if the address of bp changes, all backpointers must be adjusted as well ☹

pretty expensive
This commit is contained in:
tg 2008-11-12 05:45:28 +00:00
parent 7f17e3fc91
commit 18b38ac5c7

View File

@ -1,6 +1,6 @@
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/aalloc.c,v 1.8 2008/11/12 05:40:23 tg Exp $");
__RCSID("$MirOS: src/bin/mksh/aalloc.c,v 1.9 2008/11/12 05:45:28 tg Exp $");
/* mksh integration of aalloc */
@ -349,6 +349,7 @@ alloc(size_t nmemb, size_t size, PArea ap)
if ((bp = check_bp(ap, "alloc", 0)) == NULL)
AALLOC_ABORT("cannot continue");
if (bp->last == bp->endp) {
TPtr *tp;
size_t bsz;
/* make room for more forward ptrs in the block allocation */
@ -358,6 +359,12 @@ alloc(size_t nmemb, size_t size, PArea ap)
bp->last = (char *)bp + (bsz / 2);
bp->endp = (char *)bp + bsz;
/* all backpointers have to be adjusted */
for (tp = (TPtr *)&bp->storage; tp < (TPtr *)bp->last; ++tp) {
tp->pv = (char *)tp;
tp->iv ^= bp->cookie;
}
/* “bp” has possibly changed, enter its new value into ap */
ap->bp.pv = (char *)bp;
ap->bp.iv ^= gcookie;