mksh/lalloc.c

194 lines
4.6 KiB
C

/*-
* Copyright (c) 2009, 2010, 2011, 2013, 2014, 2016
* mirabilos <m@mirbsd.org>
*
* Provided that these terms and disclaimer and all copyright notices
* are retained or reproduced in an accompanying document, permission
* is granted to deal in this work without restriction, including un-
* limited rights to use, publicly perform, distribute, sell, modify,
* merge, give away, or sublicence.
*
* This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
* the utmost extent permitted by applicable law, neither express nor
* implied; without malicious intent or gross negligence. In no event
* may a licensor, author or contributor be held liable for indirect,
* direct, other damage, loss, or other issues arising in any way out
* of dealing in the work, even if advised of the possibility of such
* damage or existence of a defect, except proven that it results out
* of said person's immediate fault when using the work as intended.
*/
#include "sh.h"
#ifdef MKSH_ALLOC_CATCH_UNDERRUNS
#include <err.h>
#endif
__RCSID("$MirOS: src/bin/mksh/lalloc.c,v 1.25 2016/02/24 02:08:39 tg Exp $");
/* build with CPPFLAGS+= -DUSE_REALLOC_MALLOC=0 on ancient systems */
#if defined(USE_REALLOC_MALLOC) && (USE_REALLOC_MALLOC == 0)
#define remalloc(p,n) ((p) == NULL ? malloc_osi(n) : realloc_osi((p), (n)))
#else
#define remalloc(p,n) realloc_osi((p), (n))
#endif
static struct lalloc_common *findptr(struct lalloc_common **, char *, Area *);
#ifndef MKSH_ALLOC_CATCH_UNDERRUNS
#define ALLOC_ISUNALIGNED(p) (((size_t)(p)) % ALLOC_SIZE)
#else
#define ALLOC_ISUNALIGNED(p) (((size_t)(p)) & 4095)
#undef remalloc
#undef free_osimalloc
static void
free_osimalloc(void *ptr)
{
struct lalloc_item *lp = ptr;
if (munmap(lp, lp->len))
err(1, "free_osimalloc");
}
static void *
remalloc(void *ptr, size_t size)
{
struct lalloc_item *lp, *lold = ptr;
size = (size + 4095) & ~(size_t)4095;
if (lold && lold->len >= size)
return (ptr);
if ((lp = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, (off_t)0)) == MAP_FAILED)
err(1, "remalloc: mmap(%zu)", size);
if (ALLOC_ISUNALIGNED(lp))
errx(1, "remalloc: unaligned(%p)", lp);
if (mprotect(((char *)lp) + 4096, 4096, PROT_NONE))
err(1, "remalloc: mprotect");
lp->len = size;
if (lold) {
memcpy(((char *)lp) + 8192, ((char *)lold) + 8192,
lold->len - 8192);
if (munmap(lold, lold->len))
err(1, "remalloc: munmap");
}
return (lp);
}
#endif
void
ainit(Area *ap)
{
#ifdef MKSH_ALLOC_CATCH_UNDERRUNS
if (sysconf(_SC_PAGESIZE) != 4096) {
fprintf(stderr, "mksh: fatal: pagesize %lu not 4096!\n",
sysconf(_SC_PAGESIZE));
fflush(stderr);
abort();
}
#endif
/* area pointer and items share struct lalloc_common */
ap->next = NULL;
}
static struct lalloc_common *
findptr(struct lalloc_common **lpp, char *ptr, Area *ap)
{
void *lp;
#ifndef MKSH_SMALL
if (ALLOC_ISUNALIGNED(ptr))
goto fail;
#endif
/* get address of ALLOC_ITEM from user item */
/*
* note: the alignment of "ptr" to ALLOC_SIZE is checked
* above; the "void *" gets us rid of a gcc 2.95 warning
*/
*lpp = (lp = ptr - ALLOC_SIZE);
/* search for allocation item in group list */
while (ap->next != lp)
if ((ap = ap->next) == NULL) {
#ifndef MKSH_SMALL
fail:
#endif
#ifdef DEBUG
internal_warningf("rogue pointer %zX in ap %zX",
(size_t)ptr, (size_t)ap);
/* try to get a coredump */
abort();
#else
internal_errorf("rogue pointer %zX", (size_t)ptr);
#endif
}
return ((void *)ap);
}
void *
aresize2(void *ptr, size_t fac1, size_t fac2, Area *ap)
{
if (notoktomul(fac1, fac2))
internal_errorf(Tintovfl, fac1, '*', fac2);
return (aresize(ptr, fac1 * fac2, ap));
}
void *
aresize(void *ptr, size_t numb, Area *ap)
{
struct lalloc_common *lp = NULL;
/* resizing (true) or newly allocating? */
if (ptr != NULL) {
struct lalloc_common *pp;
pp = findptr(&lp, ptr, ap);
pp->next = lp->next;
}
if (notoktoadd(numb, ALLOC_SIZE) ||
(lp = remalloc(lp, numb + ALLOC_SIZE)) == NULL
#ifndef MKSH_SMALL
|| ALLOC_ISUNALIGNED(lp)
#endif
)
internal_errorf(Toomem, numb);
/* this only works because Area and ALLOC_ITEM share lalloc_common */
lp->next = ap->next;
ap->next = lp;
/* return user item address */
return ((char *)lp + ALLOC_SIZE);
}
void
afree(void *ptr, Area *ap)
{
if (ptr != NULL) {
struct lalloc_common *lp, *pp;
pp = findptr(&lp, ptr, ap);
/* unhook */
pp->next = lp->next;
/* now free ALLOC_ITEM */
free_osimalloc(lp);
}
}
void
afreeall(Area *ap)
{
struct lalloc_common *lp;
/* traverse group (linked list) */
while ((lp = ap->next) != NULL) {
/* make next ALLOC_ITEM head of list */
ap->next = lp->next;
/* free old head */
free_osimalloc(lp);
}
}