diff options
Diffstat (limited to 'sysdeps/generic/unwind-dw2-fde.c')
| -rw-r--r-- | sysdeps/generic/unwind-dw2-fde.c | 1079 |
1 files changed, 0 insertions, 1079 deletions
diff --git a/sysdeps/generic/unwind-dw2-fde.c b/sysdeps/generic/unwind-dw2-fde.c deleted file mode 100644 index 104a2552b4..0000000000 --- a/sysdeps/generic/unwind-dw2-fde.c +++ /dev/null @@ -1,1079 +0,0 @@ -/* Subroutines needed for unwinding stack frames for exception handling. */ -/* Copyright (C) 1997-2017 Free Software Foundation, Inc. - Contributed by Jason Merrill <jason@cygnus.com>. - - 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/>. */ - -#ifdef _LIBC -# include <shlib-compat.h> -#endif - -#if !defined _LIBC || SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2_5) - -#ifdef _LIBC -#include <stdlib.h> -#include <string.h> -#include <libc-lock.h> -#include <dwarf2.h> -#include <unwind.h> -#define NO_BASE_OF_ENCODED_VALUE -#include <unwind-pe.h> -#include <unwind-dw2-fde.h> -#else -#ifndef _Unwind_Find_FDE -#include "tconfig.h" -#include "tsystem.h" -#include "dwarf2.h" -#include "unwind.h" -#define NO_BASE_OF_ENCODED_VALUE -#include "unwind-pe.h" -#include "unwind-dw2-fde.h" -#include "gthr.h" -#endif -#endif - -/* The unseen_objects list contains objects that have been registered - but not yet categorized in any way. The seen_objects list has had - it's pc_begin and count fields initialized at minimum, and is sorted - by decreasing value of pc_begin. */ -static struct object *unseen_objects; -static struct object *seen_objects; - -#ifdef _LIBC - -__libc_lock_define_initialized (static, object_mutex) -#define init_object_mutex_once() -#define __gthread_mutex_lock(m) __libc_lock_lock (*(m)) -#define __gthread_mutex_unlock(m) __libc_lock_unlock (*(m)) - -void __register_frame_info_bases (void *begin, struct object *ob, - void *tbase, void *dbase); -hidden_proto (__register_frame_info_bases) -void __register_frame_info_table_bases (void *begin, - struct object *ob, - void *tbase, void *dbase); -hidden_proto (__register_frame_info_table_bases) -void *__deregister_frame_info_bases (void *begin); -hidden_proto (__deregister_frame_info_bases) - -#else - -#ifdef __GTHREAD_MUTEX_INIT -static __gthread_mutex_t object_mutex = __GTHREAD_MUTEX_INIT; -#else -static __gthread_mutex_t object_mutex; -#endif - -#ifdef __GTHREAD_MUTEX_INIT_FUNCTION -static void -init_object_mutex (void) -{ - __GTHREAD_MUTEX_INIT_FUNCTION (&object_mutex); -} - -static void -init_object_mutex_once (void) -{ - static __gthread_once_t once = __GTHREAD_ONCE_INIT; - __gthread_once (&once, init_object_mutex); -} -#else -#define init_object_mutex_once() -#endif - -#endif /* _LIBC */ - -/* Called from crtbegin.o to register the unwind info for an object. */ - -void -__register_frame_info_bases (void *begin, struct object *ob, - void *tbase, void *dbase) -{ - /* If .eh_frame is empty, don't register at all. */ - if (*(uword *) begin == 0) - return; - - ob->pc_begin = (void *)-1; - ob->tbase = tbase; - ob->dbase = dbase; - ob->u.single = begin; - ob->s.i = 0; - ob->s.b.encoding = DW_EH_PE_omit; -#ifdef DWARF2_OBJECT_END_PTR_EXTENSION - ob->fde_end = NULL; -#endif - - init_object_mutex_once (); - __gthread_mutex_lock (&object_mutex); - - ob->next = unseen_objects; - unseen_objects = ob; - - __gthread_mutex_unlock (&object_mutex); -} -hidden_def (__register_frame_info_bases) - -void -__register_frame_info (void *begin, struct object *ob) -{ - __register_frame_info_bases (begin, ob, 0, 0); -} - -void -__register_frame (void *begin) -{ - struct object *ob; - - /* If .eh_frame is empty, don't register at all. */ - if (*(uword *) begin == 0) - return; - - ob = (struct object *) malloc (sizeof (struct object)); - __register_frame_info_bases (begin, ob, 0, 0); -} - -/* Similar, but BEGIN is actually a pointer