Re: A suspicious warning in sys/boot/zfs/zfsimpl.c
On 2012-12-02 01:37, Garrett Cooper wrote: On Sat, Dec 1, 2012 at 3:05 AM, Andriy Gapon wrote: I believe that there is no actual problem there. It's probably bugs with clang dealing with alignment problems. Which bugs? These warnings (and others) go largely unnoticed because of the fact that -Werror isn't on on sys/boot. I filed kern/173932 for that and have been grinding away on warnings for the past couple days in my spare time -- with my local modifications sys/boot compiles with -Werror now with gcc, but not clang. Thanks, -Garrett /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:101:24: error: tentative definition of variable with internal linkage has incomplete non-array type 'struct zfsmount' [-Werror,-Wtentative-definition-incomplete-type] static struct zfsmount zfsmount; ^ /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:101:15: note: forward declaration of 'struct zfsmount' static struct zfsmount zfsmount; ^ This is just a programming error: struct zfsmount is declared in zfsimpl.c, but that file is included on line 151, so 50 lines after the static variable definition. Either the include should be moved up, or the definition moved down. In file included from /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:151: In file included from /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:38: /store/freebsd/head/sys/boot/i386/zfsboot/../../../cddl/boot/zfs/zfssubr.c:207:9: error: cast from 'char *' to 'zio_eck_t *' (aka 'struct zio_eck *') increases required alignment from 1 to 4 [-Werror,-Wcast-align] eck = (zio_eck_t *)((char *)data + size) - 1; ^~ Clang is right here, the alignment *is* being increased. However, on x86, there is no problem with it, so the warning can be ignored. On the other hand, if the code should be portable to alignment-sensitive arches, the code should be fixed. The same holds for all the other alignment warnings. The difference between gcc and clang is that gcc never seems to warn about alignment issues on x86. You must compile the code with a gcc targeting an alignment-sensitive arch, to get any warnings. Clang always warns, when using -Wcast-align. ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
Re: A suspicious warning in sys/boot/zfs/zfsimpl.c
On 2012-12-01 12:05, Andriy Gapon wrote: on 01/12/2012 12:59 Garrett Cooper said the following: On Mon, Jul 2, 2012 at 6:21 PM, Taku YAMAMOTO wrote: When I built the world as of r237813, clang reported a warning which caught my attention. ===> sys/boot/zfs (all) clang -O2 -pipe -march=pentium4 -DBOOTPROG=\"zfsloader\" -I/usr/src/sys/boot/zfs/../common -I/usr/src/sys/boot/zfs/../.. -I. -I/usr/src/sys/boot/zfs/../../../lib/libstand -I/usr/src/sys/boot/zfs/../../cddl/boot/zfs -ffreestanding -mpreferred-stack-boundary=2 -mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 -msoft-float -Wformat -Wall -DNDEBUG -std=gnu99 -Qunused-arguments -c /usr/src/sys/boot/zfs/zfs.c -o zfs.o In file included from /usr/src/sys/boot/zfs/zfs.c:48: /usr/src/sys/boot/zfs/zfsimpl.c:2033:19: warning: array index 264 is past the end of the array (which contains 192 elements) [-Warray-bounds] memcpy(path, &dn.dn_bonus[sizeof(znode_phys_t)], ^ /usr/src/sys/boot/zfs/../../cddl/boot/zfs/zfsimpl.h:788:2: note: array 'dn_bonus' declared here uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)]; ^ I don't have a zfs-powered machine, so I'm not sure whether this warning is false-positive or not. I'm seeing the same warnings trying to build HEAD r242903 with clang on amd64. Andriy CCed. I believe that there is no actual problem there. Indeed. The ZFS code seems to be using the dnode_phys_t::dn_bonus field as a sort of flexible struct member. These specific warnings can be ignored, or turned off. ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
Re: A suspicious warning in sys/boot/zfs/zfsimpl.c
