1 a84cbb2a 2004-04-19 devnull #include <u.h>
  2 a84cbb2a 2004-04-19 devnull #include <libc.h>
  3 a84cbb2a 2004-04-19 devnull #include <mach.h>
  4 a84cbb2a 2004-04-19 devnull #include "elf.h"
  5 a84cbb2a 2004-04-19 devnull #include "dwarf.h"
  6 a84cbb2a 2004-04-19 devnull 
  7 443d6288 2012-02-19 rsc static int mapelf(Fhdr *fp, u64int base, Map *map, Regs**);
  8 dd944ec7 2005-01-23 devnull static int unpacknote(Elf *elf, uchar *a, uchar *ea, ElfNote *note, uchar **pa);
  9 a84cbb2a 2004-04-19 devnull 
 10 a84cbb2a 2004-04-19 devnull static struct
 11 a84cbb2a 2004-04-19 devnull {
 12 a84cbb2a 2004-04-19 devnull 	uint etype;
 13 a84cbb2a 2004-04-19 devnull 	uint mtype;
 14 a84cbb2a 2004-04-19 devnull 	Mach *mach;
 15 a84cbb2a 2004-04-19 devnull 	char *name;
 16 fa325e9b 2020-01-10 cross } mtab[] =
 17 a84cbb2a 2004-04-19 devnull {	/* Font Tab 4 */
 18 a84cbb2a 2004-04-19 devnull 	ElfMachSparc,	MSPARC,		nil,		"sparc",
 19 a84cbb2a 2004-04-19 devnull 	ElfMach386,		M386,		&mach386,	"386",
 20 a84cbb2a 2004-04-19 devnull 	ElfMachMips,	MMIPS,		nil,		"mips",
 21 a84cbb2a 2004-04-19 devnull 	ElfMachArm,		MARM,		nil,		"arm",
 22 a84cbb2a 2004-04-19 devnull 	ElfMachPower,	MPOWER,		nil,		"powerpc",
 23 a84cbb2a 2004-04-19 devnull 	ElfMachPower64,	MNONE,		nil,		"powerpc64",
 24 443d6288 2012-02-19 rsc 	ElfMachAmd64,	MAMD64,	&machamd64,	"amd64",
 25 a84cbb2a 2004-04-19 devnull };
 26 a84cbb2a 2004-04-19 devnull 
 27 a84cbb2a 2004-04-19 devnull static struct
 28 a84cbb2a 2004-04-19 devnull {
 29 a84cbb2a 2004-04-19 devnull 	uint etype;
 30 a84cbb2a 2004-04-19 devnull 	uint atype;
 31 a84cbb2a 2004-04-19 devnull 	char *aname;
 32 fa325e9b 2020-01-10 cross } atab[] =
 33 a84cbb2a 2004-04-19 devnull {	/* Font Tab 4 */
 34 a84cbb2a 2004-04-19 devnull 	ElfAbiSystemV,	ALINUX,		"linux",	/* [sic] */
 35 a84cbb2a 2004-04-19 devnull 	ElfAbiLinux,	ALINUX,		"linux",
 36 a84cbb2a 2004-04-19 devnull 	ElfAbiFreeBSD,	AFREEBSD,	"freebsd",
 37 a84cbb2a 2004-04-19 devnull };
 38 a84cbb2a 2004-04-19 devnull 
 39 a84cbb2a 2004-04-19 devnull static struct
 40 a84cbb2a 2004-04-19 devnull {
 41 a84cbb2a 2004-04-19 devnull 	uint mtype;
 42 a84cbb2a 2004-04-19 devnull 	uint atype;
 43 dd944ec7 2005-01-23 devnull 	void (*elfcore)(Fhdr*, Elf*, ElfNote*);
 44 fa325e9b 2020-01-10 cross } ctab[] =
 45 a84cbb2a 2004-04-19 devnull {	/* Font Tab 4 */
 46 dd944ec7 2005-01-23 devnull 	M386,		ALINUX,		elfcorelinux386,
 47 dd944ec7 2005-01-23 devnull 	M386,		ANONE,		elfcorelinux386,	/* [sic] */
 48 443d6288 2012-02-19 rsc //	M386,		AFREEBSD,	elfcorefreebsd386,
 49 443d6288 2012-02-19 rsc 	MAMD64,		AFREEBSD,	elfcorefreebsdamd64,
