1219 lines
26 KiB
C
1219 lines
26 KiB
C
/*
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* ----------------------------------------------------------------------------
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* "THE BEER-WARE LICENSE" (Revision 42):
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* <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
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* can do whatever you want with this stuff. If we meet some day, and you think
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* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
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* ----------------------------------------------------------------------------
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*
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* $Id: malloc.c,v 1.9 1996/01/05 23:30:41 phk Exp $
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*
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*/
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/*
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* Defining EXTRA_SANITY will enable some checks which are related
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* to internal conditions and consistency in malloc.c
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*/
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#undef EXTRA_SANITY
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/*
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* Defining MALLOC_STATS will enable you to call malloc_dump() and set
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* the [dD] options in the MALLOC_OPTIONS environment variable.
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* It has no run-time performance hit.
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*/
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#define MALLOC_STATS
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#if defined(EXTRA_SANITY) && !defined(MALLOC_STATS)
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# define MALLOC_STATS /* required for EXTRA_SANITY */
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#endif
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/*
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* What to use for Junk
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*/
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#define SOME_JUNK 0xd0 /* as in "Duh" :-) */
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/*
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* If these weren't defined here, they would be calculated on the fly,
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* at a considerable cost in performance.
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*/
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#if defined(__i386__) && defined(__FreeBSD__)
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# define malloc_pagesize 4096U
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# define malloc_pageshift 12U
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# define malloc_minsize 16U
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# define malloc_maxsize ((malloc_pagesize)>>1)
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#endif /* __i386__ && __FreeBSD__ */
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <memory.h>
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#include <errno.h>
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#include <err.h>
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#include <sys/types.h>
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#include <sys/mman.h>
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#ifdef _THREAD_SAFE
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#include <pthread.h>
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#include "pthread_private.h"
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#endif
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/*
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* This structure describes a page worth of chunks.
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*/
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struct pginfo {
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struct pginfo *next; /* next on the free list */
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void *page; /* Pointer to the page */
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u_short size; /* size of this page's chunks */
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u_short shift; /* How far to shift for this size chunks */
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u_short free; /* How many free chunks */
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u_short total; /* How many chunk */
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u_long bits[1]; /* Which chunks are free */
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};
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/*
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* This structure describes a number of free pages.
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*/
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struct pgfree {
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struct pgfree *next; /* next run of free pages */
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struct pgfree *prev; /* prev run of free pages */
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void *page; /* pointer to free pages */
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void *end; /* pointer to end of free pages */
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u_long size; /* number of bytes free */
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};
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/*
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* How many bits per u_long in the bitmap.
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* Change only if not 8 bits/byte
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*/
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#define MALLOC_BITS (8*sizeof(u_long))
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/*
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* Magic values to put in the page_directory
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*/
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#define MALLOC_NOT_MINE ((struct pginfo*) 0)
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#define MALLOC_FREE ((struct pginfo*) 1)
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#define MALLOC_FIRST ((struct pginfo*) 2)
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#define MALLOC_FOLLOW ((struct pginfo*) 3)
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#define MALLOC_MAGIC ((struct pginfo*) 4)
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/*
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* The i386 architecture has some very convenient instructions.
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* We might as well use them. There are C-language backups, but
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* they are considerably slower.
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*/
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#ifdef __i386__
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#define ffs _ffs
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static __inline int
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_ffs(unsigned input)
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{
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int result;
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asm("bsfl %1,%0" : "=r" (result) : "r" (input));
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return result+1;
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}
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#define fls _fls
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static __inline int
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_fls(unsigned input)
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{
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int result;
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asm("bsrl %1,%0" : "=r" (result) : "r" (input));
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return result+1;
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}
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#define set_bit _set_bit
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static __inline void
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_set_bit(struct pginfo *pi, int bit)
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{
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asm("btsl %0,(%1)" :
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: "r" (bit & (MALLOC_BITS-1)), "r" (pi->bits+(bit/MALLOC_BITS)));
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}
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#define clr_bit _clr_bit
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static __inline void
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_clr_bit(struct pginfo *pi, int bit)
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{
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asm("btcl %0,(%1)" :
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: "r" (bit & (MALLOC_BITS-1)), "r" (pi->bits+(bit/MALLOC_BITS)));
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}
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#endif /* __i386__ */
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/*
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* Set to one when malloc_init has been called
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*/
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static unsigned initialized;
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/*
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* The size of a page.
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* Must be a integral multiplum of the granularity of mmap(2).
