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9090848d06
posix/wordexp-test.c used libc-internal.h for PTR_ALIGN_DOWN; similar to what was done with libc-diag.h, I have split the definitions of cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN to a new header, libc-pointer-arith.h. It then occurred to me that the remaining declarations in libc-internal.h are mostly to do with early initialization, and probably most of the files including it, even in the core code, don't need it anymore. Indeed, only 19 files actually need what remains of libc-internal.h. 23 others need libc-diag.h instead, and 12 need libc-pointer-arith.h instead. No file needs more than one of them, and 16 don't need any of them! So, with this patch, libc-internal.h stops including libc-diag.h as well as losing the pointer arithmetic macros, and all including files are adjusted. * include/libc-pointer-arith.h: New file. Define cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN here. * include/libc-internal.h: Definitions of above macros moved from here. Don't include libc-diag.h anymore either. * posix/wordexp-test.c: Include stdint.h and libc-pointer-arith.h. Don't include libc-internal.h. * debug/pcprofile.c, elf/dl-tunables.c, elf/soinit.c, io/openat.c * io/openat64.c, misc/ptrace.c, nptl/pthread_clock_gettime.c * nptl/pthread_clock_settime.c, nptl/pthread_cond_common.c * string/strcoll_l.c, sysdeps/nacl/brk.c * sysdeps/unix/clock_settime.c * sysdeps/unix/sysv/linux/i386/get_clockfreq.c * sysdeps/unix/sysv/linux/ia64/get_clockfreq.c * sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c * sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c: Don't include libc-internal.h. * elf/get-dynamic-info.h, iconv/loop.c * iconvdata/iso-2022-cn-ext.c, locale/weight.h, locale/weightwc.h * misc/reboot.c, nis/nis_table.c, nptl_db/thread_dbP.h * nscd/connections.c, resolv/res_send.c, soft-fp/fmadf4.c * soft-fp/fmasf4.c, soft-fp/fmatf4.c, stdio-common/vfscanf.c * sysdeps/ieee754/dbl-64/e_lgamma_r.c * sysdeps/ieee754/dbl-64/k_rem_pio2.c * sysdeps/ieee754/flt-32/e_lgammaf_r.c * sysdeps/ieee754/flt-32/k_rem_pio2f.c * sysdeps/ieee754/ldbl-128/k_tanl.c * sysdeps/ieee754/ldbl-128ibm/k_tanl.c * sysdeps/ieee754/ldbl-96/e_lgammal_r.c * sysdeps/ieee754/ldbl-96/k_tanl.c, sysdeps/nptl/futex-internal.h: Include libc-diag.h instead of libc-internal.h. * elf/dl-load.c, elf/dl-reloc.c, locale/programs/locarchive.c * nptl/nptl-init.c, string/strcspn.c, string/strspn.c * malloc/malloc.c, sysdeps/i386/nptl/tls.h * sysdeps/nacl/dl-map-segments.h, sysdeps/x86_64/atomic-machine.h * sysdeps/unix/sysv/linux/spawni.c * sysdeps/x86_64/nptl/tls.h: Include libc-pointer-arith.h instead of libc-internal.h. * elf/get-dynamic-info.h, sysdeps/nacl/dl-map-segments.h * sysdeps/x86_64/atomic-machine.h: Add multiple include guard.
364 lines
11 KiB
C
364 lines
11 KiB
C
/* Relocate a shared object and resolve its references to other loaded objects.
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Copyright (C) 1995-2017 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, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <libintl.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <ldsodefs.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 <_itoa.h>
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#include <libc-pointer-arith.h>
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#include "dynamic-link.h"
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/* Statistics function. */
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#ifdef SHARED
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# define bump_num_cache_relocations() ++GL(dl_num_cache_relocations)
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#else
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# define bump_num_cache_relocations() ((void) 0)
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#endif
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/* We are trying to perform a static TLS relocation in MAP, but it was
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dynamically loaded. This can only work if there is enough surplus in
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the static TLS area already allocated for each running thread. If this
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object's TLS segment is too big to fit, we fail. If it fits,
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we set MAP->l_tls_offset and return.
