From patchwork Wed Jan 5 01:39:46 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddhesh Poyarekar X-Patchwork-Id: 49540 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id AB06B3858432 for ; Wed, 5 Jan 2022 01:41:01 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AB06B3858432 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1641346861; bh=rZBqxoDC5XnvwRNKrxy+87PCIy9eGEyOvuNUy77cGvg=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=Xpy1IWiay6xbCHnKLbLz7y0ExC3SW0vOF/SxVHwRn3+DszqDSUwFzawohpsmUiEHG D+1HeetGjcUEzmho+a7Kg0JjpaXhcfnVI1FUVl9Mh/rzgqBLqEF3nJyUz4AqHCEXtJ J31pow0POTsgQgqb5bkFxukEmMkNINoNJHDB8i00= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from butterfly.birch.relay.mailchannels.net (butterfly.birch.relay.mailchannels.net [23.83.209.27]) by sourceware.org (Postfix) with ESMTPS id 85C63385842C for ; Wed, 5 Jan 2022 01:40:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 85C63385842C X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 47D126C1928 for ; Wed, 5 Jan 2022 01:40:00 +0000 (UTC) Received: from pdx1-sub0-mail-a306.dreamhost.com (unknown [127.0.0.6]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id B2B206C191C for ; Wed, 5 Jan 2022 01:39:59 +0000 (UTC) X-Sender-Id: dreamhost|x-authsender|siddhesh@gotplt.org Received: from pdx1-sub0-mail-a306.dreamhost.com (pop.dreamhost.com [64.90.62.162]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384) by 100.121.9.225 (trex/6.4.3); Wed, 05 Jan 2022 01:40:00 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|siddhesh@gotplt.org X-MailChannels-Auth-Id: dreamhost X-Macabre-Towering: 26890e476941bf82_1641346800119_3195261820 X-MC-Loop-Signature: 1641346800119:394751800 X-MC-Ingress-Time: 1641346800119 Received: from rhbox.intra.reserved-bit.com (unknown [1.186.123.58]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: siddhesh@gotplt.org) by pdx1-sub0-mail-a306.dreamhost.com (Postfix) with ESMTPSA id 4JTBxV27Mtz1T for ; Tue, 4 Jan 2022 17:39:57 -0800 (PST) To: libc-alpha@sourceware.org Subject: [PATCH 2/2] debug: Synchronize feature guards in fortified functions [BZ #28746] Date: Wed, 5 Jan 2022 07:09:46 +0530 Message-Id: <20220105013946.2646963-3-siddhesh@sourceware.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20220105013946.2646963-1-siddhesh@sourceware.org> References: <20220105013946.2646963-1-siddhesh@sourceware.org> MIME-Version: 1.0 X-Spam-Status: No, score=-3494.5 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_NONE, KAM_DMARC_STATUS, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, RCVD_IN_SBL, SPF_HELO_NONE, SPF_NEUTRAL, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Siddhesh Poyarekar via Libc-alpha From: Siddhesh Poyarekar Reply-To: Siddhesh Poyarekar Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Some functions (e.g. stpcpy, pread64, etc.) had moved to POSIX in the main headers as they got incorporated into the standard, but their fortified variants remained under __USE_GNU. As a result, these functions did not get fortified when _GNU_SOURCE was not defined. Add test wrappers that check all functions tested in tst-chk0 at all levels with _GNU_SOURCE undefined and then use the failures to (1) exclude checks for _GNU_SOURCE functions in these tests and (2) Fix feature macro guards in the fortified function headers so that they're the same as the ones in the main headers. This fixes BZ #28746. Signed-off-by: Siddhesh Poyarekar --- debug/Makefile | 17 +++++++----- debug/tst-chk0-nongnu.c | 3 +++ debug/tst-chk0.c | 49 ++++++++++++++++++++++++++++------ debug/tst-chk0cc-nongnu.cc | 3 +++ debug/tst-chk1-nongnu.c | 3 +++ debug/tst-chk1cc-nongnu.cc | 3 +++ debug/tst-chk2-nongnu.c | 3 +++ debug/tst-chk2cc-nongnu.cc | 3 +++ debug/tst-chk3-nongnu.c | 3 +++ debug/tst-chk3cc-nongnu.cc | 3 +++ posix/bits/unistd.h | 2 +- string/bits/string_fortified.h | 8 +++--- support/xsignal.h | 2 ++ wcsmbs/bits/wchar2.h | 2 +- 14 files changed, 85 insertions(+), 19 deletions(-) create mode 100644 debug/tst-chk0-nongnu.c create mode 100644 debug/tst-chk0cc-nongnu.cc create mode 100644 debug/tst-chk1-nongnu.c create mode 100644 debug/tst-chk1cc-nongnu.cc create mode 100644 debug/tst-chk2-nongnu.c create mode 100644 debug/tst-chk2cc-nongnu.cc create mode 100644 debug/tst-chk3-nongnu.c create mode 100644 debug/tst-chk3cc-nongnu.cc diff --git a/debug/Makefile b/debug/Makefile index fe94cd3072..cae00593a8 100644 --- a/debug/Makefile +++ b/debug/Makefile @@ -116,6 +116,8 @@ tests-chk = $(addprefix tst-chk, 0 1 2 3) tests-chk-cc = $(addsuffix cc, $(tests-chk)) tests-chk-lfs = $(addsuffix -lfs, $(tests-chk)) tests-chk-cc-lfs = $(addsuffix -lfs, $(tests-chk-cc)) +tests-chk-nongnu = $(addsuffix -nongnu, $(tests-chk)) +tests-chk-cc-nongnu = $(addsuffix -nongnu, $(tests-chk-cc)) # We know these tests have problems with format strings, this is what # we are testing. Disable that warning. They are also testing @@ -126,16 +128,17 @@ define disable-warnings CFLAGS-$(1).$(2) += -Wno-format -Wno-deprecated-declarations -Wno-error endef -$(foreach t,$(tests-chk) $(tests-chk-lfs), \ +$(foreach t,$(tests-chk) $(tests-chk-lfs) $(tests-chk-nongnu), \ $(eval $(call disable-warnings,$(t),c))) -$(foreach t,$(tests-chk-cc) $(tests-chk-cc-lfs), \ +$(foreach t,$(tests-chk-cc) $(tests-chk-cc-lfs) $(tests-chk-cc-nongnu), \ $(eval $(call disable-warnings,$(t),cc))) define link-cc LDLIBS-$(1) = -lstdc++ endef -$(foreach t,$(tests-chk-cc) $(tests-chk-cc-lfs), $(eval $(call link-cc,$(t)))) +$(foreach t,$(tests-chk-cc) $(tests-chk-cc-lfs) $(tests-chk-cc-nongnu), \ + $(eval $(call link-cc,$(t)))) # backtrace_symbols only works if we link with -rdynamic. backtrace # requires unwind tables on most architectures. @@ -156,14 +159,15 @@ tests = backtrace-tst tst-longjmp_chk \ test-strcpy_chk test-stpcpy_chk \ tst-longjmp_chk2 tst-backtrace2 tst-backtrace3 \ tst-backtrace4 tst-backtrace5 tst-backtrace6 tst-realpath-chk \ - $(tests-chk) $(tests-chk-cc) $(tests-chk-lfs) $(tests-chk-cc-lfs) + $(tests-chk) $(tests-chk-cc) $(tests-chk-lfs) $(tests-chk-cc-lfs) \ + $(tests-chk-nongnu) $(tests-chk-cc-nongnu) ifeq ($(have-ssp),yes) tests += tst-ssp-1 endif ifeq (,$(CXX)) -tests-unsupported = $(tests-chk-cc) $(tests-chk-cc-lfs) +tests-unsupported = $(tests-chk-cc) $(tests-chk-cc-lfs) $(tests-chk-cc-nongnu) endif extra-libs = libSegFault libpcprofile @@ -194,7 +198,8 @@ define chk-gen-locales $(objpfx)$(1).out: $(gen-locales) endef $(foreach t, \ - $(tests-chk) $(tests-chk-cc) $(tests-chk-lfs) $(tests-chk-cc-lfs), \ + $(tests-chk) $(tests-chk-cc) $(tests-chk-lfs) $(tests-chk-cc-lfs) \ + $(tests-chk-nongnu) $(tests-chk-cc-nongnu), \ $(eval $(call link-cc,$(t)))) endif diff --git a/debug/tst-chk0-nongnu.c b/debug/tst-chk0-nongnu.c new file mode 100644 index 0000000000..8f7dd80228 --- /dev/null +++ b/debug/tst-chk0-nongnu.c @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk0.c" diff --git a/debug/tst-chk0.c b/debug/tst-chk0.c index d11e536f87..6b2ec33f87 100644 --- a/debug/tst-chk0.c +++ b/debug/tst-chk0.c @@ -1,4 +1,5 @@ /* Copyright (C) 2004-2021 Free Software Foundation, Inc. + Copyright The GNU Toolchain Authors. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -36,6 +37,17 @@ #include #include +#ifndef _GNU_SOURCE +# define MEMPCPY memcpy +# define WMEMPCPY wmemcpy +# define MEMPCPY_RET(x) 0 +# define WMEMPCPY_RET(x) 0 +#else +# define MEMPCPY mempcpy +# define WMEMPCPY wmempcpy +# define MEMPCPY_RET(x) __builtin_strlen (x) +# define WMEMPCPY_RET(x) wcslen (x) +#endif #define obstack_chunk_alloc malloc #define obstack_chunk_free free @@ -162,7 +174,7 @@ do_test (void) if (memcmp (buf, "aabcdefghi", 10)) FAIL (); - if (mempcpy (buf + 5, "abcde", 5) != buf + 10 + if (MEMPCPY (buf + 5, "abcde", 5) != buf + 5 + MEMPCPY_RET ("abcde") || memcmp (buf, "aabcdabcde", 10)) FAIL (); @@ -207,7 +219,7 @@ do_test (void) if (memcmp (buf, "aabcdefghi", 10)) FAIL (); - if (mempcpy (buf + 5, "abcde", l0 + 5) != buf + 10 + if (MEMPCPY (buf + 5, "abcde", l0 + 5) != buf + 5 + MEMPCPY_RET ("abcde") || memcmp (buf, "aabcdabcde", 10)) FAIL (); @@ -266,7 +278,8 @@ do_test (void) if (memcmp (a.buf1, "aabcdefghi", 10)) FAIL (); - if (mempcpy (a.buf1 + 5, "abcde", l0 + 5) != a.buf1 + 10 + if (MEMPCPY (a.buf1 + 5, "abcde", l0 + 5) + != a.buf1 + 5 + MEMPCPY_RET ("abcde") || memcmp (a.buf1, "aabcdabcde", 10)) FAIL (); @@ -347,6 +360,7 @@ do_test (void) bcopy (buf + 1, buf + 2, l0 + 9); CHK_FAIL_END +#ifdef _GNU_SOURCE CHK_FAIL_START p = (char *) mempcpy (buf + 6, "abcde", 5); CHK_FAIL_END @@ -354,6 +368,7 @@ do_test (void) CHK_FAIL_START p = (char *) mempcpy (buf + 6, "abcde", l0 + 5); CHK_FAIL_END +#endif CHK_FAIL_START memset (buf + 9, 'j', 2); @@ -464,6 +479,7 @@ do_test (void) bcopy (a.buf1 + 1, a.buf1 + 2, l0 + 9); CHK_FAIL_END +#ifdef _GNU_SOURCE CHK_FAIL_START p = (char *) mempcpy (a.buf1 + 6, "abcde", 5); CHK_FAIL_END @@ -471,6 +487,7 @@ do_test (void) CHK_FAIL_START p = (char *) mempcpy (a.buf1 + 6, "abcde", l0 + 5); CHK_FAIL_END +#endif CHK_FAIL_START memset (a.buf1 + 9, 'j', 2); @@ -550,7 +567,7 @@ do_test (void) if (wmemcmp (wbuf, L"aabcdefghi", 10)) FAIL (); - if (wmempcpy (wbuf + 5, L"abcde", 5) != wbuf + 10 + if (WMEMPCPY (wbuf + 5, L"abcde", 5) != wbuf + 5 + WMEMPCPY_RET (L"abcde") || wmemcmp (wbuf, L"aabcdabcde", 10)) FAIL (); @@ -583,7 +600,8 @@ do_test (void) if (wmemcmp (wbuf, L"aabcdefghi", 10)) FAIL (); - if (wmempcpy (wbuf + 5, L"abcde", l0 + 5) != wbuf + 10 + if (WMEMPCPY (wbuf + 5, L"abcde", l0 + 5) + != wbuf + 5 + WMEMPCPY_RET (L"abcde") || wmemcmp (wbuf, L"aabcdabcde", 10)) FAIL (); @@ -625,7 +643,8 @@ do_test (void) if (wmemcmp (wa.buf1, L"aabcdefghi", 10)) FAIL (); - if (wmempcpy (wa.buf1 + 5, L"abcde", l0 + 5) != wa.buf1 + 10 + if (WMEMPCPY (wa.buf1 + 5, L"abcde", l0 + 5) + != wa.buf1 + 5 + WMEMPCPY_RET (L"abcde") || wmemcmp (wa.buf1, L"aabcdabcde", 10)) FAIL (); @@ -694,6 +713,7 @@ do_test (void) wmemmove (wbuf + 2, wbuf + 1, l0 + 9); CHK_FAIL_END +#ifdef _GNU_SOURCE CHK_FAIL_START wp = wmempcpy (wbuf + 6, L"abcde", 5); CHK_FAIL_END @@ -701,6 +721,7 @@ do_test (void) CHK_FAIL_START wp = wmempcpy (wbuf + 6, L"abcde", l0 + 5); CHK_FAIL_END +#endif CHK_FAIL_START wmemset (wbuf + 9, L'j', 2); @@ -768,6 +789,7 @@ do_test (void) wmemmove (wa.buf1 + 2, wa.buf1 + 1, l0 + 9); CHK_FAIL_END +#ifdef _GNU_SOURCE CHK_FAIL_START wp = wmempcpy (wa.buf1 + 6, L"abcde", 5); CHK_FAIL_END @@ -775,6 +797,7 @@ do_test (void) CHK_FAIL_START wp = wmempcpy (wa.buf1 + 6, L"abcde", l0 + 5); CHK_FAIL_END +#endif CHK_FAIL_START wmemset (wa.buf1 + 9, L'j', 2); @@ -906,6 +929,7 @@ do_test (void) if (fprintf (fp, buf2 + 4, str5) != 7) FAIL (); +#ifdef _GNU_SOURCE char *my_ptr = NULL; strcpy (buf2 + 2, "%n%s%n"); /* When the format string is writable and contains %n, @@ -935,6 +959,7 @@ do_test (void) if (obstack_printf (&obs, "%s%n%s%n", str4, &n1, str5, &n1) != 14) FAIL (); obstack_free (&obs, NULL); +#endif if (freopen (temp_filename, "r", stdin) == NULL) { @@ -982,6 +1007,7 @@ do_test (void) rewind (stdin); +#ifdef _GNU_SOURCE if (fgets_unlocked (buf, buf_size, stdin) != buf || memcmp (buf, "abcdefgh\n", 10)) FAIL (); @@ -1008,6 +1034,7 @@ do_test (void) #endif rewind (stdin); +#endif if (fread (buf, 1, buf_size, stdin) != buf_size || memcmp (buf, "abcdefgh\nA", 10)) @@ -1578,7 +1605,10 @@ do_test (void) ret = 1; } - int fd = posix_openpt (O_RDWR); + int fd; + +#ifdef _GNU_SOURCE + fd = posix_openpt (O_RDWR); if (fd != -1) { char enough[1000]; @@ -1594,6 +1624,7 @@ do_test (void) #endif close (fd); } +#endif #if PATH_MAX > 0 confstr (_CS_GNU_LIBC_VERSION, largebuf, sizeof (largebuf)); @@ -1711,8 +1742,9 @@ do_test (void) poll (fds, l0 + 2, 0); CHK_FAIL_END #endif +#ifdef _GNU_SOURCE ppoll (fds, 1, NULL, NULL); -#if __USE_FORTIFY_LEVEL >= 1 +# if __USE_FORTIFY_LEVEL >= 1 CHK_FAIL_START ppoll (fds, 2, NULL, NULL); CHK_FAIL_END @@ -1720,6 +1752,7 @@ do_test (void) CHK_FAIL_START ppoll (fds, l0 + 2, NULL, NULL); CHK_FAIL_END +# endif #endif return ret; diff --git a/debug/tst-chk0cc-nongnu.cc b/debug/tst-chk0cc-nongnu.cc new file mode 100644 index 0000000000..8f7dd80228 --- /dev/null +++ b/debug/tst-chk0cc-nongnu.cc @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk0.c" diff --git a/debug/tst-chk1-nongnu.c b/debug/tst-chk1-nongnu.c new file mode 100644 index 0000000000..ed953070dd --- /dev/null +++ b/debug/tst-chk1-nongnu.c @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk1.c" diff --git a/debug/tst-chk1cc-nongnu.cc b/debug/tst-chk1cc-nongnu.cc new file mode 100644 index 0000000000..ed953070dd --- /dev/null +++ b/debug/tst-chk1cc-nongnu.cc @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk1.c" diff --git a/debug/tst-chk2-nongnu.c b/debug/tst-chk2-nongnu.c new file mode 100644 index 0000000000..506f7d0396 --- /dev/null +++ b/debug/tst-chk2-nongnu.c @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk2.c" diff --git a/debug/tst-chk2cc-nongnu.cc