1 a84cbb2a 2004-04-19 devnull /*
  2 a84cbb2a 2004-04-19 devnull  * Dwarf data format parsing routines.
  3 a84cbb2a 2004-04-19 devnull  */
  4 a84cbb2a 2004-04-19 devnull 
  5 a84cbb2a 2004-04-19 devnull #include <u.h>
  6 a84cbb2a 2004-04-19 devnull #include <libc.h>
  7 a84cbb2a 2004-04-19 devnull #include <bio.h>
  8 a84cbb2a 2004-04-19 devnull #include "elf.h"
  9 a84cbb2a 2004-04-19 devnull #include "dwarf.h"
 10 a84cbb2a 2004-04-19 devnull 
 11 a84cbb2a 2004-04-19 devnull ulong
 12 a84cbb2a 2004-04-19 devnull dwarfget1(DwarfBuf *b)
 13 a84cbb2a 2004-04-19 devnull {
 14 a84cbb2a 2004-04-19 devnull 	if(b->p==nil || b->p+1 > b->ep){
 15 a84cbb2a 2004-04-19 devnull 		b->p = nil;
 16 a84cbb2a 2004-04-19 devnull 		return 0;
 17 a84cbb2a 2004-04-19 devnull 	}
 18 a84cbb2a 2004-04-19 devnull 	return *b->p++;
 19 a84cbb2a 2004-04-19 devnull }
 20 a84cbb2a 2004-04-19 devnull 
 21 a84cbb2a 2004-04-19 devnull int
 22 a84cbb2a 2004-04-19 devnull dwarfgetn(DwarfBuf *b, uchar *a, int n)
 23 a84cbb2a 2004-04-19 devnull {
 24 a84cbb2a 2004-04-19 devnull 	if(b->p==nil || b->p+n > b->ep){
 25 a84cbb2a 2004-04-19 devnull 		b->p = nil;
 26 a84cbb2a 2004-04-19 devnull 		memset(a, 0, n);
 27 a84cbb2a 2004-04-19 devnull 		return -1;
 28 a84cbb2a 2004-04-19 devnull 	}
 29 a84cbb2a 2004-04-19 devnull 	memmove(a, b->p, n);
 30 a84cbb2a 2004-04-19 devnull 	b->p += n;
 31 a84cbb2a 2004-04-19 devnull 	return 0;
 32 a84cbb2a 2004-04-19 devnull }
 33 a84cbb2a 2004-04-19 devnull 
 34 a84cbb2a 2004-04-19 devnull uchar*
 35 a84cbb2a 2004-04-19 devnull dwarfgetnref(DwarfBuf *b, ulong n)
 36 a84cbb2a 2004-04-19 devnull {
 37 a84cbb2a 2004-04-19 devnull 	uchar *p;
 38 a84cbb2a 2004-04-19 devnull 
 39 a84cbb2a 2004-04-19 devnull 	if(b->p==nil || b->p+n > b->ep){
 40 a84cbb2a 2004-04-19 devnull 		b->p = nil;
 41 a84cbb2a 2004-04-19 devnull 		return nil;
 42 a84cbb2a 2004-04-19 devnull 	}
 43 a84cbb2a 2004-04-19 devnull 	p = b->p;
 44 a84cbb2a 2004-04-19 devnull 	b->p += n;
 45 a84cbb2a 2004-04-19 devnull 	return p;
 46 a84cbb2a 2004-04-19 devnull }
 47 a84cbb2a 2004-04-19 devnull 
 48 a84cbb2a 2004-04-19 devnull char*
 49 a84cbb2a 2004-04-19 devnull dwarfgetstring(DwarfBuf *b)
 50 a84cbb2a 2004-04-19 devnull {
 51 a84cbb2a 2004-04-19 devnull 	char *s;
 52 a84cbb2a 2004-04-19 devnull 
 53 a84cbb2a 2004-04-19 devnull 	if(b->p == nil)
 54 a84cbb2a 2004-04-19 devnull 		return nil;
 55 a84cbb2a 2004-04-19 devnull 	s = (char*)b->p;
 56 a84cbb2a 2004-04-19 devnull 	while(b->p < b->ep && *b->p)