to a table of unwind entries - for different translation units. Called from the file generated by - collect2. */ - -void -__register_frame_info_table_bases (void *begin, struct object *ob, - void *tbase, void *dbase) -{ - ob->pc_begin = (void *)-1; - ob->tbase = tbase; - ob->dbase = dbase; - ob->u.array = begin; - ob->s.i = 0; - ob->s.b.from_array = 1; - ob->s.b.encoding = DW_EH_PE_omit; - - init_object_mutex_once (); - __gthread_mutex_lock (&object_mutex); - - ob->next = unseen_objects; - unseen_objects = ob; - - __gthread_mutex_unlock (&object_mutex); -} -hidden_def (__register_frame_info_table_bases) - -void -__register_frame_info_table (void *begin, struct object *ob) -{ - __register_frame_info_table_bases (begin, ob, 0, 0); -} - -void -__register_frame_table (void *begin) -{ - struct object *ob = (struct object *) malloc (sizeof (struct object)); - __register_frame_info_table_bases (begin, ob, 0, 0); -} - -/* Called from crtbegin.o to deregister the unwind info for an object. */ -/* ??? Glibc has for a while now exported __register_frame_info and - __deregister_frame_info. If we call __register_frame_info_bases - from crtbegin (wherein it is declared weak), and this object does - not get pulled from libgcc.a for other reasons, then the - invocation of __deregister_frame_info will be resolved from glibc. - Since the registration did not happen there, we'll abort. - - Therefore, declare a new deregistration entry point that does the - exact same thing, but will resolve to the same library as - implements __register_frame_info_bases. */ - -void * -__deregister_frame_info_bases (void *begin) -{ - struct object **p; - struct object *ob = 0; - struct fde_vector *tofree = NULL; - - /* If .eh_frame is empty, we haven't registered. */ - if (*(uword *) begin == 0) - return ob; - - init_object_mutex_once (); - __gthread_mutex_lock (&object_mutex); - - for (p = &unseen_objects; *p ; p = &(*p)->next) - if ((*p)->u.single == begin) - { - ob = *p; - *p = ob->next; - goto out; - } - - for (p = &seen_objects; *p ; p = &(*p)->next) - if ((*p)->s.b.sorted) - { - if ((*p)->u.sort->orig_data == begin) - { - ob = *p; - *p = ob->next; - tofree = ob->u.sort; - goto out; - } - } - else - { - if ((*p)->u.single == begin) - { - ob = *p; - *p = ob->next; - goto out; - } - } - - __gthread_mutex_unlock (&object_mutex); - abort (); - - out: - __gthread_mutex_unlock (&object_mutex); - free (tofree); - return (void *) ob; -} -hidden_def (__deregister_frame_info_bases) - -void * -__deregister_frame_info (void *begin) -{ - return __deregister_frame_info_bases (begin); -} - -void -__deregister_frame (void *begin) -{ - /* If .eh_frame is empty, we haven't registered. */ - if (*(uword *) begin != 0) - free (__deregister_frame_info_bases (begin)); -} - - -/* Like base_of_encoded_value, but take the base from a struct object - instead of an _Unwind_Context. */ - -static _Unwind_Ptr -base_from_object (unsigned char encoding, struct object *ob) -{ - if (encoding == DW_EH_PE_omit) - return 0; - - switch (encoding & 0x70) - { - case DW_EH_PE_absptr: - case DW_EH_PE_pcrel: - case DW_EH_PE_aligned: - return 0; - - case DW_EH_PE_textrel: - return (_Unwind_Ptr) ob->tbase; - case DW_EH_PE_datarel: - return (_Unwind_Ptr) ob->dbase; - } - abort (); -} - -/* Return the FDE pointer encoding from the CIE. */ -/* ??? This is a subset of extract_cie_info from unwind-dw2.c. */ - -static int -get_cie_encoding (struct dwarf_cie *cie) -{ - const unsigned char *aug, *p; - _Unwind_Ptr dummy; - _Unwind_Word utmp; - _Unwind_Sword stmp; - - aug = cie->augmentation; - if (aug[0] != 'z') - return DW_EH_PE_absptr; - - /* Skip the augmentation string. */ - p = aug + strlen ((const char *) aug) + 1; - p = read_uleb128 (p, &utmp); /* Skip code alignment. */ - p = read_sleb128 (p, &stmp); /* Skip data