File: | src/lib/libelf/elf_scn.c |
Warning: | line 207, column 8 Although the value stored to 'scn' is used in the enclosing expression, the value is never actually read from 'scn' |
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1 | /*- |
2 | * Copyright (c) 2006,2008-2010 Joseph Koshy |
3 | * All rights reserved. |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
8 | * 1. Redistributions of source code must retain the above copyright |
9 | * notice, this list of conditions and the following disclaimer. |
10 | * 2. Redistributions in binary form must reproduce the above copyright |
11 | * notice, this list of conditions and the following disclaimer in the |
12 | * documentation and/or other materials provided with the distribution. |
13 | * |
14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
24 | * SUCH DAMAGE. |
25 | */ |
26 | |
27 | #include <sys/queue.h> |
28 | |
29 | #include <assert.h> |
30 | #include <errno(*__errno()).h> |
31 | #include <gelf.h> |
32 | #include <libelf.h> |
33 | #include <stddef.h> |
34 | #include <stdint.h> |
35 | #include <stdlib.h> |
36 | |
37 | #include "_libelf.h" |
38 | |
39 | ELFTC_VCSID("$Id: elf_scn.c,v 1.2 2019/03/19 02:31:35 jsg Exp $"); |
40 | |
41 | /* |
42 | * Load an ELF section table and create a list of Elf_Scn structures. |
43 | */ |
44 | int |
45 | _libelf_load_section_headers(Elf *e, void *ehdr) |
46 | { |
47 | Elf_Scn *scn; |
48 | uint64_t shoff; |
49 | Elf32_Ehdr *eh32; |
50 | Elf64_Ehdr *eh64; |
51 | int ec, swapbytes; |
52 | unsigned char *src; |
53 | size_t fsz, i, shnum; |
54 | _libelf_translator_function *xlator; |
55 | |
56 | assert(e != NULL)((e != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_scn.c" , 56, __func__, "e != NULL")); |
57 | assert(ehdr != NULL)((ehdr != ((void *)0)) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_scn.c" , 57, __func__, "ehdr != NULL")); |
58 | assert((e->e_flags & LIBELF_F_SHDRS_LOADED) == 0)(((e->e_flags & 0x200000U) == 0) ? (void)0 : __assert2 ("/usr/src/lib/libelf/elf_scn.c", 58, __func__, "(e->e_flags & LIBELF_F_SHDRS_LOADED) == 0" )); |
59 | |
60 | #define CHECK_EHDR(E,EH)do { uintmax_t rawsize = (uintmax_t) e->e_rawsize; if (shoff > (uintmax_t) e->e_rawsize || fsz != (EH)->e_shentsize || shnum > 0xffffffffffffffffUL / fsz || fsz * shnum > rawsize - shoff) { do { (_libelf.libelf_error) = (((ELF_E_HEADER ) & 0xFF) | (((0)) << 8)); } while (0); return (0); } } while (0) do { \ |
61 | uintmax_t rawsize = (uintmax_t) e->e_rawsize; \ |
62 | if (shoff > (uintmax_t) e->e_rawsize || \ |
63 | fsz != (EH)->e_shentsize || \ |
64 | shnum > SIZE_MAX0xffffffffffffffffUL / fsz || \ |
65 | fsz * shnum > rawsize - shoff) { \ |
66 | LIBELF_SET_ERROR(HEADER, 0)do { (_libelf.libelf_error) = (((ELF_E_HEADER) & 0xFF) | ( ((0)) << 8)); } while (0); \ |
67 | return (0); \ |
68 | } \ |
69 | } while (0) |
70 | |
71 | ec = e->e_class; |
72 | fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, (size_t) 1); |
73 | assert(fsz > 0)((fsz > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_scn.c" , 73, __func__, "fsz > 0")); |
74 | |
75 | shnum = e->e_u.e_elf.e_nscn; |
76 | |
77 | if (ec == ELFCLASS321) { |
78 | eh32 = (Elf32_Ehdr *) ehdr; |
79 | shoff = (uint64_t) eh32->e_shoff; |
80 | CHECK_EHDR(e, eh32)do { uintmax_t rawsize = (uintmax_t) e->e_rawsize; if (shoff > (uintmax_t) e->e_rawsize || fsz != (eh32)->e_shentsize || shnum > 0xffffffffffffffffUL / fsz || fsz * shnum > rawsize - shoff) { do { (_libelf.libelf_error) = (((ELF_E_HEADER ) & 0xFF) | (((0)) << 8)); } while (0); return (0); } } while (0); |
