diff options
Diffstat (limited to 'REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c')
-rw-r--r-- | REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c b/REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c new file mode 100644 index 0000000000..97cedd80f1 --- /dev/null +++ b/REORG.TODO/sysdeps/mach/hurd/jmp-unwind.c @@ -0,0 +1,79 @@ +/* _longjmp_unwind -- Clean up stack frames unwound by longjmp. Hurd version. + 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 <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); +} |