diff options
Diffstat (limited to 'REORG.TODO/sysdeps/mach/hurd/i386/sigreturn.c')
| -rw-r--r-- | REORG.TODO/sysdeps/mach/hurd/i386/sigreturn.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/mach/hurd/i386/sigreturn.c b/REORG.TODO/sysdeps/mach/hurd/i386/sigreturn.c new file mode 100644 index 0000000000..ce0f656ff0 --- /dev/null +++ b/REORG.TODO/sysdeps/mach/hurd/i386/sigreturn.c @@ -0,0 +1,139 @@ +/* Copyright (C) 1991-2017 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 Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +register int *sp asm ("%esp"); + +#include <hurd.h> +#include <hurd/signal.h> +#include <hurd/threadvar.h> +#include <hurd/msg.h> +#include <stdlib.h> +#include <string.h> + +int +__sigreturn (struct sigcontext *scp) +{ + struct hurd_sigstate *ss; + struct hurd_userlink *link = (void *) &scp[1]; + 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); + + /* Remove the link on the `active resources' chain added by + _hurd_setup_sighandler. Its purpose was to make sure + that we got called; now we have, it is done. */ + _hurd_userlink_unlink (link); + + /* 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; + __spin_unlock (&ss->lock); + __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ()); + /* If a pending signal was handled, sig_post never returned. + If it did return, the pending signal didn't run a handler; + proceed as usual. */ + __spin_lock (&ss->lock); + ss->context = NULL; + } + + if (scp->sc_onstack) + { + ss->sigaltstack.ss_flags &= ~SS_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_t port = *reply_port; + + /* Assigning MACH_PORT_DEAD here tells libc's mig_get_reply_port not to + get another reply port, but avoids mig_dealloc_reply_port trying to + deallocate it after the receive fails (which it will, because the + reply port will be bogus, whether we do this or not). */ + *reply_port = MACH_PORT_DEAD; + + __mach_port_destroy (__mach_task_self (), port); + } + *reply_port = scp->sc_reply_port; + + if (scp->sc_fpused) + /* Restore the FPU state. Mach conveniently stores the state + in the format the i387 `frstor' instruction uses to restore it. */ + asm volatile ("frstor %0" : : "m" (scp->sc_fpsave)); + + { + /* 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) |