Intravision/reactos
1
0
Fork 0
mirror of https://github.com/reactos/reactos.git synced 2024-11-19 13:33:42 +00:00
Code Issues Projects Releases Packages Wiki Activity
reactos/sdk/lib/rossym_new/dwarfcfa.c

491 lines
12 KiB
C
Raw Blame History

/*
* Dwarf call frame unwinding.
*
* The call frame unwinding values are encoded using a state machine
* like the pc<->line mapping, but it's a different machine.
* The expressions to generate the old values are similar in function to the
* ``dwarf expressions'' used for locations in the code, but of course not
* the same encoding.
*/
#include <precomp.h>
#define NDEBUG
#include <debug.h>
#define trace 1
typedef struct State State;
struct State
{
ulong loc;
ulong endloc;
ulong iquantum;
ulong dquantum;
char *augmentation;
int version;
ulong rareg;
DwarfBuf init;
DwarfExpr *cfa;
DwarfExpr *ra;
DwarfExpr *r;
DwarfExpr *initr;
int nr;
DwarfExpr **stack;
int nstack;
};
static int findfde(Dwarf*, ulong, State*, DwarfBuf*);
static int dexec(DwarfBuf*, State*, int);
int
dwarfunwind(Dwarf *d, ulong pc, DwarfExpr *cfa, DwarfExpr *ra, DwarfExpr *r, int nr)
{
int i, ret;
DwarfBuf fde, b;
DwarfExpr *initr;
State s;
initr = mallocz(nr*sizeof(initr[0]), 1);
if(initr == 0)
return -1;
memset(&s, 0, sizeof s);
s.loc = 0;
s.cfa = cfa;
s.ra = ra;
s.r = r;
s.nr = nr;
if(findfde(d, pc, &s, &fde) < 0){
free(initr);
return -1;
}
memset(r, 0, nr*sizeof(r[0]));
for(i=0; i<nr; i++)
r[i].type = RuleSame;
if(trace) werrstr("s.init %p-%p, fde %p-%p", s.init.p, s.init.ep, fde.p, fde.ep);
b = s.init;
if(dexec(&b, &s, 0) < 0)
goto err;
s.initr = initr;
memmove(initr, r, nr*sizeof(initr[0]));
if(trace) werrstr("s.loc 0x%lx pc 0x%lx", s.loc, pc);
while(s.loc < pc){
if(trace) werrstr("s.loc 0x%lx pc 0x%lx", s.loc, pc);
if(dexec(&fde, &s, 1) < 0)
goto err;
}
*ra = s.r[s.rareg];
ret = 0;
goto out;
err:
ret = -1;
out:
free(initr);
for(i=0; i<s.nstack; i++)
free(s.stack[i]);
free(s.stack);
return ret;
}
/*
* XXX This turns out to be much more expensive than the actual
* running of the machine in dexec. It probably makes sense to
* cache the last 10 or so fde's we've found, since stack traces
* will keep asking for the same info over and over.
*/
static int
findfde(Dwarf *d, ulong pc, State *s, DwarfBuf *fde)
{
static int nbad;
char *aug;
uchar *next;
int i, vers;
ulong len, id, base, size;
DwarfBuf b;
if(d->frame.data == nil){
werrstr("no frame debugging information");
return -1;
}
b.d = d;
b.p = d->frame.data;
b.ep = b.p + d->frame.len;
b.addrsize = d->addrsize;
if(b.addrsize == 0)
b.addrsize = 4; /* where should i find this? */
for(; b.p < b.ep; b.p = next){
if((i = (b.p - d->frame.data) % b.addrsize))
b.p += b.addrsize - i;
len = dwarfget4(&b);
if(len > b.ep-b.p){
werrstr("bad length in cie/fde header");
return -1;
}
next = b.p+len;
id = dwarfget4(&b);
if(id == 0xFFFFFFFF){ /* CIE */
vers = dwarfget1(&b);
if (trace) werrstr("CIE len %x id %x vers %x", len, id, vers);
if(vers != 1 && vers != 2 && vers != 3){
if(++nbad == 1)
werrstr("unknown cie version %d (wanted 1-3)", vers);
continue;
}
aug = dwarfgetstring(&b);
if(aug && *aug){
if(++nbad == 1)
werrstr("unknown augmentation: %s", aug);
continue;
}
s->iquantum = dwarfget128(&b);
s->dquantum = dwarfget128s(&b);
s->rareg = dwarfget128(&b);
if(s->rareg > s->nr){
werrstr("return address is register %d but only have %d registers",
s->rareg, s->nr);
return -1;
}
s->init.p = b.p;
s->init.ep = next;
}else{ /* FDE */
base = dwarfgetaddr(&b);
size = dwarfgetaddr(&b);
if (trace) werrstr("FDE: base %x-%x (want pc %x)", base, base+size, pc);
