/* 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.
+ Copyright (C) 1995-2019 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 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
-Library General Public License for more details.
+ 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 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. */
+ 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 <sys/types.h>
-#include <sys/mman.h>
+#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>
-#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. */
+/* 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;
-void *
-malloc (size_t n)
-{
- extern int _dl_zerofd;
- static size_t pagesize;
-
- if (pagesize == 0)
- pagesize = __getpagesize ();
+/* Declarations of global functions. */
+extern void weak_function free (void *ptr);
+extern void * weak_function realloc (void *ptr, size_t n);
- if (_dl_zerofd == -1)
- _dl_zerofd = _dl_sysdep_open_zero_fill ();
+/* 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;
+ extern int _end attribute_hidden;
alloc_ptr = &_end;
- alloc_end = (void *) 0 + (((alloc_ptr - (void *) 0) + pagesize - 1)
- & ~(pagesize - 1));
+ 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) + sizeof (double) - 1)
- & ~(sizeof (double) - 1));
+ alloc_ptr = (void *) 0 + (((alloc_ptr - (void *) 0) + MALLOC_ALIGNMENT - 1)
+ & ~(MALLOC_ALIGNMENT - 1));
- if (alloc_ptr + n >= alloc_end)
+ if (alloc_ptr + n >= alloc_end || n >= -(uintptr_t) alloc_ptr)
{
- /* Insufficient space left; allocate another page. */
+ /* Insufficient space left; allocate another page plus one extra
+ page to reduce number of mmap calls. */
caddr_t page;
- assert (n <= pagesize);
- page = mmap (0, pagesize, PROT_READ|PROT_WRITE,
- MAP_ANON|MAP_PRIVATE, _dl_zerofd, 0);
- assert (page != (caddr_t) -1);
+ 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 + pagesize;
+ alloc_end = page + nup;
}
alloc_last_block = (void *) alloc_ptr;
alloc_ptr += n;
return alloc_last_block;
}
-weak_symbol (malloc)
+
+/* 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
+void weak_function
free (void *ptr)
{
/* We can free only the last block allocated. */
if (ptr == alloc_last_block)
- alloc_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;
+ }
}
-weak_symbol (free)
/* This is only called with the most recent block returned by malloc. */
-void *
+void * weak_function
realloc (void *ptr, size_t n)
{
- void *new;
+ 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;
- new = malloc (n);
- assert (new == ptr);
- return new;
+ void *new = malloc (n);
+ return new != ptr ? memcpy (new, ptr, old_size) : new;
}
-weak_symbol (realloc)
\f
/* 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)
+int weak_function
+__sigjmp_save (sigjmp_buf env, int savemask __attribute__ ((unused)))
+{
+ env[0].__mask_was_saved = 0;
+ return 0;
+}
+\f
+/* 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. */
-void
-longjmp (jmp_buf env, int val) { __longjmp (env[0].__jmpbuf, val); }
-weak_symbol (longjmp)
+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;
+}
\f
-/* Define our own stub for the localization function used by strerror.
- English-only in the dynamic linker keeps it smaller. */
+void
+__libc_fatal (const char *message)
+{
+ _dl_fatal_printf ("%s", message);
+}
+rtld_hidden_def (__libc_fatal)
-char *
-__dgettext (const char *domainname, const char *msgid)
+void
+__attribute__ ((noreturn))
+__chk_fail (void)
{
- assert (domainname == _libc_intl_domainname);
- return (char *) msgid;
+ _exit (127);
}
-weak_symbol (__dgettext)
-weak_alias (__dgettext, dgettext)
-\f
-#ifndef NDEBUG
+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
+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 (line, buf + sizeof buf - 1, 10, 0),
- ": ", function ?: "", function ? ": " : "",
- "Assertion `", assertion, "' failed!\n",
- NULL);
+ _dl_fatal_printf ("\
+Inconsistency detected by ld.so: %s: %u: %s%sAssertion `%s' failed!\n",
+ file, line, function ?: "", function ? ": " : "",
+ assertion);
}
-weak_symbol (__assert_fail)
+rtld_hidden_weak (__assert_fail)
-void
+void weak_function
__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);
+ 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));
}
-weak_symbol (__assert_perror_fail)
-
+rtld_hidden_weak (__assert_perror_fail)
#endif
+\f
+#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)
+\f
+/* 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)
projects / thirdparty / glibc.git / blobdiff