 50 a84cbb2a 2004-04-19 devnull };
 51 a84cbb2a 2004-04-19 devnull 
 52 a84cbb2a 2004-04-19 devnull int
 53 a84cbb2a 2004-04-19 devnull crackelf(int fd, Fhdr *fp)
 54 a84cbb2a 2004-04-19 devnull {
 55 dd944ec7 2005-01-23 devnull 	uchar *a, *sa, *ea;
 56 dd944ec7 2005-01-23 devnull 	int i, havetext, havedata, n;
 57 a84cbb2a 2004-04-19 devnull 	Elf *elf;
 58 dd944ec7 2005-01-23 devnull 	ElfNote note;
 59 a84cbb2a 2004-04-19 devnull 	ElfProg *p;
 60 a84cbb2a 2004-04-19 devnull 	ElfSect *s1, *s2;
 61 dd944ec7 2005-01-23 devnull 	void (*elfcore)(Fhdr*, Elf*, ElfNote*);
 62 a84cbb2a 2004-04-19 devnull 
 63 a84cbb2a 2004-04-19 devnull 	if((elf = elfinit(fd)) == nil)
 64 a84cbb2a 2004-04-19 devnull 		return -1;
 65 a84cbb2a 2004-04-19 devnull 
 66 a84cbb2a 2004-04-19 devnull 	fp->fd = fd;
 67 a84cbb2a 2004-04-19 devnull 	fp->elf = elf;
 68 a84cbb2a 2004-04-19 devnull 	fp->dwarf = dwarfopen(elf);	/* okay to fail */
 69 a84cbb2a 2004-04-19 devnull 	fp->syminit = symelf;
 70 a84cbb2a 2004-04-19 devnull 
 71 a84cbb2a 2004-04-19 devnull 	if((s1 = elfsection(elf, ".stab")) != nil && s1->link!=0 && s1->link < elf->nsect){
 72 a84cbb2a 2004-04-19 devnull 		s2 = &elf->sect[s1->link];
 73 a84cbb2a 2004-04-19 devnull 		if(elfmap(elf, s1) >= 0 && elfmap(elf, s2) >= 0){
 74 a84cbb2a 2004-04-19 devnull 			fp->stabs.stabbase = s1->base;
 75 a84cbb2a 2004-04-19 devnull 			fp->stabs.stabsize = s1->size;
 76 929ba9b9 2004-04-20 devnull 			fp->stabs.strbase = (char*)s2->base;
 77 a84cbb2a 2004-04-19 devnull 			fp->stabs.strsize = s2->size;
 78 a84cbb2a 2004-04-19 devnull 			fp->stabs.e2 = elf->hdr.e2;
 79 a84cbb2a 2004-04-19 devnull 			fp->stabs.e4 = elf->hdr.e4;
 80 a84cbb2a 2004-04-19 devnull 		}
 81 a84cbb2a 2004-04-19 devnull 	}
 82 a84cbb2a 2004-04-19 devnull 
 83 a84cbb2a 2004-04-19 devnull 	for(i=0; i<nelem(mtab); i++){
 84 a84cbb2a 2004-04-19 devnull 		if(elf->hdr.machine != mtab[i].etype)
 85 a84cbb2a 2004-04-19 devnull 			continue;
 86 a84cbb2a 2004-04-19 devnull 		fp->mach = mtab[i].mach;
 87 a84cbb2a 2004-04-19 devnull 		fp->mname = mtab[i].name;
 88 a84cbb2a 2004-04-19 devnull 		fp->mtype = mtab[i].mtype;
 89 a84cbb2a 2004-04-19 devnull 		break;
 90 a84cbb2a 2004-04-19 devnull 	}
 91 a84cbb2a 2004-04-19 devnull 	if(i == nelem(mtab)){
 92 a84cbb2a 2004-04-19 devnull 		werrstr("unsupported machine type %d", elf->hdr.machine);
 93 a84cbb2a 2004-04-19 devnull 		goto err;
 94 a84cbb2a 2004-04-19 devnull 	}
 95 a84cbb2a 2004-04-19 devnull 
 96 a84cbb2a 2004-04-19 devnull 	if(mach == nil)
 97 a84cbb2a 2004-04-19 devnull 		mach = fp->mach;
 98 a84cbb2a 2004-04-19 devnull 
 99 a84cbb2a 2004-04-19 devnull 	fp->aname = "unknown";
