0a90eb9f2f
As part of the FreeBSD powerpc* flag day (1300070), the auxv numbering was changed to match every other platform. See D20799 for more details on that change. While the kernel and rtld were adapted, libc was not, so old dynamic binaries broke for reasons other than the ABI change on powerpc64. Since it's possible to support nearly everything regarding old binaries by adding compatibility code to libc (as besides rtld, it is the main point where auxv is digested), we might as well provide compatibility code. The only unhandled case remaining should be "new format libraries that call elf_aux_info() which are dynamically linked to by old-format binaries", which should be quite rare. Reviewed by: jhibbits Sponsored by: Tag1 Consulting, Inc. Differential Revision: https://reviews.freebsd.org/D23096
335 lines
7.3 KiB
C
335 lines
7.3 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright 2010, 2012 Konstantin Belousov <kib@FreeBSD.ORG>.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "namespace.h"
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#include <elf.h>
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#include <errno.h>
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#include <link.h>
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#include <pthread.h>
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#include <string.h>
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#include <sys/auxv.h>
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#include "un-namespace.h"
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#include "libc_private.h"
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extern char **environ;
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extern int _DYNAMIC;
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#pragma weak _DYNAMIC
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void *__elf_aux_vector;
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static pthread_once_t aux_vector_once = PTHREAD_ONCE_INIT;
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static void
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init_aux_vector_once(void)
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{
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Elf_Addr *sp;
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sp = (Elf_Addr *)environ;
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while (*sp++ != 0)
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;
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__elf_aux_vector = (Elf_Auxinfo *)sp;
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}
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void
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__init_elf_aux_vector(void)
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{
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if (&_DYNAMIC != NULL)
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return;
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_once(&aux_vector_once, init_aux_vector_once);
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}
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static pthread_once_t aux_once = PTHREAD_ONCE_INIT;
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static int pagesize, osreldate, canary_len, ncpus, pagesizes_len;
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static int hwcap_present, hwcap2_present;
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static char *canary, *pagesizes, *execpath;
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static void *timekeep;
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static u_long hwcap, hwcap2;
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#ifdef __powerpc__
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static int powerpc_new_auxv_format = 0;
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static void _init_aux_powerpc_fixup(void);
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int _powerpc_elf_aux_info(int, void *, int);
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#endif
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static void
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init_aux(void)
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{
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Elf_Auxinfo *aux;
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for (aux = __elf_aux_vector; aux->a_type != AT_NULL; aux++) {
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switch (aux->a_type) {
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case AT_CANARY:
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canary = (char *)(aux->a_un.a_ptr);
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break;
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case AT_CANARYLEN:
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canary_len = aux->a_un.a_val;
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break;
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case AT_EXECPATH:
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execpath = (char *)(aux->a_un.a_ptr);
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break;
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case AT_HWCAP:
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hwcap_present = 1;
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hwcap = (u_long)(aux->a_un.a_val);
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break;
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case AT_HWCAP2:
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hwcap2_present = 1;
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hwcap2 = (u_long)(aux->a_un.a_val);
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break;
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case AT_PAGESIZES:
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pagesizes = (char *)(aux->a_un.a_ptr);
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break;
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case AT_PAGESIZESLEN:
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pagesizes_len = aux->a_un.a_val;
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break;
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case AT_PAGESZ:
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pagesize = aux->a_un.a_val;
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break;
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case AT_OSRELDATE:
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osreldate = aux->a_un.a_val;
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break;
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case AT_NCPUS:
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ncpus = aux->a_un.a_val;
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break;
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case AT_TIMEKEEP:
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timekeep = aux->a_un.a_ptr;
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break;
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#ifdef __powerpc__
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/*
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* Since AT_STACKPROT is always set, and the common
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* value 23 is mutually exclusive with the legacy powerpc
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* value 21, the existence of AT_STACKPROT proves we are
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* on the common format.
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*/
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case AT_STACKPROT: /* 23 */
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powerpc_new_auxv_format = 1;
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break;
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#endif
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}
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}
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#ifdef __powerpc__
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if (!powerpc_new_auxv_format)
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_init_aux_powerpc_fixup();
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#endif
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}
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#ifdef __powerpc__
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static void
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_init_aux_powerpc_fixup(void)
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{
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Elf_Auxinfo *aux;
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/*
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* Before 1300070, PowerPC platforms had nonstandard numbering for
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* the aux vector. When running old binaries, the kernel will pass
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* the vector using the old numbering. Reload affected variables.