fde->p = b.p;
fde->ep = next;
s->loc = base;
s->endloc = base+size;
if(base <= pc && pc < base+size)
return 0;
}
}
werrstr("cannot find call frame information for pc 0x%lx", pc);
return -1;
}
static int
checkreg(State *s, long r)
{
if(r < 0 || r >= s->nr){
werrstr("bad register number 0x%lx", r);
return -1;
}
return 0;
}
static int
dexec(DwarfBuf *b, State *s, int locstop)
{
int c;
long arg1, arg2;
DwarfExpr *e;
for(;;){
if(b->p == b->ep){
if(s->initr)
s->loc = s->endloc;
werrstr("end dexec");
return 0;
}
c = dwarfget1(b);
if(b->p == nil){
werrstr("ran out of instructions during cfa program");
if(trace) werrstr("%r");
return -1;
}
if(trace) werrstr("+ loc=0x%x op 0x%x ", s->loc, c);
switch(c>>6){
case 1: /* advance location */
arg1 = c&0x3F;
advance:
if(trace) werrstr("loc += %ld", arg1*s->iquantum);
s->loc += arg1 * s->iquantum;
if(locstop)
return 0;
continue;
case 2: /* offset rule */
arg1 = c&0x3F;
arg2 = dwarfget128(b);
offset:
if(trace) werrstr("r%ld += %ld", arg1, arg2*s->dquantum);
if(checkreg(s, arg1) < 0)
return -1;
s->r[arg1].type = RuleCfaOffset;
s->r[arg1].offset = arg2 * s->dquantum;
continue;
case 3: /* restore initial setting */
arg1 = c&0x3F;
restore:
if(trace) werrstr("r%ld = init", arg1);
if(checkreg(s, arg1) < 0)
return -1;
s->r[arg1] = s->initr[arg1];
continue;
}
switch(c){
case 0: /* nop */
if(trace) werrstr("nop");
continue;
case 0x01: /* set location */
s->loc = dwarfgetaddr(b);
if(trace) werrstr("loc = 0x%lx", s->loc);
if(locstop)
return 0;
continue;
case 0x02: /* advance loc1 */
arg1 = dwarfget1(b);
goto advance;
case 0x03: /* advance loc2 */
arg1 = dwarfget2(b);
goto advance;
case 0x04: /* advance loc4 */
arg1 = dwarfget4(b);
goto advance;
case 0x05: /* offset extended */
arg1 = dwarfget128(b);
arg2 = dwarfget128(b);
goto offset;
case 0x06: /* restore extended */
arg1 = dwarfget128(b);
goto restore;
case 0x07: /* undefined */
arg1 = dwarfget128(b);
if(trace) werrstr("r%ld = undef", arg1);
if(checkreg(s, arg1) < 0)
return -1;
s->r[arg1].type = RuleUndef;
continue;
case 0x08: /* same value */
arg1 = dwarfget128(b);
if(trace) werrstr("r%ld = same", arg1);
if(checkreg(s, arg1) < 0)
return -1;
s->r[arg1].type = RuleSame;
continue;
case 0x09: /* register */
arg1 = dwarfget128(b);
arg2 = dwarfget128(b);
if(trace) werrstr("r%ld = r%ld", arg1, arg2);
if(checkreg(s, arg1) < 0 || checkreg(s, arg2) < 0)
return -1;
s->r[arg1].type = RuleRegister;
s->r[arg1].reg = arg2;
continue;
case 0x0A: /* remember state */
e = malloc(s->nr*sizeof(e[0]));
if(trace) werrstr("push");
if(e == nil)
return -1;
void *newstack = malloc(s->nstack*sizeof(s->stack[0]));
RtlMoveMemory(newstack, s->stack, s->nstack*sizeof(s->stack[0]));
if (newstack) {
free(s->stack);
s->stack = newstack;
} else {
free(e);
return -1;
}
if(b->p == nil){
free(e);
return -1;
}
s->stack[s->nstack++] = e;
memmove(e, s->r, s->nr*sizeof(e[0]));
continue;
case 0x0B: /* restore state */
if(trace) werrstr("pop");
if(s->nstack == 0){
werrstr("restore state underflow");
return -1;
}
e = s->stack[s->nstack-1];
memmove(s->r, e, s->nr*sizeof(e[0]));
free(e);
s->nstack--;
continue;
case 0x0C: /* def cfa */
arg1 = dwarfget128(b);
arg2 = dwarfget128(b);
defcfa:
if(trace) werrstr("cfa %ld(r%ld)", arg2, arg1);
if(checkreg(s, arg1) < 0)
return -1;
s->cfa->type = RuleRegOff;
s->cfa->reg = arg1;
s->cfa->offset = arg2;
continue;
case 0x0D: /* def cfa register */
arg1 = dwarfget128(b);
if(trace) werrstr("cfa reg r%ld", arg1);
if(s->cfa->type != RuleRegOff){
werrstr("change CFA register but CFA not in register+offset form");
