2 * Copyright (c) 2003-2004 The Regents of The University of Michigan
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 // Because of the -Wundef flag we have to do this
32 #define __LIBELF_INTERNAL__ 0
33 // counterintuitive, but the flag below causes libelf to define
34 // 64-bit elf types that apparently didn't exist in some older
35 // versions of Linux. They seem to be there in 2.4.x, so don't
36 // set this now (it causes things to break on 64-bit platforms).
37 #define __LIBELF64_LINUX 0
38 #define __LIBELF_NEED_LINK_H 0
39 #define __LIBELF_SYMBOL_VERSIONS 0
41 #include <libelf/libelf.h>
42 #include <libelf/gelf.h>
44 #include "base/loader/elf_object.hh"
46 #include "mem/functional/functional.hh"
47 #include "base/loader/symtab.hh"
49 #include "base/trace.hh" // for DPRINTF
55 ElfObject::tryFile(const string
&fname
, int fd
, size_t len
, uint8_t *data
)
60 // check that header matches library version
61 if (elf_version(EV_CURRENT
) == EV_NONE
)
62 panic("wrong elf version number!");
64 // get a pointer to elf structure
65 elf
= elf_memory((char*)data
,len
);
66 // will only fail if fd is invalid
69 // Check that we actually have a elf file
70 if (gelf_getehdr(elf
, &ehdr
) ==0) {
71 DPRINTFR(Loader
, "Not ELF\n");
76 if (ehdr
.e_ident
[EI_CLASS
] == ELFCLASS32
)
77 panic("32 bit ELF Binary, Not Supported");
78 /* @todo this emachine value isn't offical yet.
79 * so we probably shouldn't check it. */
80 // if (ehdr.e_machine != EM_ALPHA)
81 // panic("Non Alpha Binary, Not Supported");
85 return new ElfObject(fname
, fd
, len
, data
,
86 ObjectFile::Alpha
, ObjectFile::Linux
);
91 ElfObject::ElfObject(const string
&_filename
, int _fd
,
92 size_t _len
, uint8_t *_data
,
93 Arch _arch
, OpSys _opSys
)
94 : ObjectFile(_filename
, _fd
, _len
, _data
, _arch
, _opSys
)
100 // check that header matches library version
101 if (elf_version(EV_CURRENT
) == EV_NONE
)
102 panic("wrong elf version number!");
104 // get a pointer to elf structure
105 elf
= elf_memory((char*)fileData
,len
);
106 // will only fail if fd is invalid
109 // Check that we actually have a elf file
110 if (gelf_getehdr(elf
, &ehdr
) ==0) {
111 panic("Not ELF, shouldn't be here");
114 entry
= ehdr
.e_entry
;
116 // initialize segment sizes to 0 in case they're not present
117 text
.size
= data
.size
= bss
.size
= 0;
119 for (int i
= 0; i
< ehdr
.e_phnum
; ++i
) {
121 if (gelf_getphdr(elf
, i
, &phdr
) == 0) {
122 panic("gelf_getphdr failed for section %d", i
);
125 // for now we don't care about non-loadable segments
126 if (!(phdr
.p_type
& PT_LOAD
))
129 // the headers don't explicitly distinguish text from data,
130 // but empirically the text segment comes first.
131 if (text
.size
== 0) { // haven't seen text segment yet
132 text
.baseAddr
= phdr
.p_vaddr
;
133 text
.size
= phdr
.p_filesz
;
134 // remember where the data is for loadSections()
135 fileTextBits
= fileData
+ phdr
.p_offset
;
136 // if there's any padding at the end that's not in the
137 // file, call it the bss. This happens in the "text"
138 // segment if there's only one loadable segment (as for
140 bss
.size
= phdr
.p_memsz
- phdr
.p_filesz
;
141 bss
.baseAddr
= phdr
.p_vaddr
+ phdr
.p_filesz
;
143 else if (data
.size
== 0) { // have text, this must be data
144 data
.baseAddr
= phdr
.p_vaddr
;
145 data
.size
= phdr
.p_filesz
;
146 // remember where the data is for loadSections()
147 fileDataBits
= fileData
+ phdr
.p_offset
;
148 // if there's any padding at the end that's not in the
149 // file, call it the bss. Warn if this happens for both
150 // the text & data segments (should only have one bss).
151 if (phdr
.p_memsz
- phdr
.p_filesz
> 0 && bss
.size
!= 0) {
152 warn("Two implied bss segments in file!\n");
154 bss
.size
= phdr
.p_memsz
- phdr
.p_filesz
;
155 bss
.baseAddr
= phdr
.p_vaddr
+ phdr
.p_filesz
;
159 // should have found at least one loadable segment
160 assert(text
.size
!= 0);
162 DPRINTFR(Loader
, "text: 0x%x %d\ndata: 0x%x %d\nbss: 0x%x %d\n",
163 text
.baseAddr
, text
.size
, data
.baseAddr
, data
.size
,
164 bss
.baseAddr
, bss
.size
);
168 // We will actually read the sections when we need to load them
173 ElfObject::loadSections(FunctionalMemory
*mem
, bool loadPhys
)
175 Addr textAddr
= text
.baseAddr
;
176 Addr dataAddr
= data
.baseAddr
;
179 textAddr
&= (ULL(1) << 40) - 1;
180 dataAddr
&= (ULL(1) << 40) - 1;
183 // Since we don't really have an MMU and all memory is
184 // zero-filled, there's no need to set up the BSS segment.
186 mem
->prot_write(textAddr
, fileTextBits
, text
.size
);
188 mem
->prot_write(dataAddr
, fileDataBits
, data
.size
);
195 ElfObject::loadSomeSymbols(SymbolTable
*symtab
, int binding
)
198 int sec_idx
= 1; // there is a 0 but it is nothing, go figure
209 // check that header matches library version
210 if (elf_version(EV_CURRENT
) == EV_NONE
)
211 panic("wrong elf version number!");
213 // get a pointer to elf structure
214 elf
= elf_memory((char*)fileData
,len
);
218 // Get the first section
219 section
= elf_getscn(elf
, sec_idx
);
221 // While there are no more sections
222 while (section
!= NULL
) {
223 gelf_getshdr(section
, &shdr
);
225 if (shdr
.sh_type
== SHT_SYMTAB
) {
227 data
= elf_getdata(section
, NULL
);
228 count
= shdr
.sh_size
/ shdr
.sh_entsize
;
229 DPRINTF(Loader
, "Found Symbol Table, %d symbols present\n", count
);
231 // loop through all the symbols, only loading global ones
232 for (ii
= 0; ii
< count
; ++ii
) {
233 gelf_getsym(data
, ii
, &sym
);
234 if (GELF_ST_BIND(sym
.st_info
) == binding
) {
235 symtab
->insert(sym
.st_value
,
236 elf_strptr(elf
, shdr
.sh_link
, sym
.st_name
));
241 section
= elf_getscn(elf
, sec_idx
);
250 ElfObject::loadGlobalSymbols(SymbolTable
*symtab
)
252 return loadSomeSymbols(symtab
, STB_GLOBAL
);
256 ElfObject::loadLocalSymbols(SymbolTable
*symtab
)
258 return loadSomeSymbols(symtab
, STB_LOCAL
);