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glibc/hurd/hurdmalloc.c
Samuel Thibault ae49f218da hurd: Fix static-PIE startup
hurd initialization stages use RUN_HOOK to run various initialization
functions.  That is however using absolute addresses which need to be
relocated, which is done later by csu.  We can however easily make the
linker compute relative addresses which thus don't need a relocation.
The new SET_RELHOOK and RUN_RELHOOK macros implement this.
2021-12-28 10:28:22 +01:00

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#include <stdlib.h>
#include <string.h>
#include "set-hooks.h"
#include "hurdmalloc.h" /* XXX see that file */
#include <mach.h>
#include <mach/spin-lock.h>
#define vm_allocate __vm_allocate
#define vm_page_size __vm_page_size
/*
* Mach Operating System
* Copyright (c) 1991,1990,1989 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* (pre-GNU) HISTORY
*
* Revision 2.7 91/05/14 17:57:34 mrt
* Correcting copyright
*
* Revision 2.6 91/02/14 14:20:26 mrt
* Added new Mach copyright
* [91/02/13 12:41:21 mrt]
*
* Revision 2.5 90/11/05 14:37:33 rpd
* Added malloc_fork* code.
* [90/11/02 rwd]
*
* Add spin_lock_t.
* [90/10/31 rwd]
*
* Revision 2.4 90/08/07 14:31:28 rpd
* Removed RCS keyword nonsense.
*
* Revision 2.3 90/06/02 15:14:00 rpd
* Converted to new IPC.
* [90/03/20 20:56:57 rpd]
*
* Revision 2.2 89/12/08 19:53:59 rwd
* Removed conditionals.
* [89/10/23 rwd]
*
* Revision 2.1 89/08/03 17:09:46 rwd
* Created.
*
*
* 13-Sep-88 Eric Cooper (ecc) at Carnegie Mellon University
* Changed realloc() to copy min(old size, new size) bytes.
* Bug found by Mike Kupfer at Olivetti.
*/
/*
* File: malloc.c
* Author: Eric Cooper, Carnegie Mellon University
* Date: July, 1988
*
* Memory allocator for use with multiple threads.
*/
#include <assert.h>
#define MCHECK
/*
* Structure of memory block header.
* When free, next points to next block on free list.
* When allocated, fl points to free list.
* Size of header is 4 bytes, so minimum usable block size is 8 bytes.
*/
#define CHECK_BUSY 0x8a3c743e
#define CHECK_FREE 0x66688b92
#ifdef MCHECK
typedef struct header {
long check;
union {
struct header *next;
struct free_list *fl;
} u;
} *header_t;
#define HEADER_SIZE sizeof (struct header)
#define HEADER_NEXT(h) ((h)->u.next)
#define HEADER_FREE(h) ((h)->u.fl)
#define HEADER_CHECK(h) ((h)->check)
#define MIN_SIZE 16
#define LOG2_MIN_SIZE 4
#else /* ! MCHECK */
typedef union header {
union header *next;
struct free_list *fl;
} *header_t;
#define HEADER_SIZE sizeof (union header)
#define HEADER_NEXT(h) ((h)->next)
#define HEADER_FREE(h) ((h)->fl)
#define MIN_SIZE 8 /* minimum block size */
#define LOG2_MIN_SIZE 3
#endif /* MCHECK */
typedef struct free_list {
spin_lock_t lock; /* spin lock for mutual exclusion */
header_t head; /* head of free list for this size */
#ifdef DEBUG
int in_use; /* # mallocs - # frees */
#endif /* DEBUG */
} *free_list_t;
/*
* Free list with index i contains blocks of size 2 ^ (i + LOG2_MIN_SIZE)
* including header. Smallest block size is MIN_SIZE, with MIN_SIZE -
* HEADER_SIZE bytes available to user. Size argument to malloc is a signed
* integer for sanity checking, so largest block size is 2^31.
*/
#define NBUCKETS 29
static struct free_list malloc_free_list[NBUCKETS];
/* Initialization just sets everything to zero, but might be necessary on a
machine where spin_lock_init does otherwise, and is necessary when
running an executable that was written by something like Emacs's unexec.
It preserves the values of data variables like malloc_free_list, but
does not save the vm_allocate'd space allocated by this malloc. */
static void attribute_used_retain
malloc_init (void)
{
int i;
for (i = 0; i < NBUCKETS; ++i)
{
spin_lock_init (&malloc_free_list[i].lock);
malloc_free_list[i].head = NULL;
#ifdef DEBUG
malloc_free_list[i].in_use = 0;
#endif
}
}
static void
more_memory(int size, free_list_t fl)
{
int amount;
int n;
vm_address_t where;
header_t h;
kern_return_t r;
if (size <= vm_page_size) {
amount = vm_page_size;
n = vm_page_size / size;
/* We lose vm_page_size - n*size bytes here. */
} else {
amount = size;
n = 1;
}
r = vm_allocate(mach_task_self(), &where, (vm_size_t) amount, TRUE);
assert_perror (r);
h = (header_t) where;
do {
HEADER_NEXT (h) = fl->head;
#ifdef MCHECK
HEADER_CHECK (h) = CHECK_FREE;
#endif
fl->head = h;
h = (header_t) ((char *) h + size);
} while (--n != 0);
}
/* Declaration changed to standard one for GNU. */
void *
malloc (size_t size)
{
int i, n;
free_list_t fl;
header_t h;
if ((int) size < 0) /* sanity check */
return 0;
size += HEADER_SIZE;
/*
* Find smallest power-of-two block size
* big enough to hold requested size plus header.
