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88462c42 | 1 | /* Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc. |
275b60d6 JJ |
2 | Contributed by Jakub Jelinek <jakub@redhat.com>. |
3 | ||
54a7b573 | 4 | This file is part of GCC. |
275b60d6 | 5 | |
54a7b573 | 6 | GCC is free software; you can redistribute it and/or modify |
275b60d6 JJ |
7 | it under the terms of the GNU General Public License as published by |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
54a7b573 | 11 | GCC is distributed in the hope that it will be useful, |
275b60d6 JJ |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
54a7b573 | 17 | along with GCC; see the file COPYING. If not, write to |
275b60d6 JJ |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* As a special exception, if you link this library with other files, | |
22 | some of which are compiled with GCC, to produce an executable, | |
23 | this library does not by itself cause the resulting executable | |
24 | to be covered by the GNU General Public License. | |
25 | This exception does not however invalidate any other reasons why | |
26 | the executable file might be covered by the GNU General Public License. */ | |
27 | ||
28 | /* Locate the FDE entry for a given address, using PT_GNU_EH_FRAME ELF | |
29 | segment and dl_iterate_phdr to avoid register/deregister calls at | |
30 | DSO load/unload. */ | |
31 | ||
703b0080 JDA |
32 | #ifndef _GNU_SOURCE |
33 | #define _GNU_SOURCE 1 | |
34 | #endif | |
35 | ||
275b60d6 JJ |
36 | #include "auto-host.h" /* For HAVE_LD_EH_FRAME_HDR. */ |
37 | #include "tconfig.h" | |
4977bab6 | 38 | #include "tsystem.h" |
72c7c913 | 39 | #ifndef inhibit_libc |
275b60d6 | 40 | #include <link.h> |
72c7c913 | 41 | #endif |
4977bab6 ZW |
42 | #include "coretypes.h" |
43 | #include "tm.h" | |
275b60d6 JJ |
44 | #include "dwarf2.h" |
45 | #include "unwind.h" | |
46 | #define NO_BASE_OF_ENCODED_VALUE | |
47 | #include "unwind-pe.h" | |
48 | #include "unwind-dw2-fde.h" | |
443728bb | 49 | #include "unwind-compat.h" |
275b60d6 JJ |
50 | #include "gthr.h" |
51 | ||
72c7c913 | 52 | #if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \ |
275b60d6 JJ |
53 | && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2) \ |
54 | || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && defined(DT_CONFIG))) | |
55 | ||
34208acf AO |
56 | #ifndef __RELOC_POINTER |
57 | # define __RELOC_POINTER(ptr, base) ((ptr) + (base)) | |
58 | #endif | |
59 | ||
a30794da | 60 | static const fde * _Unwind_Find_registered_FDE (void *pc, struct dwarf_eh_bases *bases); |
275b60d6 JJ |
61 | |
62 | #define _Unwind_Find_FDE _Unwind_Find_registered_FDE | |
63 | #include "unwind-dw2-fde.c" | |
64 | #undef _Unwind_Find_FDE | |
65 | ||
66 | #ifndef PT_GNU_EH_FRAME | |
67 | #define PT_GNU_EH_FRAME (PT_LOOS + 0x474e550) | |
68 | #endif | |
69 | ||
70 | struct unw_eh_callback_data | |
71 | { | |
72 | _Unwind_Ptr pc; | |
73 | void *tbase; | |
74 | void *dbase; | |
75 | void *func; | |
a30794da | 76 | const fde *ret; |
275b60d6 JJ |
77 | }; |
78 | ||
79 | struct unw_eh_frame_hdr | |
80 | { | |
81 | unsigned char version; | |
82 | unsigned char eh_frame_ptr_enc; | |
83 | unsigned char fde_count_enc; | |
84 | unsigned char table_enc; | |
85 | }; | |
86 | ||
3cfe49da GK |
87 | /* Like base_of_encoded_value, but take the base from a struct |
88 | unw_eh_callback_data instead of an _Unwind_Context. */ | |
41077ce4 | 89 | |
275b60d6 JJ |
90 | static _Unwind_Ptr |
91 | base_from_cb_data (unsigned char encoding, struct unw_eh_callback_data *data) | |
92 | { | |
93 | if (encoding == DW_EH_PE_omit) | |
94 | return 0; | |
95 | ||
96 | switch (encoding & 0x70) | |
97 | { | |
98 | case DW_EH_PE_absptr: | |
99 | case DW_EH_PE_pcrel: | |
100 | case DW_EH_PE_aligned: | |