alignment. */ - p++; /* Skip return address column. */ - - aug++; /* Skip 'z' */ - p = read_uleb128 (p, &utmp); /* Skip augmentation length. */ - while (1) - { - /* This is what we're looking for. */ - if (*aug == 'R') - return *p; - /* Personality encoding and pointer. */ - else if (*aug == 'P') - { - /* ??? Avoid dereferencing indirect pointers, since we're - faking the base address. Gotta keep DW_EH_PE_aligned - intact, however. */ - p = read_encoded_value_with_base (*p & 0x7F, 0, p + 1, &dummy); - } - /* LSDA encoding. */ - else if (*aug == 'L') - p++; - /* Otherwise end of string, or unknown augmentation. */ - else - return DW_EH_PE_absptr; - aug++; - } -} - -static inline int -get_fde_encoding (struct dwarf_fde *f) -{ - return get_cie_encoding (get_cie (f)); -} - - -/* Sorting an array of FDEs by address. - (Ideally we would have the linker sort the FDEs so we don't have to do - it at run time. But the linkers are not yet prepared for this.) */ - -/* Return the Nth pc_begin value from FDE x. */ - -static inline _Unwind_Ptr -get_pc_begin (fde *x, size_t n) -{ - _Unwind_Ptr p; - memcpy (&p, x->pc_begin + n * sizeof (_Unwind_Ptr), sizeof (_Unwind_Ptr)); - return p; -} - -/* Comparison routines. Three variants of increasing complexity. */ - -static int -fde_unencoded_compare (struct object *ob __attribute__((unused)), - fde *x, fde *y) -{ - _Unwind_Ptr x_ptr = get_pc_begin (x, 0); - _Unwind_Ptr y_ptr = get_pc_begin (y, 0); - - if (x_ptr > y_ptr) - return 1; - if (x_ptr < y_ptr) - return -1; - return 0; -} - -static int -fde_single_encoding_compare (struct object *ob, fde *x, fde *y) -{ - _Unwind_Ptr base, x_ptr, y_ptr; - - base = base_from_object (ob->s.b.encoding, ob); - read_encoded_value_with_base (ob->s.b.encoding, base, x->pc_begin, &x_ptr); - read_encoded_value_with_base (ob->s.b.encoding, base, y->pc_begin, &y_ptr); - - if (x_ptr > y_ptr) - return 1; - if (x_ptr < y_ptr) - return -1; - return 0; -} - -static int -fde_mixed_encoding_compare (struct object *ob, fde *x, fde *y) -{ - int x_encoding, y_encoding; - _Unwind_Ptr x_ptr, y_ptr; - - x_encoding = get_fde_encoding (x); - read_encoded_value_with_base (x_encoding, base_from_object (x_encoding, ob), - x->pc_begin, &x_ptr); - - y_encoding = get_fde_encoding (y); - read_encoded_value_with_base (y_encoding, base_from_object (y_encoding, ob), - y->pc_begin, &y_ptr); - - if (x_ptr > y_ptr) - return 1; - if (x_ptr < y_ptr) - return -1; - return 0; -} - -typedef int (*fde_compare_t) (struct object *, fde *, fde *); - - -/* This is a special mix of insertion sort and heap sort, optimized for - the data sets that actually occur. They look like - 101 102 103 127 128 105 108 110 190 111 115 119 125 160 126 129 130. - I.e. a linearly increasing sequence (coming from functions in the text - section), with additionally a few unordered elements (coming from functions - in gnu_linkonce sections) whose values are higher than the values in the - surrounding linear sequence (but not necessarily higher than the values - at the end of the linear sequence!). - The worst-case total run time is O(N) + O(n log (n)), where N is the - total number of FDEs and n is the number of erratic ones. */ - -struct fde_accumulator -{ - struct fde_vector *linear; - struct fde_vector *erratic; -}; - -static int -start_fde_sort (struct fde_accumulator *accu, size_t count) -{ - size_t size; - if (! count) - return 0; - - size = sizeof (struct fde_vector) + sizeof (fde *) * count; - if ((accu->linear = (struct fde_vector *) malloc (size))) - { - accu->linear->count = 0; - if ((accu->erratic = (struct fde_vector *) malloc (size))) - accu->erratic->count = 0; - return 1; - } - else - return 0; -} - -static inline void -fde_insert (struct fde_accumulator *accu, fde *this_fde) -{ - if (accu->linear) - accu->linear->array[accu->linear->count++] = this_fde; -} - -/* Split