100 a84cbb2a 2004-04-19 devnull 	for(i=0; i<nelem(atab); i++){
101 a84cbb2a 2004-04-19 devnull 		if(elf->hdr.abi != atab[i].etype)
102 a84cbb2a 2004-04-19 devnull 			continue;
103 a84cbb2a 2004-04-19 devnull 		fp->atype = atab[i].atype;
104 a84cbb2a 2004-04-19 devnull 		fp->aname = atab[i].aname;
105 a84cbb2a 2004-04-19 devnull 		break;
106 a84cbb2a 2004-04-19 devnull 	}
107 a84cbb2a 2004-04-19 devnull 
108 a84cbb2a 2004-04-19 devnull 	switch(elf->hdr.type){
109 a84cbb2a 2004-04-19 devnull 	default:
110 a84cbb2a 2004-04-19 devnull 		werrstr("unknown file type %d", elf->hdr.type);
111 a84cbb2a 2004-04-19 devnull 		goto err;
112 a84cbb2a 2004-04-19 devnull 	case ElfTypeExecutable:
113 a84cbb2a 2004-04-19 devnull 		fp->ftype = FEXEC;
114 a84cbb2a 2004-04-19 devnull 		fp->fname = "executable";
115 a84cbb2a 2004-04-19 devnull 		break;
116 a84cbb2a 2004-04-19 devnull 	case ElfTypeRelocatable:
117 a84cbb2a 2004-04-19 devnull 		fp->ftype = FRELOC;
118 a84cbb2a 2004-04-19 devnull 		fp->fname = "relocatable";
119 a84cbb2a 2004-04-19 devnull 		break;
120 a84cbb2a 2004-04-19 devnull 	case ElfTypeSharedObject:
121 a84cbb2a 2004-04-19 devnull 		fp->ftype = FSHOBJ;
122 a84cbb2a 2004-04-19 devnull 		fp->fname = "shared object";
123 a84cbb2a 2004-04-19 devnull 		break;
124 a84cbb2a 2004-04-19 devnull 	case ElfTypeCore:
125 a84cbb2a 2004-04-19 devnull 		fp->ftype = FCORE;
126 a84cbb2a 2004-04-19 devnull 		fp->fname = "core dump";
127 a84cbb2a 2004-04-19 devnull 		break;
128 a84cbb2a 2004-04-19 devnull 	}
129 a84cbb2a 2004-04-19 devnull 
130 a84cbb2a 2004-04-19 devnull 	fp->map = mapelf;
131 a84cbb2a 2004-04-19 devnull 
132 a84cbb2a 2004-04-19 devnull 	if(fp->ftype == FCORE){
133 dd944ec7 2005-01-23 devnull 		elfcore = nil;
134 a84cbb2a 2004-04-19 devnull 		for(i=0; i<nelem(ctab); i++){
135 a84cbb2a 2004-04-19 devnull 			if(ctab[i].atype != fp->atype
136 a84cbb2a 2004-04-19 devnull 			|| ctab[i].mtype != fp->mtype)
137 a84cbb2a 2004-04-19 devnull 				continue;
138 dd944ec7 2005-01-23 devnull 			elfcore = ctab[i].elfcore;
139 a84cbb2a 2004-04-19 devnull 			break;
140 a84cbb2a 2004-04-19 devnull 		}
141 dd944ec7 2005-01-23 devnull 		if(elfcore)
142 dd944ec7 2005-01-23 devnull 		for(i=0; i<elf->nprog; i++){
143 dd944ec7 2005-01-23 devnull 			p = &elf->prog[i];
144 dd944ec7 2005-01-23 devnull 			if(p->type != ElfProgNote)
145 dd944ec7 2005-01-23 devnull 				continue;
146 dd944ec7 2005-01-23 devnull 			n = p->filesz;
147 dd944ec7 2005-01-23 devnull 			a = malloc(n);
148 dd944ec7 2005-01-23 devnull 			if(a == nil)
149 dd944ec7 2005-01-23 devnull 				goto err;
