mirror of
https://github.com/reactos/reactos.git
synced 2024-11-10 00:34:39 +00:00
1da8f22b84
The function dexec uses the varable p only in one location where its checked against nil, It neither initialized, not used anywhere else. This is probably a typo and b->p was meant. Yes I'm completely guessing, but this code doesn't give any other chance then guessing and it will probably not be worse then using an uninitialized variable... @original author: please review. svn path=/branches/cmake-bringup/; revision=50450
407 lines
8.6 KiB
C
407 lines
8.6 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
|
|
#define NTOSAPI
|
|
#include <ntddk.h>
|
|
#include <reactos/rossym.h>
|
|
#include "rossympriv.h"
|
|
#include <ntimage.h>
|
|
|
|
#define NDEBUG
|
|
#include <debug.h>
|
|
|
|
#include "dwarf.h"
|
|
|
|
#define trace 0
|
|
|
|
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\n", 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%lux pc 0x%lux\n", s.loc, pc);
|
|
while(s.loc < pc){
|
|
if(trace) werrstr("s.loc 0x%lux pc 0x%lux\n", 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(vers != 1 && vers != 2 && vers != 3){
|
|
if(++nbad == 1)
|
|
werrstr("unknown cie version %d (wanted 1-3)\n", vers);
|
|
continue;
|
|
}
|
|
aug = dwarfgetstring(&b);
|
|
if(aug && *aug){
|
|
if(++nbad == 1)
|
|
werrstr("unknown augmentation: %s\n", 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);
|
|
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%lux", pc);
|
|
return -1;
|
|
|
|
}
|
|
|
|
static int
|
|
checkreg(State *s, long r)
|
|
{
|
|
if(r < 0 || r >= s->nr){
|
|
werrstr("bad register number 0x%lux", 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;
|
|
return 0;
|
|
}
|
|
c = dwarfget1(b);
|
|
if(b->p == nil){
|
|
werrstr("ran out of instructions during cfa program");
|
|
if(trace) werrstr("%r\n");
|
|
return -1;
|
|
}
|
|
if(trace) werrstr("+ loc=0x%lux op 0x%ux ", s->loc, c);
|
|
switch(c>>6){
|
|
case 1: /* advance location */
|
|
arg1 = c&0x3F;
|
|
advance:
|
|
if(trace) werrstr("loc += %ld\n", 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\n", 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\n", arg1);
|
|
if(checkreg(s, arg1) < 0)
|
|
return -1;
|
|
s->r[arg1] = s->initr[arg1];
|
|
continue;
|
|
}
|
|
|
|
switch(c){
|
|
case 0: /* nop */
|
|
if(trace) werrstr("nop\n");
|
|
continue;
|
|
|
|
case 0x01: /* set location */
|
|
s->loc = dwarfgetaddr(b);
|
|
if(trace) werrstr("loc = 0x%lux\n", 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\n", 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\n", 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\n", 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\n");
|
|
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\n");
|
|
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)\n", 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\n", 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\n", 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\n");
|
|
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\n", 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%ux in cfa program", c);
|
|
return -1;
|
|
}
|
|
}
|
|
/* not reached */
|
|
}
|
|
|
|
|