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__CRAZY cleanliness: pointer arithmetic

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tg 2008-11-12 05:11:05 +00:00
parent 7cbc0b6fa2
commit 4b456b1457
1 changed files with 18 additions and 17 deletions
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35
aalloc.c
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@ -1,6 +1,6 @@
#include "sh.h" #include "sh.h"
__RCSID("$MirOS: src/bin/mksh/aalloc.c,v 1.3 2008/11/12 05:05:17 tg Exp $"); __RCSID("$MirOS: src/bin/mksh/aalloc.c,v 1.4 2008/11/12 05:11:05 tg Exp $");
/* mksh integration of aalloc */ /* mksh integration of aalloc */
@ -37,7 +37,7 @@ typedef /* unsigned */ ptrdiff_t TCookie;
typedef union { typedef union {
TCookie iv; TCookie iv;
void *pv; char *pv;
} TPtr; } TPtr;
/* /*
@ -54,8 +54,8 @@ typedef union {
struct TBlock { struct TBlock {
TCookie cookie; TCookie cookie;
void *endp; char *endp;
void *last; char *last;
void *storage; void *storage;
}; };
typedef struct TBlock *PBlock; typedef struct TBlock *PBlock;
@ -172,11 +172,11 @@ anew(void)
} while (!(bp->cookie & PVMASK)); } while (!(bp->cookie & PVMASK));
/* first byte after block */ /* first byte after block */
bp->endp = bp + AALLOC_INITSZ; /* bp + size of the block */ bp->endp = (char *)bp + AALLOC_INITSZ; /* bp + size of the block */
/* next entry (forward pointer) available for new allocation */ /* next entry (forward pointer) available for new allocation */
bp->last = &bp->storage; /* first entry */ bp->last = (char *)&bp->storage; /* first entry */
ap->bp.pv = bp; ap->bp.pv = (char *)bp;
ap->bp.iv ^= gcookie; ap->bp.iv ^= gcookie;
#ifdef AALLOC_TRACK #ifdef AALLOC_TRACK
ap->prev.pv = track; ap->prev.pv = track;
@ -203,7 +203,7 @@ check_bp(PArea ap, const char *funcname, TCookie ocookie)
return (NULL); return (NULL);
} }
p.iv = ap->bp.iv ^ gcookie; p.iv = ap->bp.iv ^ gcookie;
if ((ptrdiff_t)(bp = p.pv) & PVMASK) { if ((ptrdiff_t)(bp = (PBlock)p.pv) & PVMASK) {
AALLOC_WARN("%s: area %p block pointer destroyed: %08tX", AALLOC_WARN("%s: area %p block pointer destroyed: %08tX",
funcname, ap, p.iv); funcname, ap, p.iv);
return (NULL); return (NULL);
@ -219,12 +219,12 @@ check_bp(PArea ap, const char *funcname, TCookie ocookie)
funcname, bp, bp->endp, bp->last); funcname, bp, bp->endp, bp->last);
return (NULL); return (NULL);
} }
if (bp->endp < (void *)bp) { if (bp->endp < (char *)bp) {
AALLOC_WARN("%s: block %p end pointer out of bounds: %p", AALLOC_WARN("%s: block %p end pointer out of bounds: %p",
funcname, bp, bp->endp); funcname, bp, bp->endp);
return (NULL); return (NULL);
} }
if ((bp->last < (void *)&bp->storage) || (bp->last >= bp->endp)) { if ((bp->last < (char *)&bp->storage) || (bp->last >= bp->endp)) {
AALLOC_WARN("%s: block %p last pointer out of bounds: " AALLOC_WARN("%s: block %p last pointer out of bounds: "
"%p < %p < %p", funcname, bp, &bp->storage, bp->last, "%p < %p < %p", funcname, bp, &bp->storage, bp->last,
bp->endp); bp->endp);
@ -275,13 +275,13 @@ adelete_leak(PArea ap, PBlock bp)
{ {
TPtr *cp; TPtr *cp;
