383 lines
9.2 KiB
C
383 lines
9.2 KiB
C
/* Minimal replacements for basic facilities used in the dynamic linker.
|
||
Copyright (C) 1995-2013 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 Lesser General Public
|
||
License as published by the Free Software Foundation; either
|
||
version 2.1 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
|
||
Lesser General Public License for more details.
|
||
|
||
You should have received a copy of the GNU Lesser General Public
|
||
License along with the GNU C Library; if not, see
|
||
<http://www.gnu.org/licenses/>. */
|
||
|
||
#include <errno.h>
|
||
#include <limits.h>
|
||
#include <string.h>
|
||
#include <tls.h>
|
||
#include <unistd.h>
|
||
#include <sys/mman.h>
|
||
#include <sys/param.h>
|
||
#include <sys/types.h>
|
||
#include <ldsodefs.h>
|
||
#include <_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;
|
||
|
||
/* Declarations of global functions. */
|
||
extern void weak_function free (void *ptr);
|
||
extern void * weak_function realloc (void *ptr, size_t n);
|
||
extern unsigned long int weak_function __strtoul_internal (const char *nptr,
|
||
char **endptr,
|
||
int base,
|
||
int group);
|
||
extern unsigned long int weak_function strtoul (const char *nptr,
|
||
char **endptr, int base);
|
||
|
||
|
||
/* Allocate an aligned memory block. */
|
||
void * weak_function
|
||
__libc_memalign (size_t align, size_t n)
|
||
{
|
||
if (alloc_end == 0)
|
||
{
|
||
/* Consume any unused space in the last page of our data segment. */
|
||
extern int _end attribute_hidden;
|
||
alloc_ptr = &_end;
|
||
alloc_end = (void *) 0 + (((alloc_ptr - (void *) 0)
|
||
+ GLRO(dl_pagesize) - 1)
|
||
& ~(GLRO(dl_pagesize) - 1));
|
||
}
|
||
|
||
/* Make sure the allocation pointer is ideally aligned. */
|
||
alloc_ptr = (void *) 0 + (((alloc_ptr - (void *) 0) + align - 1)
|
||
& ~(align - 1));
|
||
|
||
if (alloc_ptr + n >= alloc_end || n >= -(uintptr_t) alloc_ptr)
|
||
{
|
||
/* Insufficient space left; allocate another page. */
|
||
caddr_t page;
|
||
size_t nup = (n + GLRO(dl_pagesize) - 1) & ~(GLRO(dl_pagesize) - 1);
|
||
if (__builtin_expect (nup == 0, 0))
|
||
{
|
||
if (n)
|
||
return NULL;
|
||
nup = GLRO(dl_pagesize);
|
||
}
|
||
page = __mmap (0, nup, PROT_READ|PROT_WRITE,
|
||
MAP_ANON|MAP_PRIVATE, -1, 0);
|
||
if (page == MAP_FAILED)
|
||
return NULL;
|
||
if (page != alloc_end)
|
||
alloc_ptr = page;
|
||
alloc_end = page + nup;
|
||
}
|
||
|
||
alloc_last_block = (void *) alloc_ptr;
|
||
alloc_ptr += n;
|
||
return alloc_last_block;
|
||
}
|
||
|
||
void * weak_function
|
||
malloc (size_t n)
|
||
{
|
||
return __libc_memalign (sizeof (double), n);
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
/* New memory from the trivial malloc above is always already cleared.
|
||
(We make sure that's true in the rare occasion it might not be,
|
||
by clearing memory in free, below.) */
|
||
size_t bytes = nmemb * size;
|
||
|
||
#define HALF_SIZE_T (((size_t) 1) << (8 * sizeof (size_t) / 2))
|
||
if (__builtin_expect ((nmemb | size) >= HALF_SIZE_T, 0)
|
||
&& size != 0 && bytes / size != nmemb)
|
||
return NULL;
|
||
|
||
return malloc (bytes);
|
||
}
|
||
|
||
/* This will rarely be called. */
|
||
void weak_function
|
||
free (void *ptr)
|
||
{
|
||
/* We can free only the last block allocated. */
|
||
if (ptr == alloc_last_block)
|
||
{
|
||
/* Since this is rare, we clear the freed block here
|
||
so that calloc can presume malloc returns cleared memory. */
|
||
memset (alloc_last_block, '\0', alloc_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)
|
||
{
|
||
if (ptr == NULL)
|
||
return malloc (n);
|
||
assert (ptr == alloc_last_block);
|
||
size_t old_size = alloc_ptr - alloc_last_block;
|
||
alloc_ptr = alloc_last_block;
|
||
void *new = malloc (n);
|
||
return new != ptr ? memcpy (new, ptr, old_size) : new;
|
||
}
|
||
|
||
