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/* Minimal replacements for basic facilities used in the dynamic linker.
Copyright (C) 1995, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <sys/types.h>
#include <sys/mman.h>
#include <unistd.h>
#include <assert.h>
#include <string.h>
#include <link.h>
#include "../stdio-common/_itoa.h"
/* Minimal `malloc' allocator for use while loading shared libraries.
Only small blocks are allocated, and none are ever freed. */
static void *alloc_ptr, *alloc_end, *alloc_last_block;
void *
malloc (size_t n)
{
extern int _dl_zerofd;
if (_dl_pagesize == 0)
_dl_pagesize = __getpagesize ();
if (_dl_zerofd == -1)
_dl_zerofd = _dl_sysdep_open_zero_fill ();
if (alloc_end == 0)
{
/* Consume any unused space in the last page of our data segment. */
extern int _end;
alloc_ptr = &_end;
alloc_end = (void *) 0 + (((alloc_ptr - (void *) 0) + _dl_pagesize - 1)
& ~(_dl_pagesize - 1));
}
/* Make sure the allocation pointer is ideally aligned. */
alloc_ptr = (void *) 0 + (((alloc_ptr - (void *) 0) + sizeof (double) - 1)
& ~(sizeof (double) - 1));
if (alloc_ptr + n >= alloc_end)
{
/* Insufficient space left; allocate another page. */
caddr_t page;
assert (n <= _dl_pagesize);
page = __mmap (0, _dl_pagesize, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, _dl_zerofd, 0);
assert (page != (caddr_t) -1);
if (page != alloc_end)
alloc_ptr = page;
alloc_end = page + _dl_pagesize;
}
alloc_last_block = (void *) alloc_ptr;
alloc_ptr += n;
return alloc_last_block;
}
weak_symbol (malloc)
/* This will rarely be called. */
void
free (void *ptr)
{
/* We can free only the last block allocated. */
if (ptr == alloc_last_block)
alloc_ptr = alloc_last_block;
}
weak_symbol (free)
/* This is only called with the most recent block returned by malloc. */
void *
realloc (void *ptr, size_t n)
{
void *new;
assert (ptr == alloc_last_block);
alloc_ptr = alloc_last_block;
new = malloc (n);
assert (new == ptr);
return new;
}
weak_symbol (realloc)
/* Avoid signal frobnication in setjmp/longjmp. Keeps things smaller. */
#include <setjmp.h>
int __sigjmp_save (sigjmp_buf env, int savemask)
{ env[0].__mask_was_saved = savemask; return 0; }
weak_symbol (__sigjmp_save)
void
longjmp (jmp_buf env, int val) { __longjmp (env[0].__jmpbuf, val); }
weak_symbol (longjmp)
/* Define our own stub for the localization function used by strerror.
English-only in the dynamic linker keeps it smaller. */
char *
__dgettext (const char *domainname, const char *msgid)
{
assert (domainname == _libc_intl_domainname);
return (char *) msgid;
}
weak_symbol (__dgettext)
weak_alias (__dgettext, dgettext)
#ifndef NDEBUG
/* Define (weakly) our own assert failure function which doesn't use stdio.
If we are linked into the user program (-ldl), the normal __assert_fail
defn can override this one. */
void
__assert_fail (const char *assertion,
const char *file, unsigned int line, const char *function)
{
char buf[64];
buf[sizeof buf - 1] = '\0';
_dl_sysdep_fatal ("BUG IN DYNAMIC LINKER ld.so: ",
file, ": ", _itoa (line, buf + sizeof buf - 1, 10, 0),
": ", function ?: "", function ? ": " : "",
"Assertion `", assertion, "' failed!\n",
NULL);
}
weak_symbol (__assert_fail)
void
__assert_perror_fail (int errnum,
const char *file, unsigned int line,
const char *function)
{
char buf[64];
buf[sizeof buf - 1] = '\0';
_dl_sysdep_fatal ("BUG IN DYNAMIC LINKER ld.so: ",
file, ": ", _itoa (line, buf + sizeof buf - 1, 10, 0),
": ", function ?: "", function ? ": " : "",
"Unexpected error: ", strerror (errnum), "\n", NULL);
}
weak_symbol (__assert_perror_fail)
#endif
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