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* Your toes will curl if it isn't a power of two
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*/
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#ifndef malloc_pagesize
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static unsigned malloc_pagesize;
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#endif /* malloc_pagesize */
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/*
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* A mask for the offset inside a page.
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*/
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#define malloc_pagemask ((malloc_pagesize)-1)
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#define pageround(foo) (((foo) + (malloc_pagemask))&(~(malloc_pagemask)))
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#define ptr2index(foo) (((u_long)(foo) >> malloc_pageshift)-malloc_origo)
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/*
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* malloc_pagesize == 1 << malloc_pageshift
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*/
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#ifndef malloc_pageshift
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static unsigned malloc_pageshift;
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#endif /* malloc_pageshift */
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/*
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* The smallest allocation we bother about.
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* Must be power of two
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*/
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#ifndef malloc_minsize
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static unsigned malloc_minsize;
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#endif /* malloc_minsize */
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/*
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* The largest chunk we care about.
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* Must be smaller than pagesize
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* Must be power of two
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*/
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#ifndef malloc_maxsize
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static unsigned malloc_maxsize;
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#endif /* malloc_maxsize */
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/*
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* The minimum size (in bytes) of the free page cache.
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*/
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#ifndef malloc_cache
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static unsigned malloc_cache;
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#endif /* malloc_cache */
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/*
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* The offset from pagenumber to index into the page directory
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*/
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static u_long malloc_origo;
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/*
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* The last index in the page directory we care about
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*/
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static u_long last_index;
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/*
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* Pointer to page directory.
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* Allocated "as if with" malloc
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*/
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static struct pginfo **page_dir;
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/*
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* How many slots in the page directory
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*/
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static unsigned malloc_ninfo;
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/*
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* Free pages line up here
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*/
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static struct pgfree free_list;
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/*
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* Abort() if we fail to get VM ?
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*/
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static int malloc_abort;
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/*
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* Are we trying to die ?
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*/
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static int suicide;
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#ifdef MALLOC_STATS
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/*
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* dump statistics
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*/
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static int malloc_stats;
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#endif /* MALLOC_STATS */
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/*
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* always realloc ?
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*/
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static int malloc_realloc;
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/*
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* zero fill ?
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*/
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static int malloc_zero;
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/*
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* junk fill ?
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*/
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static int malloc_junk;
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/*
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* my last break.
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*/
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static void *malloc_brk;
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/*
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* one location cache for free-list holders
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*/
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static struct pgfree *px;
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/*
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* Necessary function declarations
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*/
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static int extend_pgdir(u_long index);
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#ifdef MALLOC_STATS
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void
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malloc_dump(FILE *fd)
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{
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struct pginfo **pd;
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struct pgfree *pf;
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int j;
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pd = page_dir;
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/* print out all the pages */
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for(j=0;j<=last_index;j++) {
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fprintf(fd,"%08lx %5d ",(j+malloc_origo) << malloc_pageshift,j);
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if (pd[j] == MALLOC_NOT_MINE) {
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for(j++;j<=last_index && pd[j] == MALLOC_NOT_MINE;j++)
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;
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j--;
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fprintf(fd,".. %5d not mine\n", j);
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} else if (pd[j] == MALLOC_FREE) {
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for(j++;j<=last_index && pd[j] == MALLOC_FREE;j++)
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;
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j--;
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fprintf(fd,".. %5d free\n", j);
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} else if (pd[j] == MALLOC_FIRST) {
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for(j++;j<=last_index && pd[j] == MALLOC_FOLLOW;j++)
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;
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j--;
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fprintf(fd,".. %5d in use\n", j);
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} else if (pd[j] < MALLOC_MAGIC) {
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fprintf(fd,"(%p)\n", pd[j]);
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} else {
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fprintf(fd,"%p %d (of %d) x %d @ %p --> %p\n",
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pd[j],pd[j]->free, pd[j]->total,
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pd[j]->size, pd[j]->page, pd[j]->next);
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}
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}
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for(pf=free_list.next; pf; pf=pf->next) {
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fprintf(fd,"Free: @%p [%p...%p[ %ld ->%p <-%p\n",
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pf,pf->page,pf->end,pf->size,pf->prev,pf->next);
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if (pf == pf->next) {
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fprintf(fd,"Free_list loops.\n");
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break;
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}
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}