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This function intentionally does not return any value but signals error
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directly, as static TLS should be rare and code handling it should
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not be inlined as much as possible. */
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int
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internal_function
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_dl_try_allocate_static_tls (struct link_map *map)
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{
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/* If we've already used the variable with dynamic access, or if the
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alignment requirements are too high, fail. */
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if (map->l_tls_offset == FORCED_DYNAMIC_TLS_OFFSET
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|| map->l_tls_align > GL(dl_tls_static_align))
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{
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fail:
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return -1;
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}
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#if TLS_TCB_AT_TP
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size_t freebytes = GL(dl_tls_static_size) - GL(dl_tls_static_used);
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if (freebytes < TLS_TCB_SIZE)
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goto fail;
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freebytes -= TLS_TCB_SIZE;
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size_t blsize = map->l_tls_blocksize + map->l_tls_firstbyte_offset;
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if (freebytes < blsize)
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goto fail;
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size_t n = (freebytes - blsize) / map->l_tls_align;
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size_t offset = GL(dl_tls_static_used) + (freebytes - n * map->l_tls_align
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- map->l_tls_firstbyte_offset);
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map->l_tls_offset = GL(dl_tls_static_used) = offset;
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#elif TLS_DTV_AT_TP
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/* dl_tls_static_used includes the TCB at the beginning. */
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size_t offset = (ALIGN_UP(GL(dl_tls_static_used)
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- map->l_tls_firstbyte_offset,
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map->l_tls_align)
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+ map->l_tls_firstbyte_offset);
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size_t used = offset + map->l_tls_blocksize;
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if (used > GL(dl_tls_static_size))
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goto fail;
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map->l_tls_offset = offset;
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map->l_tls_firstbyte_offset = GL(dl_tls_static_used);
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GL(dl_tls_static_used) = used;
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#else
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# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
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#endif
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/* If the object is not yet relocated we cannot initialize the
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static TLS region. Delay it. */
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if (map->l_real->l_relocated)
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{
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#ifdef SHARED
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if (__builtin_expect (THREAD_DTV()[0].counter != GL(dl_tls_generation),
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0))
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/* Update the slot information data for at least the generation of
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the DSO we are allocating data for. */
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(void) _dl_update_slotinfo (map->l_tls_modid);
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#endif
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GL(dl_init_static_tls) (map);
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}
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else
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map->l_need_tls_init = 1;
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return 0;
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}
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void
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internal_function __attribute_noinline__
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_dl_allocate_static_tls (struct link_map *map)
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{
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if (map->l_tls_offset == FORCED_DYNAMIC_TLS_OFFSET
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|| _dl_try_allocate_static_tls (map))
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{
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_dl_signal_error (0, map->l_name, NULL, N_("\
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cannot allocate memory in static TLS block"));
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}
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}
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/* Initialize static TLS area and DTV for current (only) thread.
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libpthread implementations should provide their own hook
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to handle all threads. */
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void
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_dl_nothread_init_static_tls (struct link_map *map)
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{
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#if TLS_TCB_AT_TP
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void *dest = (char *) THREAD_SELF - map->l_tls_offset;
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#elif TLS_DTV_AT_TP
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void *dest = (char *) THREAD_SELF + map->l_tls_offset + TLS_PRE_TCB_SIZE;
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#else
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# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
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#endif
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/* Initialize the memory. */
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memset (__mempcpy (dest, map->l_tls_initimage, map->l_tls_initimage_size),
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'\0', map->l_tls_blocksize - map->l_tls_initimage_size);
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}
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void
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_dl_relocate_object (struct link_map *l, struct r_scope_elem *scope[],
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int reloc_mode, int consider_profiling)
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{
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struct textrels
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{
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caddr_t start;
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size_t len;
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int prot;
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struct textrels *next;
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} *textrels = NULL;
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/* Initialize it to make the compiler happy. */
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const char *errstring = NULL;
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int lazy = reloc_mode & RTLD_LAZY;
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int skip_ifunc = reloc_mode & __RTLD_NOIFUNC;
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#ifdef SHARED
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/* If we are auditing, install the same handlers we need for profiling. */
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if ((reloc_mode & __RTLD_AUDIT) == 0)
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consider_profiling |= GLRO(dl_audit) != NULL;
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#elif defined PROF
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/* Never use dynamic linker profiling for gprof profiling code. */
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# define consider_profiling 0
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#endif
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if (l->l_relocated)
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return;
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/* If DT_BIND_NOW is set relocate all references in this object. We
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do not do this if we are profiling, of course. */
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// XXX Correct for auditing?