LINEAR into a linear sequence with low values and an erratic - sequence with high values, put the linear one (of longest possible - length) into LINEAR and the erratic one into ERRATIC. This is O(N). - - Because the longest linear sequence we are trying to locate within the - incoming LINEAR array can be interspersed with (high valued) erratic - entries. We construct a chain indicating the sequenced entries. - To avoid having to allocate this chain, we overlay it onto the space of - the ERRATIC array during construction. A final pass iterates over the - chain to determine what should be placed in the ERRATIC array, and - what is the linear sequence. This overlay is safe from aliasing. */ - -static void -fde_split (struct object *ob, fde_compare_t fde_compare, - struct fde_vector *linear, struct fde_vector *erratic) -{ - static fde *marker; - size_t count = linear->count; - fde **chain_end = ▮ - size_t i, j, k; - - /* This should optimize out, but it is wise to make sure this assumption - is correct. Should these have different sizes, we cannot cast between - them and the overlaying onto ERRATIC will not work. */ - if (sizeof (fde *) != sizeof (fde **)) - abort (); - - for (i = 0; i < count; i++) - { - fde **probe; - - for (probe = chain_end; - probe != &marker && fde_compare (ob, linear->array[i], *probe) < 0; - probe = chain_end) - { - chain_end = (fde **) erratic->array[probe - linear->array]; - erratic->array[probe - linear->array] = NULL; - } - erratic->array[i] = (fde *) chain_end; - chain_end = &linear->array[i]; - } - - /* Each entry in LINEAR which is part of the linear sequence we have - discovered will correspond to a non-NULL entry in the chain we built in - the ERRATIC array. */ - for (i = j = k = 0; i < count; i++) - if (erratic->array[i]) - linear->array[j++] = linear->array[i]; - else - erratic->array[k++] = linear->array[i]; - linear->count = j; - erratic->count = k; -} - -/* This is O(n log(n)). BSD/OS defines heapsort in stdlib.h, so we must - use a name that does not conflict. */ - -static void -frame_heapsort (struct object *ob, fde_compare_t fde_compare, - struct fde_vector *erratic) -{ - /* For a description of this algorithm, see: - Samuel P. Harbison, Guy L. Steele Jr.: C, a reference manual, 2nd ed., - p. 60-61. */ - fde ** a = erratic->array; - /* A portion of the array is called a "heap" if for all i>=0: - If i and 2i+1 are valid indices, then a[i] >= a[2i+1]. - If i and 2i+2 are valid indices, then a[i] >= a[2i+2]. */ -#define SWAP(x,y) do { fde * tmp = x; x = y; y = tmp; } while (0) - size_t n = erratic->count; - size_t m = n; - size_t i; - - while (m > 0) - { - /* Invariant: a[m..n-1] is a heap. */ - m--; - for (i = m; 2*i+1 < n; ) - { - if (2*i+2 < n - && fde_compare (ob, a[2*i+2], a[2*i+1]) > 0 - && fde_compare (ob, a[2*i+2], a[i]) > 0) - { - SWAP (a[i], a[2*i+2]); - i = 2*i+2; - } - else if (fde_compare (ob, a[2*i+1], a[i]) > 0) - { - SWAP (a[i], a[2*i+1]); - i = 2*i+1; - } - else - break; - } - } - while (n > 1) - { - /* Invariant: a[0..n-1] is a heap. */ - n--; - SWAP (a[0], a[n]); - for (i = 0; 2*i+1 < n; ) - { - if (2*i+2 < n - && fde_compare (ob, a[2*i+2], a[2*i+1]) > 0 - && fde_compare (ob, a[2*i+2], a[i]) > 0) - { - SWAP (a[i], a[2*i+2]); - i = 2*i+2; - } - else if (fde_compare (ob, a[2*i+1], a[i]) > 0) - { - SWAP (a[i], a[2*i+1]); - i = 2*i+1; - } - else - break; - } - } -#undef SWAP -} - -/* Merge V1 and V2, both sorted, and put the result into V1. */ -static void -fde_merge (struct object *ob, fde_compare_t fde_compare, - struct fde_vector *v1, struct fde_vector *v2) -{ - size_t i1, i2; - fde * fde2; - - i2 = v2->count; - if (i2 > 0) - { - i1 = v1->count; - do - { - i2--; - fde2 = v2->array[i2]; - while (i1 > 0 && fde_compare (ob, v1->array[i1-1], fde2) > 