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/* print out various info */
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fprintf(fd,"Minsize\t%d\n",malloc_minsize);
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fprintf(fd,"Maxsize\t%d\n",malloc_maxsize);
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fprintf(fd,"Pagesize\t%d\n",malloc_pagesize);
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fprintf(fd,"Pageshift\t%d\n",malloc_pageshift);
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fprintf(fd,"FirstPage\t%ld\n",malloc_origo);
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fprintf(fd,"LastPage\t%ld %lx\n",last_index+malloc_pageshift,
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(last_index + malloc_pageshift) << malloc_pageshift);
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fprintf(fd,"Break\t%ld\n",(u_long)sbrk(0) >> malloc_pageshift);
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}
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#endif /* MALLOC_STATS */
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static void
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wrterror(char *p)
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{
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char *q = "Malloc error: ";
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suicide = 1;
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write(2,q,strlen(q));
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write(2,p,strlen(p));
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#ifdef MALLOC_STATS
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if (malloc_stats)
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malloc_dump(stderr);
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#endif /* MALLOC_STATS */
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abort();
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}
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static void
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wrtwarning(char *p)
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{
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char *q = "Malloc warning: ";
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if (malloc_abort)
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wrterror(p);
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write(2,q,strlen(q));
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write(2,p,strlen(p));
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}
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#ifdef EXTRA_SANITY
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static void
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malloc_exit()
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{
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FILE *fd = fopen("malloc.out","a");
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char *q = "malloc() warning: Couldn't dump stats.\n";
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if (fd) {
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malloc_dump(fd);
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fclose(fd);
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} else
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write(2,q,strlen(q));
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}
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#endif /* EXTRA_SANITY */
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/*
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* Allocate a number of pages from the OS
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*/
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static caddr_t
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map_pages(int pages)
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{
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caddr_t result,tail;
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result = (caddr_t)pageround((u_long)sbrk(0));
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tail = result + (pages << malloc_pageshift);
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if (brk(tail)) {
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#ifdef EXTRA_SANITY
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wrterror("(internal): map_pages fails\n");
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#endif /* EXTRA_SANITY */
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return 0;
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}
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last_index = ptr2index(tail) - 1;
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malloc_brk = tail;
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if ((last_index+1) >= malloc_ninfo && !extend_pgdir(last_index))
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return 0;;
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return result;
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}
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/*
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* Set a bit in the bitmap
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*/
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#ifndef set_bit
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static __inline void
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set_bit(struct pginfo *pi, int bit)
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{
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pi->bits[bit/MALLOC_BITS] |= 1<<(bit%MALLOC_BITS);
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}
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#endif /* set_bit */
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/*
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* Clear a bit in the bitmap
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*/
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#ifndef clr_bit
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static __inline void
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clr_bit(struct pginfo *pi, int bit)
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{
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pi->bits[bit/MALLOC_BITS] &= ~(1<<(bit%MALLOC_BITS));
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}
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#endif /* clr_bit */
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#ifndef tst_bit
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/*
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* Test a bit in the bitmap
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*/
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static __inline int
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tst_bit(struct pginfo *pi, int bit)
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{
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return pi->bits[bit/MALLOC_BITS] & (1<<(bit%MALLOC_BITS));
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}
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#endif /* tst_bit */
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/*
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* Find last bit
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*/
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#ifndef fls
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static __inline int
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fls(int size)
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{
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int i = 1;
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while (size >>= 1)
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i++;
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return i;
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}
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#endif /* fls */
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/*
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* Extend page directory
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*/
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static int
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extend_pgdir(u_long index)
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{
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struct pginfo **new,**old;
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int i, oldlen;
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/* Make it this many pages */
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i = index * sizeof *page_dir;
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i /= malloc_pagesize;
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i += 2;
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/* remember the old mapping size */
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oldlen = malloc_ninfo * sizeof *page_dir;
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/*
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* NOTE: we allocate new pages and copy the directory rather than tempt
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* fate by trying to "grow" the region.. There is nothing to prevent
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* us from accidently re-mapping space that's been allocated by our caller
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* via dlopen() or other mmap().
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*
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* The copy problem is not too bad, as there is 4K of page index per
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* 4MB of malloc arena.
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*
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* We can totally avoid the copy if we open a file descriptor to associate
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* the anon mappings with. Then, when we remap the pages at the new
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* address, the old pages will be "magically" remapped.. But this means
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* keeping open a "secret" file descriptor.....