101 | return 0; | |
41077ce4 | 102 | |
275b60d6 JJ |
103 | case DW_EH_PE_textrel: |
104 | return (_Unwind_Ptr) data->tbase; | |
105 | case DW_EH_PE_datarel: | |
106 | return (_Unwind_Ptr) data->dbase; | |
107 | } | |
108 | abort (); | |
109 | } | |
110 | ||
111 | static int | |
112 | _Unwind_IteratePhdrCallback (struct dl_phdr_info *info, size_t size, void *ptr) | |
113 | { | |
114 | struct unw_eh_callback_data *data = (struct unw_eh_callback_data *) ptr; | |
115 | const ElfW(Phdr) *phdr, *p_eh_frame_hdr, *p_dynamic; | |
116 | long n, match; | |
34208acf AO |
117 | #ifdef __FRV_FDPIC__ |
118 | struct elf32_fdpic_loadaddr load_base; | |
119 | #else | |
275b60d6 | 120 | _Unwind_Ptr load_base; |
34208acf | 121 | #endif |
275b60d6 JJ |
122 | const unsigned char *p; |
123 | const struct unw_eh_frame_hdr *hdr; | |
124 | _Unwind_Ptr eh_frame; | |
125 | struct object ob; | |
126 | ||
127 | /* Make sure struct dl_phdr_info is at least as big as we need. */ | |
128 | if (size < offsetof (struct dl_phdr_info, dlpi_phnum) | |
129 | + sizeof (info->dlpi_phnum)) | |
130 | return -1; | |
131 | ||
132 | match = 0; | |
133 | phdr = info->dlpi_phdr; | |
134 | load_base = info->dlpi_addr; | |
135 | p_eh_frame_hdr = NULL; | |
136 | p_dynamic = NULL; | |
137 | ||
138 | /* See if PC falls into one of the loaded segments. Find the eh_frame | |
139 | segment at the same time. */ | |
140 | for (n = info->dlpi_phnum; --n >= 0; phdr++) | |
141 | { | |
142 | if (phdr->p_type == PT_LOAD) | |
143 | { | |
34208acf AO |
144 | _Unwind_Ptr vaddr = (_Unwind_Ptr) |
145 | __RELOC_POINTER (phdr->p_vaddr, load_base); | |
275b60d6 JJ |
146 | if (data->pc >= vaddr && data->pc < vaddr + phdr->p_memsz) |
147 | match = 1; | |
148 | } | |
149 | else if (phdr->p_type == PT_GNU_EH_FRAME) | |
150 | p_eh_frame_hdr = phdr; | |
151 | else if (phdr->p_type == PT_DYNAMIC) | |
152 | p_dynamic = phdr; | |
153 | } | |
154 | if (!match || !p_eh_frame_hdr) | |
155 | return 0; | |
156 | ||
157 | /* Read .eh_frame_hdr header. */ | |
158 | hdr = (const struct unw_eh_frame_hdr *) | |
34208acf | 159 | __RELOC_POINTER (p_eh_frame_hdr->p_vaddr, load_base); |
275b60d6 JJ |
160 | if (hdr->version != 1) |
161 | return 1; | |
162 | ||
163 | #ifdef CRT_GET_RFIB_DATA | |
164 | # ifdef __i386__ | |
165 | data->dbase = NULL; | |
166 | if (p_dynamic) | |
167 | { | |
3d042e77 | 168 | /* For dynamically linked executables and shared libraries, |
275b60d6 | 169 | DT_PLTGOT is the gp value for that object. */ |
34208acf AO |
170 | ElfW(Dyn) *dyn = (ElfW(Dyn) *) |
171 | __RELOC_POINTER (p_dynamic->p_vaddr, load_base); | |
275b60d6 JJ |
172 | for (; dyn->d_tag != DT_NULL ; dyn++) |
173 | if (dyn->d_tag == DT_PLTGOT) | |
174 | { | |
175 | /* On IA-32, _DYNAMIC is writable and GLIBC has relocated it. */ | |
176 | data->dbase = (void *) dyn->d_un.d_ptr; | |
177 | break; | |
178 | } | |
179 | } | |
34208acf AO |
180 | # elif defined __FRV_FDPIC__ && defined __linux__ |
181 | data->dbase = load_base.got_value; | |
275b60d6 JJ |
182 | # else |
183 | # error What is DW_EH_PE_datarel base on this platform? | |
184 | # endif | |
275b60d6 JJ |
185 | #endif |
186 | ||
187 | p = read_encoded_value_with_base (hdr->eh_frame_ptr_enc, | |
188 | base_from_cb_data (hdr->eh_frame_ptr_enc, | |
189 | data), | |
190 | (const unsigned char *) (hdr + 1), | |
191 | &eh_frame); | |
192 | ||
193 | /* We require here specific table encoding to speed things up. | |
194 | Also, DW_EH_PE_datarel here means using PT_GNU_EH_FRAME start | |
195 | as base, not the processor specific DW_EH_PE_datarel. */ | |
196 | if (hdr->fde_count_enc != DW_EH_PE_omit | |
197 | && hdr->table_enc == (DW_EH_PE_datarel | DW_EH_PE_sdata4)) | |
198 | { | |
199 | _Unwind_Ptr fde_count; | |
200 | ||