 57 a84cbb2a 2004-04-19 devnull 		b->p++;
 58 a84cbb2a 2004-04-19 devnull 	if(b->p >= b->ep){
 59 a84cbb2a 2004-04-19 devnull 		b->p = nil;
 60 a84cbb2a 2004-04-19 devnull 		return nil;
 61 a84cbb2a 2004-04-19 devnull 	}
 62 a84cbb2a 2004-04-19 devnull 	b->p++;
 63 a84cbb2a 2004-04-19 devnull 	return s;
 64 a84cbb2a 2004-04-19 devnull }
 65 a84cbb2a 2004-04-19 devnull 
 66 a84cbb2a 2004-04-19 devnull void
 67 a84cbb2a 2004-04-19 devnull dwarfskip(DwarfBuf *b, int n)
 68 a84cbb2a 2004-04-19 devnull {
 69 a84cbb2a 2004-04-19 devnull 	if(b->p==nil || b->p+n > b->ep)
 70 a84cbb2a 2004-04-19 devnull 		b->p = nil;
 71 a84cbb2a 2004-04-19 devnull 	else
 72 a84cbb2a 2004-04-19 devnull 		b->p += n;
 73 a84cbb2a 2004-04-19 devnull }
 74 a84cbb2a 2004-04-19 devnull 
 75 a84cbb2a 2004-04-19 devnull ulong
 76 a84cbb2a 2004-04-19 devnull dwarfget2(DwarfBuf *b)
 77 a84cbb2a 2004-04-19 devnull {
 78 a84cbb2a 2004-04-19 devnull 	ulong v;
 79 a84cbb2a 2004-04-19 devnull 
 80 a84cbb2a 2004-04-19 devnull 	if(b->p==nil || b->p+2 > b->ep){
 81 a84cbb2a 2004-04-19 devnull 		b->p = nil;
 82 a84cbb2a 2004-04-19 devnull 		return 0;
 83 a84cbb2a 2004-04-19 devnull 	}
 84 a84cbb2a 2004-04-19 devnull 	v = b->d->elf->hdr.e2(b->p);
 85 a84cbb2a 2004-04-19 devnull 	b->p += 2;
 86 a84cbb2a 2004-04-19 devnull 	return v;
 87 a84cbb2a 2004-04-19 devnull }
 88 a84cbb2a 2004-04-19 devnull 
 89 a84cbb2a 2004-04-19 devnull ulong
 90 a84cbb2a 2004-04-19 devnull dwarfget4(DwarfBuf *b)
 91 a84cbb2a 2004-04-19 devnull {
 92 a84cbb2a 2004-04-19 devnull 	ulong v;
 93 a84cbb2a 2004-04-19 devnull 
 94 a84cbb2a 2004-04-19 devnull 	if(b->p==nil || b->p+4 > b->ep){
 95 a84cbb2a 2004-04-19 devnull 		b->p = nil;
 96 a84cbb2a 2004-04-19 devnull 		return 0;
 97 a84cbb2a 2004-04-19 devnull 	}
 98 a84cbb2a 2004-04-19 devnull 	v = b->d->elf->hdr.e4(b->p);
 99 a84cbb2a 2004-04-19 devnull 	b->p += 4;
100 a84cbb2a 2004-04-19 devnull 	return v;
101 a84cbb2a 2004-04-19 devnull }
102 a84cbb2a 2004-04-19 devnull 
103 a84cbb2a 2004-04-19 devnull uvlong
104 a84cbb2a 2004-04-19 devnull dwarfget8(DwarfBuf *b)
105 a84cbb2a 2004-04-19 devnull {
106 a84cbb2a 2004-04-19 devnull 	uvlong v;
107 a84cbb2a 2004-04-19 devnull 
108 a84cbb2a 2004-04-19 devnull 	if(b->p==nil || b->p+8 > b->ep){
109 a84cbb2a 2004-04-19 devnull 		b->p = nil;
110 a84cbb2a 2004-04-19 devnull 		return 0;
111 a84cbb2a 2004-04-19 devnull 	}
112 a84cbb2a 2004-04-19 devnull 	v = b->d->elf->hdr.e8(b->p);
