1 a84cbb2a 2004-04-19 devnull /*
  2 a84cbb2a 2004-04-19 devnull  * Dwarf call frame unwinding.
  3 a84cbb2a 2004-04-19 devnull  *
  4 fa325e9b 2020-01-10 cross  * The call frame unwinding values are encoded using a state machine
  5 fa325e9b 2020-01-10 cross  * like the pc<->line mapping, but it's a different machine.
  6 fa325e9b 2020-01-10 cross  * The expressions to generate the old values are similar in function to the
  7 a84cbb2a 2004-04-19 devnull  * ``dwarf expressions'' used for locations in the code, but of course not
  8 fa325e9b 2020-01-10 cross  * the same encoding.
  9 a84cbb2a 2004-04-19 devnull  */
 10 a84cbb2a 2004-04-19 devnull #include <u.h>
 11 a84cbb2a 2004-04-19 devnull #include <libc.h>
 12 a84cbb2a 2004-04-19 devnull #include <bio.h>
 13 a84cbb2a 2004-04-19 devnull #include "elf.h"
 14 a84cbb2a 2004-04-19 devnull #include "dwarf.h"
 15 a84cbb2a 2004-04-19 devnull 
 16 a84cbb2a 2004-04-19 devnull #define trace 0
 17 a84cbb2a 2004-04-19 devnull 
 18 a84cbb2a 2004-04-19 devnull typedef struct State State;
 19 a84cbb2a 2004-04-19 devnull struct State
 20 a84cbb2a 2004-04-19 devnull {
 21 a84cbb2a 2004-04-19 devnull 	ulong loc;
 22 a84cbb2a 2004-04-19 devnull 	ulong endloc;
 23 a84cbb2a 2004-04-19 devnull 	ulong iquantum;
 24 a84cbb2a 2004-04-19 devnull 	ulong dquantum;
 25 a84cbb2a 2004-04-19 devnull 	char *augmentation;
 26 a84cbb2a 2004-04-19 devnull 	int version;
 27 a84cbb2a 2004-04-19 devnull 	ulong rareg;
 28 a84cbb2a 2004-04-19 devnull 	DwarfBuf init;
 29 a84cbb2a 2004-04-19 devnull 	DwarfExpr *cfa;
 30 a84cbb2a 2004-04-19 devnull 	DwarfExpr *ra;
 31 a84cbb2a 2004-04-19 devnull 	DwarfExpr *r;
 32 a84cbb2a 2004-04-19 devnull 	DwarfExpr *initr;
 33 a84cbb2a 2004-04-19 devnull 	int nr;
 34 a84cbb2a 2004-04-19 devnull 	DwarfExpr **stack;
 35 a84cbb2a 2004-04-19 devnull 	int nstack;
 36 a84cbb2a 2004-04-19 devnull };
 37 a84cbb2a 2004-04-19 devnull 
 38 a84cbb2a 2004-04-19 devnull static int findfde(Dwarf*, ulong, State*, DwarfBuf*);
 39 a84cbb2a 2004-04-19 devnull static int dexec(DwarfBuf*, State*, int);
 40 a84cbb2a 2004-04-19 devnull 
 41 a84cbb2a 2004-04-19 devnull int
 42 a84cbb2a 2004-04-19 devnull dwarfunwind(Dwarf *d, ulong pc, DwarfExpr *cfa, DwarfExpr *ra, DwarfExpr *r, int nr)
 43 a84cbb2a 2004-04-19 devnull {
 44 a84cbb2a 2004-04-19 devnull 	int i, ret;
 45 a84cbb2a 2004-04-19 devnull 	DwarfBuf fde, b;
 46 a84cbb2a 2004-04-19 devnull 	DwarfExpr *initr;
 47 a84cbb2a 2004-04-19 devnull 	State s;
 48 a84cbb2a 2004-04-19 devnull 
 49 a84cbb2a 2004-04-19 devnull 	initr = mallocz(nr*sizeof(initr[0]), 1);
 50 a84cbb2a 2004-04-19 devnull 	if(initr == 0)