while (bp->last > (void *)&bp->storage) { while (bp->last > (char *)&bp->storage) {
bp->last -= PVALIGN; bp->last -= PVALIGN;
cp = *((void **)bp->last); cp = *((void **)bp->last);
cp->iv ^= bp->cookie; cp->iv ^= bp->cookie;
AALLOC_WARN("leaking %s pointer %p in area %p (%p %tu)", AALLOC_WARN("leaking %s pointer %p in area %p (%p %tu)",
cp->pv == bp->last ? "valid" : "underflown", cp->pv == bp->last ? "valid" : "underflown",
(char *)cp + PVALIGN, ap, bp, bp->endp - (void *)bp); (char *)cp + PVALIGN, ap, bp, bp->endp - (char *)bp);
free(cp); free(cp);
} }
} }
@ -296,7 +296,7 @@ adelete(PArea *pap)
/* ignore invalid areas */ /* ignore invalid areas */
if ((bp = check_bp(*pap, "adelete", 0)) == NULL) { if ((bp = check_bp(*pap, "adelete", 0)) == NULL) {
if (bp->last != &bp->storage) if (bp->last != (char *)&bp->storage)
adelete_leak(*pap, bp); adelete_leak(*pap, bp);
free(bp); free(bp);
} }
@ -351,12 +351,12 @@ alloc(size_t nmemb, size_t size, PArea ap)
size_t bsz; size_t bsz;
/* make room for more forward ptrs in the block allocation */ /* make room for more forward ptrs in the block allocation */
bsz = bp->endp - (void *)bp; bsz = bp->endp - (char *)bp;
safe_muladd((size_t)2, bsz, 0); safe_muladd((size_t)2, bsz, 0);
safe_realloc(bp, bsz); safe_realloc(bp, bsz);
/* “bp” has possibly changed, enter its new value into ap */ /* “bp” has possibly changed, enter its new value into ap */
ap->bp.pv = bp; ap->bp.pv = (char *)bp;
ap->bp.iv ^= gcookie; ap->bp.iv ^= gcookie;
} }
*((void **)bp->last) = ptr; /* next available forward ptr */ *((void **)bp->last) = ptr; /* next available forward ptr */
@ -424,7 +424,7 @@ check_ptr(void *vp, PArea ap, PBlock *bpp, const char *what, const char *extra)
if ((bp = check_bp(ap, what, 0)) == NULL) if ((bp = check_bp(ap, what, 0)) == NULL)
AALLOC_ABORT("cannot continue"); AALLOC_ABORT("cannot continue");
ptr->iv ^= bp->cookie; ptr->iv ^= bp->cookie;
if (ptr->pv < (void *)&bp->storage || ptr->pv >= bp->last) { if (ptr->pv < (char *)&bp->storage || ptr->pv >= bp->last) {
AALLOC_WARN("trying to %s rogue pointer %p from area %p " AALLOC_WARN("trying to %s rogue pointer %p from area %p "
"(block %p..%p), backpointer %p out of bounds%s", "(block %p..%p), backpointer %p out of bounds%s",
what + 1, vp, ap, bp, bp->last, ptr->pv, extra); what + 1, vp, ap, bp, bp->last, ptr->pv, extra);
@ -460,8 +460,9 @@ afree(void *vp, PArea ap)
bp->last -= PVALIGN; /* mark the last forward pointer as free */ bp->last -= PVALIGN; /* mark the last forward pointer as free */
/* if our forward pointer was not the last one, relocate the latter */ /* if our forward pointer was not the last one, relocate the latter */
if (ptr->pv < bp->last) { if (ptr->pv < bp->last) {
TPtr *tmp = bp->last; /* former last forward pointer */ TPtr *tmp;
tmp = (TPtr *)bp->last; /* former last forward pointer */
tmp->pv = ptr->pv; /* its backpointer to former our … */ tmp->pv = ptr->pv; /* its backpointer to former our … */
tmp->iv ^= bp->cookie; /* … forward pointer, and cookie it */ tmp->iv ^= bp->cookie; /* … forward pointer, and cookie it */