1134 lines
25 KiB
C
1134 lines
25 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 1.38 1998/06/09 08:30:32 jb Exp $
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*
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*/
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/*
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* Defining EXTRA_SANITY will enable extra checks which are related
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* to internal conditions and consistency in malloc.c. This has a
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* noticeable runtime performance hit, and generally will not do you
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* any good unless you fiddle with the internals of malloc or want
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* to catch random pointer corruption as early as possible.
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*/
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#ifndef MALLOC_EXTRA_SANITY
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#undef MALLOC_EXTRA_SANITY
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#endif
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/*
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* What to use for Junk. This is the byte value we use to fill with
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* when the 'J' option is enabled.
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*/
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#define SOME_JUNK 0xd0 /* as in "Duh" :-) */
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/*
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* The basic parameters you can tweak.
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*
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* malloc_pageshift pagesize = 1 << malloc_pageshift
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* It's probably best if this is the native
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* page size, but it doesn't have to be.
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*
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* malloc_minsize minimum size of an allocation in bytes.
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* If this is too small it's too much work
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* to manage them. This is also the smallest
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* unit of alignment used for the storage
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* returned by malloc/realloc.
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*
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*/
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#if defined(__FreeBSD__)
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# if defined(__i386__)
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# define malloc_pageshift 12U
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# define malloc_minsize 16U
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# endif
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# if !defined(__NETBSD_SYSCALLS)
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# define HAS_UTRACE
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# endif
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/*
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* Make malloc/free/realloc thread-safe in libc for use with
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* kernel threads.
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*/
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# include "libc_private.h"
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# include "spinlock.h"
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static spinlock_t thread_lock = _SPINLOCK_INITIALIZER;
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# define THREAD_LOCK() if (__isthreaded) _SPINLOCK(&thread_lock);
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# define THREAD_UNLOCK() if (__isthreaded) _SPINUNLOCK(&thread_lock);
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#endif /* __FreeBSD__ */
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#if defined(__sparc__) && defined(sun)
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# define malloc_pageshift 12U
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# define malloc_minsize 16U
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# define MAP_ANON (0)
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static int fdzero;
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# define MMAP_FD fdzero
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# define INIT_MMAP() \
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{ if ((fdzero=open("/dev/zero", O_RDWR, 0000)) == -1) \
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wrterror("open of /dev/zero"); }
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# define MADV_FREE MADV_DONTNEED
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#endif /* __sparc__ */
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/* Insert your combination here... */
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#if defined(__FOOCPU__) && defined(__BAROS__)
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# define malloc_pageshift 12U
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# define malloc_minsize 16U
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#endif /* __FOOCPU__ && __BAROS__ */
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/*
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* No user serviceable parts behind this point.
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*/
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#include <sys/types.h>
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#include <sys/mman.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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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_int 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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size_t size; /* number of bytes free */
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};
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/*
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* How many bits per u_int 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_int))
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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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#ifndef malloc_pageshift
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#define malloc_pageshift 12U
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#endif
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#ifndef malloc_minsize
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#define malloc_minsize 16U
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#endif
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#if !defined(malloc_pagesize)
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#define malloc_pagesize (1UL<<malloc_pageshift)
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#endif
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#if ((1<<malloc_pageshift) != malloc_pagesize)
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#error "(1<<malloc_pageshift) != malloc_pagesize"
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#endif
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#ifndef malloc_maxsize
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#define malloc_maxsize ((malloc_pagesize)>>1)
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#endif
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/* A mask for the offset inside a page. */
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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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#ifndef THREAD_LOCK
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#define THREAD_LOCK()
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#endif
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#ifndef THREAD_UNLOCK
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#define THREAD_UNLOCK()
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#endif
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#ifndef MMAP_FD
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#define MMAP_FD (-1)
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#endif
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#ifndef INIT_MMAP
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#define INIT_MMAP()
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#endif
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/* Set when initialization has been done */
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static unsigned malloc_started;
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/* Recusion flag for public interface. */
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static int malloc_active;
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/* Number of free pages we cache */
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static unsigned malloc_cache = 16;
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/* The offset from pagenumber to index into the page directory */
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static u_long malloc_origo;
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/* The last index in the page directory we care about */
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static u_long last_index;
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/* Pointer to page directory. Allocated "as if with" malloc */
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static struct pginfo **page_dir;
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/* How many slots in the page directory */
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static unsigned malloc_ninfo;
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/* Free pages line up here */
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static struct pgfree free_list;