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*/
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/* Get new pages */
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new = (struct pginfo**) mmap(0, i * malloc_pagesize, PROT_READ|PROT_WRITE,
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MAP_ANON|MAP_PRIVATE, -1, 0);
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if (new == (struct pginfo **)-1)
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return 0;
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/* Copy the old stuff */
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memcpy(new, page_dir,
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malloc_ninfo * sizeof *page_dir);
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/* register the new size */
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malloc_ninfo = i * malloc_pagesize / sizeof *page_dir;
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/* swap the pointers */
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old = page_dir;
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page_dir = new;
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/* Now free the old stuff */
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munmap((caddr_t)old, oldlen);
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return 1;
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}
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|
|
/*
|
|
* Initialize the world
|
|
*/
|
|
static void
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malloc_init ()
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{
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char *p;
|
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|
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#ifdef EXTRA_SANITY
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malloc_junk = 1;
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#endif /* EXTRA_SANITY */
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|
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for (p=getenv("MALLOC_OPTIONS"); p && *p; p++) {
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switch (*p) {
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case 'a': malloc_abort = 0; break;
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case 'A': malloc_abort = 1; break;
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#ifdef MALLOC_STATS
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case 'd': malloc_stats = 0; break;
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case 'D': malloc_stats = 1; break;
|
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#endif /* MALLOC_STATS */
|
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case 'r': malloc_realloc = 0; break;
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case 'R': malloc_realloc = 1; break;
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case 'j': malloc_junk = 0; break;
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case 'J': malloc_junk = 1; break;
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case 'z': malloc_zero = 0; break;
|
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case 'Z': malloc_zero = 1; break;
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|
default:
|
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wrtwarning("(Init): Unknown char in MALLOC_OPTIONS\n");
|
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p = 0;
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break;
|
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}
|
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}
|
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|
|
/*
|
|
* We want junk in the entire allocation, and zero only in the part
|
|
* the user asked for.
|
|
*/
|
|
if (malloc_zero)
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malloc_junk=1;
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|
|
#ifdef EXTRA_SANITY
|
|
if (malloc_stats)
|
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atexit(malloc_exit);
|
|
#endif /* EXTRA_SANITY */
|
|
|
|
#ifndef malloc_pagesize
|
|
/* determine our pagesize */
|
|
malloc_pagesize = getpagesize();
|
|
#endif /* malloc_pagesize */
|
|
|
|
#ifndef malloc_maxsize
|
|
malloc_maxsize = malloc_pagesize >> 1;
|
|
#endif /* malloc_maxsize */
|
|
|
|
#ifndef malloc_pageshift
|
|
{
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int i;
|
|
/* determine how much we shift by to get there */
|
|
for (i = malloc_pagesize; i > 1; i >>= 1)
|
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malloc_pageshift++;
|
|
}
|
|
#endif /* malloc_pageshift */
|
|
|
|
#ifndef malloc_cache
|
|
malloc_cache = 100 << malloc_pageshift;
|
|
#endif /* malloc_cache */
|
|
|
|
#ifndef malloc_minsize
|
|
{
|
|
int i;
|
|
/*
|
|
* find the smallest size allocation we will bother about.
|
|
* this is determined as the smallest allocation that can hold
|
|
* it's own pginfo;
|
|
*/
|
|
i = 2;
|
|
for(;;) {
|
|
int j;
|
|
|
|
/* Figure out the size of the bits */
|
|
j = malloc_pagesize/i;
|
|
j /= 8;
|
|
if (j < sizeof(u_long))
|
|
j = sizeof (u_long);
|
|
if (sizeof(struct pginfo) + j - sizeof (u_long) <= i)
|
|
break;
|
|
i += i;
|
|
}
|
|
malloc_minsize = i;
|
|
}
|
|
#endif /* malloc_minsize */
|
|
|
|
/* Allocate one page for the page directory */
|
|
page_dir = (struct pginfo **) mmap(0, malloc_pagesize, PROT_READ|PROT_WRITE,
|
|
MAP_ANON|MAP_PRIVATE, -1, 0);
|
|
if (page_dir == (struct pginfo **) -1)
|
|
wrterror("(Init) my first mmap failed. (check limits ?)\n");
|
|
|
|
/*
|
|
* We need a maximum of malloc_pageshift buckets, steal these from the
|
|
* front of the page_directory;
|
|
*/
|
|
malloc_origo = ((u_long)pageround((u_long)sbrk(0))) >> malloc_pageshift;
|
|
malloc_origo -= malloc_pageshift;
|
|
|
|
malloc_ninfo = malloc_pagesize / sizeof *page_dir;
|
|
|
|
/* Been here, done that */
|
|
initialized++;
|
|
|
|
/*
|
|
* This is a nice hack from Kaleb Keithly (kaleb@x.org).
|
|
* We can sbrk(2) further back when we keep this on a low address.
