpu.h>
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#include <linux/linkage.h>
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#include <asm/entry.h>
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#include <asm/ucontext.h>
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#include <linux/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <linux/syscalls.h>
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#include <asm/cacheflush.h>
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#include <asm/syscalls.h>
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#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
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asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_sycall);
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/*
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* Atomically swap in the new signal mask, and wait for a signal.
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*/
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asmlinkage int
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sys_sigsuspend(old_sigset_t mask, struct pt_regs *regs)
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{
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sigset_t saveset;
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mask &= _BLOCKABLE;
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spin_lock_irq(¤t->sighand->siglock);
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saveset = current->blocked;
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siginitset(¤t->blocked, mask);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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regs->r3 = -EINTR;
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while (1) {
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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if (do_signal(regs, &saveset, 1))
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return -EINTR;
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}
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}
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asmlinkage int
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sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize,
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struct pt_regs *regs)
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{
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sigset_t saveset, newset;
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/* XXX: Don't preclude handling different sized sigset_t's. */
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if (sigsetsize != sizeof(sigset_t))
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return -EINVAL;
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if (copy_from_user(&newset, unewset, sizeof(newset)))
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return -EFAULT;
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sigdelsetmask(&newset, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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saveset = current->blocked;
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current->blocked = newset;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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regs->r3 = -EINTR;
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while (1) {
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current->state = TASK_INTERRUPTIBLE;
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schedule();
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if (do_signal(regs, &saveset, 1))
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return -EINTR;
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}
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}
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asmlinkage int
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sys_sigaction(int sig, const struct old_sigaction *act,
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struct old_sigaction *oact)
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{
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struct k_sigaction new_ka, old_ka;
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int ret;
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if (act) {
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old_sigset_t mask;
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if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
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__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
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__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
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return -EFAULT;
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__get_user(new_ka.sa.sa_flags, &act->sa_flags);
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__get_user(mask, &act->sa_mask);
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siginitset(&new_ka.sa.sa_mask, mask);
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}
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ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
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if (!ret && oact) {
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if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
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__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
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__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
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return -EFAULT;
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__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
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__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
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}
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return ret;
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}
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asmlinkage int
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sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
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struct pt_regs *regs)
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{
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return do_sigaltstack(uss, uoss, regs->r1);
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}
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/*
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* Do a signal return; undo the signal stack.
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*/
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struct sigframe {
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struct sigcontext sc;
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unsigned long extramask[_NSIG_WORDS-1];
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unsigned long tramp[2]; /* signal trampoline */
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};
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struct rt_sigframe {
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struct siginfo info;
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struct ucontext uc;
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unsigned long tramp[2]; /* signal trampoline */
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};
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static int restore_sigcontext(struct pt_regs *regs,
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struct sigcontext __user *sc, int *rval_p)
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{
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unsigned int err = 0;
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#define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); }
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COPY(r0);
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COPY(r1);
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COPY(r2); COPY(r3); COPY(r4); COPY(r5);
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COPY(r6); COPY(r7); COPY(r8); COPY(r9);
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COPY(r10); COPY(r11); COPY(r12); COPY(r13);
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COPY(r14); COPY(r15); COPY(r16); COPY(r17);
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COPY(r18); COPY(r19); COPY(r20); COPY(r21);
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COPY(r22); COPY(r23); COPY(r24); COPY(r25);
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COPY(r26); COPY(r27); COPY(r28); COPY(r29);
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COPY(r30); COPY(r31);
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COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
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#undef COPY
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*rval_p = regs->r3;
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return err;
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}
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asmlinkage int sys_sigreturn(struct pt_regs *regs)
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{
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struct sigframe *frame =
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(struct sigframe *)(regs->r1 + STATE_SAVE_ARG_SPACE);
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sigset_t set;
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int rval;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__get_user(set.sig[0], &frame->sc.oldmask)
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|| (_NSIG_WORDS > 1
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&& __copy_from_user(&set.sig[1], &frame->extramask,
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sizeof(frame->extramask))))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->sc, &rval))
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goto badframe;
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return rval;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
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{
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struct rt_sigframe __user *frame =
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(struct rt_sigframe __user *)(regs->r1 + STATE_SAVE_ARG_SPACE);
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sigset_t set;
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int rval;
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if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
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goto badframe;
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if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
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goto badframe;
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sigdelsetmask(&set, ~_BLOCKABLE);
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spin_lock_irq(¤t->sighand->siglock);
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current->blocked = set;
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
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goto badframe;
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/* It is more difficult to avoid calling this function than to
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call it and ignore errors. */
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if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->r1))
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goto badframe;
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return rval;
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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/*
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* Set up a signal frame.
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*/
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static int
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setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
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unsigned long mask)
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{
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int err = 0;
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#define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); }
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COPY(r0);
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COPY(r1);
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COPY(r2); COPY(r3); COPY(r4); COPY(r5);
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COPY(r6); COPY(r7); COPY(r8); COPY(r9);
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COPY(r10); COPY(r11); COPY(r12); COPY(r13);
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COPY(r14); COPY(r15); COPY(r16); COPY(r17);
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COPY(r18); COPY(r19); COPY(r20); COPY(r21);
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COPY(r22); COPY(r23); COPY(r24); COPY(r25);
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COPY(r26); COPY(r27); COPY(r28); COPY(r29);
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COPY(r30); COPY(r31);
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COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
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#undef COPY
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err |= __put_user(mask, &sc->oldmask);
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return err;
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}
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/*
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* Determine which stack to use..