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if (!consider_profiling
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&& __builtin_expect (l->l_info[DT_BIND_NOW] != NULL, 0))
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lazy = 0;
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if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_RELOC))
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_dl_debug_printf ("\nrelocation processing: %s%s\n",
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DSO_FILENAME (l->l_name), lazy ? " (lazy)" : "");
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/* DT_TEXTREL is now in level 2 and might phase out at some time.
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But we rewrite the DT_FLAGS entry to a DT_TEXTREL entry to make
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testing easier and therefore it will be available at all time. */
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if (__glibc_unlikely (l->l_info[DT_TEXTREL] != NULL))
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{
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/* Bletch. We must make read-only segments writable
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long enough to relocate them. */
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const ElfW(Phdr) *ph;
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for (ph = l->l_phdr; ph < &l->l_phdr[l->l_phnum]; ++ph)
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if (ph->p_type == PT_LOAD && (ph->p_flags & PF_W) == 0)
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{
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struct textrels *newp;
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newp = (struct textrels *) alloca (sizeof (*newp));
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newp->len = ALIGN_UP (ph->p_vaddr + ph->p_memsz, GLRO(dl_pagesize))
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- ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
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newp->start = PTR_ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize))
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+ (caddr_t) l->l_addr;
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if (__mprotect (newp->start, newp->len, PROT_READ|PROT_WRITE) < 0)
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{
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errstring = N_("cannot make segment writable for relocation");
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call_error:
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_dl_signal_error (errno, l->l_name, NULL, errstring);
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}
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#if (PF_R | PF_W | PF_X) == 7 && (PROT_READ | PROT_WRITE | PROT_EXEC) == 7
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newp->prot = (PF_TO_PROT
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>> ((ph->p_flags & (PF_R | PF_W | PF_X)) * 4)) & 0xf;
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#else
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newp->prot = 0;
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if (ph->p_flags & PF_R)
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newp->prot |= PROT_READ;
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if (ph->p_flags & PF_W)
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newp->prot |= PROT_WRITE;
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if (ph->p_flags & PF_X)
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newp->prot |= PROT_EXEC;
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#endif
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newp->next = textrels;
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textrels = newp;
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}
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}
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{
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/* Do the actual relocation of the object's GOT and other data. */
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/* String table object symbols. */
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const char *strtab = (const void *) D_PTR (l, l_info[DT_STRTAB]);
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/* This macro is used as a callback from the ELF_DYNAMIC_RELOCATE code. */
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#define RESOLVE_MAP(ref, version, r_type) \
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((ELFW(ST_BIND) ((*ref)->st_info) != STB_LOCAL \
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&& __glibc_likely (!dl_symbol_visibility_binds_local_p (*ref))) \
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? ((__builtin_expect ((*ref) == l->l_lookup_cache.sym, 0) \
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&& elf_machine_type_class (r_type) == l->l_lookup_cache.type_class) \
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? (bump_num_cache_relocations (), \
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(*ref) = l->l_lookup_cache.ret, \
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l->l_lookup_cache.value) \
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: ({ lookup_t _lr; \
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int _tc = elf_machine_type_class (r_type); \
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l->l_lookup_cache.type_class = _tc; \
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l->l_lookup_cache.sym = (*ref); \
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const struct r_found_version *v = NULL; \
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if ((version) != NULL && (version)->hash != 0) \
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v = (version); \
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_lr = _dl_lookup_symbol_x (strtab + (*ref)->st_name, l, (ref), \
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scope, v, _tc, \
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DL_LOOKUP_ADD_DEPENDENCY, NULL); \
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l->l_lookup_cache.ret = (*ref); \
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l->l_lookup_cache.value = _lr; })) \
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: l)
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#include "dynamic-link.h"
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ELF_DYNAMIC_RELOCATE (l, lazy, consider_profiling, skip_ifunc);
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#ifndef PROF
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if (__glibc_unlikely (consider_profiling)
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&& l->l_info[DT_PLTRELSZ] != NULL)
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{
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/* Allocate the array which will contain the already found