b/debug/tst-chk2cc-nongnu.cc new file mode 100644 index 0000000000..506f7d0396 --- /dev/null +++ b/debug/tst-chk2cc-nongnu.cc @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk2.c" diff --git a/debug/tst-chk3-nongnu.c b/debug/tst-chk3-nongnu.c new file mode 100644 index 0000000000..44fea0ea0d --- /dev/null +++ b/debug/tst-chk3-nongnu.c @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk3.c" diff --git a/debug/tst-chk3cc-nongnu.cc b/debug/tst-chk3cc-nongnu.cc new file mode 100644 index 0000000000..44fea0ea0d --- /dev/null +++ b/debug/tst-chk3cc-nongnu.cc @@ -0,0 +1,3 @@ +#undef _GNU_SOURCE +#define _LARGEFILE64_SOURCE 1 +#include "tst-chk3.c" diff --git a/posix/bits/unistd.h b/posix/bits/unistd.h index 697dcbbf7b..1df7e5ceef 100644 --- a/posix/bits/unistd.h +++ b/posix/bits/unistd.h @@ -40,7 +40,7 @@ read (int __fd, void *__buf, size_t __nbytes) __fd, __buf, __nbytes); } -#ifdef __USE_UNIX98 +#if defined __USE_UNIX98 || defined __USE_XOPEN2K8 extern ssize_t __pread_chk (int __fd, void *__buf, size_t __nbytes, __off_t __offset, size_t __bufsize) __wur __attr_access ((__write_only__, 2, 3)); diff --git a/string/bits/string_fortified.h b/string/bits/string_fortified.h index 5731274848..fac5794c14 100644 --- a/string/bits/string_fortified.h +++ b/string/bits/string_fortified.h @@ -79,7 +79,7 @@ __NTH (strcpy (char *__restrict __dest, const char *__restrict __src)) return __builtin___strcpy_chk (__dest, __src, __glibc_objsize (__dest)); } -#ifdef __USE_GNU +#ifdef __USE_XOPEN2K8 __fortify_function char * __NTH (stpcpy (char *__restrict __dest, const char *__restrict __src)) { @@ -96,14 +96,15 @@ __NTH (strncpy (char *__restrict __dest, const char *__restrict __src, __glibc_objsize (__dest)); } -#if __GNUC_PREREQ (4, 7) || __glibc_clang_prereq (2, 6) +#if __USE_XOPEN2K8 +# if __GNUC_PREREQ (4, 7) || __glibc_clang_prereq (2, 6) __fortify_function char * __NTH (stpncpy (char *__dest, const char *__src, size_t __n)) { return __builtin___stpncpy_chk (__dest, __src, __n, __glibc_objsize (__dest)); } -#else +# else extern char *__stpncpy_chk (char *__dest, const char *__src, size_t __n, size_t __destlen) __THROW __fortified_attr_access ((__write_only__, 1, 3)) @@ -119,6 +120,7 @@ __NTH (stpncpy (char *__dest, const char *__src, size_t __n)) return __stpncpy_chk (__dest, __src, __n, __bos (__dest)); return __stpncpy_alias (__dest, __src, __n); } +# endif #endif diff --git a/support/xsignal.h b/support/xsignal.h index 8ee1fa6b4d..692e0f2c42 100644 --- a/support/xsignal.h +++ b/support/xsignal.h @@ -28,7 +28,9 @@ __BEGIN_DECLS terminate the process on error. */ void xraise (int sig); +#ifdef _GNU_SOURCE sighandler_t xsignal (int sig, sighandler_t handler); +#endif void xsigaction (int sig, const struct sigaction *newact, struct sigaction *oldact); diff --git a/wcsmbs/bits/wchar2.h b/wcsmbs/bits/wchar2.h index 26012ef936..88c1fdfcd3 100644 --- a/wcsmbs/bits/wchar2.h +++ b/wcsmbs/bits/wchar2.h @@ -457,7 +457,7 @@ __NTH (wcsrtombs (char *__restrict __dst, const wchar_t **__restrict __src, } -#ifdef __USE_GNU +#ifdef __USE_XOPEN2K8 extern size_t __mbsnrtowcs_chk (wchar_t *__restrict __dst, const char **__restrict __src, size_t __nmc, size_t __len, mbstate_t *__restrict __ps,