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/* Abort(), user doesn't handle problems. */
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static int malloc_abort;
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/* Are we trying to die ? */
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static int suicide;
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/* always realloc ? */
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static int malloc_realloc;
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/* pass the kernel a hint on free pages ? */
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static int malloc_hint = 1;
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/* xmalloc behaviour ? */
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static int malloc_xmalloc;
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/* sysv behaviour for malloc(0) ? */
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static int malloc_sysv;
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/* zero fill ? */
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static int malloc_zero;
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/* junk fill ? */
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static int malloc_junk;
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#ifdef HAS_UTRACE
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/* utrace ? */
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static int malloc_utrace;
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struct ut { void *p; size_t s; void *r; };
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void utrace __P((struct ut *, int));
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#define UTRACE(a, b, c) \
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if (malloc_utrace) \
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{struct ut u; u.p=a; u.s = b; u.r=c; utrace(&u, sizeof u);}
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#else /* !HAS_UTRACE */
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#define UTRACE(a,b,c)
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#endif /* HAS_UTRACE */
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/* my last break. */
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static void *malloc_brk;
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/* one location cache for free-list holders */
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static struct pgfree *px;
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/* compile-time options */
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char *malloc_options;
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/* Name of the current public function */
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static char *malloc_func;
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/* Macro for mmap */
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#define MMAP(size) \
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mmap(0, (size), PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, \
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MMAP_FD, 0);
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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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static void *imalloc(size_t size);
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static void ifree(void *ptr);
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static void *irealloc(void *ptr, size_t size);
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extern char *__progname;
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static void
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wrterror(char *p)
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{
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char *q = " error: ";
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write(STDERR_FILENO, __progname, strlen(__progname));
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write(STDERR_FILENO, malloc_func, strlen(malloc_func));
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write(STDERR_FILENO, q, strlen(q));
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write(STDERR_FILENO, p, strlen(p));
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suicide = 1;
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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 = " warning: ";
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if (malloc_abort)
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wrterror(p);
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write(STDERR_FILENO, __progname, strlen(__progname));
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write(STDERR_FILENO, malloc_func, strlen(malloc_func));
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write(STDERR_FILENO, q, strlen(q));
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write(STDERR_FILENO, p, strlen(p));
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}
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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 void *
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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("(ES): 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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* 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(i * malloc_pagesize);
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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(old, oldlen);
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return 1;
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}
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/*
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* Initialize the world
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*/
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static void
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malloc_init ()
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{
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char *p, b[64];
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int i, j;
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int errnosave;
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INIT_MMAP();
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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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for (i = 0; i < 3; i++) {
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if (i == 0) {
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errnosave = errno;
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j = readlink("/etc/malloc.conf", b, sizeof b - 1);
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errno = errnosave;
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if (j <= 0)
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continue;
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b[j] = '\0';
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p = b;
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} else if (i == 1) {
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p = getenv("MALLOC_OPTIONS");
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} else {
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p = malloc_options;
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}
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for (; p && *p; p++) {
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switch (*p) {
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case '>': malloc_cache <<= 1; break;
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case '<': malloc_cache >>= 1; break;
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case 'a': malloc_abort = 0; break;
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case 'A': malloc_abort = 1; break;
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case 'h': malloc_hint = 0; break;
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case 'H': malloc_hint = 1; break;
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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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#ifdef HAS_UTRACE
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case 'u': malloc_utrace = 0; break;
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case 'U': malloc_utrace = 1; break;
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#endif
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case 'v': malloc_sysv = 0; break;
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case 'V': malloc_sysv = 1; break;
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case 'x': malloc_xmalloc = 0; break;
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case 'X': malloc_xmalloc = 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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j = malloc_abort;
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malloc_abort = 0;
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wrtwarning("unknown char in MALLOC_OPTIONS\n");
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malloc_abort = j;
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break;
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}
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}
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}
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UTRACE(0, 0, 0);
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/*
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* We want junk in the entire allocation, and zero only in the part
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* the user asked for.
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*/
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if (malloc_zero)
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malloc_junk=1;
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/*
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* If we run with junk (or implicitly from above: zero), we want to
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* force realloc() to get new storage, so we can DTRT with it.