150 dd944ec7 2005-01-23 devnull 			if(seek(fp->fd, p->offset, 0) < 0 || readn(fp->fd, a, n) != n){
151 dd944ec7 2005-01-23 devnull 				free(a);
152 dd944ec7 2005-01-23 devnull 				continue;
153 dd944ec7 2005-01-23 devnull 			}
154 dd944ec7 2005-01-23 devnull 			sa = a;
155 dd944ec7 2005-01-23 devnull 			ea = a+n;
156 dd944ec7 2005-01-23 devnull 			while(a < ea){
157 dd944ec7 2005-01-23 devnull 				note.offset = (a-sa) + p->offset;
158 dd944ec7 2005-01-23 devnull 				if(unpacknote(elf, a, ea, &note, &a) < 0)
159 dd944ec7 2005-01-23 devnull 					break;
160 dd944ec7 2005-01-23 devnull 				elfcore(fp, elf, &note);
161 dd944ec7 2005-01-23 devnull 			}
162 dd944ec7 2005-01-23 devnull 			free(sa);
163 dd944ec7 2005-01-23 devnull 		}
164 a84cbb2a 2004-04-19 devnull 		return 0;
165 a84cbb2a 2004-04-19 devnull 	}
166 a84cbb2a 2004-04-19 devnull 
167 a84cbb2a 2004-04-19 devnull 	fp->entry = elf->hdr.entry;
168 a84cbb2a 2004-04-19 devnull 
169 a84cbb2a 2004-04-19 devnull 	/* First r-x section we find is the text and initialized data */
170 a84cbb2a 2004-04-19 devnull 	/* First rw- section we find is the r/w data */
171 a84cbb2a 2004-04-19 devnull 	havetext = 0;
172 a84cbb2a 2004-04-19 devnull 	havedata = 0;
173 a84cbb2a 2004-04-19 devnull 	for(i=0; i<elf->nprog; i++){
174 a84cbb2a 2004-04-19 devnull 		p = &elf->prog[i];
175 a84cbb2a 2004-04-19 devnull 		if(p->type != ElfProgLoad)
176 a84cbb2a 2004-04-19 devnull 			continue;
177 a84cbb2a 2004-04-19 devnull 		if(!havetext && p->flags == (ElfProgFlagRead|ElfProgFlagExec) && p->align >= mach->pgsize){
178 a84cbb2a 2004-04-19 devnull 			havetext = 1;
179 a84cbb2a 2004-04-19 devnull 			fp->txtaddr = p->vaddr;
180 a84cbb2a 2004-04-19 devnull 			fp->txtsz = p->memsz;
181 a84cbb2a 2004-04-19 devnull 			fp->txtoff = p->offset;
182 a84cbb2a 2004-04-19 devnull 		}
183 a84cbb2a 2004-04-19 devnull 		if(!havedata && p->flags == (ElfProgFlagRead|ElfProgFlagWrite) && p->align >= mach->pgsize){
184 a84cbb2a 2004-04-19 devnull 			havedata = 1;
185 a84cbb2a 2004-04-19 devnull 			fp->dataddr = p->vaddr;
186 a84cbb2a 2004-04-19 devnull 			fp->datsz = p->filesz;
187 a84cbb2a 2004-04-19 devnull 			fp->datoff = p->offset;
188 a84cbb2a 2004-04-19 devnull 			fp->bsssz = p->memsz - p->filesz;
189 a84cbb2a 2004-04-19 devnull 		}
190 a84cbb2a 2004-04-19 devnull 	}
191 a84cbb2a 2004-04-19 devnull 	if(!havetext){
192 a84cbb2a 2004-04-19 devnull 		werrstr("did not find text segment in elf binary");
193 a84cbb2a 2004-04-19 devnull 		goto err;
194 a84cbb2a 2004-04-19 devnull 	}
195 a84cbb2a 2004-04-19 devnull 	if(!havedata){
196 a84cbb2a 2004-04-19 devnull 		werrstr("did not find data segment in elf binary");
