From 28f540f45bbacd939bfd07f213bcad2bf730b1bf Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Sat, 18 Feb 1995 01:27:10 +0000 Subject: initial import --- sysdeps/mach/hurd/i386/sigreturn.c | 126 +++++++++++++++++++++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 sysdeps/mach/hurd/i386/sigreturn.c (limited to 'sysdeps/mach/hurd/i386/sigreturn.c') diff --git a/sysdeps/mach/hurd/i386/sigreturn.c b/sysdeps/mach/hurd/i386/sigreturn.c new file mode 100644 index 0000000000..df8960669f --- /dev/null +++ b/sysdeps/mach/hurd/i386/sigreturn.c @@ -0,0 +1,126 @@ +/* Copyright (C) 1991, 1992, 1994, 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +register int *sp asm ("%esp"); + +#include +#include +#include +#include +#include + +int +__sigreturn (struct sigcontext *scp) +{ + struct hurd_sigstate *ss; + mach_port_t *reply_port; + + if (scp == NULL || (scp->sc_mask & _SIG_CANT_MASK)) + { + errno = EINVAL; + return -1; + } + + ss = _hurd_self_sigstate (); + __spin_lock (&ss->lock); + + /* Restore the set of blocked signals, and the intr_port slot. */ + ss->blocked = scp->sc_mask; + ss->intr_port = scp->sc_intr_port; + + /* Check for pending signals that were blocked by the old set. */ + if (ss->pending & ~ss->blocked) + { + /* There are pending signals that just became unblocked. Wake up the + signal thread to deliver them. But first, squirrel away SCP where + the signal thread will notice it if it runs another handler, and + arrange to have us called over again in the new reality. */ + ss->context = scp; + /* Clear the intr_port slot, since we are not in fact doing + an interruptible RPC right now. If SS->intr_port is not null, + the SCP context is doing an interruptible RPC, but the signal + thread will examine us while we are blocked in the sig_post RPC. */ + ss->intr_port = MACH_PORT_NULL; + __spin_unlock (&ss->lock); + __msg_sig_post (_hurd_msgport, 0, __mach_task_self ()); + /* If a pending signal was handled, sig_post never returned. */ + __spin_lock (&ss->lock); + } + + if (scp->sc_onstack) + { + ss->sigaltstack.ss_flags &= ~SA_ONSTACK; /* XXX threadvars */ + /* XXX cannot unlock until off sigstack */ + abort (); + } + else + __spin_unlock (&ss->lock); + + /* Destroy the MiG reply port used by the signal handler, and restore the + reply port in use by the thread when interrupted. */ + reply_port = + (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY); + if (*reply_port) + __mach_port_destroy (__mach_task_self (), *reply_port); + *reply_port = scp->sc_reply_port; + + if (scp->sc_fpused) + { + /* XXX should restore FPU state here XXX roland needs 387 manual */ + /* abort (); */ + } + + { + /* There are convenient instructions to pop state off the stack, so we + copy the registers onto the user's stack, switch there, pop and + return. */ + + int *usp = (int *) scp->sc_uesp; + + *--usp = scp->sc_eip; + *--usp = scp->sc_efl; + memcpy (usp -= 12, &scp->sc_i386_thread_state, 12 * sizeof (int)); + + sp = usp; + +#define A(line) asm volatile (#line) + /* The members in the sigcontext are arranged in this order + so we can pop them easily. */ + + /* Pop the segment registers (except %cs and %ss, done last). */ + A (popl %gs); + A (popl %fs); + A (popl %es); + A (popl %ds); + /* Pop the general registers. */ + A (popa); + /* Pop the processor flags. */ + A (popf); + /* Return to the saved PC. */ + A (ret); + + /* Firewall. */ + A (hlt); +#undef A + } + + /* NOTREACHED */ + return -1; +} + +weak_alias (__sigreturn, sigreturn) -- cgit 1.4.1