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relocations. If the shared object lacks a PLT (for example
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if it only contains lead function) the l_info[DT_PLTRELSZ]
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will be NULL. */
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size_t sizeofrel = l->l_info[DT_PLTREL]->d_un.d_val == DT_RELA
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? sizeof (ElfW(Rela))
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: sizeof (ElfW(Rel));
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size_t relcount = l->l_info[DT_PLTRELSZ]->d_un.d_val / sizeofrel;
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l->l_reloc_result = calloc (sizeof (l->l_reloc_result[0]), relcount);
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if (l->l_reloc_result == NULL)
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{
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errstring = N_("\
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%s: out of memory to store relocation results for %s\n");
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_dl_fatal_printf (errstring, RTLD_PROGNAME, l->l_name);
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}
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}
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#endif
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}
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/* Mark the object so we know this work has been done. */
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l->l_relocated = 1;
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/* Undo the segment protection changes. */
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while (__builtin_expect (textrels != NULL, 0))
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{
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if (__mprotect (textrels->start, textrels->len, textrels->prot) < 0)
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{
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errstring = N_("cannot restore segment prot after reloc");
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goto call_error;
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}
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#ifdef CLEAR_CACHE
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CLEAR_CACHE (textrels->start, textrels->start + textrels->len);
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#endif
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textrels = textrels->next;
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}
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/* In case we can protect the data now that the relocations are
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done, do it. */
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if (l->l_relro_size != 0)
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_dl_protect_relro (l);
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}
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void internal_function
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_dl_protect_relro (struct link_map *l)
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{
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ElfW(Addr) start = ALIGN_DOWN((l->l_addr
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+ l->l_relro_addr),
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GLRO(dl_pagesize));
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ElfW(Addr) end = ALIGN_DOWN((l->l_addr
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+ l->l_relro_addr
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+ l->l_relro_size),
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GLRO(dl_pagesize));
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if (start != end
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&& __mprotect ((void *) start, end - start, PROT_READ) < 0)
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{
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static const char errstring[] = N_("\
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cannot apply additional memory protection after relocation");
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_dl_signal_error (errno, l->l_name, NULL, errstring);
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}
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}
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void
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internal_function __attribute_noinline__
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_dl_reloc_bad_type (struct link_map *map, unsigned int type, int plt)
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{
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#define DIGIT(b) _itoa_lower_digits[(b) & 0xf];
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/* XXX We cannot translate these messages. */
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static const char msg[2][32
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#if __ELF_NATIVE_CLASS == 64
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+ 6
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#endif
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] = { "unexpected reloc type 0x",
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"unexpected PLT reloc type 0x" };
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char msgbuf[sizeof (msg[0])];
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char *cp;
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cp = __stpcpy (msgbuf, msg[plt]);
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#if __ELF_NATIVE_CLASS == 64
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if (__builtin_expect(type > 0xff, 0))
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{
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*cp++ = DIGIT (type >> 28);
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*cp++ = DIGIT (type >> 24);
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*cp++ = DIGIT (type >> 20);
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*cp++ = DIGIT (type >> 16);
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*cp++ = DIGIT (type >> 12);
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*cp++ = DIGIT (type >> 8);
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}
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#endif
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*cp++ = DIGIT (type >> 4);
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*cp++ = DIGIT (type);
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*cp = '\0';
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_dl_signal_error (0, map->l_name, NULL, msgbuf);
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}
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