197 a84cbb2a 2004-04-19 devnull 		goto err;
198 a84cbb2a 2004-04-19 devnull 	}
199 a84cbb2a 2004-04-19 devnull 	return 0;
200 a84cbb2a 2004-04-19 devnull 
201 a84cbb2a 2004-04-19 devnull err:
202 a84cbb2a 2004-04-19 devnull 	elfclose(elf);
203 a84cbb2a 2004-04-19 devnull 	return -1;
204 a84cbb2a 2004-04-19 devnull }
205 a84cbb2a 2004-04-19 devnull 
206 a84cbb2a 2004-04-19 devnull static int
207 443d6288 2012-02-19 rsc mapelf(Fhdr *fp, u64int base, Map *map, Regs **regs)
208 a84cbb2a 2004-04-19 devnull {
209 a84cbb2a 2004-04-19 devnull 	int i;
210 a84cbb2a 2004-04-19 devnull 	Elf *elf;
211 a84cbb2a 2004-04-19 devnull 	ElfProg *p;
212 443d6288 2012-02-19 rsc 	u64int sz;
213 443d6288 2012-02-19 rsc 	u64int lim;
214 a84cbb2a 2004-04-19 devnull 	Seg s;
215 a84cbb2a 2004-04-19 devnull 
216 a84cbb2a 2004-04-19 devnull 	elf = fp->elf;
217 a84cbb2a 2004-04-19 devnull 	if(elf == nil){
218 a84cbb2a 2004-04-19 devnull 		werrstr("not an elf file");
219 a84cbb2a 2004-04-19 devnull 		return -1;
220 a84cbb2a 2004-04-19 devnull 	}
221 a84cbb2a 2004-04-19 devnull 
222 a84cbb2a 2004-04-19 devnull 	for(i=0; i<elf->nprog; i++){
223 a84cbb2a 2004-04-19 devnull 		p = &elf->prog[i];
224 a84cbb2a 2004-04-19 devnull 		if(p->type != ElfProgLoad)
225 a84cbb2a 2004-04-19 devnull 			continue;
226 a84cbb2a 2004-04-19 devnull 		if(p->align < mach->pgsize)
227 a84cbb2a 2004-04-19 devnull 			continue;
228 a84cbb2a 2004-04-19 devnull 		if(p->filesz){
229 a84cbb2a 2004-04-19 devnull 			memset(&s, 0, sizeof s);
230 a84cbb2a 2004-04-19 devnull 			s.file = fp->filename;
231 a84cbb2a 2004-04-19 devnull 			s.fd = fp->fd;
232 a84cbb2a 2004-04-19 devnull 			if(fp->ftype == FCORE)
233 a84cbb2a 2004-04-19 devnull 				s.name = "core";
234 a84cbb2a 2004-04-19 devnull 			else if(p->flags == 5)
235 a84cbb2a 2004-04-19 devnull 				s.name = "text";
236 a84cbb2a 2004-04-19 devnull 			else
237 a84cbb2a 2004-04-19 devnull 				s.name = "data";
238 a84cbb2a 2004-04-19 devnull 			s.base = base+p->vaddr;
239 a84cbb2a 2004-04-19 devnull 			s.size = p->filesz;
240 a84cbb2a 2004-04-19 devnull 			s.offset = p->offset;
241 a84cbb2a 2004-04-19 devnull 			if(addseg(map, s) < 0)
242 a84cbb2a 2004-04-19 devnull 				return -1;
243 a84cbb2a 2004-04-19 devnull 		}
244 a84cbb2a 2004-04-19 devnull 		/*
245 a84cbb2a 2004-04-19 devnull 		 * If memsz > filesz, we're supposed to zero fill.
246 a84cbb2a 2004-04-19 devnull 		 * Core files have zeroed sections where the pages
247 a84cbb2a 2004-04-19 devnull 		 * can be filled in from the text file, so if this is a core
248 a84cbb2a 2004-04-19 devnull 		 * we only fill in that which isn't yet mapped.
