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posibly a saner implementation (plist)

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This commit is contained in:
Kyryl Melekhin
2021-10-15 20:32:09 +00:00
parent 55a582230c
commit 3c384b905e
2 changed files with 14 additions and 14 deletions
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2
README
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@@ -124,7 +124,7 @@ chance of overflowing the int and getting a run on a false state
left from previous use of the regex. Though if overflow never left from previous use of the regex. Though if overflow never
happens there is no chance of getting a false state. Overflows happens there is no chance of getting a false state. Overflows
like this pose a high security threat, if the hacker knows like this pose a high security threat, if the hacker knows
how many cycles he needs to overflow the gen varible and get how many cycles he needs to overflow the gen variable and get
inconsistent result. It is possible to reset the marks if we inconsistent result. It is possible to reset the marks if we
near the overflow, but as you may guess that does not come near the overflow, but as you may guess that does not come
for free. for free.

26
pike.c
View File

@@ -458,17 +458,17 @@ if (--csub->ref == 0) { \
#define deccheck(nn) \ #define deccheck(nn) \
{ decref(nsub) goto rec_check##nn; } \ { decref(nsub) goto rec_check##nn; } \
#define onnlist(nn, list, listidx, when, pre) \ #define onnlist(nn) \
when for (j = 0; j < listidx; j++) \ for (j = 0; j < plistidx; j++) \
if (npc == list[j].pc) \ if (npc == plist[j]) \
{ pre deccheck(nn) } \ deccheck(nn) \
plist[plistidx++] = npc; \
#define onclist(nn, list, listidx, i, pre) \ #define onclist(nn) \
#define fastrec(nn, list, listidx) \ #define fastrec(nn, list, listidx) \
nsub->ref++; \ nsub->ref++; \
if (*npc < WBEG) { \ if (*npc < WBEG) { \
on##list(nn, list, listidx, /*nop*/, subs[i++] = nsub;) \
list[listidx].sub = nsub; \ list[listidx].sub = nsub; \
list[listidx++].pc = npc; \ list[listidx++].pc = npc; \
npc = pcs[i]; \ npc = pcs[i]; \
@@ -490,7 +490,6 @@ memcpy(s1->sub, nsub->sub, osubp); \
int i = 0; \ int i = 0; \
rec##nn: \ rec##nn: \
if (*npc < WBEG) { \ if (*npc < WBEG) { \
on##list(nn, list, listidx, if (i), /*nop*/) \
list[listidx].sub = nsub; \ list[listidx].sub = nsub; \
list[listidx++].pc = npc; \ list[listidx++].pc = npc; \
rec_check##nn: \ rec_check##nn: \
@@ -507,10 +506,12 @@ memcpy(s1->sub, nsub->sub, osubp); \
npc += 2 + npc[1]; \ npc += 2 + npc[1]; \
goto rec##nn; \ goto rec##nn; \
case SPLIT: \ case SPLIT: \
on##list(nn) \
npc += 2; \ npc += 2; \
pcs[i] = npc + npc[-1]; \ pcs[i] = npc + npc[-1]; \
fastrec(nn, list, listidx) \ fastrec(nn, list, listidx) \
case RSPLIT: \ case RSPLIT: \
on##list(nn) \
npc += 2; \ npc += 2; \
pcs[i] = npc; \ pcs[i] = npc; \
npc += npc[-1]; \ npc += npc[-1]; \
@@ -551,11 +552,11 @@ memcpy(s1->sub, nsub->sub, osubp); \
int re_pikevm(rcode *prog, const char *s, const char **subp, int nsubp) int re_pikevm(rcode *prog, const char *s, const char **subp, int nsubp)
{ {
int rsubsize = sizeof(rsub)+(sizeof(char*)*nsubp); int rsubsize = sizeof(rsub)+(sizeof(char*)*nsubp);
int i, j, c, suboff = rsubsize, *npc; int i, j, c, suboff = rsubsize, *npc, osubp = nsubp * sizeof(char*);
int clistidx = 0, nlistidx = 0, osubp = nsubp * sizeof(char*); int clistidx = 0, nlistidx = 0, plistidx = 0;
const char *sp = s, *_sp = s; const char *sp = s, *_sp = s;
int *insts = prog->insts; int *insts = prog->insts;
int *pcs[prog->splits]; int *pcs[prog->splits], *plist[prog->splits];
rsub *subs[prog->splits]; rsub *subs[prog->splits];
char nsubs[500000]; char nsubs[500000];
rsub *nsub, *s1, *matched = NULL, *freesub = NULL; rsub *nsub, *s1, *matched = NULL, *freesub = NULL;
@@ -597,14 +598,13 @@ int re_pikevm(rcode *prog, const char *s, const char **subp, int nsubp)
clist = nlist; clist = nlist;
nlist = tmp; nlist = tmp;
clistidx = nlistidx; clistidx = nlistidx;
nlistidx = 0; nlistidx = 0; plistidx = 0;
if (!matched) { if (!matched) {
jmp_start: jmp_start:
newsub(memset(s1->sub, 0, osubp);, /*nop*/) newsub(memset(s1->sub, 0, osubp);, /*nop*/)
s1->ref = 1; s1->ref = 1;
s1->sub[0] = _sp; s1->sub[0] = _sp;
nsub = s1; nsub = s1; npc = insts;
npc = insts;
addthread(1, clist, clistidx) addthread(1, clist, clistidx)
} else if (!clistidx) } else if (!clistidx)
break; break;