glibc/elf/dl-minimal.c

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/* Minimal replacements for basic facilities used in the dynamic linker.
Copyright (C) 1995,96,97,98,2000 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <limits.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <ldsodefs.h>
#include <stdio-common/_itoa.h>
#include <assert.h>
/* Minimal `malloc' allocator for use while loading shared libraries.
No block is ever freed. */
static void *alloc_ptr, *alloc_end, *alloc_last_block;
void * weak_function
malloc (size_t n)
{
#ifdef MAP_ANON
#define _dl_zerofd (-1)
#else
extern int _dl_zerofd;
if (_dl_zerofd == -1)
_dl_zerofd = _dl_sysdep_open_zero_fill ();
#define MAP_ANON 0
#endif
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;
size_t nup = (n + _dl_pagesize - 1) & ~(_dl_pagesize - 1);
page = __mmap (0, nup, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, _dl_zerofd, 0);
assert (page != MAP_FAILED);
if (page != alloc_end)
alloc_ptr = page;
alloc_end = page + nup;
}
alloc_last_block = (void *) alloc_ptr;
alloc_ptr += n;
return alloc_last_block;
}
/* We use this function occasionally since the real implementation may
be optimized when it can assume the memory it returns already is
set to NUL. */
void * weak_function
calloc (size_t nmemb, size_t size)
{
size_t total = nmemb * size;
void *result = malloc (total);
return memset (result, '\0', total);
}
/* This will rarely be called. */
void weak_function
free (void *ptr)
{
/* We can free only the last block allocated. */
if (ptr == alloc_last_block)
alloc_ptr = alloc_last_block;
}
/* This is only called with the most recent block returned by malloc. */
void * weak_function
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;
}
/* Avoid signal frobnication in setjmp/longjmp. Keeps things smaller. */
#include <setjmp.h>
int weak_function
__sigjmp_save (sigjmp_buf env, int savemask)
{
env[0].__mask_was_saved = savemask;
return 0;
}
void weak_function
longjmp (jmp_buf env, int val)
{
__longjmp (env[0].__jmpbuf, val);
}
/* Define our own version of the internal function used by strerror. We
only provide the messages for some common errors. This avoids pulling
in the whole error list. */
char * weak_function
__strerror_r (int errnum, char *buf, size_t buflen)
{
char *msg;
switch (errnum)
{
case ENOMEM:
msg = (char *) "Cannot allocate memory";
break;
case EINVAL:
msg = (char *) "Invalid argument";
break;
case ENOENT:
msg = (char *) "No such file or directory";
break;
case EPERM:
msg = (char *) "Operation not permitted";
break;
case EIO:
msg = (char *) "Input/output error";
break;
case EACCES:
msg = (char *) "Permission denied";
break;
default:
/* No need to check buffer size, all calls in the dynamic linker
provide enough space. */
buf[buflen - 1] = '\0';
msg = _itoa_word (errnum, buf + buflen - 1, 10, 0);
msg = memcpy (msg - (sizeof ("Error ") - 1), "Error ",
sizeof ("Error ") - 1);
break;
}
return msg;
}
#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 weak_function
__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_word (line, buf + sizeof buf - 1, 10, 0),
": ", function ?: "", function ? ": " : "",
"Assertion `", assertion, "' failed!\n",
NULL);
}
void weak_function
__assert_perror_fail (int errnum,
const char *file, unsigned int line,
const char *function)
{
char errbuf[64];
char buf[64];
buf[sizeof buf - 1] = '\0';
_dl_sysdep_fatal ("BUG IN DYNAMIC LINKER ld.so: ",
file, ": ", _itoa_word (line, buf + sizeof buf - 1, 10, 0),
": ", function ?: "", function ? ": " : "",
"Unexpected error: ",
__strerror_r (errnum, errbuf, sizeof (errbuf)), "\n",
NULL);
}
#endif
/* This function is only used in eval.c. */
long int weak_function
__strtol_internal (const char *nptr, char **endptr, int base, int group)
{
unsigned long int result = 0;
long int sign = 1;
while (*nptr == ' ' || *nptr == '\t')
++nptr;
if (*nptr == '-')
{
sign = -1;
++nptr;
}
else if (*nptr == '+')
++nptr;
if (*nptr < '0' || *nptr > '9')
{
if (endptr != NULL)
*endptr = (char *) nptr;
return 0L;
}
assert (base == 0);
base = 10;
if (*nptr == '0')
{
if (nptr[1] == 'x' || nptr[1] == 'X')
{
base = 16;
nptr += 2;
}
else
base = 8;
}
while (*nptr >= '0' && *nptr <= '9')
{
unsigned long int digval = *nptr - '0';
if (result > LONG_MAX / 10
|| (sign > 0 ? result == LONG_MAX / 10 && digval > LONG_MAX % 10
: (result == ((unsigned long int) LONG_MAX + 1) / 10
&& digval > ((unsigned long int) LONG_MAX + 1) % 10)))
{
errno = ERANGE;
return sign > 0 ? LONG_MAX : LONG_MIN;
}
result *= base;
result += digval;
++nptr;
}
return (long int) result * sign;
}
long int weak_function
strtol (const char *nptr, char **endptr, int base)
{
return __strtol_internal (nptr, endptr, base, 0);
}
unsigned long int weak_function
__strtoul_internal (const char *nptr, char **endptr, int base, int group)
{
unsigned long int result = 0;
long int sign = 1;
while (*nptr == ' ' || *nptr == '\t')
++nptr;
if (*nptr == '-')
{
sign = -1;
++nptr;
}
else if (*nptr == '+')
++nptr;
if (*nptr < '0' || *nptr > '9')
{
if (endptr != NULL)
*endptr = (char *) nptr;
return 0UL;
}
assert (base == 0);
base = 10;
if (*nptr == '0')
{
if (nptr[1] == 'x' || nptr[1] == 'X')
{
base = 16;
nptr += 2;
}
else
base = 8;
}
while (*nptr >= '0' && *nptr <= '9')
{
unsigned long int digval = *nptr - '0';
if (result > LONG_MAX / 10
|| (result == ULONG_MAX / 10 && digval > ULONG_MAX % 10))
{
errno = ERANGE;
return ULONG_MAX;
}
result *= base;
result += digval;
++nptr;
}
return result * sign;
}
unsigned long int weak_function
strtoul (const char *nptr, char **endptr, int base)
{
return (unsigned long int) __strtoul_internal (nptr, endptr, base, 0);
}