*/
i = 0;
n = MIN_SIZE;
while (n < size) {
i += 1;
n <<= 1;
}
assert(i < NBUCKETS);
fl = &malloc_free_list[i];
spin_lock(&fl->lock);
h = fl->head;
if (h == 0) {
/*
* Free list is empty;
* allocate more blocks.
*/
more_memory(n, fl);
h = fl->head;
if (h == 0) {
/*
* Allocation failed.
*/
spin_unlock(&fl->lock);
return 0;
}
}
/*
* Pop block from free list.
*/
fl->head = HEADER_NEXT (h);
#ifdef MCHECK
assert (HEADER_CHECK (h) == CHECK_FREE);
HEADER_CHECK (h) = CHECK_BUSY;
#endif
#ifdef DEBUG
fl->in_use += 1;
#endif /* DEBUG */
spin_unlock(&fl->lock);
/*
* Store free list pointer in block header
* so we can figure out where it goes
* at free() time.
*/
HEADER_FREE (h) = fl;
/*
* Return pointer past the block header.
*/
return ((char *) h) + HEADER_SIZE;
}
/* Declaration changed to standard one for GNU. */
void
free (void *base)
{
header_t h;
free_list_t fl;
int i;
if (base == 0)
return;
/*
* Find free list for block.
*/
h = (header_t) (base - HEADER_SIZE);
#ifdef MCHECK
assert (HEADER_CHECK (h) == CHECK_BUSY);
#endif
fl = HEADER_FREE (h);
i = fl - malloc_free_list;
/*
* Sanity checks.
*/
if (i < 0 || i >= NBUCKETS) {
assert(0 <= i && i < NBUCKETS);
return;
}
if (fl != &malloc_free_list[i]) {
assert(fl == &malloc_free_list[i]);
return;
}
/*
* Push block on free list.
*/
spin_lock(&fl->lock);
HEADER_NEXT (h) = fl->head;
#ifdef MCHECK
HEADER_CHECK (h) = CHECK_FREE;
#endif
fl->head = h;
#ifdef DEBUG
fl->in_use -= 1;
#endif /* DEBUG */
spin_unlock(&fl->lock);
return;
}
/* Declaration changed to standard one for GNU. */
void *
realloc (void *old_base, size_t new_size)
{
header_t h;
free_list_t fl;
int i;
unsigned int old_size;
char *new_base;
if (old_base == 0)
return malloc (new_size);
/*
* Find size of old block.
*/
h = (header_t) (old_base - HEADER_SIZE);
#ifdef MCHECK
assert (HEADER_CHECK (h) == CHECK_BUSY);
#endif
fl = HEADER_FREE (h);
i = fl - malloc_free_list;
/*
* Sanity checks.
*/
if (i < 0 || i >= NBUCKETS) {
assert(0 <= i && i < NBUCKETS);
return 0;
}
if (fl != &malloc_free_list[i]) {
assert(fl == &malloc_free_list[i]);
return 0;
}
/*
* Free list with index i contains blocks of size
* 2 ^ (i + * LOG2_MIN_SIZE) including header.
*/
old_size = (1 << (i + LOG2_MIN_SIZE)) - HEADER_SIZE;
if (new_size <= old_size
&& new_size > (((old_size + HEADER_SIZE) >> 1) - HEADER_SIZE))
/* The new size still fits in the same block, and wouldn't fit in
the next smaller block! */
return old_base;
/*
* Allocate new block, copy old bytes, and free old block.
*/
new_base = malloc(new_size);
if (new_base)
memcpy (new_base, old_base,
(int) (old_size < new_size ? old_size : new_size));
if (new_base || new_size == 0)
/* Free OLD_BASE, but only if the malloc didn't fail. */
free (old_base);
return new_base;
}
#ifdef DEBUG
void
print_malloc_free_list (void)
{
int i, size;
free_list_t fl;
int n;
header_t h;
int total_used = 0;
int total_free = 0;
fprintf(stderr, " Size In Use Free Total\n");
for (i = 0, size = MIN_SIZE, fl = malloc_free_list;
i < NBUCKETS;
i += 1, size <<= 1, fl += 1) {
spin_lock(&fl->lock);
if (fl->in_use != 0 || fl->head != 0) {
total_used += fl->in_use * size;
for (n = 0, h = fl->head; h != 0; h = HEADER_NEXT (h), n += 1)
;
total_free += n * size;
fprintf(stderr, "%10d %10d %10d %10d\n",
size, fl->in_use, n, fl->in_use + n);
}
spin_unlock(&fl->lock);
}
fprintf(stderr, " all sizes %10d %10d %10d\n",
total_used, total_free, total_used + total_free);
}
#endif /* DEBUG */
void
_hurd_malloc_fork_prepare(void)
/*
* Prepare the malloc module for a fork by insuring that no thread is in a
* malloc critical section.
*/
{
int i;
for (i = 0; i < NBUCKETS; i++) {
spin_lock(&malloc_free_list[i].lock);
}
}
void
_hurd_malloc_fork_parent(void)
/*
* Called in the parent process after a fork() to resume normal operation.
*/
{
int i;
for (i = NBUCKETS-1; i >= 0; i--) {
spin_unlock(&malloc_free_list[i].lock);
}
}
void
_hurd_malloc_fork_child(void)
/*
* Called in the child process after a fork() to resume normal operation.
*/
{
int i;
for (i = NBUCKETS-1; i >= 0; i--) {
spin_unlock(&malloc_free_list[i].lock);
}
}
SET_RELHOOK (_hurd_preinit_hook, malloc_init);