368 lines
9.0 KiB
C
368 lines
9.0 KiB
C
/* Minimal replacements for basic facilities used in the dynamic linker.
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Copyright (C) 1995-1998,2000-2002,2004-2006,2007,2009
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Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <errno.h>
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#include <limits.h>
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#include <string.h>
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#include <tls.h>
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#include <unistd.h>
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#include <sys/mman.h>
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#include <sys/param.h>
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#include <sys/types.h>
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#include <ldsodefs.h>
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#include <stdio-common/_itoa.h>
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#include <assert.h>
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/* Minimal `malloc' allocator for use while loading shared libraries.
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No block is ever freed. */
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static void *alloc_ptr, *alloc_end, *alloc_last_block;
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/* Declarations of global functions. */
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extern void weak_function free (void *ptr);
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extern void * weak_function realloc (void *ptr, size_t n);
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extern unsigned long int weak_function __strtoul_internal (const char *nptr,
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char **endptr,
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int base,
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int group);
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extern unsigned long int weak_function strtoul (const char *nptr,
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char **endptr, int base);
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/* Allocate an aligned memory block. */
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void * weak_function
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__libc_memalign (size_t align, size_t n)
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{
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if (alloc_end == 0)
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{
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/* Consume any unused space in the last page of our data segment. */
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extern int _end attribute_hidden;
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alloc_ptr = &_end;
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alloc_end = (void *) 0 + (((alloc_ptr - (void *) 0)
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+ GLRO(dl_pagesize) - 1)
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& ~(GLRO(dl_pagesize) - 1));
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}
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/* Make sure the allocation pointer is ideally aligned. */
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alloc_ptr = (void *) 0 + (((alloc_ptr - (void *) 0) + align - 1)
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& ~(align - 1));
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if (alloc_ptr + n >= alloc_end || n >= -(uintptr_t) alloc_ptr)
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{
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/* Insufficient space left; allocate another page. */
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caddr_t page;
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size_t nup = (n + GLRO(dl_pagesize) - 1) & ~(GLRO(dl_pagesize) - 1);
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if (__builtin_expect (nup == 0, 0))
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{
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if (n)
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return NULL;
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nup = GLRO(dl_pagesize);
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}
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page = __mmap (0, nup, PROT_READ|PROT_WRITE,
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MAP_ANON|MAP_PRIVATE, -1, 0);
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if (page == MAP_FAILED)
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return NULL;
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if (page != alloc_end)
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alloc_ptr = page;
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alloc_end = page + nup;
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}
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alloc_last_block = (void *) alloc_ptr;
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alloc_ptr += n;
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return alloc_last_block;
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}
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void * weak_function
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malloc (size_t n)
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{
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return __libc_memalign (sizeof (double), n);
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}
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/* We use this function occasionally since the real implementation may
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be optimized when it can assume the memory it returns already is
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set to NUL. */
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void * weak_function
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calloc (size_t nmemb, size_t size)
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{
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/* New memory from the trivial malloc above is always already cleared.
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(We make sure that's true in the rare occasion it might not be,
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by clearing memory in free, below.) */
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size_t bytes = nmemb * size;
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#define HALF_SIZE_T (((size_t) 1) << (8 * sizeof (size_t) / 2))
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if (__builtin_expect ((nmemb | size) >= HALF_SIZE_T, 0)
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&& size != 0 && bytes / size != nmemb)
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return NULL;
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return malloc (bytes);
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}
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/* This will rarely be called. */
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void weak_function
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free (void *ptr)
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{
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/* We can free only the last block allocated. */
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if (ptr == alloc_last_block)
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{
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/* Since this is rare, we clear the freed block here
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so that calloc can presume malloc returns cleared memory. */
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memset (alloc_last_block, '\0', alloc_ptr - alloc_last_block);
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alloc_ptr = alloc_last_block;
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}
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}
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/* This is only called with the most recent block returned by malloc. */
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void * weak_function
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realloc (void *ptr, size_t n)
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{
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if (ptr == NULL)
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return malloc (n);
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assert (ptr == alloc_last_block);
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size_t old_size = alloc_ptr - alloc_last_block;
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alloc_ptr = alloc_last_block;
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void *new = malloc (n);
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return new != ptr ? memcpy (new, ptr, old_size) : new;
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}
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/* Avoid signal frobnication in setjmp/longjmp. Keeps things smaller. */
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#include <setjmp.h>
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int weak_function
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__sigjmp_save (sigjmp_buf env, int savemask __attribute__ ((unused)))
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{
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env[0].__mask_was_saved = 0;
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return 0;
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}
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/* Define our own version of the internal function used by strerror. We
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only provide the messages for some common errors. This avoids pulling
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in the whole error list. */
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char * weak_function
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__strerror_r (int errnum, char *buf, size_t buflen)
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{
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char *msg;
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switch (errnum)
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{
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case ENOMEM:
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msg = (char *) "Cannot allocate memory";
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break;
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case EINVAL:
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msg = (char *) "Invalid argument";
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break;
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case ENOENT:
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msg = (char *) "No such file or directory";
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break;
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case EPERM:
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msg = (char *) "Operation not permitted";
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break;
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case EIO:
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msg = (char *) "Input/output error";
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break;
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case EACCES:
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msg = (char *) "Permission denied";
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break;
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default:
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/* No need to check buffer size, all calls in the dynamic linker
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provide enough space. */
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buf[buflen - 1] = '\0';
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msg = _itoa (errnum, buf + buflen - 1, 10, 0);
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msg = memcpy (msg - (sizeof ("Error ") - 1), "Error ",
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sizeof ("Error ") - 1);
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break;
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}
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return msg;
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}
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#ifndef NDEBUG
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/* Define (weakly) our own assert failure function which doesn't use stdio.