return -1;
}
if(checkreg(s, arg1) < 0)
return -1;
s->cfa->reg = arg1;
continue;
case 0x0E: /* def cfa offset */
arg1 = dwarfget128(b);
cfaoffset:
if(trace) werrstr("cfa off %ld", arg1);
if(s->cfa->type != RuleRegOff){
werrstr("change CFA offset but CFA not in register+offset form");
return -1;
}
s->cfa->offset = arg1;
continue;
case 0x0F: /* def cfa expression */
if(trace) werrstr("cfa expr");
s->cfa->type = RuleLocation;
s->cfa->loc.len = dwarfget128(b);
s->cfa->loc.data = dwarfgetnref(b, s->cfa->loc.len);
continue;
case 0x10: /* def reg expression */
arg1 = dwarfget128(b);
if(trace) werrstr("reg expr r%ld", arg1);
if(checkreg(s, arg1) < 0)
return -1;
s->r[arg1].type = RuleLocation;
s->r[arg1].loc.len = dwarfget128(b);
s->r[arg1].loc.data = dwarfgetnref(b, s->r[arg1].loc.len);
continue;
case 0x11: /* offset extended */
arg1 = dwarfget128(b);
arg2 = dwarfget128s(b);
goto offset;
case 0x12: /* cfa sf */
arg1 = dwarfget128(b);
arg2 = dwarfget128s(b);
goto defcfa;
case 0x13: /* cfa offset sf */
arg1 = dwarfget128s(b);
goto cfaoffset;
default: /* unknown */
werrstr("unknown opcode 0x%x in cfa program", c);
return -1;
}
}
/* not reached */
}
int dwarfcomputecfa(Dwarf *d, DwarfExpr *cfa, PROSSYM_REGISTERS registers, ulong *cfaLocation)
{
switch (cfa->type) {
case RuleRegOff:
*cfaLocation = registers->Registers[cfa->reg] + cfa->offset;
werrstr("cfa reg %d (%x) offset %x = %x", cfa->reg, (ulong)registers->Registers[cfa->reg], cfa->offset, cfaLocation);
break;
default:
werrstr("cfa->type %x", cfa->type);
return -1;
}
return 0;
}
int dwarfregunwind(Dwarf *d, ulong pc, ulong fde, DwarfExpr *cfa, PROSSYM_REGISTERS registers)
{
int i;
State s = { };
DwarfExpr initr[sizeof(registers->Registers) / sizeof(registers->Registers[0])] = { };
DwarfExpr r[sizeof(registers->Registers) / sizeof(registers->Registers[0])] = { };
DwarfExpr ra;
int nr = s.nr = sizeof(registers->Registers) / sizeof(registers->Registers[0]);
s.initr = initr;
s.r = r;
for (i = 0; i < sizeof(r) / sizeof(r[0]); i++) {
r[i].type = RuleRegister;
r[i].offset = registers->Registers[i];
r[i].reg = i;
}
int res = dwarfunwind(d, pc, cfa, &ra, initr, sizeof(initr) / sizeof(initr[0]));
if (res == -1) return -1;
ulong cfaLocation;
if (dwarfcomputecfa(d, cfa, registers, &cfaLocation) == -1)
return -1;
for (i = 0; i < nr; i++) {
switch (r[i].type) {
case RuleUndef:
werrstr("Undefined register slot %d", i);
assert(FALSE);
break;
case RuleSame:
break;
case RuleRegister:
registers->Registers[i] = registers->Registers[r[i].reg];
break;
case RuleRegOff: {
BOOLEAN success =
RosSymCallbacks.MemGetProc
(d->pe->fd,
&registers->Registers[i],
r[i].offset + registers->Registers[r[i].reg],
d->addrsize);
if (!success) return -1;
} break;
case RuleCfaOffset:
{
BOOLEAN success =
RosSymCallbacks.MemGetProc
(d->pe->fd,
&registers->Registers[i],
r[i].offset + cfaLocation,
d->addrsize);
werrstr("reg[%d] = %x: cfa offset (cfa %x, offset %x) -> @%x", i, (ulong)registers->Registers[i], cfaLocation, initr[i].offset, r[i].offset + cfaLocation);
if (!success) return -1;
} break;
default:
werrstr("We don't yet support cfa rule %d in slot %d", r[i].type, i);
assert(FALSE);
break;
}
}
ulong cfaSpace[4];
for (i = 0; i < sizeof(cfaSpace) / sizeof(cfaSpace[0]); i++) {
RosSymCallbacks.MemGetProc
(d->pe->fd, &cfaSpace[i], cfaLocation + (i * 4), d->addrsize);
}
werrstr("CFA(%x) [%08x, %08x, %08x, %08x]",
cfaLocation, cfaSpace[0], cfaSpace[1], cfaSpace[2], cfaSpace[3]);
return 0;
}
Reference in a new issue View git blame Copy permalink