81 | } else { |
82 | eh64 = (Elf64_Ehdr *) ehdr; |
83 | shoff = eh64->e_shoff; |
84 | CHECK_EHDR(e, eh64)do { uintmax_t rawsize = (uintmax_t) e->e_rawsize; if (shoff > (uintmax_t) e->e_rawsize || fsz != (eh64)->e_shentsize || shnum > 0xffffffffffffffffUL / fsz || fsz * shnum > rawsize - shoff) { do { (_libelf.libelf_error) = (((ELF_E_HEADER ) & 0xFF) | (((0)) << 8)); } while (0); return (0); } } while (0); |
85 | } |
86 | |
87 | xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec, |
88 | _libelf_elfmachine(e)); |
89 | |
90 | swapbytes = e->e_byteorder != LIBELF_PRIVATE(byteorder)(_libelf.libelf_byteorder); |
91 | src = e->e_rawfile + shoff; |
92 | |
93 | /* |
94 | * If the file is using extended numbering then section #0 |
95 | * would have already been read in. |
96 | */ |
97 | |
98 | i = 0; |
99 | if (!STAILQ_EMPTY(&e->e_u.e_elf.e_scn)(((&e->e_u.e_elf.e_scn)->stqh_first) == ((void *)0) )) { |
100 | assert(STAILQ_FIRST(&e->e_u.e_elf.e_scn) ==((((&e->e_u.e_elf.e_scn)->stqh_first) == (((((& e->e_u.e_elf.e_scn))->stqh_first) == ((void *)0)) ? ((void *)0) : ((struct _Elf_Scn *)(void *) ((char *)((&e->e_u .e_elf.e_scn)->stqh_last) - __builtin_offsetof(struct _Elf_Scn , s_next))))) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_scn.c" , 101, __func__, "STAILQ_FIRST(&e->e_u.e_elf.e_scn) == STAILQ_LAST(&e->e_u.e_elf.e_scn, _Elf_Scn, s_next)" )) |
101 | STAILQ_LAST(&e->e_u.e_elf.e_scn, _Elf_Scn, s_next))((((&e->e_u.e_elf.e_scn)->stqh_first) == (((((& e->e_u.e_elf.e_scn))->stqh_first) == ((void *)0)) ? ((void *)0) : ((struct _Elf_Scn *)(void *) ((char *)((&e->e_u .e_elf.e_scn)->stqh_last) - __builtin_offsetof(struct _Elf_Scn , s_next))))) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_scn.c" , 101, __func__, "STAILQ_FIRST(&e->e_u.e_elf.e_scn) == STAILQ_LAST(&e->e_u.e_elf.e_scn, _Elf_Scn, s_next)" )); |
102 | |
103 | i = 1; |
104 | src += fsz; |
105 | } |
106 | |
107 | for (; i < shnum; i++, src += fsz) { |
108 | if ((scn = _libelf_allocate_scn(e, i)) == NULL((void *)0)) |
109 | return (0); |
110 | |
111 | (*xlator)((unsigned char *) &scn->s_shdr, sizeof(scn->s_shdr), |
112 | src, (size_t) 1, swapbytes); |
113 | |
114 | if (ec == ELFCLASS321) { |
115 | scn->s_offset = scn->s_rawoff = |
116 | scn->s_shdr.s_shdr32.sh_offset; |
117 | scn->s_size = scn->s_shdr.s_shdr32.sh_size; |
118 | } else { |
119 | scn->s_offset = scn->s_rawoff = |
120 | scn->s_shdr.s_shdr64.sh_offset; |
121 | scn->s_size = scn->s_shdr.s_shdr64.sh_size; |
122 | } |
123 | } |
124 | |
125 | e->e_flags |= LIBELF_F_SHDRS_LOADED0x200000U; |
126 | |
127 | return (1); |
128 | } |
129 | |
130 | |
131 | Elf_Scn * |
132 | elf_getscn(Elf *e, size_t index) |
133 | { |
134 | int ec; |
135 | void *ehdr; |
136 | Elf_Scn *s; |
137 | |
138 | if (e == NULL((void *)0) || e->e_kind != ELF_K_ELF || |
139 | ((ec = e->e_class) != ELFCLASS321 && ec != ELFCLASS642)) { |
140 | LIBELF_SET_ERROR(ARGUMENT, 0)do { (_libelf.libelf_error) = (((ELF_E_ARGUMENT) & 0xFF) | (((0)) << 8)); } while (0); |
141 | return (NULL((void *)0)); |
142 | } |
143 | |
144 | if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL((void *)0)) |
145 | return (NULL((void *)0)); |
146 | |
147 | if (e->e_cmd != ELF_C_WRITE && |
148 | (e->e_flags & LIBELF_F_SHDRS_LOADED0x200000U) == 0 && |
149 | _libelf_load_section_headers(e, ehdr) == 0) |
150 | return (NULL((void *)0)); |
151 | |
152 | STAILQ_FOREACH(s, &e->e_u.e_elf.e_scn, s_next)for ((s) = ((&e->e_u.e_elf.e_scn)->stqh_first); (s) != ((void *)0); (s) = ((s)->s_next.stqe_next)) |