 51 a84cbb2a 2004-04-19 devnull 		return -1;
 52 a84cbb2a 2004-04-19 devnull 
 53 a84cbb2a 2004-04-19 devnull 	memset(&s, 0, sizeof s);
 54 a84cbb2a 2004-04-19 devnull 	s.loc = 0;
 55 a84cbb2a 2004-04-19 devnull 	s.cfa = cfa;
 56 a84cbb2a 2004-04-19 devnull 	s.ra = ra;
 57 a84cbb2a 2004-04-19 devnull 	s.r = r;
 58 a84cbb2a 2004-04-19 devnull 	s.nr = nr;
 59 a84cbb2a 2004-04-19 devnull 
 60 a84cbb2a 2004-04-19 devnull 	if(findfde(d, pc, &s, &fde) < 0){
 61 a84cbb2a 2004-04-19 devnull 		free(initr);
 62 a84cbb2a 2004-04-19 devnull 		return -1;
 63 a84cbb2a 2004-04-19 devnull 	}
 64 a84cbb2a 2004-04-19 devnull 
 65 a84cbb2a 2004-04-19 devnull 	memset(r, 0, nr*sizeof(r[0]));
 66 a84cbb2a 2004-04-19 devnull 	for(i=0; i<nr; i++)
 67 a84cbb2a 2004-04-19 devnull 		r[i].type = RuleSame;
 68 a84cbb2a 2004-04-19 devnull 	if(trace) fprint(2, "s.init %p-%p, fde %p-%p\n", s.init.p, s.init.ep, fde.p, fde.ep);
 69 a84cbb2a 2004-04-19 devnull 	b = s.init;
 70 a84cbb2a 2004-04-19 devnull 	if(dexec(&b, &s, 0) < 0)
 71 a84cbb2a 2004-04-19 devnull 		goto err;
 72 a84cbb2a 2004-04-19 devnull 
 73 a84cbb2a 2004-04-19 devnull 	s.initr = initr;
 74 a84cbb2a 2004-04-19 devnull 	memmove(initr, r, nr*sizeof(initr[0]));
 75 a84cbb2a 2004-04-19 devnull 
 76 a84cbb2a 2004-04-19 devnull 	if(trace) fprint(2, "s.loc 0x%lux pc 0x%lux\n", s.loc, pc);
 77 a84cbb2a 2004-04-19 devnull 	while(s.loc < pc){
 78 a84cbb2a 2004-04-19 devnull 		if(trace) fprint(2, "s.loc 0x%lux pc 0x%lux\n", s.loc, pc);
 79 a84cbb2a 2004-04-19 devnull 		if(dexec(&fde, &s, 1) < 0)
 80 a84cbb2a 2004-04-19 devnull 			goto err;
 81 a84cbb2a 2004-04-19 devnull 	}
 82 a84cbb2a 2004-04-19 devnull 	*ra = s.r[s.rareg];
 83 a84cbb2a 2004-04-19 devnull 
 84 a84cbb2a 2004-04-19 devnull 	ret = 0;
 85 a84cbb2a 2004-04-19 devnull 	goto out;
 86 a84cbb2a 2004-04-19 devnull 
 87 a84cbb2a 2004-04-19 devnull err:
 88 a84cbb2a 2004-04-19 devnull 	ret = -1;
 89 a84cbb2a 2004-04-19 devnull out:
 90 a84cbb2a 2004-04-19 devnull 	free(initr);
 91 a84cbb2a 2004-04-19 devnull 	for(i=0; i<s.nstack; i++)
 92 a84cbb2a 2004-04-19 devnull 		free(s.stack[i]);
 93 a84cbb2a 2004-04-19 devnull 	free(s.stack);
 94 a84cbb2a 2004-04-19 devnull 	return ret;
 95 a84cbb2a 2004-04-19 devnull }
 96 a84cbb2a 2004-04-19 devnull 
 97 a84cbb2a 2004-04-19 devnull /*
 98 a84cbb2a 2004-04-19 devnull  * XXX This turns out to be much more expensive than the actual
 99 a84cbb2a 2004-04-19 devnull  * running of the machine in dexec.  It probably makes sense to
100 fa325e9b 2020-01-10 cross  * cache the last 10 or so fde's we've found, since stack traces
101 a84cbb2a 2004-04-19 devnull  * will keep asking for the same info over and over.