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If we are linked into the user program (-ldl), the normal __assert_fail
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defn can override this one. */
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void weak_function
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__assert_fail (const char *assertion,
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const char *file, unsigned int line, const char *function)
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{
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_dl_fatal_printf ("\
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Inconsistency detected by ld.so: %s: %u: %s%sAssertion `%s' failed!\n",
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file, line, function ?: "", function ? ": " : "",
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assertion);
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}
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rtld_hidden_weak(__assert_fail)
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void weak_function
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__assert_perror_fail (int errnum,
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const char *file, unsigned int line,
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const char *function)
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{
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char errbuf[400];
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_dl_fatal_printf ("\
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Inconsistency detected by ld.so: %s: %u: %s%sUnexpected error: %s.\n",
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file, line, function ?: "", function ? ": " : "",
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__strerror_r (errnum, errbuf, sizeof errbuf));
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}
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rtld_hidden_weak (__assert_perror_fail)
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#endif
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unsigned long int weak_function
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__strtoul_internal (const char *nptr, char **endptr, int base, int group)
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{
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unsigned long int result = 0;
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long int sign = 1;
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while (*nptr == ' ' || *nptr == '\t')
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++nptr;
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if (*nptr == '-')
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{
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sign = -1;
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++nptr;
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}
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else if (*nptr == '+')
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++nptr;
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if (*nptr < '0' || *nptr > '9')
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{
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if (endptr != NULL)
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*endptr = (char *) nptr;
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return 0UL;
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}
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assert (base == 0);
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base = 10;
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if (*nptr == '0')
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{
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if (nptr[1] == 'x' || nptr[1] == 'X')
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{
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base = 16;
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nptr += 2;
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}
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else
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base = 8;
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}
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while (*nptr >= '0' && *nptr <= '9')
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{
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unsigned long int digval = *nptr - '0';
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if (result > ULONG_MAX / 10
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|| (result == ULONG_MAX / 10 && digval > ULONG_MAX % 10))
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{
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errno = ERANGE;
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if (endptr != NULL)
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*endptr = (char *) nptr;
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return ULONG_MAX;
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}
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result *= base;
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result += digval;
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++nptr;
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}
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if (endptr != NULL)
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*endptr = (char *) nptr;
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return result * sign;
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}
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#undef _itoa
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/* We always use _itoa instead of _itoa_word in ld.so since the former
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also has to be present and it is never about speed when these
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functions are used. */
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char *
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_itoa (value, buflim, base, upper_case)
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unsigned long long int value;
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char *buflim;
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unsigned int base;
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int upper_case;
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{
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extern const char INTUSE(_itoa_lower_digits)[] attribute_hidden;
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assert (! upper_case);
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do
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*--buflim = INTUSE(_itoa_lower_digits)[value % base];
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while ((value /= base) != 0);
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return buflim;
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}
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/* The following is not a complete strsep implementation. It cannot
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handle empty delimiter strings. But this isn't necessary for the
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execution of ld.so. */
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#undef strsep
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#undef __strsep
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char *
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__strsep (char **stringp, const char *delim)
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{
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char *begin;
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assert (delim[0] != '\0');
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begin = *stringp;
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if (begin != NULL)
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{
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char *end = begin;
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while (*end != '\0' || (end = NULL))
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{
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const char *dp = delim;
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do
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if (*dp == *end)
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break;
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while (*++dp != '\0');
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if (*dp != '\0')
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{
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*end++ = '\0';
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break;
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}
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++end;
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}
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*stringp = end;
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}
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return begin;
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}
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weak_alias (__strsep, strsep)
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strong_alias (__strsep, __strsep_g)
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void
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__attribute__ ((noreturn))
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__chk_fail (void)
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{
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_exit (127);
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}
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rtld_hidden_def (__chk_fail)
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/* The '_itoa_lower_digits' variable in libc.so is able to handle bases
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up to 36. We don't need this here. */
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const char INTUSE(_itoa_lower_digits)[16] attribute_hidden
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= "0123456789abcdef";
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