153 | if (s->s_ndx == index) |
154 | return (s); |
155 | |
156 | LIBELF_SET_ERROR(ARGUMENT, 0)do { (_libelf.libelf_error) = (((ELF_E_ARGUMENT) & 0xFF) | (((0)) << 8)); } while (0); |
157 | return (NULL((void *)0)); |
158 | } |
159 | |
160 | size_t |
161 | elf_ndxscn(Elf_Scn *s) |
162 | { |
163 | if (s == NULL((void *)0)) { |
164 | LIBELF_SET_ERROR(ARGUMENT, 0)do { (_libelf.libelf_error) = (((ELF_E_ARGUMENT) & 0xFF) | (((0)) << 8)); } while (0); |
165 | return (SHN_UNDEF0); |
166 | } |
167 | return (s->s_ndx); |
168 | } |
169 | |
170 | Elf_Scn * |
171 | elf_newscn(Elf *e) |
172 | { |
173 | int ec; |
174 | void *ehdr; |
175 | Elf_Scn *scn; |
176 | |
177 | if (e == NULL((void *)0) || e->e_kind != ELF_K_ELF) { |
178 | LIBELF_SET_ERROR(ARGUMENT, 0)do { (_libelf.libelf_error) = (((ELF_E_ARGUMENT) & 0xFF) | (((0)) << 8)); } while (0); |
179 | return (NULL((void *)0)); |
180 | } |
181 | |
182 | if ((ec = e->e_class) != ELFCLASS321 && ec != ELFCLASS642) { |
183 | LIBELF_SET_ERROR(CLASS, 0)do { (_libelf.libelf_error) = (((ELF_E_CLASS) & 0xFF) | ( ((0)) << 8)); } while (0); |
184 | return (NULL((void *)0)); |
185 | } |
186 | |
187 | if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL((void *)0)) |
188 | return (NULL((void *)0)); |
189 | |
190 | /* |
191 | * The application may be asking for a new section descriptor |
192 | * on an ELF object opened with ELF_C_RDWR or ELF_C_READ. We |
193 | * need to bring in the existing section information before |
194 | * appending a new one to the list. |
195 | * |
196 | * Per the ELF(3) API, an application is allowed to open a |
197 | * file using ELF_C_READ, mess with its internal structure and |
198 | * use elf_update(...,ELF_C_NULL) to compute its new layout. |
199 | */ |
200 | if (e->e_cmd != ELF_C_WRITE && |
201 | (e->e_flags & LIBELF_F_SHDRS_LOADED0x200000U) == 0 && |
202 | _libelf_load_section_headers(e, ehdr) == 0) |
203 | return (NULL((void *)0)); |
204 | |
205 | if (STAILQ_EMPTY(&e->e_u.e_elf.e_scn)(((&e->e_u.e_elf.e_scn)->stqh_first) == ((void *)0) )) { |
206 | assert(e->e_u.e_elf.e_nscn == 0)((e->e_u.e_elf.e_nscn == 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_scn.c" , 206, __func__, "e->e_u.e_elf.e_nscn == 0")); |
207 | if ((scn = _libelf_allocate_scn(e, (size_t) SHN_UNDEF0)) == |
Although the value stored to 'scn' is used in the enclosing expression, the value is never actually read from 'scn' | |
208 | NULL((void *)0)) |
209 | return (NULL((void *)0)); |
210 | e->e_u.e_elf.e_nscn++; |
211 | } |
212 | |
213 | assert(e->e_u.e_elf.e_nscn > 0)((e->e_u.e_elf.e_nscn > 0) ? (void)0 : __assert2("/usr/src/lib/libelf/elf_scn.c" , 213, __func__, "e->e_u.e_elf.e_nscn > 0")); |
214 | |
215 | if ((scn = _libelf_allocate_scn(e, e->e_u.e_elf.e_nscn)) == NULL((void *)0)) |
216 | return (NULL((void *)0)); |
217 | |
218 | e->e_u.e_elf.e_nscn++; |
219 | |
220 | (void) elf_flagscn(scn, ELF_C_SET, ELF_F_DIRTY0x002U); |
221 | |
222 | return (scn); |
223 | } |
224 | |
225 | Elf_Scn * |
226 | elf_nextscn(Elf *e, Elf_Scn *s) |
227 | { |
228 | if (e == NULL((void *)0) || (e->e_kind != ELF_K_ELF) || |
229 | (s && s->s_elf != e)) { |
230 | LIBELF_SET_ERROR(ARGUMENT, 0)do { (_libelf.libelf_error) = (((ELF_E_ARGUMENT) & 0xFF) | (((0)) << 8)); } while (0); |
231 | return (NULL((void *)0)); |
232 | } |
233 | |
234 | return (s == NULL((void *)0) ? elf_getscn(e, (size_t) 1) : |
235 | STAILQ_NEXT(s, s_next)((s)->s_next.stqe_next)); |
236 | } |