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*/
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if (malloc_junk)
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malloc_realloc=1;
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/* Allocate one page for the page directory */
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page_dir = (struct pginfo **) MMAP(malloc_pagesize);
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if (page_dir == (struct pginfo **) -1)
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wrterror("mmap(2) failed, check limits.\n");
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|
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/*
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* We need a maximum of malloc_pageshift buckets, steal these from the
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* front of the page_directory;
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*/
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malloc_origo = ((u_long)pageround((u_long)sbrk(0))) >> malloc_pageshift;
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malloc_origo -= malloc_pageshift;
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malloc_ninfo = malloc_pagesize / sizeof *page_dir;
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|
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/* Recalculate the cache size in bytes, and make sure it's nonzero */
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|
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if (!malloc_cache)
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malloc_cache++;
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malloc_cache <<= malloc_pageshift;
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|
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/*
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|
* This is a nice hack from Kaleb Keithly (kaleb@x.org).
|
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* We can sbrk(2) further back when we keep this on a low address.
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*/
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px = (struct pgfree *) imalloc (sizeof *px);
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|
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/* Been here, done that */
|
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malloc_started++;
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}
|
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|
|
/*
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* Allocate a number of complete pages
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*/
|
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static void *
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malloc_pages(size_t size)
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{
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void *p, *delay_free = 0;
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int i;
|
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struct pgfree *pf;
|
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u_long index;
|
|
|
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size = pageround(size);
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p = 0;
|
|
|
|
/* Look for free pages before asking for more */
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for(pf = free_list.next; pf; pf = pf->next) {
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|
|
#ifdef EXTRA_SANITY
|
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if (pf->size & malloc_pagemask)
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wrterror("(ES): junk length entry on free_list\n");
|
|
if (!pf->size)
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wrterror("(ES): zero length entry on free_list\n");
|
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if (pf->page == pf->end)
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wrterror("(ES): zero entry on free_list\n");
|
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if (pf->page > pf->end)
|
|
wrterror("(ES): sick entry on free_list\n");
|
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if ((void*)pf->page >= (void*)sbrk(0))
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wrterror("(ES): entry on free_list past brk\n");
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if (page_dir[ptr2index(pf->page)] != MALLOC_FREE)
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wrterror("(ES): non-free first page on free-list\n");
