xref: /openbsd-src/sys/lib/libsa/loadfile_elf.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /* $NetBSD: loadfile.c,v 1.10 2000/12/03 02:53:04 tsutsui Exp $ */
2 /* $OpenBSD: loadfile_elf.c,v 1.5 2008/06/26 05:42:20 ray Exp $ */
3 
4 /*-
5  * Copyright (c) 1997 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
10  * NASA Ames Research Center and by Christos Zoulas.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1992, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * This code is derived from software contributed to Berkeley by
39  * Ralph Campbell.
40  *
41  * Redistribution and use in source and binary forms, with or without
42  * modification, are permitted provided that the following conditions
43  * are met:
44  * 1. Redistributions of source code must retain the above copyright
45  *    notice, this list of conditions and the following disclaimer.
46  * 2. Redistributions in binary form must reproduce the above copyright
47  *    notice, this list of conditions and the following disclaimer in the
48  *    documentation and/or other materials provided with the distribution.
49  * 3. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  *	@(#)boot.c	8.1 (Berkeley) 6/10/93
66  */
67 
68 int ELFNAME(exec)(int, Elf_Ehdr *, u_long *, int);
69 
70 int
71 ELFNAME(exec)(int fd, Elf_Ehdr *elf, u_long *marks, int flags)
72 {
73 	Elf_Shdr *shp;
74 	Elf_Phdr *phdr;
75 	Elf_Off off;
76 	int i;
77 	size_t sz;
78 	int first;
79 	int havesyms;
80 	paddr_t minp = ~0, maxp = 0, pos = 0;
81 	paddr_t offset = marks[MARK_START], shpp, elfp;
82 
83 	sz = elf->e_phnum * sizeof(Elf_Phdr);
84 	phdr = ALLOC(sz);
85 
86 	if (lseek(fd, (off_t)elf->e_phoff, SEEK_SET) == -1)  {
87 		WARN(("lseek phdr"));
88 		FREE(phdr, sz);
89 		return 1;
90 	}
91 	if (read(fd, phdr, sz) != sz) {
92 		WARN(("read program headers"));
93 		FREE(phdr, sz);
94 		return 1;
95 	}
96 
97 	for (first = 1, i = 0; i < elf->e_phnum; i++) {
98 
99 		if (phdr[i].p_type != PT_LOAD ||
100 		    (phdr[i].p_flags & (PF_W|PF_R|PF_X)) == 0)
101 			continue;
102 
103 #define IS_TEXT(p)	(p.p_flags & PF_X)
104 #define IS_DATA(p)	((p.p_flags & PF_X) == 0)
105 #define IS_BSS(p)	(p.p_filesz < p.p_memsz)
106 		/*
107 		 * XXX: Assume first address is lowest
108 		 */
109 		if ((IS_TEXT(phdr[i]) && (flags & LOAD_TEXT)) ||
110 		    (IS_DATA(phdr[i]) && (flags & LOAD_DATA))) {
111 
112 			/* Read in segment. */
113 			PROGRESS(("%s%lu", first ? "" : "+",
114 			    (u_long)phdr[i].p_filesz));
115 
116 			if (lseek(fd, (off_t)phdr[i].p_offset, SEEK_SET) == -1) {
117 				WARN(("lseek text"));
118 				FREE(phdr, sz);
119 				return 1;
120 			}
121 			if (READ(fd, phdr[i].p_paddr, phdr[i].p_filesz) !=
122 			    phdr[i].p_filesz) {
123 				WARN(("read text"));
124 				FREE(phdr, sz);
125 				return 1;
126 			}
127 
128 			first = 0;
129 		}
130 
131 		if ((IS_TEXT(phdr[i]) && (flags & (LOAD_TEXT | COUNT_TEXT))) ||
132 		    (IS_DATA(phdr[i]) && (flags & (LOAD_DATA | COUNT_TEXT)))) {
133 			pos = phdr[i].p_paddr;
134 			if (minp > pos)
135 				minp = pos;
136 			pos += phdr[i].p_filesz;
137 			if (maxp < pos)
138 				maxp = pos;
139 		}
140 
141 		/* Zero out BSS. */
142 		if (IS_BSS(phdr[i]) && (flags & LOAD_BSS)) {
143 			PROGRESS(("+%lu",
144 			    (u_long)(phdr[i].p_memsz - phdr[i].p_filesz)));
145 			BZERO((phdr[i].p_paddr + phdr[i].p_filesz),
146 			    phdr[i].p_memsz - phdr[i].p_filesz);
147 		}
148 		if (IS_BSS(phdr[i]) && (flags & (LOAD_BSS|COUNT_BSS))) {
149 			pos += phdr[i].p_memsz - phdr[i].p_filesz;
150 			if (maxp < pos)
151 				maxp = pos;
152 		}
153 	}
154 	FREE(phdr, sz);
155 
156 	/*
157 	 * Copy the ELF and section headers.
