/* Minimal replacements for basic facilities used in the dynamic linker.

   Copyright (C) 1995-2018 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 <stdio.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 <malloc/malloc-internal.h>

#include <assert.h>

/* Minimal malloc allocator for used during initial link.  After the

   initial link, a full malloc implementation is interposed, either

   the one in libc, or a different one supplied by the user through

   interposition.  */

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);

/* Allocate an aligned memory block.  */

void * weak_function

malloc (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) + MALLOC_ALIGNMENT - 1)

			    & ~(MALLOC_ALIGNMENT - 1));

  if (alloc_ptr + n >= alloc_end || n >= -(uintptr_t) alloc_ptr)

    {

      /* Insufficient space left; allocate another page plus one extra

	 page to reduce number of mmap calls.  */

      caddr_t page;

      size_t nup = (n + GLRO(dl_pagesize) - 1) & ~(GLRO(dl_pagesize) - 1);

      if (__glibc_unlikely (nup == 0 && n != 0))

	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;

}

/* 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;

}

void

__libc_fatal (const char *message)

{

  _dl_fatal_printf ("%s", message);

}

rtld_hidden_def (__libc_fatal)

void

__attribute__ ((noreturn))

__chk_fail (void)

{

  _exit (127);

}

rtld_hidden_def (__chk_fail)

#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

#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 (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 '_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)

/* 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)