Using a sockaddr_storage and casting a sockaddr pointer to it breaks C's aliasing rules. See: https://bugzilla.redhat.com/show_bug.cgi?id=448743 Replacing sockaddr_storage makes this code less likely to break when optimized by gcc. It also saves a significant amount of stack space by replacing a 130 byte structure with a union that is less than 32 bytes. Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- utils/mount/stropts.c | 32 +++++++++++++++++++------------- 1 files changed, 19 insertions(+), 13 deletions(-) diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c index 40f8bd9..c4fccbc 100644 --- a/utils/mount/stropts.c +++ b/utils/mount/stropts.c @@ -77,12 +77,18 @@ extern char *progname; extern int verbose; extern int sloppy; +union nfs_sockaddr { + struct sockaddr sa; + struct sockaddr_in s4; + struct sockaddr_in6 s6; +}; + struct nfsmount_info { const char *spec, /* server:/path */ *node, /* mounted-on dir */ *type; /* "nfs" or "nfs4" */ char *hostname; /* server's hostname */ - struct sockaddr_storage address; /* server's address */ + union nfs_sockaddr address; socklen_t salen; /* size of server's address */ struct mount_options *options; /* parsed mount options */ @@ -205,9 +211,9 @@ static int nfs_append_clientaddr_option(const struct sockaddr *sap, socklen_t salen, struct mount_options *options) { - struct sockaddr_storage dummy; - struct sockaddr *my_addr = (struct sockaddr *)&dummy; - socklen_t my_len = sizeof(dummy); + union nfs_sockaddr address; + struct sockaddr *my_addr = &address.sa; + socklen_t my_len = sizeof(address); if (po_contains(options, "clientaddr") == PO_FOUND) return 1; @@ -224,9 +230,9 @@ static int nfs_append_clientaddr_option(const struct sockaddr *sap, */ static int nfs_fix_mounthost_option(struct mount_options *options) { - struct sockaddr_storage dummy; - struct sockaddr *sap = (struct sockaddr *)&dummy; - socklen_t salen = sizeof(dummy); + union nfs_sockaddr address; + struct sockaddr *sap = &address.sa; + socklen_t salen = sizeof(address); char *mounthost; mounthost = po_get(options, "mounthost"); @@ -320,7 +326,7 @@ static int nfs_set_version(struct nfsmount_info *mi) */ static int nfs_validate_options(struct nfsmount_info *mi) { - struct sockaddr *sap = (struct sockaddr *)&mi->address; + struct sockaddr *sap = &mi->address.sa; if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL)) return 0; @@ -453,12 +459,12 @@ static int nfs_construct_new_options(struct mount_options *options, static int nfs_rewrite_pmap_mount_options(struct mount_options *options) { - struct sockaddr_storage nfs_address; - struct sockaddr *nfs_saddr = (struct sockaddr *)&nfs_address; + union nfs_sockaddr nfs_address; + struct sockaddr *nfs_saddr = &nfs_address.sa; socklen_t nfs_salen = sizeof(nfs_address); struct pmap nfs_pmap; - struct sockaddr_storage mnt_address; - struct sockaddr *mnt_saddr = (struct sockaddr *)&mnt_address; + union nfs_sockaddr mnt_address; + struct sockaddr *mnt_saddr = &mnt_address.sa; socklen_t mnt_salen = sizeof(mnt_address); struct pmap mnt_pmap; char *option; @@ -594,7 +600,7 @@ out_fail: */ static int nfs_try_mount_v4(struct nfsmount_info *mi) { - struct sockaddr *sap = (struct sockaddr *)&mi->address; + struct sockaddr *sap = &mi->address.sa; struct mount_options *options = po_dup(mi->options); int result = 0; -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