113 a84cbb2a 2004-04-19 devnull 	b->p += 8;
114 a84cbb2a 2004-04-19 devnull 	return v;
115 a84cbb2a 2004-04-19 devnull }
116 a84cbb2a 2004-04-19 devnull 
117 a84cbb2a 2004-04-19 devnull ulong
118 a84cbb2a 2004-04-19 devnull dwarfgetaddr(DwarfBuf *b)
119 a84cbb2a 2004-04-19 devnull {
120 a84cbb2a 2004-04-19 devnull 	static int nbad;
121 a84cbb2a 2004-04-19 devnull 
122 a84cbb2a 2004-04-19 devnull 	if(b->addrsize == 0)
123 a84cbb2a 2004-04-19 devnull 		b->addrsize = b->d->addrsize;
124 a84cbb2a 2004-04-19 devnull 
125 a84cbb2a 2004-04-19 devnull 	switch(b->addrsize){
126 a84cbb2a 2004-04-19 devnull 	case 1:
127 a84cbb2a 2004-04-19 devnull 		return dwarfget1(b);
128 a84cbb2a 2004-04-19 devnull 	case 2:
129 a84cbb2a 2004-04-19 devnull 		return dwarfget2(b);
130 a84cbb2a 2004-04-19 devnull 	case 4:
131 a84cbb2a 2004-04-19 devnull 		return dwarfget4(b);
132 a84cbb2a 2004-04-19 devnull 	case 8:
133 a84cbb2a 2004-04-19 devnull 		return dwarfget8(b);
134 a84cbb2a 2004-04-19 devnull 	default:
135 a84cbb2a 2004-04-19 devnull 		if(++nbad == 1)
136 a84cbb2a 2004-04-19 devnull 			fprint(2, "dwarf: unexpected address size %lud in dwarfgetaddr\n", b->addrsize);
137 a84cbb2a 2004-04-19 devnull 		b->p = nil;
138 a84cbb2a 2004-04-19 devnull 		return 0;
139 a84cbb2a 2004-04-19 devnull 	}
140 a84cbb2a 2004-04-19 devnull }
141 a84cbb2a 2004-04-19 devnull 
142 a84cbb2a 2004-04-19 devnull int n1, n2, n3, n4, n5;
143 a84cbb2a 2004-04-19 devnull 
144 a84cbb2a 2004-04-19 devnull /* An inline function picks off the calls to dwarfget128 for 1-byte encodings,
145 a84cbb2a 2004-04-19 devnull  * more than by far the common case (99.999% on most binaries!). */
146 a84cbb2a 2004-04-19 devnull ulong
147 a84cbb2a 2004-04-19 devnull dwarfget128(DwarfBuf *b)
148 a84cbb2a 2004-04-19 devnull {
149 a84cbb2a 2004-04-19 devnull 	static int nbad;
150 a84cbb2a 2004-04-19 devnull 	ulong c, d;
151 a84cbb2a 2004-04-19 devnull 
152 a84cbb2a 2004-04-19 devnull 	if(b->p == nil)
153 a84cbb2a 2004-04-19 devnull 		return 0;
154 a84cbb2a 2004-04-19 devnull 	c = *b->p++;
155 a84cbb2a 2004-04-19 devnull 	if(!(c&0x80))
156 a84cbb2a 2004-04-19 devnull {n1++;
157 a84cbb2a 2004-04-19 devnull 		return c;
158 a84cbb2a 2004-04-19 devnull }
159 be36ff68 2004-04-29 devnull 	c &= ~0x80;
160 a84cbb2a 2004-04-19 devnull 	d = *b->p++;
161 a84cbb2a 2004-04-19 devnull 	c |= (d&0x7F)<<7;
162 a84cbb2a 2004-04-19 devnull 	if(!(d&0x80))
163 a84cbb2a 2004-04-19 devnull {n2++;
164 a84cbb2a 2004-04-19 devnull 		return c;