|
|
*/
|
|
px = (struct pgfree *) malloc (sizeof *px);
|
|
}
|
|
|
|
/*
|
|
* Allocate a number of complete pages
|
|
*/
|
|
void *
|
|
malloc_pages(size_t size)
|
|
{
|
|
void *p,*delay_free = 0;
|
|
int i;
|
|
struct pgfree *pf;
|
|
u_long index;
|
|
|
|
size = pageround(size);
|
|
|
|
p = 0;
|
|
/* Look for free pages before asking for more */
|
|
for(pf = free_list.next; pf; pf = pf->next) {
|
|
|
|
#ifdef EXTRA_SANITY
|
|
if (pf->size & malloc_pagemask)
|
|
wrterror("(ES): junk length entry on free_list\n");
|
|
if (!pf->size)
|
|
wrterror("(ES): zero length entry on free_list\n");
|
|
if (pf->page == pf->end)
|
|
wrterror("(ES): zero entry on free_list\n");
|
|
if (pf->page > pf->end)
|
|
wrterror("(ES): sick entry on free_list\n");
|
|
if ((void*)pf->page >= (void*)sbrk(0))
|
|
wrterror("(ES): entry on free_list past brk\n");
|
|
if (page_dir[ptr2index(pf->page)] != MALLOC_FREE)
|
|
wrterror("(ES): non-free first page on free-list\n");
|
|
if (page_dir[ptr2index(pf->end)-1] != MALLOC_FREE)
|
|
wrterror("(ES): non-free last page on free-list\n");
|
|
#endif /* EXTRA_SANITY */
|
|
|
|
if (pf->size < size)
|
|
continue;
|
|
|
|
if (pf->size == size) {
|
|
p = pf->page;
|
|
if (pf->next)
|
|
pf->next->prev = pf->prev;
|
|
pf->prev->next = pf->next;
|
|
delay_free = pf;
|
|
break;
|
|
}
|
|
|
|
p = pf->page;
|
|
pf->page += size;
|
|
pf->size -= size;
|
|
break;
|
|
}
|
|
|
|
#ifdef EXTRA_SANITY
|
|
if (p && page_dir[ptr2index(p)] != MALLOC_FREE)
|
|
wrterror("(ES): allocated non-free page on free-list\n");
|
|
#endif /* EXTRA_SANITY */
|
|
|
|
size >>= malloc_pageshift;
|
|
|
|
/* Map new pages */
|
|
if (!p)
|
|
p = map_pages(size);
|
|
|
|
if (p) {
|
|
|
|
index = ptr2index(p);
|
|
page_dir[index] = MALLOC_FIRST;
|
|
for (i=1;i<size;i++)
|
|
page_dir[index+i] = MALLOC_FOLLOW;
|
|
|
|
if (malloc_junk)
|
|
memset(p, SOME_JUNK,size << malloc_pageshift);
|
|
}
|
|
|
|
if (delay_free) {
|
|
if (!px)
|
|
px = delay_free;
|
|
else
|
|
free(delay_free);
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
/*
|
|
* Allocate a page of fragments
|
|
*/
|
|
|
|
static __inline int
|
|
malloc_make_chunks(int bits)
|
|
{
|
|
struct pginfo *bp;
|
|
void *pp;
|
|
int i,k,l;
|
|
|
|
/* Allocate a new bucket */
|
|
pp = malloc_pages(malloc_pagesize);
|
|
if (!pp)
|
|
return 0;
|
|
|
|
/* Find length of admin structure */
|
|
l = sizeof *bp - sizeof(u_long);
|
|
l += sizeof(u_long) *
|
|
(((malloc_pagesize >> bits)+MALLOC_BITS-1) / MALLOC_BITS);
|
|
|
|
/* Don't waste more than two chunks on this */
|
|
if ((1<<(bits)) <= l+l) {
|
|
bp = (struct pginfo *)pp;
|
|
} else {
|
|
bp = (struct pginfo *)malloc(l);
|
|
if (!bp)
|
|
return 0;
|
|
}
|
|
|
|
bp->size = (1<<bits);
|
|
bp->shift = bits;
|
|
bp->total = bp->free = malloc_pagesize >> bits;
|
|
bp->page = pp;
|
|
|
|
page_dir[ptr2index(pp)] = bp;
|
|
|
|
bp->next = page_dir[bits];
|
|
page_dir[bits] = bp;
|
|
|
|
/* set all valid bits in the bits */
|
|
k = bp->total;
|
|
i = 0;
|
|
|
|
/* Do a bunch at a time */
|
|
for(;k-i >= MALLOC_BITS; i += MALLOC_BITS)
|
|
bp->bits[i / MALLOC_BITS] = ~0;
|
|
|
|
for(; i < k; i++)
|
|
set_bit(bp,i);
|
|
|
|
if (bp == bp->page) {
|
|
/* Mark the ones we stole for ourselves */
|
|
for(i=0;l > 0;i++) {
|
|
clr_bit(bp,i);
|
|
bp->free--;
|
|
bp->total--;
|
|
l -= (1 << bits);
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Allocate a fragment
|
|
*/
|
|
static void *
|
|
malloc_bytes(size_t size)
|
|
{
|
|
int j;