0) - { - v1->array[i1+i2] = v1->array[i1-1]; - i1--; - } - v1->array[i1+i2] = fde2; - } - while (i2 > 0); - v1->count += v2->count; - } -} - -static void -end_fde_sort (struct object *ob, struct fde_accumulator *accu, size_t count) -{ - fde_compare_t fde_compare; - - if (accu->linear->count != count) - abort (); - - if (ob->s.b.mixed_encoding) - fde_compare = fde_mixed_encoding_compare; - else if (ob->s.b.encoding == DW_EH_PE_absptr) - fde_compare = fde_unencoded_compare; - else - fde_compare = fde_single_encoding_compare; - - if (accu->erratic) - { - fde_split (ob, fde_compare, accu->linear, accu->erratic); - if (accu->linear->count + accu->erratic->count != count) - abort (); - frame_heapsort (ob, fde_compare, accu->erratic); - fde_merge (ob, fde_compare, accu->linear, accu->erratic); - free (accu->erratic); - } - else - { - /* We've not managed to malloc an erratic array, - so heap sort in the linear one. */ - frame_heapsort (ob, fde_compare, accu->linear); - } -} - - -/* Update encoding, mixed_encoding, and pc_begin for OB for the - fde array beginning at THIS_FDE. Return the number of fdes - encountered along the way. */ - -static size_t -classify_object_over_fdes (struct object *ob, fde *this_fde) -{ - struct dwarf_cie *last_cie = 0; - size_t count = 0; - int encoding = DW_EH_PE_absptr; - _Unwind_Ptr base = 0; - - for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) - { - struct dwarf_cie *this_cie; - _Unwind_Ptr mask, pc_begin; - - /* Skip CIEs. */ - if (this_fde->CIE_delta == 0) - continue; - - /* Determine the encoding for this FDE. Note mixed encoded - objects for later. */ - this_cie = get_cie (this_fde); - if (this_cie != last_cie) - { - last_cie = this_cie; - encoding = get_cie_encoding (this_cie); - base = base_from_object (encoding, ob); - if (ob->s.b.encoding == DW_EH_PE_omit) - ob->s.b.encoding = encoding; - else if (ob->s.b.encoding != encoding) - ob->s.b.mixed_encoding = 1; - } - - read_encoded_value_with_base (encoding, base, this_fde->pc_begin, - &pc_begin); - - /* Take care to ignore link-once functions that were removed. - In these cases, the function address will be NULL, but if - the encoding is smaller than a pointer a true NULL may not - be representable. Assume 0 in the representable bits is NULL. */ - mask = size_of_encoded_value (encoding); - if (mask < sizeof (void *)) - mask = (1L << (mask << 3)) - 1; - else - mask = -1; - - if ((pc_begin & mask) == 0) - continue; - - count += 1; - if ((void *) pc_begin < ob->pc_begin) - ob->pc_begin = (void *) pc_begin; - } - - return count; -} - -static void -add_fdes (struct object *ob, struct fde_accumulator *accu, fde *this_fde) -{ - struct dwarf_cie *last_cie = 0; - int encoding = ob->s.b.encoding; - _Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob); - - for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) - { - struct dwarf_cie *this_cie; - - /* Skip CIEs. */ - if (this_fde->CIE_delta == 0) - continue; - - if (ob->s.b.mixed_encoding) - { - /* Determine the encoding for this FDE. Note mixed encoded - objects for later. */ - this_cie = get_cie (this_fde); - if (this_cie != last_cie) - { - last_cie = this_cie; - encoding = get_cie_encoding (this_cie); - base = base_from_object (encoding, ob); - } - } - - if (encoding == DW_EH_PE_absptr) - { - if (get_pc_begin (this_fde, 0) == 0) - continue; - } - else - { - _Unwind_Ptr pc_begin, mask; - - read_encoded_value_with_base (encoding, base, this_fde->pc_begin, - &pc_begin); - - /* Take care to ignore link-once functions that were removed. - In these cases, the function address will be NULL, but if - the encoding is smaller than a pointer a true NULL may not - be representable. Assume 0 in the representable bits is NULL. */ - mask = size_of_encoded_value (encoding); - if (mask < sizeof (void *)) - mask = (1L << (mask << 3)) - 