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6a1cefac19
Bug 16458 reports that the endian-conversion macros in <endian.h> and
<netinet/in.h>, in the case where no endian conversion is needed, just
return their arguments without converting to the expected return type,
so failing to act as expected for a macro version of a function. (The
<netinet/in.h> macros, in particular, are described with prototypes in
POSIX so should act like correspondingly prototyped functions.)
Where previously this was a fairly obscure issue, it now results in
glibc build with GCC mainline breaking for big-endian systems:
nss_hesiod/hesiod-service.c: In function '_nss_hesiod_getservbyport_r':
nss_hesiod/hesiod-service.c:142:39: error: '%d' directive output may be truncated writing between 1 and 11 bytes into a region of size 6 [-Werror=format-truncation=]
snprintf (portstr, sizeof portstr, "%d", ntohs (port));
^~
nss_hesiod/hesiod-service.c:142:38: note: using the range [1, -2147483648] for directive argument
snprintf (portstr, sizeof portstr, "%d", ntohs (port));
^~~~
nss_hesiod/hesiod-service.c:142:3: note: format output between 2 and 12 bytes into a destination of size 6
snprintf (portstr, sizeof portstr, "%d", ntohs (port));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The port argument is passed as int to this function, so when ntohs
does not convert the compiler cannot tell that the result is within
the range of uint16_t. (I don't know if in fact it's possible for
out-of-range values to reach this function and so get truncated as
strings without this patch or as integers with it.)
This patch arranges for these macros to use identity functions to
ensure appropriate conversions while having warnings for implicit
conversions of function arguments that might not occur with a cast.
Tested for x86_64 and x86; with build-many-glibcs.py with GCC 6; and
with build-many-glibcs.py with GCC mainline for powerpc to test the
build fix.
[BZ #16458]
* bits/uintn-identity.h: New file.
* inet/netinet/in.h: Include <bits/uintn-identity.h>.
[__BYTE_ORDER == __BIG_ENDIAN] (ntohl): Use __uint32_identity.
[__BYTE_ORDER == __BIG_ENDIAN] (ntohs): Use __uint16_identity.
[__BYTE_ORDER == __BIG_ENDIAN] (htonl): Use __uint32_identity.
[__BYTE_ORDER == __BIG_ENDIAN] (htohs): Use __uint16_identity.
* string/endian.h: Include <bits/uintn-identity.h>.
[__BYTE_ORDER == __LITTLE_ENDIAN] (htole16): Use
__uint16_identity.
[__BYTE_ORDER == __LITTLE_ENDIAN] (le16toh): Likewise.
[__BYTE_ORDER == __LITTLE_ENDIAN] (htole32): Use
__uint32_identity.
[__BYTE_ORDER == __LITTLE_ENDIAN] (le32toh): Likewise.
[__BYTE_ORDER == __LITTLE_ENDIAN] (htole64): Use
__uint64_identity.
[__BYTE_ORDER == __LITTLE_ENDIAN] (le64toh): Likewise.
[__BYTE_ORDER != __LITTLE_ENDIAN] (htobe16): Use
__uint16_identity.
[__BYTE_ORDER != __LITTLE_ENDIAN] (be16toh): Likewise.
[__BYTE_ORDER != __LITTLE_ENDIAN] (htobe32): Use
__uint32_identity.
[__BYTE_ORDER != __LITTLE_ENDIAN] (be32toh): Likewise.
[__BYTE_ORDER != __LITTLE_ENDIAN] (htobe64): Use
__uint64_identity.
[__BYTE_ORDER != __LITTLE_ENDIAN] (be64toh): Likewise.
* string/Makefile (headers): Add bits/uintn-identity.h.
(tests): Add test-endian-types.
* string/test-endian-types.c: New file.
* inet/Makefile (tests): Add test-hnto-types.
* inet/test-hnto-types.c: New file.
97 lines
3.3 KiB
Makefile
97 lines
3.3 KiB
Makefile
# Copyright (C) 1991-2017 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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#
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# Sub-makefile for inet portion of the library.