On Sat, Dec 1, 2012 at 3:05 AM, Andriy Gapon wrote: > I believe that there is no actual problem there. It's probably bugs with clang dealing with alignment problems. These warnings (and others) go largely unnoticed because of the fact that -Werror isn't on on sys/boot. I filed kern/173932 for that and have been grinding away on warnings for the past couple days in my spare time -- with my local modifications sys/boot compiles with -Werror now with gcc, but not clang. Thanks, -Garrett /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:101:24: error: tentative definition of variable with internal linkage has incomplete non-array type 'struct zfsmount' [-Werror,-Wtentative-definition-incomplete-type] static struct zfsmount zfsmount; ^ /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:101:15: note: forward declaration of 'struct zfsmount' static struct zfsmount zfsmount; ^ In file included from /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:151: In file included from /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:38: /store/freebsd/head/sys/boot/i386/zfsboot/../../../cddl/boot/zfs/zfssubr.c:207:9: error: cast from 'char *' to 'zio_eck_t *' (aka 'struct zio_eck *') increases required alignment from 1 to 4 [-Werror,-Wcast-align] eck = (zio_eck_t *)((char *)data + size) - 1; ^~ ===> lib/libpam/modules/pam_rhosts (all) In file included from /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:151: ===> usr.sbin/devinfo (all) `kldstat.o' is up to date. /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:876:28: error: cast from 'char *' to 'vdev_phys_t *' (aka 'struct vdev_phys *') increases required alignment from 1 to 4 [-Werror,-Wcast-align] vdev_phys_t *vdev_label = (vdev_phys_t *) zap_scratch; ^~~ /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:1043:7: error: cast from 'char *' to 'const struct uberblock *' increases required alignment from 1 to 4 [-Werror,-Wcast-align] up = (const struct uberblock *)upbuf; ^~~ /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:1223:12: error: cast from 'char *' to 'const blkptr_t *' (aka 'const struct blkptr *') increases required alignment from 1 to 4 [-Werror,-Wcast-align] indbp = (const blkptr_t *) dnode_cache_buf; ^~ /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:1262:7: error: cast from 'char *' to 'const mzap_phys_t *' (aka 'const struct mzap_phys *') increases required alignment from 1 to 4 [-Werror,-Wcast-align] mz = (const mzap_phys_t *) zap_scratch; ^ /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:1289:8: error: cast from 'uint16_t *' (aka 'unsigned short *') to 'zap_leaf_chunk_t *' (aka 'union zap_leaf_chunk *') increases required alignment from 2 to 4 [-Werror,-Wcast-align] nc = &ZAP_LEAF_CHUNK(zl, zc->l_entry.le_name_chunk); ^ /store/freebsd/head/sys/boot/i386/zfsboot/../../../cddl/boot/zfs/zfsimpl.h:1139:3: note: expanded from macro 'ZAP_LEAF_CHUNK' ((zap_leaf_chunk_t *) \ ^~ In file included from /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:151: /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:1300:9: error: cast from 'uint16_t *' (aka 'unsigned short *') to 'zap_leaf_chunk_t *' (aka 'union zap_leaf_chunk *') increases required alignment from 2 to 4 [-Werror,-Wcast-align] nc = &ZAP_LEAF_CHUNK(zl, nc->l_array.la_next); ^~~ /store/freebsd/head/sys/boot/i386/zfsboot/../../../cddl/boot/zfs/zfsimpl.h:1139:3: note: expanded from macro 'ZAP_LEAF_CHUNK' ((zap_leaf_chunk_t *) \ ^~ In file included from /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:151: /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:1317:8: error: cast from 'uint16_t *' (aka 'unsigned short *') to 'zap_leaf_chunk_t *' (aka 'union zap_leaf_chunk *') increases required alignment from 2 to 4 [-Werror,-Wcast-align] vc = &ZAP_LEAF_CHUNK(zl, zc->l_entry.le_value_chunk); ^~ /store/freebsd/head/sys/boot/i386/zfsboot/../../../cddl/boot/zfs/zfsimpl.h:1139:3: note: expanded from macro 'ZAP_LEAF_CHUNK' ((zap_leaf_chunk_t *) \ ^~ In file included from /store/freebsd/head/sys/boot/i386/zfsboot/zfsboot.c:151: /store/freebsd/head/sys/boot/i386/zfsboot/../../zfs/zfsimpl.c:1333:19: error: cast from 'char *' to 'zap_phys_t *' (aka 'struct zap_phys *') increases required alignment from 1 to 4 [-Werror,-Wcast-align]