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*/
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static inline void __user *
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get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
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{
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/* Default to using normal stack */
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unsigned long sp = regs->r1;
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if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack(sp))
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sp = current->sas_ss_sp + current->sas_ss_size;
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return (void __user *)((sp - frame_size) & -8UL);
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}
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static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
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sigset_t *set, struct pt_regs *regs)
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{
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struct rt_sigframe __user *frame;
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int err = 0;
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int signal;
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frame = get_sigframe(ka, regs, sizeof(*frame));
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if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
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goto give_sigsegv;
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signal = current_thread_info()->exec_domain
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&& current_thread_info()->exec_domain->signal_invmap
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&& sig < 32
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? current_thread_info()->exec_domain->signal_invmap[sig]
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: sig;
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if (info)
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err |= copy_siginfo_to_user(&frame->info, info);
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/* Create the ucontext. */
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err |= __put_user(0, &frame->uc.uc_flags);
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err |= __put_user(0, &frame->uc.uc_link);
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err |= __put_user((void *)current->sas_ss_sp,
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&frame->uc.uc_stack.ss_sp);
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err |= __put_user(sas_ss_flags(regs->r1),
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&frame->uc.uc_stack.ss_flags);
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err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
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err |= setup_sigcontext(&frame->uc.uc_mcontext,
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regs, set->sig[0]);
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err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
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/* Set up to return from userspace. If provided, use a stub
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already in userspace. */
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/* minus 8 is offset to cater for "rtsd r15,8" */
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if (ka->sa.sa_flags & SA_RESTORER) {
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regs->r15 = ((unsigned long)ka->sa.sa_restorer)-8;
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} else {
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/* addi r12, r0, __NR_sigreturn */
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err |= __put_user(0x31800000 | __NR_rt_sigreturn ,
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frame->tramp + 0);
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/* brki r14, 0x8 */
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err |= __put_user(0xb9cc0008, frame->tramp + 1);
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/* Return from sighandler will jump to the tramp.
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Negative 8 offset because return is rtsd r15, 8 */
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regs->r15 = ((unsigned long)frame->tramp)-8;
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__invalidate_cache_sigtramp((unsigned long)frame->tramp);
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}
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if (err)
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goto give_sigsegv;
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/* Set up registers for signal handler */
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regs->r1 = (unsigned long) frame - STATE_SAVE_ARG_SPACE;
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/* Signal handler args: */
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regs->r5 = signal; /* arg 0: signum */
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regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
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regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
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/* Offset to handle microblaze rtid r14, 0 */
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regs->pc = (unsigned long)ka->sa.sa_handler;
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set_fs(USER_DS);
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#ifdef DEBUG_SIG
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printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n",
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current->comm, current->pid, frame, regs->pc);
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#endif
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return;
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give_sigsegv:
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if (sig == SIGSEGV)
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ka->sa.sa_handler = SIG_DFL;
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force_sig(SIGSEGV, current);
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}
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/* Handle restarting system calls */
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static inline void
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handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
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{
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switch (regs->r3) {
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case -ERESTART_RESTARTBLOCK:
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case -ERESTARTNOHAND:
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if (!has_handler)
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goto do_restart;
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regs->r3 = -EINTR;
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break;
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case -ERESTARTSYS:
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if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
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regs->r3 = -EINTR;
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break;
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}
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/* fallthrough */
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case -ERESTARTNOINTR:
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do_restart:
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/* offset of 4 bytes to re-execute trap (brki) instruction */
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regs->pc -= 4;
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break;
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}
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}
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/*
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* OK, we're invoking a handler
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*/
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static void
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handle_signal(unsigned long sig, struct k_sigaction *ka,
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siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
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{
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/* Set up the stack frame */
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if (ka->sa.sa_flags & SA_SIGINFO)
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setup_rt_frame(sig, ka, info, oldset, regs);
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else
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setup_rt_frame(sig, ka, NULL, oldset, regs);
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if (ka->sa.sa_flags & SA_ONESHOT)
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ka->sa.sa_handler = SIG_DFL;
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if (!(ka->sa.sa_flags & SA_NODEFER)) {
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spin_lock_irq(¤t->sighand->siglock);
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sigorsets(¤t->blocked,
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¤t->blocked, &ka->sa.sa_mask);
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sigaddset(¤t->blocked, sig);
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recalc_sigpending();
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spin_unlock_irq(¤t->sighand->siglock);
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}
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}
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/*
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* Note that 'init' is a special process: it doesn't get signals it doesn't
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* want to handle. Thus you cannot kill init even with a SIGKILL even by
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* mistake.
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*
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* Note that we go through the signals twice: once to check the signals that
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* the kernel can handle, and then we build all the user-level signal handling
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* stack-frames in one go after that.
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*/
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int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall)
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{
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siginfo_t info;
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int signr;
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struct k_sigaction ka;
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#ifdef DEBUG_SIG
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printk(KERN_INFO "do signal: %p %p %d\n", regs, oldset, in_syscall);
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printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
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regs->r12, current_thread_info()->flags);
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#endif
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/*
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* We want the common case to go fast, which
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* is why we may in certain cases get here from
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* kernel mode. Just return without doing anything
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* if so.
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*/
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if (kernel_mode(regs))
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return 1;
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if (!oldset)
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oldset = ¤t->blocked;
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signr = get_signal_to_deliver(&info, &ka, regs, NULL);
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if (signr > 0) {
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/* Whee! Actually deliver the signal. */
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if (in_syscall)
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handle_restart(regs, &ka, 1);
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handle_signal(signr, &ka, &info, oldset, regs);
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return 1;
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}
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if (in_syscall)
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handle_restart(regs, NULL, 0);
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/* Did we come from a system call? */
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return 0;
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}
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