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#
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subdir := inet
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include ../Makeconfig
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headers := netinet/ether.h netinet/in.h netinet/in_systm.h \
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netinet/if_ether.h netinet/igmp.h \
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netinet/tcp.h netinet/ip.h $(wildcard arpa/*.h protocols/*.h) \
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aliases.h ifaddrs.h netinet/ip6.h netinet/icmp6.h bits/in.h
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routines := htonl htons \
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inet_lnaof inet_mkadr \
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inet_netof inet_ntoa inet_net herrno herrno-loc \
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gethstbyad gethstbyad_r gethstbynm gethstbynm2 gethstbynm2_r \
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gethstbynm_r gethstent gethstent_r \
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getnetbyad getnetbyad_r getnetbynm getnetent getnetent_r \
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getnetbynm_r \
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getproto getproto_r getprtent getprtent_r getprtname getprtname_r \
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getsrvbynm getsrvbynm_r getsrvbypt getsrvbypt_r getservent \
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getservent_r \
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ether_aton ether_aton_r ether_hton ether_line \
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ether_ntoa ether_ntoa_r ether_ntoh \
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rcmd rexec ruserpass \
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getnetgrent_r getnetgrent \
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getaliasent_r getaliasent getaliasname getaliasname_r \
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in6_addr getnameinfo if_index ifaddrs inet6_option \
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getipv4sourcefilter setipv4sourcefilter \
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getsourcefilter setsourcefilter inet6_opt inet6_rth \
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inet6_scopeid_pton
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aux := check_pf check_native ifreq
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tests := htontest test_ifindex tst-ntoa tst-ether_aton tst-network \
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tst-gethnm test-ifaddrs bug-if1 test-inet6_opt tst-ether_line \
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tst-getni1 tst-getni2 tst-inet6_rth tst-checks tst-checks-posix \
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tst-sockaddr tst-inet6_scopeid_pton test-hnto-types
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include ../Rules
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ifeq ($(have-thread-library),yes)
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CFLAGS-gethstbyad_r.c = -fexceptions
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CFLAGS-gethstbyad.c = -fexceptions
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CFLAGS-gethstbynm_r.c = -fexceptions
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CFLAGS-gethstbynm.c = -fexceptions
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CFLAGS-gethstbynm2_r.c = -fexceptions
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CFLAGS-gethstbynm2.c = -fexceptions
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CFLAGS-gethstent_r.c = -fexceptions
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CFLAGS-gethstent.c = -fexceptions
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CFLAGS-rcmd.c = -fexceptions
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CFLAGS-getnetbynm_r.c = -fexceptions
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CFLAGS-getnetbynm.c = -fexceptions
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CFLAGS-getnetbyad_r.c = -fexceptions
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CFLAGS-getnetbyad.c = -fexceptions
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CFLAGS-getnetent_r.c = -fexceptions
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CFLAGS-getnetent.c = -fexceptions
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CFLAGS-getaliasent_r.c = -fexceptions
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CFLAGS-getaliasent.c = -fexceptions
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CFLAGS-getrpcent_r.c = -fexceptions
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CFLAGS-getrpcent.c = -fexceptions
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CFLAGS-getservent_r.c = -fexceptions
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CFLAGS-getservent.c = -fexceptions
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CFLAGS-getprtent_r.c = -fexceptions
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CFLAGS-getprtent.c = -fexceptions
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CFLAGS-either_ntoh.c = -fexceptions
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CFLAGS-either_hton.c = -fexceptions
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CFLAGS-getnetgrent.c = -fexceptions
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CFLAGS-getnetgrent_r.c = -fexceptions
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CFLAGS-tst-checks-posix.c = -std=c99
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CFLAGS-tst-sockaddr.c = -fno-strict-aliasing
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endif
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ifeq ($(build-static-nss),yes)
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CFLAGS += -DSTATIC_NSS
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endif
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