158 	 */
159 	elfp = maxp = roundup(maxp, sizeof(Elf_Addr));
160 	if (flags & (LOAD_HDR | COUNT_HDR))
161 		maxp += sizeof(Elf_Ehdr);
162 
163 	if (flags & (LOAD_SYM | COUNT_SYM)) {
164 		if (lseek(fd, (off_t)elf->e_shoff, SEEK_SET) == -1)  {
165 			WARN(("lseek section headers"));
166 			return 1;
167 		}
168 		sz = elf->e_shnum * sizeof(Elf_Shdr);
169 		shp = ALLOC(sz);
170 
171 		if (read(fd, shp, sz) != sz) {
172 			WARN(("read section headers"));
173 			FREE(shp, sz);
174 			return 1;
175 		}
176 
177 		shpp = maxp;
178 		maxp += roundup(sz, sizeof(Elf_Addr));
179 
180 		/*
181 		 * Now load the symbol sections themselves. Make sure the
182 		 * sections are aligned. Don't bother with string tables if
183 		 * there are no symbol sections.
184 		 */
185 		off = roundup((sizeof(Elf_Ehdr) + sz), sizeof(Elf_Addr));
186 
187 		for (havesyms = i = 0; i < elf->e_shnum; i++)
188 			if (shp[i].sh_type == SHT_SYMTAB)
189 				havesyms = 1;
190 
191 		for (first = 1, i = 0; i < elf->e_shnum; i++) {
192 			if (shp[i].sh_type == SHT_SYMTAB ||
193 			    shp[i].sh_type == SHT_STRTAB) {
194 				if (havesyms && (flags & LOAD_SYM)) {
195 					PROGRESS(("%s%ld", first ? " [" : "+",
196 					    (u_long)shp[i].sh_size));
197 					if (lseek(fd, (off_t)shp[i].sh_offset,
198 					    SEEK_SET) == -1) {
199 						WARN(("lseek symbols"));
200 						FREE(shp, sz);
201 						return 1;
202 					}
203 					if (READ(fd, maxp, shp[i].sh_size) !=
204 					    shp[i].sh_size) {
205 						WARN(("read symbols"));
206 						FREE(shp, sz);
207 						return 1;
208 					}
209 				}
210 				maxp += roundup(shp[i].sh_size,
211 				    sizeof(Elf_Addr));
212 				shp[i].sh_offset = off;
213 				off += roundup(shp[i].sh_size, sizeof(Elf_Addr));
214 				first = 0;
215 			}
216 		}
217 		if (flags & LOAD_SYM) {
218 			BCOPY(shp, shpp, sz);
219 
220 			if (havesyms && first == 0)
221 				PROGRESS(("]"));
222 		}
223 		FREE(shp, sz);
224 	}
225 
226 	/*
227 	 * Frob the copied ELF header to give information relative
228 	 * to elfp.
229 	 */
230 	if (flags & LOAD_HDR) {
231 		elf->e_phoff = 0;
232 		elf->e_shoff = sizeof(Elf_Ehdr);
233 		elf->e_phentsize = 0;
234 		elf->e_phnum = 0;
235 		BCOPY(elf, elfp, sizeof(*elf));
236 	}
237 
238 	marks[MARK_START] = LOADADDR(minp);
239 	marks[MARK_ENTRY] = LOADADDR(elf->e_entry);
240 	marks[MARK_NSYM] = 1;	/* XXX: Kernel needs >= 0 */
241 	marks[MARK_SYM] = LOADADDR(elfp);
242 	marks[MARK_END] = LOADADDR(maxp);
243 
244 	return 0;
245 }
246