diff options
Diffstat (limited to 'sysdeps/nptl/unwind-forcedunwind.c')
| -rw-r--r-- | sysdeps/nptl/unwind-forcedunwind.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/sysdeps/nptl/unwind-forcedunwind.c b/sysdeps/nptl/unwind-forcedunwind.c new file mode 100644 index 0000000000..9d7bdc5b90 --- /dev/null +++ b/sysdeps/nptl/unwind-forcedunwind.c @@ -0,0 +1,151 @@ +/* Copyright (C) 2003-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek <jakub@redhat.com>. + + 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; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#include <dlfcn.h> +#include <stdio.h> +#include <unwind.h> +#include <pthreadP.h> +#include <sysdep.h> +#include <gnu/lib-names.h> + +static void *libgcc_s_handle; +static void (*libgcc_s_resume) (struct _Unwind_Exception *exc); +static _Unwind_Reason_Code (*libgcc_s_personality) + (int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *, + struct _Unwind_Context *); +static _Unwind_Reason_Code (*libgcc_s_forcedunwind) + (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *); +static _Unwind_Word (*libgcc_s_getcfa) (struct _Unwind_Context *); + +void +__attribute_noinline__ +pthread_cancel_init (void) +{ + void *resume; + void *personality; + void *forcedunwind; + void *getcfa; + void *handle; + + if (__glibc_likely (libgcc_s_handle != NULL)) + { + /* Force gcc to reload all values. */ + asm volatile ("" ::: "memory"); + return; + } + + handle = __libc_dlopen (LIBGCC_S_SO); + + if (handle == NULL + || (resume = __libc_dlsym (handle, "_Unwind_Resume")) == NULL + || (personality = __libc_dlsym (handle, "__gcc_personality_v0")) == NULL + || (forcedunwind = __libc_dlsym (handle, "_Unwind_ForcedUnwind")) + == NULL + || (getcfa = __libc_dlsym (handle, "_Unwind_GetCFA")) == NULL +#ifdef ARCH_CANCEL_INIT + || ARCH_CANCEL_INIT (handle) +#endif + ) + __libc_fatal (LIBGCC_S_SO " must be installed for pthread_cancel to work\n"); + + PTR_MANGLE (resume); + libgcc_s_resume = resume; + PTR_MANGLE (personality); + libgcc_s_personality = personality; + PTR_MANGLE (forcedunwind); + libgcc_s_forcedunwind = forcedunwind; + PTR_MANGLE (getcfa); + libgcc_s_getcfa = getcfa; + /* Make sure libgcc_s_handle is written last. Otherwise, + pthread_cancel_init might return early even when the pointer the + caller is interested in is not initialized yet. */ + atomic_write_barrier (); + libgcc_s_handle = handle; +} + +void +__libc_freeres_fn_section +__unwind_freeres (void) +{ + void *handle = libgcc_s_handle; + if (handle != NULL) + { + libgcc_s_handle = NULL; + __libc_dlclose (handle); + } +} + +void +_Unwind_Resume (struct _Unwind_Exception *exc) +{ + if (__glibc_unlikely (libgcc_s_handle == NULL)) + pthread_cancel_init (); + else + atomic_read_barrier (); + + void (*resume) (struct _Unwind_Exception *exc) = libgcc_s_resume; + PTR_DEMANGLE (resume); + resume (exc); +} + +_Unwind_Reason_Code +__gcc_personality_v0 (int version, _Unwind_Action actions, + _Unwind_Exception_Class exception_class, + struct _Unwind_Exception *ue_header, + struct _Unwind_Context *context) +{ + if (__glibc_unlikely (libgcc_s_handle == NULL)) + pthread_cancel_init (); + else + atomic_read_barrier (); + + _Unwind_Reason_Code (*personality) + (int, _Unwind_Action, _Unwind_Exception_Class, struct _Unwind_Exception *, + struct _Unwind_Context *) = libgcc_s_personality; + PTR_DEMANGLE (personality); + return personality (version, actions, exception_class, ue_header, context); +} + +_Unwind_Reason_Code +_Unwind_ForcedUnwind (struct _Unwind_Exception *exc, _Unwind_Stop_Fn stop, + void *stop_argument) +{ + if (__glibc_unlikely (libgcc_s_handle == NULL)) + pthread_cancel_init (); + else + atomic_read_barrier (); + + _Unwind_Reason_Code (*forcedunwind) + (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *) + = libgcc_s_forcedunwind; + PTR_DEMANGLE (forcedunwind); + return forcedunwind (exc, stop, stop_argument); +} + +_Unwind_Word +_Unwind_GetCFA (struct _Unwind_Context *context) +{ + if (__glibc_unlikely (libgcc_s_handle == NULL)) + pthread_cancel_init (); + else + atomic_read_barrier (); + + _Unwind_Word (*getcfa) (struct _Unwind_Context *) = libgcc_s_getcfa; + PTR_DEMANGLE (getcfa); + return getcfa (context); +} |