201 | p = read_encoded_value_with_base (hdr->fde_count_enc, | |
202 | base_from_cb_data (hdr->fde_count_enc, | |
203 | data), | |
204 | p, &fde_count); | |
205 | /* Shouldn't happen. */ | |
206 | if (fde_count == 0) | |
207 | return 1; | |
208 | if ((((_Unwind_Ptr) p) & 3) == 0) | |
209 | { | |
210 | struct fde_table { | |
211 | signed initial_loc __attribute__ ((mode (SI))); | |
212 | signed fde __attribute__ ((mode (SI))); | |
213 | }; | |
214 | const struct fde_table *table = (const struct fde_table *) p; | |
215 | size_t lo, hi, mid; | |
216 | _Unwind_Ptr data_base = (_Unwind_Ptr) hdr; | |
217 | fde *f; | |
218 | unsigned int f_enc, f_enc_size; | |
219 | _Unwind_Ptr range; | |
220 | ||
221 | mid = fde_count - 1; | |
222 | if (data->pc < table[0].initial_loc + data_base) | |
223 | return 1; | |
224 | else if (data->pc < table[mid].initial_loc + data_base) | |
225 | { | |
226 | lo = 0; | |
227 | hi = mid; | |
228 | ||
229 | while (lo < hi) | |
230 | { | |
231 | mid = (lo + hi) / 2; | |
232 | if (data->pc < table[mid].initial_loc + data_base) | |
233 | hi = mid; | |
234 | else if (data->pc >= table[mid + 1].initial_loc + data_base) | |
235 | lo = mid + 1; | |
236 | else | |
237 | break; | |
238 | } | |
239 | ||
240 | if (lo >= hi) | |
241 | __gxx_abort (); | |
242 | } | |
243 | ||
244 | f = (fde *) (table[mid].fde + data_base); | |
245 | f_enc = get_fde_encoding (f); | |
246 | f_enc_size = size_of_encoded_value (f_enc); | |
247 | read_encoded_value_with_base (f_enc & 0x0f, 0, | |
248 | &f->pc_begin[f_enc_size], &range); | |
249 | if (data->pc < table[mid].initial_loc + data_base + range) | |
250 | data->ret = f; | |
251 | data->func = (void *) (table[mid].initial_loc + data_base); | |
252 | return 1; | |
253 | } | |
254 | } | |
255 | ||
256 | /* We have no sorted search table, so need to go the slow way. | |
257 | As soon as GLIBC will provide API so to notify that a library has been | |
258 | removed, we could cache this (and thus use search_object). */ | |
259 | ob.pc_begin = NULL; | |
260 | ob.tbase = data->tbase; | |
261 | ob.dbase = data->dbase; | |
262 | ob.u.single = (fde *) eh_frame; | |
263 | ob.s.i = 0; | |
264 | ob.s.b.mixed_encoding = 1; /* Need to assume worst case. */ | |
265 | data->ret = linear_search_fdes (&ob, (fde *) eh_frame, (void *) data->pc); | |
266 | if (data->ret != NULL) | |
267 | { | |
268 | unsigned int encoding = get_fde_encoding (data->ret); | |
269 | read_encoded_value_with_base (encoding, | |
270 | base_from_cb_data (encoding, data), | |
271 | data->ret->pc_begin, | |
272 | (_Unwind_Ptr *)&data->func); | |
273 | } | |
274 | return 1; | |
275 | } | |
276 | ||
a30794da | 277 | const fde * |
275b60d6 JJ |
278 | _Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases) |
279 | { | |
280 | struct unw_eh_callback_data data; | |
a30794da | 281 | const fde *ret; |
275b60d6 JJ |
282 | |
283 | ret = _Unwind_Find_registered_FDE (pc, bases); | |
284 | if (ret != NULL) | |
285 | return ret; | |
286 | ||
287 | data.pc = (_Unwind_Ptr) pc; | |
288 | data.tbase = NULL; | |
289 | data.dbase = NULL; | |
290 | data.func = NULL; | |
291 | data.ret = NULL; | |
292 | ||
293 | if (dl_iterate_phdr (_Unwind_IteratePhdrCallback, &data) < 0) | |
294 | return NULL; | |
295 | ||
296 | if (data.ret) | |
297 | { | |
298 | bases->tbase = data.tbase; | |
299 | bases->dbase = data.dbase; | |
300 | bases->func = data.func; | |
301 | } | |
302 | return data.ret; | |
303 | } | |
304 | ||
305 | #else | |
5f77a9c5 ZW |
306 | /* Prevent multiple include of header files. */ |
307 | #define _Unwind_Find_FDE _Unwind_Find_FDE | |
275b60d6 JJ |
308 | #include "unwind-dw2-fde.c" |
309 | #endif | |
443728bb L |
310 | |
311 | #if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS) | |
312 | alias (_Unwind_Find_FDE); | |
313 | #endif |