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if (page_dir[ptr2index(pf->end)-1] != MALLOC_FREE)
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wrterror("(ES): non-free last page on free-list\n");
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#endif /* EXTRA_SANITY */
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|
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if (pf->size < size)
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continue;
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|
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if (pf->size == size) {
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p = pf->page;
|
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if (pf->next)
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pf->next->prev = pf->prev;
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pf->prev->next = pf->next;
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delay_free = pf;
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break;
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}
|
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|
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p = pf->page;
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pf->page = (char *)pf->page + size;
|
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pf->size -= size;
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break;
|
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}
|
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|
|
#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
|
|
ifree(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 = offsetof(struct pginfo, bits[0]);
|
|
l += sizeof bp->bits[0] *
|
|
(((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 *)imalloc(l);
|
|
if (!bp) {
|
|
ifree(pp);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
bp->size = (1<<bits);
|
|
bp->shift = bits;
|
|
bp->total = bp->free = malloc_pagesize >> bits;
|
|
bp->page = pp;
|
|
|
|
/* set all valid bits in the bitmap */
|
|
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++)
|
|
bp->bits[i/MALLOC_BITS] |= 1<<(i%MALLOC_BITS);
|
|
|
|
if (bp == bp->page) {
|
|
/* Mark the ones we stole for ourselves */
|
|
for(i=0;l > 0;i++) {
|
|
bp->bits[i/MALLOC_BITS] &= ~(1<<(i%MALLOC_BITS));
|
|
bp->free--;
|
|
bp->total--;
|
|
l -= (1 << bits);
|
|
}
|
|
}
|
|
|
|
/* MALLOC_LOCK */
|
|
|
|
page_dir[ptr2index(pp)] = bp;
|
|
|
|
bp->next = page_dir[bits];
|
|
page_dir[bits] = bp;
|
|
|
|
/* MALLOC_UNLOCK */
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Allocate a fragment
|
|
*/
|
|
static void *
|
|
malloc_bytes(size_t size)
|
|
{
|
|
int i,j;
|
|
u_int u;
|
|
struct pginfo *bp;
|
|
int k;
|
|
u_int *lp;
|
|
|
|
/* Don't bother with anything less than this */
|
|
if (size < malloc_minsize)
|
|
size = malloc_minsize;
|
|
|
|
/* Find the right bucket */
|
|
j = 1;
|
|
i = size-1;
|
|
while (i >>= 1)
|
|
j++;
|
|
|
|
/* 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 */
|
|
u = 1;
|
|
k = 0;
|
|
while (!(*lp & u)) {
|
|
u += u;
|
|
k++;
|
|
}
|
|
*lp ^= u;
|
|
|
|
/* 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((u_char*)bp->page + k, SOME_JUNK, bp->size);
|
|
|
|
return (u_char *)bp->page + k;
|
|
}
|
|
|
|
/*
|
|
* Allocate a piece of memory
|
|
*/
|
|
static void *
|
|
imalloc(size_t size)
|
|
{
|
|
void *result;
|
|
|
|
if (suicide)
|
|
abort();
|
|
|
|
if ((size + malloc_pagesize) < size) /* Check for overflow */
|
|
result = 0;
|
|
else if (size <= malloc_maxsize)
|
|
result = malloc_bytes(size);
|
|
else
|
|
result = malloc_pages(size);
|
|
|
|
if (malloc_abort && !result)
|
|
wrterror("allocation failed.\n");
|
|
|
|
if (malloc_zero && result)
|
|
memset(result, 0, size);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Change the size of an allocation.
|
|
*/
|
|
static void *
|
|
irealloc(void *ptr, size_t size)
|
|
{
|
|
void *p;
|
|
u_long osize, index;
|
|
struct pginfo **mp;
|
|
int i;
|
|
|
|
if (suicide)
|
|
abort();
|
|
|
|
index = ptr2index(ptr);
|
|
|
|
if (index < malloc_pageshift) {
|
|
wrtwarning("junk pointer, too low to make sense.\n");
|
|
return 0;
|
|
}
|
|
|
|
if (index > last_index) {
|
|
wrtwarning("junk pointer, too high to make sense.\n");
|
|
return 0;
|
|
}
|
|
|
|
mp = &page_dir[index];
|
|
|
|
if (*mp == MALLOC_FIRST) { /* Page allocation */
|
|
|
|
/* Check the pointer */
|
|
if ((u_long)ptr & malloc_pagemask) {
|
|
wrtwarning("modified (page-) pointer.\n");
|
|
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, */