|
|
struct pginfo *bp;
|
|
int k;
|
|
u_long *lp;
|
|
|
|
/* Don't bother with anything less than this */
|
|
if (size < malloc_minsize)
|
|
size = malloc_minsize;
|
|
|
|
/* Find the right bucket */
|
|
j = fls((size)-1);
|
|
|
|
/* If it's empty, make a page more of that size chunks */
|
|
if (!page_dir[j] && !malloc_make_chunks(j))
|
|
return 0;
|
|
|
|
bp = page_dir[j];
|
|
|
|
/* Find first word of bitmap which isn't empty */
|
|
for (lp = bp->bits; !*lp; lp++)
|
|
;
|
|
|
|
/* Find that bit, and tweak it */
|
|
k = ffs(*lp) - 1;
|
|
*lp ^= 1<<k;
|
|
|
|
/* If there are no more free, remove from free-list */
|
|
if (!--bp->free) {
|
|
page_dir[j] = bp->next;
|
|
bp->next = 0;
|
|
}
|
|
|
|
/* Adjust to the real offset of that chunk */
|
|
k += (lp-bp->bits)*MALLOC_BITS;
|
|
k <<= bp->shift;
|
|
|
|
if (malloc_junk)
|
|
memset(bp->page + k, SOME_JUNK, bp->size);
|
|
|
|
return bp->page + k;
|
|
}
|
|
|
|
/*
|
|
* Allocate a piece of memory
|
|
*/
|
|
void *
|
|
malloc(size_t size)
|
|
{
|
|
void *result;
|
|
#ifdef _THREAD_SAFE
|
|
int status;
|
|
#endif
|
|
|
|
if (!initialized)
|
|
malloc_init();
|
|
|
|
if (suicide)
|
|
abort();
|
|
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_block(&status);
|
|
#endif
|
|
if (size <= malloc_maxsize)
|
|
result = malloc_bytes(size);
|
|
else
|
|
result = malloc_pages(size);
|
|
|
|
if (malloc_abort && !result)
|
|
wrterror("malloc(): returns NULL\n");
|
|
|
|
if (malloc_zero)
|
|
memset(result,0,size);
|
|
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Change the size of an allocation.
|
|
*/
|
|
void *
|
|
realloc(void *ptr, size_t size)
|
|
{
|
|
void *p;
|
|
u_long osize,index;
|
|
struct pginfo **mp;
|
|
int i;
|
|
#ifdef _THREAD_SAFE
|
|
int status;
|
|
#endif
|
|
|
|
if (suicide)
|
|
return 0;
|
|
|
|
if (!ptr) /* Bounce to malloc() */
|
|
return malloc(size);
|
|
|
|
if (!initialized) {
|
|
wrtwarning("realloc(): malloc() never got called.\n");
|
|
return 0;
|
|
}
|
|
|
|
if (ptr && !size) { /* Bounce to free() */
|
|
free(ptr);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_block(&status);
|
|
#endif
|
|
index = ptr2index(ptr);
|
|
|
|
if (index < malloc_pageshift) {
|
|
wrtwarning("realloc(): junk pointer (too low)\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
if (index > last_index) {
|
|
wrtwarning("realloc(): junk pointer (too high)\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
mp = &page_dir[index];
|
|
|
|
if (*mp == MALLOC_FIRST) { /* Page allocation */
|
|
|
|
/* Check the pointer */
|
|
if ((u_long)ptr & malloc_pagemask) {
|
|
wrtwarning("realloc(): modified page pointer.\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* Find the size in bytes */
|
|
for (osize = malloc_pagesize; *++mp == MALLOC_FOLLOW;)
|
|
osize += malloc_pagesize;
|
|
|
|
if (!malloc_realloc && /* unless we have to, */
|
|
size <= osize && /* .. or are too small, */
|
|
size > (osize - malloc_pagesize)) { /* .. or can free a page, */
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return ptr; /* don't do anything. */
|
|
}
|
|
|
|
} else if (*mp >= MALLOC_MAGIC) { /* Chunk allocation */
|
|
|
|
/* Check the pointer for sane values */
|
|
if (((u_long)ptr & ((*mp)->size-1))) {
|
|
wrtwarning("realloc(): modified chunk pointer.\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* Find the chunk index in the page */
|
|
i = ((u_long)ptr & malloc_pagemask) >> (*mp)->shift;
|
|
|
|
/* Verify that it isn't a free chunk already */