102 a84cbb2a 2004-04-19 devnull  */
103 a84cbb2a 2004-04-19 devnull static int
104 a84cbb2a 2004-04-19 devnull findfde(Dwarf *d, ulong pc, State *s, DwarfBuf *fde)
105 a84cbb2a 2004-04-19 devnull {
106 a84cbb2a 2004-04-19 devnull 	static int nbad;
107 a84cbb2a 2004-04-19 devnull 	char *aug;
108 a84cbb2a 2004-04-19 devnull 	uchar *next;
109 a84cbb2a 2004-04-19 devnull 	int i, vers;
110 a84cbb2a 2004-04-19 devnull 	ulong len, id, base, size;
111 a84cbb2a 2004-04-19 devnull 	DwarfBuf b;
112 a84cbb2a 2004-04-19 devnull 
113 ebd39545 2004-04-20 devnull 	if(d->frame.data == nil){
114 ebd39545 2004-04-20 devnull 		werrstr("no frame debugging information");
115 ebd39545 2004-04-20 devnull 		return -1;
116 ebd39545 2004-04-20 devnull 	}
117 a84cbb2a 2004-04-19 devnull 	b.d = d;
118 a84cbb2a 2004-04-19 devnull 	b.p = d->frame.data;
119 a84cbb2a 2004-04-19 devnull 	b.ep = b.p + d->frame.len;
120 a84cbb2a 2004-04-19 devnull 	b.addrsize = d->addrsize;
121 a84cbb2a 2004-04-19 devnull 	if(b.addrsize == 0)
122 a84cbb2a 2004-04-19 devnull 		b.addrsize = 4;	/* where should i find this? */
123 a84cbb2a 2004-04-19 devnull 
124 a84cbb2a 2004-04-19 devnull 	for(; b.p < b.ep; b.p = next){
125 a84cbb2a 2004-04-19 devnull 		if((i = (b.p - d->frame.data) % b.addrsize))
126 a84cbb2a 2004-04-19 devnull 			b.p += b.addrsize - i;
127 a84cbb2a 2004-04-19 devnull 		len = dwarfget4(&b);
128 a84cbb2a 2004-04-19 devnull 		if(len > b.ep-b.p){
129 a84cbb2a 2004-04-19 devnull 			werrstr("bad length in cie/fde header");
130 a84cbb2a 2004-04-19 devnull 			return -1;
131 a84cbb2a 2004-04-19 devnull 		}
132 a84cbb2a 2004-04-19 devnull 		next = b.p+len;
133 a84cbb2a 2004-04-19 devnull 		id = dwarfget4(&b);
134 a84cbb2a 2004-04-19 devnull 		if(id == 0xFFFFFFFF){	/* CIE */
135 a84cbb2a 2004-04-19 devnull 			vers = dwarfget1(&b);
136 a84cbb2a 2004-04-19 devnull 			if(vers != 1 && vers != 2 && vers != 3){
137 a84cbb2a 2004-04-19 devnull 				if(++nbad == 1)
138 a84cbb2a 2004-04-19 devnull 					fprint(2, "unknown cie version %d (wanted 1-3)\n", vers);
139 a84cbb2a 2004-04-19 devnull 				continue;
140 a84cbb2a 2004-04-19 devnull 			}
141 a84cbb2a 2004-04-19 devnull 			aug = dwarfgetstring(&b);
142 a84cbb2a 2004-04-19 devnull 			if(aug && *aug){
143 a84cbb2a 2004-04-19 devnull 				if(++nbad == 1)
144 a84cbb2a 2004-04-19 devnull 					fprint(2, "unknown augmentation: %s\n", aug);
145 a84cbb2a 2004-04-19 devnull 				continue;
146 a84cbb2a 2004-04-19 devnull 			}
147 a84cbb2a 2004-04-19 devnull 			s->iquantum = dwarfget128(&b);
148 a84cbb2a 2004-04-19 devnull 			s->dquantum = dwarfget128s(&b);
149 a84cbb2a 2004-04-19 devnull 			s->rareg = dwarfget128(&b);
150 a84cbb2a 2004-04-19 devnull 			if(s->rareg > s->nr){
151 a84cbb2a 2004-04-19 devnull 				werrstr("return address is register %d but only have %d registers",
152 a84cbb2a 2004-04-19 devnull 					s->rareg, s->nr);
153 a84cbb2a 2004-04-19 devnull 				return -1;
154 a84cbb2a 2004-04-19 devnull 			}
155 a84cbb2a 2004-04-19 devnull 			s->init.p = b.p;
156 a84cbb2a 2004-04-19 devnull 			s->init.ep = next;
157 a84cbb2a 2004-04-19 devnull 		}else{	/* FDE */
158 a84cbb2a 2004-04-19 devnull 			base = dwarfgetaddr(&b);
159 a84cbb2a 2004-04-19 devnull 			size = dwarfgetaddr(&b);