1; - else - mask = -1; - - if ((pc_begin & mask) == 0) - continue; - } - - fde_insert (accu, this_fde); - } -} - -/* Set up a sorted array of pointers to FDEs for a loaded object. We - count up the entries before allocating the array because it's likely to - be faster. We can be called multiple times, should we have failed to - allocate a sorted fde array on a previous occasion. */ - -static void -init_object (struct object* ob) -{ - struct fde_accumulator accu; - size_t count; - - count = ob->s.b.count; - if (count == 0) - { - if (ob->s.b.from_array) - { - fde **p = ob->u.array; - for (count = 0; *p; ++p) - count += classify_object_over_fdes (ob, *p); - } - else - count = classify_object_over_fdes (ob, ob->u.single); - - /* The count field we have in the main struct object is somewhat - limited, but should suffice for virtually all cases. If the - counted value doesn't fit, re-write a zero. The worst that - happens is that we re-count next time -- admittedly non-trivial - in that this implies some 2M fdes, but at least we function. */ - ob->s.b.count = count; - if (ob->s.b.count != count) - ob->s.b.count = 0; - } - - if (!start_fde_sort (&accu, count)) - return; - - if (ob->s.b.from_array) - { - fde **p; - for (p = ob->u.array; *p; ++p) - add_fdes (ob, &accu, *p); - } - else - add_fdes (ob, &accu, ob->u.single); - - end_fde_sort (ob, &accu, count); - - /* Save the original fde pointer, since this is the key by which the - DSO will deregister the object. */ - accu.linear->orig_data = ob->u.single; - ob->u.sort = accu.linear; - - ob->s.b.sorted = 1; -} - -/* A linear search through a set of FDEs for the given PC. This is - used when there was insufficient memory to allocate and sort an - array. */ - -static fde * -linear_search_fdes (struct object *ob, fde *this_fde, void *pc) -{ - struct dwarf_cie *last_cie = 0; - int encoding = ob->s.b.encoding; - _Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob); - - for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) - { - struct dwarf_cie *this_cie; - _Unwind_Ptr pc_begin, pc_range; - - /* Skip CIEs. */ - if (this_fde->CIE_delta == 0) - continue; - - if (ob->s.b.mixed_encoding) - { - /* Determine the encoding for this FDE. Note mixed encoded - objects for later. */ - this_cie = get_cie (this_fde); - if (this_cie != last_cie) - { - last_cie = this_cie; - encoding = get_cie_encoding (this_cie); - base = base_from_object (encoding, ob); - } - } - - if (encoding == DW_EH_PE_absptr) - { - pc_begin = get_pc_begin (this_fde, 0); - pc_range = get_pc_begin (this_fde, 1); - if (pc_begin == 0) - continue; - } - else - { - _Unwind_Ptr mask; - const unsigned char *p; - - p = read_encoded_value_with_base (encoding, base, - this_fde->pc_begin, &pc_begin); - read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); - - /* Take care to ignore link-once functions that were removed. - In these cases, the function address will be NULL, but if - the encoding is smaller than a pointer a true NULL may not - be representable. Assume 0 in the representable bits is NULL. */ - mask = size_of_encoded_value (encoding); - if (mask < sizeof (void *)) - mask = (1L << (mask << 3)) - 1; - else - mask = -1; - - if ((pc_begin & mask) == 0) - continue; - } - - if ((_Unwind_Ptr) pc - pc_begin < pc_range) - return this_fde; - } - - return NULL; -} - -/* Binary search for an FDE containing the given PC. Here are three - implementations of increasing complexity. */ - -static fde * -binary_search_unencoded_fdes (struct object *ob, void *pc) -{ - struct fde_vector *vec = ob->u.sort; - size_t lo, hi; - - for (lo = 0, hi = vec->count; lo < hi; ) - { - size_t i = (lo + hi) / 2; - fde *f = vec->array[i]; - void *pc_begin; - uaddr pc_range; - - pc_begin = (void *) get_pc_begin (f, 0); - pc_range = (uaddr) get_pc_begin (f, 1); - - if (pc < pc_begin) - hi = i; - else if (pc >= pc_begin + pc_range) - lo = i + 1; - else - return f; - } - - return NULL; -} - -static fde * -binary_search_single_encoding_fdes (struct object *ob, void *pc) -{ - struct fde_vector *vec = ob->u.sort; - int encoding = ob->s.b.encoding; - _Unwind_Ptr base = base_from_object (encoding, ob); - size_t lo, hi; - - for (lo = 0, hi = vec->count; lo < hi; ) - { - size_t i = (lo + hi) / 2; - fde *f = vec->array[i]; - _Unwind_Ptr pc_begin, pc_range; - const unsigned char *p; - - p = read_encoded_value_with_base (encoding, base, f->pc_begin, - &pc_begin); - read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); - - if ((_Unwind_Ptr) pc < pc_begin) - hi = i; - else if ((_Unwind_Ptr) pc >= pc_begin + pc_range) - lo = i + 1; - else - return f; - } - - return NULL; -} - -static fde * -binary_search_mixed_encoding_fdes (struct object *ob, void *pc) -{ - struct fde_vector *vec = ob->u.sort; - size_t lo, hi; - - for (lo = 0, hi = vec->count; lo < hi; ) - { - size_t i = (lo + hi) / 2; - fde *f = vec->array[i]; - _Unwind_Ptr pc_begin, pc_range; - const unsigned char *p; - int encoding; - - encoding = get_fde_encoding (f); - p = read_encoded_value_with_base (encoding, - base_from_object (encoding, ob), - f->pc_begin, &pc_begin); - read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); - - if ((_Unwind_Ptr) pc < pc_begin) - hi = i; - else if ((_Unwind_Ptr) pc >= pc_begin + pc_range) - lo = i + 1; - else - return f; - } - - return NULL; -} - -static fde * -search_object (struct object* ob, void *pc) -{ - /* If the data hasn't been sorted, try to do this now. We may have - more memory available than last time we tried. */ - if (! ob->s.b.sorted) - { - init_object (ob); - - /* Despite the above comment, the normal reason to get here is - that we've not processed this object before. A quick range - check is in order. */ - if (pc < ob->pc_begin) - return NULL; - } - - if (ob->s.b.sorted) - { - if (ob->s.b.mixed_encoding) - return binary_search_mixed_encoding_fdes (ob, pc); - else if (ob->s.b.encoding == DW_EH_PE_absptr) - return binary_search_unencoded_fdes (ob, pc); - else - return binary_search_single_encoding_fdes (ob, pc); - } - else - { - /* Long slow labourious linear search, cos we've no memory. */ - if (ob->s.b.from_array) - { - fde **p; - for (p = ob->u.array; *p ; p++) - { - fde *f = linear_search_fdes (ob, *p, pc); - if (f) - return f; - } - return NULL; - } - else - return linear_search_fdes (ob, ob->u.single, pc); - } -} - -fde * -_Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases) -{ - struct object *ob; - fde *f = NULL; - - init_object_mutex_once (); - __gthread_mutex_lock (&object_mutex); - - /* Linear search through the classified objects, to find the one - containing the pc. Note that pc_begin is sorted descending, and - we expect objects to be non-overlapping. */ - for (ob = seen_objects; ob; ob = ob->next) - if (pc >= ob->pc_begin) - { - f = search_object (ob, pc); - if (f) - goto fini; - break; - } - - /* Classify and search the objects we've not yet processed. */ - while ((ob = unseen_objects)) - { - struct object **p; - - unseen_objects = ob->next; - f = search_object (ob, pc); - - /* Insert the object into the classified list. */ - for (p = &seen_objects; *p ; p = &(*p)->next) - if ((*p)->pc_begin < ob->pc_begin) - break; - ob->next = *p; - *p = ob; - - if (f) - goto fini; - } - - fini: - __gthread_mutex_unlock (&object_mutex); - - if (f) - { - int encoding; - _Unwind_Ptr func; - - bases->tbase = ob->tbase; - bases->dbase = ob->dbase; - - encoding = ob->s.b.encoding; - if (ob->s.b.mixed_encoding) - encoding = get_fde_encoding (f); - read_encoded_value_with_base (encoding, base_from_object (encoding, ob), - f->pc_begin, &func); - bases->func = (void *) func; - } - - return f; -} - -#endif |