|
|
if (tst_bit(*mp,i)) {
|
|
wrtwarning("realloc(): already free chunk.\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
osize = (*mp)->size;
|
|
|
|
if (!malloc_realloc && /* Unless we have to, */
|
|
size < osize && /* ..or are too small, */
|
|
(size > osize/2 || /* ..or could use a smaller size, */
|
|
osize == malloc_minsize)) { /* ..(if there is one) */
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return ptr; /* ..Don't do anything */
|
|
}
|
|
|
|
} else {
|
|
wrtwarning("realloc(): wrong page pointer.\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
p = malloc(size);
|
|
|
|
if (p) {
|
|
/* copy the lesser of the two sizes, and free the old one */
|
|
if (osize < size)
|
|
memcpy(p,ptr,osize);
|
|
else
|
|
memcpy(p,ptr,size);
|
|
free(ptr);
|
|
}
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return p;
|
|
}
|
|
|
|
/*
|
|
* Free a sequence of pages
|
|
*/
|
|
|
|
static __inline void
|
|
free_pages(void *ptr, int index, struct pginfo *info)
|
|
{
|
|
int i;
|
|
struct pgfree *pf,*pt;
|
|
u_long l;
|
|
void *tail;
|
|
|
|
if (info == MALLOC_FREE) {
|
|
wrtwarning("free(): already free page.\n");
|
|
return;
|
|
}
|
|
|
|
if (info != MALLOC_FIRST) {
|
|
wrtwarning("free(): freeing wrong page.\n");
|
|
return;
|
|
}
|
|
|
|
if ((u_long)ptr & malloc_pagemask) {
|
|
wrtwarning("free(): modified page pointer.\n");
|
|
return;
|
|
}
|
|
|
|
/* Count how many pages and mark them free at the same time */
|
|
page_dir[index] = MALLOC_FREE;
|
|
for (i = 1; page_dir[index+i] == MALLOC_FOLLOW; i++)
|
|
page_dir[index + i] = MALLOC_FREE;
|
|
|
|
l = i << malloc_pageshift;
|
|
|
|
tail = ptr+l;
|
|
|
|
/* add to free-list */
|
|
if (!px)
|
|
px = malloc(sizeof *pt); /* This cannot fail... */
|
|
px->page = ptr;
|
|
px->end = tail;
|
|
px->size = l;
|
|
if (!free_list.next) {
|
|
|
|
/* Nothing on free list, put this at head */
|
|
px->next = free_list.next;
|
|
px->prev = &free_list;
|
|
free_list.next = px;
|
|
pf = px;
|
|
px = 0;
|
|
|
|
} else {
|
|
|
|
/* Find the right spot, leave pf pointing to the modified entry. */
|
|
tail = ptr+l;
|
|
|
|
for(pf = free_list.next; pf->end < ptr && pf->next; pf = pf->next)
|
|
; /* Race ahead here */
|
|
|
|
if (pf->page > tail) {
|
|
/* Insert before entry */
|
|
px->next = pf;
|
|
px->prev = pf->prev;
|
|
pf->prev = px;
|
|
px->prev->next = px;
|
|
pf = px;
|
|
px = 0;
|
|
} else if (pf->end == ptr ) {
|
|
/* Append to the previous entry */
|
|
pf->end += l;
|
|
pf->size += l;
|
|
if (pf->next && pf->end == pf->next->page ) {
|
|
/* And collapse the next too. */
|
|
pt = pf->next;
|
|
pf->end = pt->end;
|
|
pf->size += pt->size;
|
|
pf->next = pt->next;
|
|
if (pf->next)
|
|
pf->next->prev = pf;
|
|
free(pt);
|
|
}
|
|
} else if (pf->page == tail) {
|
|
/* Prepend to entry */
|
|
pf->size += l;
|
|
pf->page = ptr;
|
|
} else if (!pf->next) {
|
|
/* Append at tail of chain */
|
|
px->next = 0;
|
|
px->prev = pf;
|
|
pf->next = px;
|
|
pf = px;
|
|
px = 0;
|
|
} else {
|
|
wrterror("messed up free list");
|
|
}
|
|
}
|
|
|
|
/* Return something to OS ? */
|
|
if (!pf->next && /* If we're the last one, */
|
|
pf->size > malloc_cache && /* ..and the cache is full, */
|
|
pf->end == malloc_brk && /* ..and none behind us, */
|
|
malloc_brk == sbrk(0)) { /* ..and it's OK to do... */
|
|
|
|
/*
|
|
* Keep the cache intact. Notice that the '>' above guarantees that
|
|
* the pf will always have at least one page afterwards.
