1 #include <u.h>
2 #include <libc.h>
3 #include <mach.h>
4 #include "elf.h"
5 
6 /*
7 aggr Linkdebug
8 {
9 	'X' 0 version;
10 	'X' 4 map;
11 };
12 
13 aggr Linkmap
14 {
15 	'X' 0 addr;
16 	'X' 4 name;
17 	'X' 8 dynsect;
18 	'X' 12 next;
19 	'X' 16 prev;
20 };
21 */
22 enum
23 {
24 	DT_NULL = 0,
25 	DT_NEEDED,
26 	DT_PLTRRELSZ,
27 	DT_PLTGOT,
28 	DT_HASH,
29 	DT_STRTAB,
30 	DT_SYMTAB,
31 	DT_RELA,
32 	DT_RELASZ = 8,
33 	DT_RELAENT,
34 	DT_STSZ,
35 	DT_SYMENT,
36 	DT_INIT,
37 	DT_FINI,
38 	DT_SONAME,
39 	DT_RPATH,
40 	DT_SYMBOLIC = 16,
41 	DT_REL,
42 	DT_RELSZ,
43 	DT_RELENT,
44 	DT_PLTREL,
45 	DT_DEBUG,
46 	DT_TEXTREL,
47 	DT_JMPREL
48 };
49 
50 static int
51 getstr(Map *map, ulong addr, char *buf, uint nbuf)
52 {
53 	int i;
54 
55 	for(i=0; i<nbuf; i++){
56 		if(get1(map, addr+i, (uchar*)buf+i, 1) < 0)
57 			return -1;
58 		if(buf[i] == 0)
59 			return 0;
60 	}
61 	return -1;	/* no nul */
62 }
63 
64 static ulong
65 dyninfo(Fhdr *hdr, int x)
66 {
67 	u32int addr, u;
68 
69 	if(hdr == nil || (addr = ((Elf*)hdr->elf)->dynamic) == 0){
70 		fprint(2, "no hdr/dynamic %p\n", hdr);
71 		return 0;
72 	}
73 	addr += hdr->base;
74 
75 	while(addr != 0){
76 		if(get4(cormap, addr, &u) < 0)
77 			return 0;
78 		if(u == x){
79 			if(get4(cormap, addr+4, &u) < 0)
80 				return 0;
81 			return u;
82 		}
83 		addr += 8;
84 	}
85 	return 0;
86 }
87 
88 void
89 elfdl386mapdl(int verbose)
90 {
91 	int i;
92 	Fhdr *hdr;
93 	u32int linkdebug, linkmap, name, addr;
94 	char buf[1024];
95 
96 	if((linkdebug = dyninfo(symhdr, DT_DEBUG)) == 0){
97 		fprint(2, "no dt_debug section\n");
98 		return;
99 	}
100 	if(get4(cormap, linkdebug+4, &linkmap) < 0){
101 		fprint(2, "get4 linkdebug+4 (0x%lux) failed\n", linkdebug);
102 		return;
103 	}
104 
105 	for(i=0; i<100 && linkmap != 0; i++){
106 		if(get4(cormap, linkmap, &addr) < 0
107 		|| get4(cormap, linkmap+4, &name) < 0
108 		|| get4(cormap, linkmap+12, &linkmap) < 0)
109 			break;
110 
111 		if(name == 0 || getstr(cormap, name, buf, sizeof buf) < 0 || buf[0] == 0)
112 			continue;
113 		if((hdr = crackhdr(buf, OREAD)) == nil){
114 			fprint(2, "crackhdr %s: %r\n", buf);
115 			continue;
116 		}
117 		hdr->base = addr;
118 		if(verbose)
119 			fprint(2, "%s: %s %s %s\n", buf, hdr->aname, hdr->mname, hdr->fname);
120 		if(mapfile(hdr, addr, symmap, nil) < 0)
121 			fprint(2, "mapping %s: %r\n", buf);
122 		if(corhdr){
123 			/*
124 			 * Need to map the text file under the core file.
125 			 */
126 			unmapfile(corhdr, cormap);
127 			mapfile(hdr, addr, cormap, nil);
128 			mapfile(corhdr, 0, cormap, nil);
129 		}
130 		if(symopen(hdr) < 0)
131 			fprint(2, "syminit %s: %r\n", buf);
132 	}
133 }