160 a84cbb2a 2004-04-19 devnull 			fde->p = b.p;
161 a84cbb2a 2004-04-19 devnull 			fde->ep = next;
162 a84cbb2a 2004-04-19 devnull 			s->loc = base;
163 a84cbb2a 2004-04-19 devnull 			s->endloc = base+size;
164 a84cbb2a 2004-04-19 devnull 			if(base <= pc && pc < base+size)
165 a84cbb2a 2004-04-19 devnull 				return 0;
166 a84cbb2a 2004-04-19 devnull 		}
167 a84cbb2a 2004-04-19 devnull 	}
168 a84cbb2a 2004-04-19 devnull 	werrstr("cannot find call frame information for pc 0x%lux", pc);
169 a84cbb2a 2004-04-19 devnull 	return -1;
170 fa325e9b 2020-01-10 cross 
171 a84cbb2a 2004-04-19 devnull }
172 a84cbb2a 2004-04-19 devnull 
173 a84cbb2a 2004-04-19 devnull static int
174 a84cbb2a 2004-04-19 devnull checkreg(State *s, long r)
175 a84cbb2a 2004-04-19 devnull {
176 a84cbb2a 2004-04-19 devnull 	if(r < 0 || r >= s->nr){
177 a84cbb2a 2004-04-19 devnull 		werrstr("bad register number 0x%lux", r);
178 a84cbb2a 2004-04-19 devnull 		return -1;
179 a84cbb2a 2004-04-19 devnull 	}
180 a84cbb2a 2004-04-19 devnull 	return 0;
181 a84cbb2a 2004-04-19 devnull }
182 a84cbb2a 2004-04-19 devnull 
183 a84cbb2a 2004-04-19 devnull static int
184 a84cbb2a 2004-04-19 devnull dexec(DwarfBuf *b, State *s, int locstop)
185 a84cbb2a 2004-04-19 devnull {
186 a84cbb2a 2004-04-19 devnull 	int c;
187 a84cbb2a 2004-04-19 devnull 	long arg1, arg2;
188 a84cbb2a 2004-04-19 devnull 	DwarfExpr *e, **p;
189 a84cbb2a 2004-04-19 devnull 
190 a84cbb2a 2004-04-19 devnull 	for(;;){
191 a84cbb2a 2004-04-19 devnull 		if(b->p == b->ep){
192 a84cbb2a 2004-04-19 devnull 			if(s->initr)
193 a84cbb2a 2004-04-19 devnull 				s->loc = s->endloc;
194 a84cbb2a 2004-04-19 devnull 			return 0;
195 a84cbb2a 2004-04-19 devnull 		}
196 a84cbb2a 2004-04-19 devnull 		c = dwarfget1(b);
197 a84cbb2a 2004-04-19 devnull 		if(b->p == nil){
198 a84cbb2a 2004-04-19 devnull 			werrstr("ran out of instructions during cfa program");
199 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "%r\n");
200 a84cbb2a 2004-04-19 devnull 			return -1;
201 a84cbb2a 2004-04-19 devnull 		}
202 a84cbb2a 2004-04-19 devnull 		if(trace) fprint(2, "+ loc=0x%lux op 0x%ux ", s->loc, c);
203 a84cbb2a 2004-04-19 devnull 		switch(c>>6){
204 a84cbb2a 2004-04-19 devnull 		case 1:	/* advance location */
205 a84cbb2a 2004-04-19 devnull 			arg1 = c&0x3F;
206 a84cbb2a 2004-04-19 devnull 		advance:
207 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "loc += %ld\n", arg1*s->iquantum);
208 a84cbb2a 2004-04-19 devnull 			s->loc += arg1 * s->iquantum;
209 a84cbb2a 2004-04-19 devnull 			if(locstop)
210 a84cbb2a 2004-04-19 devnull 				return 0;
211 a84cbb2a 2004-04-19 devnull 			continue;
212 fa325e9b 2020-01-10 cross 
213 a84cbb2a 2004-04-19 devnull 		case 2:	/* offset rule */
214 a84cbb2a 2004-04-19 devnull 			arg1 = c&0x3F;
215 a84cbb2a 2004-04-19 devnull 			arg2 = dwarfget128(b);
216 a84cbb2a 2004-04-19 devnull 		offset:
217 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "r%ld += %ld\n", arg1, arg2*s->dquantum);
218 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0)
219 a84cbb2a 2004-04-19 devnull 				return -1;
220 a84cbb2a 2004-04-19 devnull 			s->r[arg1].type = RuleCfaOffset;
221 a84cbb2a 2004-04-19 devnull 			s->r[arg1].offset = arg2 * s->dquantum;
