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Diffstat (limited to 'libpthread/nptl/unwind.c')
| -rw-r--r-- | libpthread/nptl/unwind.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/libpthread/nptl/unwind.c b/libpthread/nptl/unwind.c new file mode 100644 index 000000000..56a423815 --- /dev/null +++ b/libpthread/nptl/unwind.c @@ -0,0 +1,176 @@ +/* Copyright (C) 2003, 2004 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com> + and Richard Henderson <rth@redhat.com>, 2003. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <setjmp.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include "pthreadP.h" +#include "jmpbuf-unwind.h" + +#ifdef HAVE_FORCED_UNWIND + +#ifdef _STACK_GROWS_DOWN +# define FRAME_LEFT(frame, other, adj) \ + ((uintptr_t) frame - adj >= (uintptr_t) other - adj) +#elif _STACK_GROWS_UP +# define FRAME_LEFT(frame, other, adj) \ + ((uintptr_t) frame - adj <= (uintptr_t) other - adj) +#else +# error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP" +#endif + +static _Unwind_Reason_Code +unwind_stop (int version, _Unwind_Action actions, + _Unwind_Exception_Class exc_class, + struct _Unwind_Exception *exc_obj, + struct _Unwind_Context *context, void *stop_parameter) +{ + struct pthread_unwind_buf *buf = stop_parameter; + struct pthread *self = THREAD_SELF; + struct _pthread_cleanup_buffer *curp = THREAD_GETMEM (self, cleanup); + int do_longjump = 0; + + /* Adjust all pointers used in comparisons, so that top of thread's + stack is at the top of address space. Without that, things break + if stack is allocated above the main stack. */ + uintptr_t adj = (uintptr_t) self->stackblock + self->stackblock_size; + + /* Do longjmp if we're at "end of stack", aka "end of unwind data". + We assume there are only C frame without unwind data in between + here and the jmp_buf target. Otherwise simply note that the CFA + of a function is NOT within it's stack frame; it's the SP of the + previous frame. */ + if ((actions & _UA_END_OF_STACK) + || ! _JMPBUF_CFA_UNWINDS_ADJ (buf->cancel_jmp_buf[0].jmp_buf, context, + adj)) + do_longjump = 1; + + if (__builtin_expect (curp != NULL, 0)) + { + /* Handle the compatibility stuff. Execute all handlers + registered with the old method which would be unwound by this + step. */ + struct _pthread_cleanup_buffer *oldp = buf->priv.data.cleanup; + void *cfa = (void *) _Unwind_GetCFA (context); + + if (curp != oldp && (do_longjump || FRAME_LEFT (cfa, curp, adj))) + { + do + { + /* Pointer to the next element. */ + struct _pthread_cleanup_buffer *nextp = curp->__prev; + + /* Call the handler. */ + curp->__routine (curp->__arg); + + /* To the next. */ + curp = nextp; + } + while (curp != oldp + && (do_longjump || FRAME_LEFT (cfa, curp, adj))); + + /* Mark the current element as handled. */ + THREAD_SETMEM (self, cleanup, curp); + } + } + + if (do_longjump) + __libc_unwind_longjmp ((struct __jmp_buf_tag *) buf->cancel_jmp_buf, 1); + + return _URC_NO_REASON; +} + + +static void +unwind_cleanup (_Unwind_Reason_Code reason, struct _Unwind_Exception *exc) +{ + /* When we get here a C++ catch block didn't rethrow the object. We + cannot handle this case and therefore abort. */ +# define STR_N_LEN(str) str, strlen (str) + INTERNAL_SYSCALL_DECL (err); + INTERNAL_SYSCALL (write, err, 3, STDERR_FILENO, + STR_N_LEN ("FATAL: exception not rethrown\n")); + abort (); +} + +#endif /* have forced unwind */ + + +void +__cleanup_fct_attribute __attribute ((noreturn)) +__pthread_unwind (__pthread_unwind_buf_t *buf) +{ + struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf; + struct pthread *self = THREAD_SELF; + +#ifdef HAVE_FORCED_UNWIND + /* This is not a catchable exception, so don't provide any details about + the exception type. We do need to initialize the field though. */ + THREAD_SETMEM (self, exc.exception_class, 0); + THREAD_SETMEM (self, exc.exception_cleanup, unwind_cleanup); + + _Unwind_ForcedUnwind (&self->exc, unwind_stop, ibuf); +#else + /* Handle the compatibility stuff first. Execute all handlers + registered with the old method. We don't execute them in order, + instead, they will run first. */ + struct _pthread_cleanup_buffer *oldp = ibuf->priv.data.cleanup; + struct _pthread_cleanup_buffer *curp = THREAD_GETMEM (self, cleanup); + + if (curp != oldp) + { + do + { + /* Pointer to the next element. */ + struct _pthread_cleanup_buffer *nextp = curp->__prev; + + /* Call the handler. */ + curp->__routine (curp->__arg); + + /* To the next. */ + curp = nextp; + } + while (curp != oldp); + + /* Mark the current element as handled. */ + THREAD_SETMEM (self, cleanup, curp); + } + + /* We simply jump to the registered setjmp buffer. */ + __libc_unwind_longjmp ((struct __jmp_buf_tag *) ibuf->cancel_jmp_buf, 1); +#endif + /* NOTREACHED */ + + /* We better do not get here. */ + abort (); +} +hidden_def (__pthread_unwind) + + +void +__cleanup_fct_attribute __attribute ((noreturn)) +__pthread_unwind_next (__pthread_unwind_buf_t *buf) +{ + struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf; + + __pthread_unwind ((__pthread_unwind_buf_t *) ibuf->priv.data.prev); +} +hidden_def (__pthread_unwind_next) |