/* Avoid signal frobnication in setjmp/longjmp. Keeps things smaller. */
|
||
|
||
#include <setjmp.h>
|
||
|
||
int weak_function
|
||
__sigjmp_save (sigjmp_buf env, int savemask __attribute__ ((unused)))
|
||
{
|
||
env[0].__mask_was_saved = 0;
|
||
return 0;
|
||
}
|
||
|
||
/* 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 (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)
|
||
{
|
||
_dl_fatal_printf ("\
|
||
Inconsistency detected by ld.so: %s: %u: %s%sAssertion `%s' failed!\n",
|
||
file, line, function ?: "", function ? ": " : "",
|
||
assertion);
|
||
|
||
}
|
||
rtld_hidden_weak(__assert_fail)
|
||
|
||
void weak_function
|
||
__assert_perror_fail (int errnum,
|
||
const char *file, unsigned int line,
|
||
const char *function)
|
||
{
|
||
char errbuf[400];
|
||
_dl_fatal_printf ("\
|
||
Inconsistency detected by ld.so: %s: %u: %s%sUnexpected error: %s.\n",
|
||
file, line, function ?: "", function ? ": " : "",
|
||
__strerror_r (errnum, errbuf, sizeof errbuf));
|
||
|
||
}
|
||
rtld_hidden_weak (__assert_perror_fail)
|
||
#endif
|
||
|
||
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;
|
||
unsigned max_digit;
|
||
|
||
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;
|
||
max_digit = 9;
|
||
if (*nptr == '0')
|
||
{
|
||
if (nptr[1] == 'x' || nptr[1] == 'X')
|
||
{
|
||
base = 16;
|
||
nptr += 2;
|
||
}
|
||
else
|
||
{
|
||
base = 8;
|
||
max_digit = 7;
|
||
}
|
||
}
|
||
|
||
while (1)
|
||
{
|
||
unsigned long int digval;
|
||
if (*nptr >= '0' && *nptr <= '0' + max_digit)
|
||
digval = *nptr - '0';
|
||
else if (base == 16)
|
||
{
|
||
if (*nptr >= 'a' && *nptr <= 'f')
|
||
digval = *nptr - 'a' + 10;
|
||
else if (*nptr >= 'A' && *nptr <= 'F')
|
||
digval = *nptr - 'A' + 10;
|
||
else
|
||
break;
|
||
}
|
||
else
|
||
break;
|
||
|
||
if (result > ULONG_MAX / base
|
||
|| (result == ULONG_MAX / base && digval > ULONG_MAX % base))
|
||
{
|
||
errno = ERANGE;
|
||
if (endptr != NULL)
|
||
*endptr = (char *) nptr;
|
||
return ULONG_MAX;
|
||
}
|
||
result *= base;
|
||
result += digval;
|
||
++nptr;
|
||
}
|
||
|
||
if (endptr != NULL)
|
||
*endptr = (char *) nptr;
|
||
return result * sign;
|
||
}
|
||
|
||
|
||
#undef _itoa
|
||
/* We always use _itoa instead of _itoa_word in ld.so since the former
|
||
also has to be present and it is never about speed when these
|
||
functions are used. */
|
||
char *
|
||
_itoa (value, buflim, base, upper_case)
|
||
unsigned long long int value;
|
||
char *buflim;
|
||
unsigned int base;
|
||
int upper_case;
|
||
{
|
||
assert (! upper_case);
|
||
|
||
do
|
||
*--buflim = _itoa_lower_digits[value % base];
|
||
while ((value /= base) != 0);
|
||
|
||
return buflim;
|
||
}
|
||
|
||
|
||
/* The following is not a complete strsep implementation. It cannot
|
||
handle empty delimiter strings. But this isn't necessary for the
|
||
execution of ld.so. */
|
||
#undef strsep
|
||
#undef __strsep
|
||
char *
|
||
__strsep (char **stringp, const char *delim)
|
||
{
|
||
char *begin;
|
||
|
||
assert (delim[0] != '\0');
|
||
|
||
begin = *stringp;
|
||
if (begin != NULL)
|
||
{
|
||
char *end = begin;
|
||
|
||
while (*end != '\0' || (end = NULL))
|
||
{
|
||
const char *dp = delim;
|
||
|
||
do
|
||
if (*dp == *end)
|
||
break;
|
||
while (*++dp != '\0');
|
||
|
||
if (*dp != '\0')
|
||
{
|
||
*end++ = '\0';
|
||
break;
|
||
}
|
||
|
||
++end;
|
||
}
|
||
|
||
*stringp = end;
|
||
}
|
||
|
||
return begin;
|
||
}
|
||
weak_alias (__strsep, strsep)
|
||
strong_alias (__strsep, __strsep_g)
|
||
|
||
void
|
||
__attribute__ ((noreturn))
|
||
__chk_fail (void)
|
||
{
|
||
_exit (127);
|
||
}
|
||
rtld_hidden_def (__chk_fail)
|
||
|
||
/* The '_itoa_lower_digits' variable in libc.so is able to handle bases
|
||
up to 36. We don't need this here. */
|
||
const char _itoa_lower_digits[16] = "0123456789abcdef";
|
||
rtld_hidden_data_def (_itoa_lower_digits)
|