129 lines
2.3 KiB
C
129 lines
2.3 KiB
C
/* $OpenBSD: alloc.c,v 1.19 2018/01/16 22:52:32 jca Exp $ */
|
|
|
|
/* Public domain, like most of the rest of ksh */
|
|
|
|
/*
|
|
* area-based allocation built on malloc/free
|
|
*/
|
|
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
|
|
#include "sh.h"
|
|
|
|
struct link {
|
|
struct link *prev;
|
|
struct link *next;
|
|
};
|
|
|
|
Area *
|
|
ainit(Area *ap)
|
|
{
|
|
ap->freelist = NULL;
|
|
return ap;
|
|
}
|
|
|
|
void
|
|
afreeall(Area *ap)
|
|
{
|
|
struct link *l, *l2;
|
|
|
|
for (l = ap->freelist; l != NULL; l = l2) {
|
|
l2 = l->next;
|
|
free(l);
|
|
}
|
|
ap->freelist = NULL;
|
|
}
|
|
|
|
#define L2P(l) ( (void *)(((char *)(l)) + sizeof(struct link)) )
|
|
#define P2L(p) ( (struct link *)(((char *)(p)) - sizeof(struct link)) )
|
|
|
|
void *
|
|
alloc(size_t size, Area *ap)
|
|
{
|
|
struct link *l;
|
|
|
|
/* ensure that we don't overflow by allocating space for link */
|
|
if (size > SIZE_MAX - sizeof(struct link))
|
|
internal_errorf("unable to allocate memory");
|
|
|
|
l = malloc(sizeof(struct link) + size);
|
|
if (l == NULL)
|
|
internal_errorf("unable to allocate memory");
|
|
l->next = ap->freelist;
|
|
l->prev = NULL;
|
|
if (ap->freelist)
|
|
ap->freelist->prev = l;
|
|
ap->freelist = l;
|
|
|
|
return L2P(l);
|
|
}
|
|
|
|
/*
|
|
* Copied from calloc().
|
|
*
|
|
* This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
|
|
* if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
|
|
*/
|
|
#define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 4))
|
|
|
|
void *
|
|
areallocarray(void *ptr, size_t nmemb, size_t size, Area *ap)
|
|
{
|
|
/* condition logic cloned from calloc() */
|
|
if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
|
|
nmemb > 0 && SIZE_MAX / nmemb < size) {
|
|
internal_errorf("unable to allocate memory");
|
|
}
|
|
|
|
return aresize(ptr, nmemb * size, ap);
|
|
}
|
|
|
|
void *
|
|
aresize(void *ptr, size_t size, Area *ap)
|
|
{
|
|
struct link *l, *l2, *lprev, *lnext;
|
|
|
|
if (ptr == NULL)
|
|
return alloc(size, ap);
|
|
|
|
/* ensure that we don't overflow by allocating space for link */
|
|
if (size > SIZE_MAX - sizeof(struct link))
|
|
internal_errorf("unable to allocate memory");
|
|
|
|
l = P2L(ptr);
|
|
lprev = l->prev;
|
|
lnext = l->next;
|
|
|
|
l2 = realloc(l, sizeof(struct link) + size);
|
|
if (l2 == NULL)
|
|
internal_errorf("unable to allocate memory");
|
|
if (lprev)
|
|
lprev->next = l2;
|
|
else
|
|
ap->freelist = l2;
|
|
if (lnext)
|
|
lnext->prev = l2;
|
|
|
|
return L2P(l2);
|
|
}
|
|
|
|
void
|
|
afree(void *ptr, Area *ap)
|
|
{
|
|
struct link *l;
|
|
|
|
if (!ptr)
|
|
return;
|
|
|
|
l = P2L(ptr);
|
|
if (l->prev)
|
|
l->prev->next = l->next;
|
|
else
|
|
ap->freelist = l->next;
|
|
if (l->next)
|
|
l->next->prev = l->prev;
|
|
|
|
free(l);
|
|
}
|