| /* _longjmp_unwind -- Clean up stack frames unwound by longjmp. Hurd version. |
| Copyright (C) 1995-2014 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 <jmpbuf-unwind.h> |
| #include <hurd/userlink.h> |
| #include <hurd/signal.h> |
| #include <hurd/sigpreempt.h> |
| #include <assert.h> |
| #include <stdint.h> |
| |
| |
| #ifndef _JMPBUF_UNWINDS |
| #error "<jmpbuf-unwind.h> fails to define _JMPBUF_UNWINDS" |
| #endif |
| |
| static inline uintptr_t |
| demangle_ptr (uintptr_t x) |
| { |
| # ifdef PTR_DEMANGLE |
| PTR_DEMANGLE (x); |
| # endif |
| return x; |
| } |
| |
| /* This function is called by `longjmp' (with its arguments) to restore |
| active resources to a sane state before the frames code using them are |
| jumped out of. */ |
| |
| void |
| _longjmp_unwind (jmp_buf env, int val) |
| { |
| struct hurd_sigstate *ss = _hurd_self_sigstate (); |
| struct hurd_userlink *link; |
| |
| /* All access to SS->active_resources must take place inside a critical |
| section where signal handlers cannot run. */ |
| __spin_lock (&ss->lock); |
| assert (! __spin_lock_locked (&ss->critical_section_lock)); |
| __spin_lock (&ss->critical_section_lock); |
| |
| /* Remove local signal preemptors being unwound past. */ |
| while (ss->preemptors && |
| _JMPBUF_UNWINDS (env[0].__jmpbuf, ss->preemptors, demangle_ptr)) |
| ss->preemptors = ss->preemptors->next; |
| |
| __spin_unlock (&ss->lock); |
| |
| /* Iterate over the current thread's list of active resources. |
| Process the head portion of the list whose links reside |
| in stack frames being unwound by this jump. */ |
| |
| for (link = ss->active_resources; |
| link && _JMPBUF_UNWINDS (env[0].__jmpbuf, link, demangle_ptr); |
| link = link->thread.next) |
| /* Remove this link from the resource's users list, |
| since the frame using the resource is being unwound. |
| This call returns nonzero if that was the last user. */ |
| if (_hurd_userlink_unlink (link)) |
| /* One of the frames being unwound by the longjmp was the last user |
| of its resource. Call the cleanup function to deallocate it. */ |
| (*link->cleanup) (link->cleanup_data, env, val); |
| |
| _hurd_critical_section_unlock (ss); |
| } |