1 #include <u.h>
2 #include <libc.h>
3 #include <mach.h>
4 #include "macho.h"
5 
6 static int mapmacho(Fhdr *fp, u64int base, Map *map, Regs**);
7 
8 static struct
9 {
10 	uint etype;
11 	uint mtype;
12 	Mach *mach;
13 	char *name;
14 	int (*coreregs)(Macho*, uchar**);
15 } mtab[] =
16 {
17 	MachoCpuPower,	MPOWER,		&machpower, 		"powerpc",	coreregsmachopower,
18 };
19 
20 static uchar*
21 load(int fd, ulong off, int size)
22 {
23 	uchar *a;
24 
25 	a = malloc(size);
26 	if(a == nil)
27 		return nil;
28 	if(seek(fd, off, 0) < 0 || readn(fd, a, size) != size){
29 		free(a);
30 		return nil;
31 	}
32 	return a;
33 }
34 
35 int
36 crackmacho(int fd, Fhdr *fp)
37 {
38 	int i;
39 	Macho *m;
40 
41 	if((m = machoinit(fd)) == nil)
42 		return -1;
43 
44 	fp->fd = fd;
45 	fp->macho = m;
46 
47 	for(i=0; i<nelem(mtab); i++){
48 		if(m->cputype != mtab[i].etype)
49 			continue;
50 		fp->mach = mtab[i].mach;
51 		fp->mtype = mtab[i].mtype;
52 		fp->mname = mtab[i].name;
53 		m->coreregs = mtab[i].coreregs;
54 		break;
55 	}
56 	if(i == nelem(mtab)){
57 		werrstr("unsupported cpu type %ud", m->cputype);
58 		goto err;
59 	}
60 
61 	fp->atype = AMACH;
62 	fp->aname = "mach";
63 
64 	if(mach == nil)
65 		mach = fp->mach;
66 
67 	switch(m->filetype){
68 	default:
69 		werrstr("unsupported macho file type %lud", m->filetype);
70 		goto err;
71 	case MachoFileObject:
72 		fp->ftype = FOBJ;
73 		fp->fname = "object";
74 		break;
75 	case MachoFileExecutable:
76 		fp->ftype = FEXEC;
77 		fp->fname = "executable";
78 		break;
79 	case MachoFileFvmlib:
80 		fp->ftype = FSHLIB;
81 		fp->fname = "shared library";
82 		break;
83 	case MachoFileCore:
84 		fp->ftype = FCORE;
85 		fp->fname = "core";
86 		break;
87 	case MachoFilePreload:
88 		fp->ftype = FBOOT;
89 		fp->fname = "preloaded executable";
90 		break;
91 	}
92 
93 	fp->txtaddr = fp->dataddr = 0;
94 	fp->txtsz = fp->datsz = 0;
95 	for(i=0; i<m->ncmd; i++){
96 		if(m->cmd[i].type != MachoCmdSegment)
97 			continue;
98 		if(strcmp(m->cmd[i].seg.name, "__TEXT") == 0){
99 			fp->txtaddr = m->cmd[i].seg.vmaddr;
100 			fp->txtsz = m->cmd[i].seg.vmsize;
101 			fp->txtoff = m->cmd[i].seg.fileoff;
102 		}
103 		if(strcmp(m->cmd[i].seg.name, "__DATA") == 0){
104 			fp->dataddr = m->cmd[i].seg.vmaddr;
105 			fp->datsz = m->cmd[i].seg.filesz;
106 			fp->datoff = m->cmd[i].seg.fileoff;
107 			fp->bsssz = m->cmd[i].seg.vmsize - fp->datsz;
108 		}
109 	}
110 
111 	fp->map = mapmacho;
112 	fp->syminit = symmacho;
113 
114 	for(i=0; i<m->ncmd; i++)
115 		if(m->cmd[i].type == MachoCmdSymtab)
116 			break;
117 	if(i < m->ncmd){
118 		fp->stabs.stabbase = load(fp->fd, m->cmd[i].sym.symoff, m->cmd[i].sym.nsym*16);
119 		fp->stabs.stabsize = m->cmd[i].sym.nsym*16;
120 		fp->stabs.strbase = (char*)load(fp->fd, m->cmd[i].sym.stroff, m->cmd[i].sym.strsize);
121 		if(fp->stabs.stabbase == nil || fp->stabs.strbase == nil){
122 			fp->stabs.stabbase = nil;
123 			fp->stabs.strbase = nil;
124 		}else{
125 			fp->stabs.strsize = m->cmd[i].sym.strsize;
126 			fp->stabs.e2 = (m->e4==beload4 ? beload2 : leload2);
127 			fp->stabs.e4 = m->e4;
128 		}
129 	}
130 
131 	return 0;
132 
133 err:
134 	machoclose(m);
135 	return -1;
136 }
137 
138 static int
139 mapmacho(Fhdr *fp, u64int base, Map *map, Regs **rp)
140 {
141 	int i, n;
142 	uchar *u;
143 	Macho *m;
144 	MachoCmd *c;
145 	Seg s;
146 	UregRegs *r;
147 
148 	m = fp->macho;
149 	if(m == nil){
150 		werrstr("not a macho file");
151 		return -1;
152 	}
153 
154 	for(i=0; i<m->ncmd; i++){
155 		c = &m->cmd[i];
156 		if(c->type != MachoCmdSegment)
157 			continue;
158 		if(c->seg.filesz){
159 			memset(&s, 0, sizeof s);
160 			s.file = fp->filename;
161 			s.fd = fp->fd;
162 			if(fp->ftype == FCORE)
163 				s.name = "core";
164 			else if(strcmp(c->seg.name, "__DATA") == 0)
165 				s.name = "data";
166 			else
167 				s.name = "text";
168 			s.base = base+c->seg.vmaddr;
169 			s.size = c->seg.filesz;
170 			s.offset = c->seg.fileoff;
171 			if(addseg(map, s) < 0)
172 				return -1;
173 		}
174 		if(c->seg.filesz < c->seg.vmsize){
175 			memset(&s, 0, sizeof s);
176 			s.name = "zero";
177 			s.base = base + c->seg.vmaddr + c->seg.filesz;
178 			s.size = c->seg.vmsize - c->seg.filesz;
179 			if(addseg(map, s) < 0)
180 				return -1;
181 		}
182 	}
183 
184 	if(fp->ftype == FCORE && m->coreregs){
185 		n = m->coreregs(m, &u);
186 		if(n < 0){
187 			fprint(2, "mapping registers: %r\n");
188 			goto noregs;
189 		}
190 		if((r = mallocz(sizeof *r, 1)) == nil)
191 			return -1;
192 		r->r.rw = _uregrw;
193 		r->ureg = u;
194 		*rp = &r->r;
195 	}
196 noregs:
197 	return 0;
198 }