|
|
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("modified (chunk-) pointer.\n");
|
|
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 ((*mp)->bits[i/MALLOC_BITS] & (1<<(i%MALLOC_BITS))) {
|
|
wrtwarning("chunk is already free.\n");
|
|
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) */
|
|
return ptr; /* ..Don't do anything */
|
|
}
|
|
|
|
} else {
|
|
wrtwarning("pointer to wrong page.\n");
|
|
return 0;
|
|
}
|
|
|
|
p = imalloc(size);
|
|
|
|
if (p) {
|
|
/* copy the lesser of the two sizes, and free the old one */
|
|
if (!size || !osize)
|
|
;
|
|
else if (osize < size)
|
|
memcpy(p, ptr, osize);
|
|
else
|
|
memcpy(p, ptr, size);
|
|
ifree(ptr);
|
|
}
|
|
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=0;
|
|
u_long l;
|
|
void *tail;
|
|
|
|
if (info == MALLOC_FREE) {
|
|
wrtwarning("page is already free.\n");
|
|
return;
|
|
}
|
|
|
|
if (info != MALLOC_FIRST) {
|
|
wrtwarning("pointer to wrong page.\n");
|
|
return;
|
|
}
|
|
|
|
if ((u_long)ptr & malloc_pagemask) {
|
|
wrtwarning("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;
|
|
|
|
if (malloc_junk)
|
|
memset(ptr, SOME_JUNK, l);
|
|
|
|
if (malloc_hint)
|
|
madvise(ptr, l, MADV_FREE);
|
|
|
|
tail = (char *)ptr+l;
|
|
|
|
/* add to free-list */
|
|
if (!px)
|
|
px = imalloc(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 = (char *)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 = (char *)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;
|
|
}
|
|
} 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("freelist is destroyed.\n");
|
|
}
|
|
}
|
|
|
|
/* 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 = (char *)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. */
|
|
}
|
|
if (pt)
|
|
ifree(pt);
|
|
}
|
|
|
|
/*
|
|
* 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("modified (chunk-) pointer.\n");
|
|
return;
|
|
}
|
|
|
|
if (info->bits[i/MALLOC_BITS] & (1<<(i%MALLOC_BITS))) {
|
|
wrtwarning("chunk is already free.\n");
|
|
return;
|
|
}
|
|
|
|
if (malloc_junk)
|
|
memset(ptr, SOME_JUNK, info->size);
|
|
|
|
info->bits[i/MALLOC_BITS] |= 1<<(i%MALLOC_BITS);
|
|
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)
|
|
ifree(info);
|
|
ifree(vp);
|
|
}
|
|
|
|
static void
|
|
ifree(void *ptr)
|
|
{
|
|
struct pginfo *info;
|
|
int index;
|
|
|
|
/* This is legal */
|
|
if (!ptr)
|
|
return;
|
|
|
|
if (!malloc_started) {
|
|
wrtwarning("malloc() has never been called.\n");
|
|
return;
|
|
}
|
|
|
|
/* If we're already sinking, don't make matters any worse. */
|
|
if (suicide)
|
|
return;
|
|
|
|
index = ptr2index(ptr);
|
|
|
|
if (index < malloc_pageshift) {
|
|
wrtwarning("junk pointer, too low to make sense.\n");
|
|
return;
|
|
}
|
|
|
|
if (index > last_index) {
|
|
wrtwarning("junk pointer, too high to make sense.\n");
|
|
return;
|
|
}
|
|
|
|
info = page_dir[index];
|
|
|
|
if (info < MALLOC_MAGIC)
|
|
free_pages(ptr, index, info);
|
|
else
|
|
free_bytes(ptr, index, info);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* These are the public exported interface routines.
|
|
*/
|
|
|
|
|
|
void *
|
|
malloc(size_t size)
|
|
{
|
|
register void *r;
|
|
|
|
malloc_func = " in malloc():";
|
|
THREAD_LOCK();
|
|
if (malloc_active++) {
|
|
wrtwarning("recursive call.\n");
|
|
malloc_active--;
|
|
return (0);
|
|
}
|
|
if (!malloc_started)
|
|
malloc_init();
|
|
if (malloc_sysv && !size)
|
|
r = 0;
|
|
else
|
|
r = imalloc(size);
|
|
UTRACE(0, size, r);
|
|
malloc_active--;
|
|
THREAD_UNLOCK();
|
|
if (malloc_xmalloc && !r)
|
|
wrterror("out of memory.\n");
|
|
return (r);
|
|
}
|
|
|
|
void
|
|
free(void *ptr)
|
|
{
|
|
malloc_func = " in free():";
|
|
THREAD_LOCK();
|
|
if (malloc_active++) {
|
|
wrtwarning("recursive call.\n");
|
|
malloc_active--;
|
|
return;
|
|
}
|
|
ifree(ptr);
|
|
UTRACE(ptr, 0, 0);
|
|
malloc_active--;
|
|
THREAD_UNLOCK();
|
|
return;
|
|
}
|
|
|
|
void *
|
|
realloc(void *ptr, size_t size)
|
|
{
|
|
register void *r;
|
|
|
|
malloc_func = " in realloc():";
|
|
THREAD_LOCK();
|
|
if (malloc_active++) {
|
|
wrtwarning("recursive call.\n");
|
|
malloc_active--;
|
|
return (0);
|
|
}
|
|
if (ptr && !malloc_started) {
|
|
wrtwarning("malloc() has never been called.\n");
|
|
ptr = 0;
|
|
}
|
|
if (!malloc_started)
|
|
malloc_init();
|
|
if (malloc_sysv && !size) {
|
|
ifree(ptr);
|
|
r = 0;
|
|
} else if (!ptr) {
|
|
r = imalloc(size);
|
|
} else {
|
|
r = irealloc(ptr, size);
|
|
}
|
|
UTRACE(ptr, size, r);
|
|
malloc_active--;
|
|
THREAD_UNLOCK();
|
|
if (malloc_xmalloc && !r)
|
|
wrterror("out of memory.\n");
|
|
return (r);
|
|
}
|
|
|