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Diffstat (limited to 'elf/dl-minimal.c')
| -rw-r--r-- | elf/dl-minimal.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/elf/dl-minimal.c b/elf/dl-minimal.c new file mode 100644 index 0000000000..332f21e0b0 --- /dev/null +++ b/elf/dl-minimal.c @@ -0,0 +1,153 @@ +/* Minimal replacements for basic facilities used in the dynamic linker. +Copyright (C) 1995 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., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <sys/types.h> +#include <sys/mman.h> +#include <unistd.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. */ + +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 (); + + if (_dl_zerofd == -1) + _dl_zerofd = _dl_sysdep_open_zero_fill (); + + 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) + pagesize - 1) + & ~(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; + assert (n <= pagesize); + page = mmap (0, pagesize, PROT_READ|PROT_WRITE, MAP_ANON, _dl_zerofd, 0); + assert (page != (caddr_t) -1); + if (page != alloc_end) + alloc_ptr = page; + alloc_end = page + pagesize; + } + + alloc_last_block = (void *) alloc_ptr; + alloc_ptr += n; + return alloc_last_block; +} +weak_symbol (malloc) + +/* This will rarely be called. */ +void +free (void *ptr) +{ + /* We can free only the last block allocated. */ + if (ptr == alloc_last_block) + alloc_ptr = alloc_last_block; +} +weak_symbol (free) + +/* This is never called. */ +void * +realloc (void *ptr, size_t n) +{ ptr += n; abort (); } +weak_symbol (realloc) + +/* 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) + +void +longjmp (jmp_buf env, int val) { __longjmp (env[0].__jmpbuf, val); } +weak_symbol (longjmp) + + +/* Define our own stub for the localization function used by strerror. + English-only in the dynamic linker keeps it smaller. */ + +char * +__dgettext (const char *domainname, const char *msgid) +{ + assert (domainname == _libc_intl_domainname); + return (char *) msgid; +} +weak_symbol (__dgettext) +weak_alias (__dgettext, dgettext) + +#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 +__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); + +} +weak_symbol (__assert_fail) + +void +__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); + +} +weak_symbol (__assert_perror_fail) + +#endif |