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*/
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for (aux = __elf_aux_vector; aux->a_type != AT_NULL; aux++) {
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switch (aux->a_type) {
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case AT_OLD_CANARY:
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canary = (char *)(aux->a_un.a_ptr);
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break;
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case AT_OLD_CANARYLEN:
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canary_len = aux->a_un.a_val;
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break;
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case AT_OLD_EXECPATH:
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execpath = (char *)(aux->a_un.a_ptr);
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break;
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case AT_OLD_PAGESIZES:
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pagesizes = (char *)(aux->a_un.a_ptr);
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break;
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case AT_OLD_PAGESIZESLEN:
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pagesizes_len = aux->a_un.a_val;
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break;
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case AT_OLD_OSRELDATE:
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osreldate = aux->a_un.a_val;
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break;
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case AT_OLD_NCPUS:
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ncpus = aux->a_un.a_val;
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break;
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}
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}
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}
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int
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_powerpc_elf_aux_info(int aux, void *buf, int buflen)
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{
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/*
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* If we are in the old auxv format, we need to translate the aux
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* parameter of elf_aux_info() calls into the common auxv format.
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* Internal libc calls always use the common format, and they
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* directly call _elf_aux_info instead of using the weak symbol.
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*/
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if (!powerpc_new_auxv_format) {
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switch (aux) {
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case AT_OLD_EXECPATH:
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aux = AT_EXECPATH;
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break;
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case AT_OLD_CANARY:
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aux = AT_CANARY;
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break;
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case AT_OLD_CANARYLEN:
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aux = AT_CANARYLEN;
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break;
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case AT_OLD_OSRELDATE:
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aux = AT_OSRELDATE;
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break;
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case AT_OLD_NCPUS:
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aux = AT_NCPUS;
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break;
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case AT_OLD_PAGESIZES:
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aux = AT_PAGESIZES;
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break;
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case AT_OLD_PAGESIZESLEN:
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aux = AT_PAGESIZESLEN;
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break;
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case AT_OLD_STACKPROT:
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aux = AT_STACKPROT;
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break;
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}
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}
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return _elf_aux_info(aux, buf, buflen);
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}
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__weak_reference(_powerpc_elf_aux_info, elf_aux_info);
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#else
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__weak_reference(_elf_aux_info, elf_aux_info);
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#endif
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int
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_elf_aux_info(int aux, void *buf, int buflen)
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{
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int res;
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__init_elf_aux_vector();
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if (__elf_aux_vector == NULL)
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return (ENOSYS);
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_once(&aux_once, init_aux);
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switch (aux) {
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case AT_CANARY:
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if (canary != NULL && canary_len >= buflen) {
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memcpy(buf, canary, buflen);
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memset(canary, 0, canary_len);
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canary = NULL;
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res = 0;
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} else
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res = ENOENT;
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break;
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case AT_EXECPATH:
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if (execpath == NULL)
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res = ENOENT;
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else if (buf == NULL)
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res = EINVAL;
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else {
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if (strlcpy(buf, execpath, buflen) >= buflen)
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res = EINVAL;
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else
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res = 0;
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}
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break;
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case AT_HWCAP:
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if (hwcap_present && buflen == sizeof(u_long)) {
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*(u_long *)buf = hwcap;
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res = 0;
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} else
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res = ENOENT;
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break;
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case AT_HWCAP2:
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if (hwcap2_present && buflen == sizeof(u_long)) {
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*(u_long *)buf = hwcap2;
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res = 0;
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} else
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res = ENOENT;
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break;
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case AT_PAGESIZES:
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if (pagesizes != NULL && pagesizes_len >= buflen) {
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memcpy(buf, pagesizes, buflen);
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res = 0;
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} else
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res = ENOENT;
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break;
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case AT_PAGESZ:
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if (buflen == sizeof(int)) {
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if (pagesize != 0) {
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*(int *)buf = pagesize;
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res = 0;
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} else
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res = ENOENT;
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} else
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res = EINVAL;
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break;
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case AT_OSRELDATE:
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if (buflen == sizeof(int)) {
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if (osreldate != 0) {
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*(int *)buf = osreldate;
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res = 0;
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} else
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res = ENOENT;
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} else
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res = EINVAL;
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break;
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case AT_NCPUS:
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if (buflen == sizeof(int)) {
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if (ncpus != 0) {
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*(int *)buf = ncpus;
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res = 0;
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} else
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res = ENOENT;
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} else
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res = EINVAL;
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break;
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case AT_TIMEKEEP:
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if (buflen == sizeof(void *)) {
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if (timekeep != NULL) {
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*(void **)buf = timekeep;
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res = 0;
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} else
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res = ENOENT;
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} else
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res = EINVAL;
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break;
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default:
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res = ENOENT;
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break;
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}
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return (res);
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}
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