165 a84cbb2a 2004-04-19 devnull }
166 a84cbb2a 2004-04-19 devnull 	d = *b->p++;
167 a84cbb2a 2004-04-19 devnull 	c |= (d&0x7F)<<14;
168 a84cbb2a 2004-04-19 devnull 	if(!(d&0x80))
169 a84cbb2a 2004-04-19 devnull {n3++;
170 a84cbb2a 2004-04-19 devnull 		return c;
171 a84cbb2a 2004-04-19 devnull }
172 a84cbb2a 2004-04-19 devnull 	d = *b->p++;
173 a84cbb2a 2004-04-19 devnull 	c |= (d&0x7F)<<21;
174 a84cbb2a 2004-04-19 devnull 	if(!(d&0x80))
175 a84cbb2a 2004-04-19 devnull {n4++;
176 a84cbb2a 2004-04-19 devnull 		return c;
177 a84cbb2a 2004-04-19 devnull }
178 a84cbb2a 2004-04-19 devnull 	d = *b->p++;
179 a84cbb2a 2004-04-19 devnull 	c |= (d&0x7F)<<28;
180 a84cbb2a 2004-04-19 devnull 	if(!(d&0x80))
181 a84cbb2a 2004-04-19 devnull {n5++;
182 a84cbb2a 2004-04-19 devnull 		return c;
183 a84cbb2a 2004-04-19 devnull }
184 a84cbb2a 2004-04-19 devnull 	while(b->p<b->ep && *b->p&0x80)
185 a84cbb2a 2004-04-19 devnull 		b->p++;
186 a84cbb2a 2004-04-19 devnull 	if(++nbad == 1)
187 a84cbb2a 2004-04-19 devnull 		fprint(2, "dwarf: overflow during parsing of uleb128 integer\n");
188 a84cbb2a 2004-04-19 devnull 	return c;
189 a84cbb2a 2004-04-19 devnull }
190 a84cbb2a 2004-04-19 devnull 
191 a84cbb2a 2004-04-19 devnull long
192 a84cbb2a 2004-04-19 devnull dwarfget128s(DwarfBuf *b)
193 a84cbb2a 2004-04-19 devnull {
194 a84cbb2a 2004-04-19 devnull 	int nb, c;
195 a84cbb2a 2004-04-19 devnull 	ulong v;
196 a84cbb2a 2004-04-19 devnull 	static int nbad;
197 a84cbb2a 2004-04-19 devnull 
198 a84cbb2a 2004-04-19 devnull 	v = 0;
199 a84cbb2a 2004-04-19 devnull 	nb = 0;
200 a84cbb2a 2004-04-19 devnull 	if(b->p==nil)
201 a84cbb2a 2004-04-19 devnull 		return 0;
202 a84cbb2a 2004-04-19 devnull 	while(b->p<b->ep){
203 a84cbb2a 2004-04-19 devnull 		c = *b->p++;
204 a84cbb2a 2004-04-19 devnull 		v |= (c & 0x7F)<<nb;
205 a84cbb2a 2004-04-19 devnull 		nb += 7;
206 a84cbb2a 2004-04-19 devnull 		if(!(c&0x80))
207 a84cbb2a 2004-04-19 devnull 			break;
208 a84cbb2a 2004-04-19 devnull 	}
209 a84cbb2a 2004-04-19 devnull 	if(v&(1<<(nb-1)))
210 a84cbb2a 2004-04-19 devnull 		v |= ~(((ulong)1<<nb)-1);
211 a84cbb2a 2004-04-19 devnull 	if(nb > 8*sizeof(ulong)){
212 a84cbb2a 2004-04-19 devnull 		if(0)
213 a84cbb2a 2004-04-19 devnull 		if(++nbad == 1)
214 a84cbb2a 2004-04-19 devnull 			fprint(2, "dwarf: overflow during parsing of sleb128 integer: got %d bits\n", nb);
215 a84cbb2a 2004-04-19 devnull 	}
216 a84cbb2a 2004-04-19 devnull 	return v;
217 a84cbb2a 2004-04-19 devnull }