222 a84cbb2a 2004-04-19 devnull 			continue;
223 a84cbb2a 2004-04-19 devnull 
224 a84cbb2a 2004-04-19 devnull 		case 3:	/* restore initial setting */
225 a84cbb2a 2004-04-19 devnull 			arg1 = c&0x3F;
226 a84cbb2a 2004-04-19 devnull 		restore:
227 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "r%ld = init\n", arg1);
228 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0)
229 a84cbb2a 2004-04-19 devnull 				return -1;
230 a84cbb2a 2004-04-19 devnull 			s->r[arg1] = s->initr[arg1];
231 a84cbb2a 2004-04-19 devnull 			continue;
232 a84cbb2a 2004-04-19 devnull 		}
233 a84cbb2a 2004-04-19 devnull 
234 a84cbb2a 2004-04-19 devnull 		switch(c){
235 a84cbb2a 2004-04-19 devnull 		case 0:	/* nop */
236 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "nop\n");
237 a84cbb2a 2004-04-19 devnull 			continue;
238 a84cbb2a 2004-04-19 devnull 
239 a84cbb2a 2004-04-19 devnull 		case 0x01:	/* set location */
240 a84cbb2a 2004-04-19 devnull 			s->loc = dwarfgetaddr(b);
241 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "loc = 0x%lux\n", s->loc);
242 a84cbb2a 2004-04-19 devnull 			if(locstop)
243 a84cbb2a 2004-04-19 devnull 				return 0;
244 a84cbb2a 2004-04-19 devnull 			continue;
245 a84cbb2a 2004-04-19 devnull 
246 a84cbb2a 2004-04-19 devnull 		case 0x02:	/* advance loc1 */
247 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget1(b);
248 a84cbb2a 2004-04-19 devnull 			goto advance;
249 a84cbb2a 2004-04-19 devnull 
250 a84cbb2a 2004-04-19 devnull 		case 0x03:	/* advance loc2 */
251 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget2(b);
252 a84cbb2a 2004-04-19 devnull 			goto advance;
253 a84cbb2a 2004-04-19 devnull 
254 a84cbb2a 2004-04-19 devnull 		case 0x04:	/* advance loc4 */
255 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget4(b);
256 a84cbb2a 2004-04-19 devnull 			goto advance;
257 a84cbb2a 2004-04-19 devnull 
258 a84cbb2a 2004-04-19 devnull 		case 0x05:	/* offset extended */
259 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
260 a84cbb2a 2004-04-19 devnull 			arg2 = dwarfget128(b);
261 a84cbb2a 2004-04-19 devnull 			goto offset;
262 a84cbb2a 2004-04-19 devnull 
263 a84cbb2a 2004-04-19 devnull 		case 0x06:	/* restore extended */
264 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
265 a84cbb2a 2004-04-19 devnull 			goto restore;
266 a84cbb2a 2004-04-19 devnull 
267 a84cbb2a 2004-04-19 devnull 		case 0x07:	/* undefined */
268 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
269 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "r%ld = undef\n", arg1);
270 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0)
271 a84cbb2a 2004-04-19 devnull 				return -1;
272 a84cbb2a 2004-04-19 devnull 			s->r[arg1].type = RuleUndef;
273 a84cbb2a 2004-04-19 devnull 			continue;
274 a84cbb2a 2004-04-19 devnull 
275 a84cbb2a 2004-04-19 devnull 		case 0x08:	/* same value */
276 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
277 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "r%ld = same\n", arg1);
278 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0)
279 a84cbb2a 2004-04-19 devnull 				return -1;
280 a84cbb2a 2004-04-19 devnull 			s->r[arg1].type = RuleSame;