Re: A suspicious warning in sys/boot/zfs/zfsimpl.c
On Mon, Jul 2, 2012 at 6:21 PM, Taku YAMAMOTO wrote: > When I built the world as of r237813, clang reported a warning which > caught my attention. > > ===> sys/boot/zfs (all) > clang -O2 -pipe -march=pentium4 -DBOOTPROG=\"zfsloader\" > -I/usr/src/sys/boot/zfs/../common -I/usr/src/sys/boot/zfs/../.. -I. > -I/usr/src/sys/boot/zfs/../../../lib/libstand > -I/usr/src/sys/boot/zfs/../../cddl/boot/zfs -ffreestanding > -mpreferred-stack-boundary=2 -mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 > -msoft-float -Wformat -Wall -DNDEBUG -std=gnu99 -Qunused-arguments -c > /usr/src/sys/boot/zfs/zfs.c -o zfs.o > In file included from /usr/src/sys/boot/zfs/zfs.c:48: > /usr/src/sys/boot/zfs/zfsimpl.c:2033:19: warning: array index 264 is past the > end of the array (which contains 192 elements) [-Warray-bounds] > memcpy(path, > &dn.dn_bonus[sizeof(znode_phys_t)], > ^ > /usr/src/sys/boot/zfs/../../cddl/boot/zfs/zfsimpl.h:788:2: note: array > 'dn_bonus' declared here > uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)]; > ^ > > I don't have a zfs-powered machine, so I'm not sure whether this > warning is false-positive or not. I'm seeing the same warnings trying to build HEAD r242903 with clang on amd64. Andriy CCed. Thanks, -Garrett ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
Re: A suspicious warning in sys/boot/zfs/zfsimpl.c
on 01/12/2012 12:59 Garrett Cooper said the following: > On Mon, Jul 2, 2012 at 6:21 PM, Taku YAMAMOTO wrote: >> When I built the world as of r237813, clang reported a warning which >> caught my attention. >> >> ===> sys/boot/zfs (all) >> clang -O2 -pipe -march=pentium4 -DBOOTPROG=\"zfsloader\" >> -I/usr/src/sys/boot/zfs/../common -I/usr/src/sys/boot/zfs/../.. -I. >> -I/usr/src/sys/boot/zfs/../../../lib/libstand >> -I/usr/src/sys/boot/zfs/../../cddl/boot/zfs -ffreestanding >> -mpreferred-stack-boundary=2 -mno-mmx -mno-3dnow -mno-sse -mno-sse2 >> -mno-sse3 -msoft-float -Wformat -Wall -DNDEBUG -std=gnu99 -Qunused-arguments >> -c /usr/src/sys/boot/zfs/zfs.c -o zfs.o >> In file included from /usr/src/sys/boot/zfs/zfs.c:48: >> /usr/src/sys/boot/zfs/zfsimpl.c:2033:19: warning: array index 264 is past >> the end of the array (which contains 192 elements) [-Warray-bounds] >> memcpy(path, >> &dn.dn_bonus[sizeof(znode_phys_t)], >> ^ >> >> /usr/src/sys/boot/zfs/../../cddl/boot/zfs/zfsimpl.h:788:2: note: array >> 'dn_bonus' declared here >> uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)]; >> ^ >> >> I don't have a zfs-powered machine, so I'm not sure whether this >> warning is false-positive or not. > > I'm seeing the same warnings trying to build HEAD r242903 with > clang on amd64. Andriy CCed. I believe that there is no actual problem there. -- Andriy Gapon ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
A suspicious warning in sys/boot/zfs/zfsimpl.c
When I built the world as of r237813, clang reported a warning which caught my attention. ===> sys/boot/zfs (all) clang -O2 -pipe -march=pentium4 -DBOOTPROG=\"zfsloader\" -I/usr/src/sys/boot/zfs/../common -I/usr/src/sys/boot/zfs/../.. -I. -I/usr/src/sys/boot/zfs/../../../lib/libstand -I/usr/src/sys/boot/zfs/../../cddl/boot/zfs -ffreestanding -mpreferred-stack-boundary=2 -mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 -msoft-float -Wformat -Wall -DNDEBUG -std=gnu99 -Qunused-arguments -c /usr/src/sys/boot/zfs/zfs.c -o zfs.o In file included from /usr/src/sys/boot/zfs/zfs.c:48: /usr/src/sys/boot/zfs/zfsimpl.c:2033:19: warning: array index 264 is past the end of the array (which contains 192 elements) [-Warray-bounds] memcpy(path, &dn.dn_bonus[sizeof(znode_phys_t)], ^ /usr/src/sys/boot/zfs/../../cddl/boot/zfs/zfsimpl.h:788:2: note: array 'dn_bonus' declared here uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)]; ^ I don't have a zfs-powered machine, so I'm not sure whether this warning is false-positive or not. -- -|-__ YAMAMOTO, Taku | __ < - A chicken is an egg's way of producing more eggs. - ___ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