|
|
*/
|
|
pf->end = pf->page + malloc_cache;
|
|
pf->size = malloc_cache;
|
|
|
|
brk(pf->end);
|
|
malloc_brk = pf->end;
|
|
|
|
index = ptr2index(pf->end);
|
|
last_index = index - 1;
|
|
|
|
for(i=index;i <= last_index;)
|
|
page_dir[i++] = MALLOC_NOT_MINE;
|
|
|
|
/* XXX: We could realloc/shrink the pagedir here I guess. */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Free a chunk, and possibly the page it's on, if the page becomes empty.
|
|
*/
|
|
|
|
static __inline void
|
|
free_bytes(void *ptr, int index, struct pginfo *info)
|
|
{
|
|
int i;
|
|
struct pginfo **mp;
|
|
void *vp;
|
|
|
|
/* Find the chunk number on the page */
|
|
i = ((u_long)ptr & malloc_pagemask) >> info->shift;
|
|
|
|
if (((u_long)ptr & (info->size-1))) {
|
|
wrtwarning("free(): modified pointer.\n");
|
|
return;
|
|
}
|
|
|
|
if (tst_bit(info,i)) {
|
|
wrtwarning("free(): already free chunk.\n");
|
|
return;
|
|
}
|
|
|
|
set_bit(info,i);
|
|
info->free++;
|
|
|
|
mp = page_dir + info->shift;
|
|
|
|
if (info->free == 1) {
|
|
|
|
/* Page became non-full */
|
|
|
|
mp = page_dir + info->shift;
|
|
/* Insert in address order */
|
|
while (*mp && (*mp)->next && (*mp)->next->page < info->page)
|
|
mp = &(*mp)->next;
|
|
info->next = *mp;
|
|
*mp = info;
|
|
return;
|
|
}
|
|
|
|
if (info->free != info->total)
|
|
return;
|
|
|
|
/* Find & remove this page in the queue */
|
|
while (*mp != info) {
|
|
mp = &((*mp)->next);
|
|
#ifdef EXTRA_SANITY
|
|
if (!*mp)
|
|
wrterror("(ES): Not on queue\n");
|
|
#endif /* EXTRA_SANITY */
|
|
}
|
|
*mp = info->next;
|
|
|
|
/* Free the page & the info structure if need be */
|
|
page_dir[ptr2index(info->page)] = MALLOC_FIRST;
|
|
vp = info->page; /* Order is important ! */
|
|
if(vp != (void*)info)
|
|
free(info);
|
|
free(vp);
|
|
}
|
|
|
|
void
|
|
free(void *ptr)
|
|
{
|
|
struct pginfo *info;
|
|
int index;
|
|
#ifdef _THREAD_SAFE
|
|
int status;
|
|
#endif
|
|
|
|
/* This is legal */
|
|
if (!ptr)
|
|
return;
|
|
|
|
if (!initialized) {
|
|
wrtwarning("free(): malloc() never got called.\n");
|
|
return;
|
|
}
|
|
|
|
/* If we're already sinking, don't make matters any worse. */
|
|
if (suicide)
|
|
return;
|
|
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_block(&status);
|
|
#endif
|
|
index = ptr2index(ptr);
|
|
|
|
if (index < malloc_pageshift) {
|
|
wrtwarning("free(): junk pointer (too low)\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
if (index > last_index) {
|
|
wrtwarning("free(): junk pointer (too high)\n");
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
info = page_dir[index];
|
|
|
|
if (info < MALLOC_MAGIC)
|
|
free_pages(ptr,index,info);
|
|
else
|
|
free_bytes(ptr,index,info);
|
|
#ifdef _THREAD_SAFE
|
|
_thread_kern_sig_unblock(status);
|
|
#endif
|
|
return;
|
|
}
|