281 a84cbb2a 2004-04-19 devnull 			continue;
282 a84cbb2a 2004-04-19 devnull 
283 a84cbb2a 2004-04-19 devnull 		case 0x09:	/* register */
284 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
285 a84cbb2a 2004-04-19 devnull 			arg2 = dwarfget128(b);
286 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "r%ld = r%ld\n", arg1, arg2);
287 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0 || checkreg(s, arg2) < 0)
288 a84cbb2a 2004-04-19 devnull 				return -1;
289 a84cbb2a 2004-04-19 devnull 			s->r[arg1].type = RuleRegister;
290 a84cbb2a 2004-04-19 devnull 			s->r[arg1].reg = arg2;
291 a84cbb2a 2004-04-19 devnull 			continue;
292 a84cbb2a 2004-04-19 devnull 
293 a84cbb2a 2004-04-19 devnull 		case 0x0A:	/* remember state */
294 a84cbb2a 2004-04-19 devnull 			e = malloc(s->nr*sizeof(e[0]));
295 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "push\n");
296 a84cbb2a 2004-04-19 devnull 			if(e == nil)
297 a84cbb2a 2004-04-19 devnull 				return -1;
298 a84cbb2a 2004-04-19 devnull 			p = realloc(s->stack, (s->nstack+1)*sizeof(s->stack[0]));
299 a84cbb2a 2004-04-19 devnull 			if(p == nil){
300 a84cbb2a 2004-04-19 devnull 				free(e);
301 a84cbb2a 2004-04-19 devnull 				return -1;
302 a84cbb2a 2004-04-19 devnull 			}
303 a84cbb2a 2004-04-19 devnull 			s->stack[s->nstack++] = e;
304 a84cbb2a 2004-04-19 devnull 			memmove(e, s->r, s->nr*sizeof(e[0]));
305 a84cbb2a 2004-04-19 devnull 			continue;
306 a84cbb2a 2004-04-19 devnull 
307 a84cbb2a 2004-04-19 devnull 		case 0x0B:	/* restore state */
308 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "pop\n");
309 a84cbb2a 2004-04-19 devnull 			if(s->nstack == 0){
310 a84cbb2a 2004-04-19 devnull 				werrstr("restore state underflow");
311 a84cbb2a 2004-04-19 devnull 				return -1;
312 a84cbb2a 2004-04-19 devnull 			}
313 a84cbb2a 2004-04-19 devnull 			e = s->stack[s->nstack-1];
314 a84cbb2a 2004-04-19 devnull 			memmove(s->r, e, s->nr*sizeof(e[0]));
315 a84cbb2a 2004-04-19 devnull 			p = realloc(s->stack, (s->nstack-1)*sizeof(s->stack[0]));
316 a84cbb2a 2004-04-19 devnull 			if(p == nil)
317 a84cbb2a 2004-04-19 devnull 				return -1;
318 a84cbb2a 2004-04-19 devnull 			free(e);
319 a84cbb2a 2004-04-19 devnull 			s->nstack--;
320 a84cbb2a 2004-04-19 devnull 			continue;
321 a84cbb2a 2004-04-19 devnull 
322 a84cbb2a 2004-04-19 devnull 		case 0x0C:	/* def cfa */
323 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
324 a84cbb2a 2004-04-19 devnull 			arg2 = dwarfget128(b);
325 a84cbb2a 2004-04-19 devnull 		defcfa:
326 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "cfa %ld(r%ld)\n", arg2, arg1);
327 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0)
328 a84cbb2a 2004-04-19 devnull 				return -1;
329 a84cbb2a 2004-04-19 devnull 			s->cfa->type = RuleRegOff;
330 a84cbb2a 2004-04-19 devnull 			s->cfa->reg = arg1;
331 a84cbb2a 2004-04-19 devnull 			s->cfa->offset = arg2;
332 a84cbb2a 2004-04-19 devnull 			continue;
333 a84cbb2a 2004-04-19 devnull 
334 fa325e9b 2020-01-10 cross 		case 0x0D:	/* def cfa register */
335 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
336 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "cfa reg r%ld\n", arg1);
337 a84cbb2a 2004-04-19 devnull 			if(s->cfa->type != RuleRegOff){
