diff options
Diffstat (limited to 'hurd/sigunwind.c')
| -rw-r--r-- | hurd/sigunwind.c | 149 |
1 files changed, 0 insertions, 149 deletions
diff --git a/hurd/sigunwind.c b/hurd/sigunwind.c deleted file mode 100644 index 8025599665..0000000000 --- a/hurd/sigunwind.c +++ /dev/null @@ -1,149 +0,0 @@ -/* longjmp cleanup function for unwinding past signal handlers. - Copyright (C) 1995-2017 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/>. */ - -#include <hurd.h> -#include <thread_state.h> -#include <jmpbuf-unwind.h> -#include <assert.h> -#include <stdint.h> - - -/* _hurd_setup_sighandler puts a link on the `active resources' chain so that - _longjmp_unwind will call this function with the `struct sigcontext *' - describing the context interrupted by the signal, when `longjmp' is jumping - to an environment that unwinds past the interrupted frame. */ - -void -_hurdsig_longjmp_from_handler (void *data, jmp_buf env, int val) -{ - struct sigcontext *scp = data; - struct hurd_sigstate *ss = _hurd_self_sigstate (); - int onstack; - inline void cleanup (void) - { - /* Destroy the MiG reply port used by the signal handler, and restore - the reply port in use by the thread when interrupted. */ - mach_port_t *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, regardless). */ - *reply_port = MACH_PORT_DEAD; - __mach_port_destroy (__mach_task_self (), port); - } - if (scp->sc_reply_port) - __mach_port_destroy (__mach_task_self (), scp->sc_reply_port); - } - - __spin_lock (&ss->lock); - /* We should only ever be called from _longjmp_unwind (in jmp-unwind.c), - which calls us inside a critical section. */ - assert (__spin_lock_locked (&ss->critical_section_lock)); - /* Are we on the alternate signal stack now? */ - onstack = (ss->sigaltstack.ss_flags & SS_ONSTACK); - __spin_unlock (&ss->lock); - - if (onstack && ! scp->sc_onstack) - { - /* We are unwinding off the signal stack. We must use sigreturn to - do it robustly. Mutate the sigcontext so that when sigreturn - resumes from that context, it will be as if `__longjmp (ENV, VAL)' - were done. */ - - struct hurd_userlink *link; - - inline uintptr_t demangle_ptr (uintptr_t x) - { -# ifdef PTR_DEMANGLE - PTR_DEMANGLE (x); -# endif - return x; - } - - /* Continue _longjmp_unwind's job of running the unwind - forms for frames being unwound, since we will not - return to its loop like this one, which called us. */ - for (link = ss->active_resources; - link && _JMPBUF_UNWINDS (env[0].__jmpbuf, link, demangle_ptr); - link = link->thread.next) - if (_hurd_userlink_unlink (link)) - { - if (link->cleanup == &_hurdsig_longjmp_from_handler) - { - /* We are unwinding past another signal handler invocation. - Just finish the cleanup for this (inner) one, and then - swap SCP to restore to the outer context. */ - cleanup (); - scp = link->cleanup_data; - } - else - (*link->cleanup) (link->cleanup_data, env, val); - } - -#define sc_machine_thread_state paste(sc_,machine_thread_state) -#define paste(a,b) paste1(a,b) -#define paste1(a,b) a##b - - /* There are no more unwind forms to be run! - Now we can just have the sigreturn do the longjmp for us. */ - _hurd_longjmp_thread_state - ((struct machine_thread_state *) &scp->sc_machine_thread_state, - env, val); - - /* Restore to the same current signal mask. If sigsetjmp saved the - mask, longjmp has already restored it as desired; if not, we - should leave it as it is. */ - scp->sc_mask = ss->blocked; - - /* sigreturn expects the link added by _hurd_setup_sighandler - to still be there, but _longjmp_unwind removed it just before - calling us. Put it back now so sigreturn can find it. */ - link = (void *) &scp[1]; - assert (! link->resource.next && ! link->resource.prevp); - assert (link->thread.next == ss->active_resources); - assert (link->thread.prevp == &ss->active_resources); - if (link->thread.next) - link->thread.next->thread.prevp = &link->thread.next; - ss->active_resources = link; - - /* We must momentarily exit the critical section so that sigreturn - does not get upset with us. But we don't want signal handlers - running right now, because we are presently in the bogus state of - having run all the unwind forms back to ENV's frame, but our SP is - still inside those unwound frames. */ - __spin_lock (&ss->lock); - __spin_unlock (&ss->critical_section_lock); - ss->blocked = ~(sigset_t) 0 & ~_SIG_CANT_MASK; - __spin_unlock (&ss->lock); - - /* Restore to the modified signal context that now - performs `longjmp (ENV, VAL)'. */ - __sigreturn (scp); - assert (! "sigreturn returned!"); - } - - /* We are not unwinding off the alternate signal stack. So nothing - really funny is going on here. We can just clean up this handler - frame and let _longjmp_unwind continue unwinding. */ - cleanup (); - ss->intr_port = scp->sc_intr_port; -} |