249 a84cbb2a 2004-04-19 devnull 		 */
250 a84cbb2a 2004-04-19 devnull 		if(fp->ftype == FCORE){
251 a84cbb2a 2004-04-19 devnull 			sz = p->filesz;
252 a84cbb2a 2004-04-19 devnull 			while(sz < p->memsz){
253 a84cbb2a 2004-04-19 devnull 				if(addrtoseg(map, base+p->vaddr+sz, &s) < 0){
254 a84cbb2a 2004-04-19 devnull 					lim = base + p->vaddr + p->memsz;
255 a84cbb2a 2004-04-19 devnull 					if(addrtosegafter(map, base+p->vaddr+sz, &s) >= 0 && s.base < lim)
256 a84cbb2a 2004-04-19 devnull 						lim = s.base;
257 a84cbb2a 2004-04-19 devnull 					memset(&s, 0, sizeof s);
258 a84cbb2a 2004-04-19 devnull 					s.name = "zero";
259 a84cbb2a 2004-04-19 devnull 					s.base = base + p->vaddr + sz;
260 a84cbb2a 2004-04-19 devnull 					s.size = lim - s.base;
261 a84cbb2a 2004-04-19 devnull 					s.offset = p->offset;
262 a84cbb2a 2004-04-19 devnull 					if(addseg(map, s) < 0)
263 a84cbb2a 2004-04-19 devnull 						return -1;
264 a84cbb2a 2004-04-19 devnull 				}else
265 a84cbb2a 2004-04-19 devnull 					sz = (s.base+s.size) - (base + p->vaddr);
266 a84cbb2a 2004-04-19 devnull 			}
267 a84cbb2a 2004-04-19 devnull 		}else{
268 a84cbb2a 2004-04-19 devnull 			if(p->filesz < p->memsz){
269 a84cbb2a 2004-04-19 devnull 				memset(&s, 0, sizeof s);
270 a84cbb2a 2004-04-19 devnull 				s.name = "zero";
271 a84cbb2a 2004-04-19 devnull 				s.base = base + p->vaddr + p->filesz;
272 a84cbb2a 2004-04-19 devnull 				s.size = p->memsz - p->filesz;
273 a84cbb2a 2004-04-19 devnull 				if(addseg(map, s) < 0)
274 a84cbb2a 2004-04-19 devnull 					return -1;
275 a84cbb2a 2004-04-19 devnull 			}
276 fa325e9b 2020-01-10 cross 		}
277 a84cbb2a 2004-04-19 devnull 	}
278 a84cbb2a 2004-04-19 devnull 
279 dd944ec7 2005-01-23 devnull 	if(fp->nthread && regs)
280 dd944ec7 2005-01-23 devnull 		*regs = coreregs(fp, fp->thread[0].id);
281 a84cbb2a 2004-04-19 devnull 
282 fa325e9b 2020-01-10 cross 	return 0;
283 a84cbb2a 2004-04-19 devnull }
284 a84cbb2a 2004-04-19 devnull 
285 a84cbb2a 2004-04-19 devnull static int
286 a84cbb2a 2004-04-19 devnull unpacknote(Elf *elf, uchar *a, uchar *ea, ElfNote *note, uchar **pa)
287 a84cbb2a 2004-04-19 devnull {
288 a84cbb2a 2004-04-19 devnull 	if(a+12 > ea)
289 a84cbb2a 2004-04-19 devnull 		return -1;
290 a84cbb2a 2004-04-19 devnull 	note->namesz = elf->hdr.e4(a);
291 a84cbb2a 2004-04-19 devnull 	note->descsz = elf->hdr.e4(a+4);
292 a84cbb2a 2004-04-19 devnull 	note->type = elf->hdr.e4(a+8);
293 a84cbb2a 2004-04-19 devnull 	a += 12;
294 a84cbb2a 2004-04-19 devnull 	note->name = (char*)a;
295 a84cbb2a 2004-04-19 devnull /* XXX fetch alignment constants from elsewhere */
296 a84cbb2a 2004-04-19 devnull 	a += (note->namesz+3)&~3;
297 a84cbb2a 2004-04-19 devnull 	note->desc = (uchar*)a;
298 a84cbb2a 2004-04-19 devnull 	a += (note->descsz+3)&~3;
299 a84cbb2a 2004-04-19 devnull 	if(a > ea)
300 a84cbb2a 2004-04-19 devnull 		return -1;
301 a84cbb2a 2004-04-19 devnull 	*pa = a;
302 a84cbb2a 2004-04-19 devnull 	return 0;
303 a84cbb2a 2004-04-19 devnull }