338 a84cbb2a 2004-04-19 devnull 				werrstr("change CFA register but CFA not in register+offset form");
339 fa325e9b 2020-01-10 cross 				return -1;
340 a84cbb2a 2004-04-19 devnull 			}
341 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0)
342 a84cbb2a 2004-04-19 devnull 				return -1;
343 a84cbb2a 2004-04-19 devnull 			s->cfa->reg = arg1;
344 a84cbb2a 2004-04-19 devnull 			continue;
345 a84cbb2a 2004-04-19 devnull 
346 a84cbb2a 2004-04-19 devnull 		case 0x0E:	/* def cfa offset */
347 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
348 a84cbb2a 2004-04-19 devnull 		cfaoffset:
349 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "cfa off %ld\n", arg1);
350 a84cbb2a 2004-04-19 devnull 			if(s->cfa->type != RuleRegOff){
351 a84cbb2a 2004-04-19 devnull 				werrstr("change CFA offset but CFA not in register+offset form");
352 a84cbb2a 2004-04-19 devnull 				return -1;
353 a84cbb2a 2004-04-19 devnull 			}
354 a84cbb2a 2004-04-19 devnull 			s->cfa->offset = arg1;
355 a84cbb2a 2004-04-19 devnull 			continue;
356 a84cbb2a 2004-04-19 devnull 
357 a84cbb2a 2004-04-19 devnull 		case 0x0F:	/* def cfa expression */
358 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "cfa expr\n");
359 a84cbb2a 2004-04-19 devnull 			s->cfa->type = RuleLocation;
360 a84cbb2a 2004-04-19 devnull 			s->cfa->loc.len = dwarfget128(b);
361 a84cbb2a 2004-04-19 devnull 			s->cfa->loc.data = dwarfgetnref(b, s->cfa->loc.len);
362 a84cbb2a 2004-04-19 devnull 			continue;
363 a84cbb2a 2004-04-19 devnull 
364 a84cbb2a 2004-04-19 devnull 		case 0x10:	/* def reg expression */
365 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
366 a84cbb2a 2004-04-19 devnull 			if(trace) fprint(2, "reg expr r%ld\n", arg1);
367 a84cbb2a 2004-04-19 devnull 			if(checkreg(s, arg1) < 0)
368 a84cbb2a 2004-04-19 devnull 				return -1;
369 a84cbb2a 2004-04-19 devnull 			s->r[arg1].type = RuleLocation;
370 a84cbb2a 2004-04-19 devnull 			s->r[arg1].loc.len = dwarfget128(b);
371 a84cbb2a 2004-04-19 devnull 			s->r[arg1].loc.data = dwarfgetnref(b, s->r[arg1].loc.len);
372 a84cbb2a 2004-04-19 devnull 			continue;
373 a84cbb2a 2004-04-19 devnull 
374 a84cbb2a 2004-04-19 devnull 		case 0x11:	/* offset extended */
375 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
376 a84cbb2a 2004-04-19 devnull 			arg2 = dwarfget128s(b);
377 a84cbb2a 2004-04-19 devnull 			goto offset;
378 a84cbb2a 2004-04-19 devnull 
379 a84cbb2a 2004-04-19 devnull 		case 0x12:	/* cfa sf */
380 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128(b);
381 a84cbb2a 2004-04-19 devnull 			arg2 = dwarfget128s(b);
382 a84cbb2a 2004-04-19 devnull 			goto defcfa;
383 a84cbb2a 2004-04-19 devnull 
384 a84cbb2a 2004-04-19 devnull 		case 0x13:	/* cfa offset sf */
385 a84cbb2a 2004-04-19 devnull 			arg1 = dwarfget128s(b);
386 a84cbb2a 2004-04-19 devnull 			goto cfaoffset;
387 a84cbb2a 2004-04-19 devnull 
388 a84cbb2a 2004-04-19 devnull 		default:	/* unknown */
389 a84cbb2a 2004-04-19 devnull 			werrstr("unknown opcode 0x%ux in cfa program", c);
390 a84cbb2a 2004-04-19 devnull 			return -1;
391 a84cbb2a 2004-04-19 devnull 		}
392 a84cbb2a 2004-04-19 devnull 	}
393 fa325e9b 2020-01-10 cross 	/* not reached */
394 a84cbb2a 2004-04-19 devnull }