From: Chuck Lever <[email protected]> fileattr_fill_xflags() and fileattr_fill_flags() memset the entire file_kattr struct before populating select fields, so callers cannot pre-set fields in fa->fsx_xflags without having their values clobbered. Darrick Wong noted that a function named "fill_xflags" touching more than xflags forces callers to know implementation details beyond its apparent scope.
Drop the memset from both fill functions and initialize at the entry points instead: ioctl_setflags(), ioctl_fssetxattr(), the file_setattr() syscall, and xfs_ioc_fsgetxattra() now declare fa with an aggregate initializer. ioctl_getflags(), ioctl_fsgetxattr(), and the file_getattr() syscall already aggregate-initialize fa to pass flags_valid/fsx_valid hints into vfs_fileattr_get(). Subsequent patches rely on this so that ->fileattr_get() handlers can set case-sensitivity flags (FS_XFLAG_CASEFOLD, FS_XFLAG_CASENONPRESERVING) in fa->fsx_xflags before the fill functions run. Suggested-by: Darrick J. Wong <[email protected]> Reviewed-by: Jan Kara <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Reviewed-by: Roland Mainz <[email protected]> Signed-off-by: Chuck Lever <[email protected]> --- fs/file_attr.c | 12 ++++-------- fs/xfs/xfs_ioctl.c | 2 +- 2 files changed, 5 insertions(+), 9 deletions(-) diff --git a/fs/file_attr.c b/fs/file_attr.c index da983e105d70..f429da66a317 100644 --- a/fs/file_attr.c +++ b/fs/file_attr.c @@ -15,12 +15,10 @@ * @fa: fileattr pointer * @xflags: FS_XFLAG_* flags * - * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags). All - * other fields are zeroed. + * Set ->fsx_xflags, ->fsx_valid and ->flags (translated xflags). */ void fileattr_fill_xflags(struct file_kattr *fa, u32 xflags) { - memset(fa, 0, sizeof(*fa)); fa->fsx_valid = true; fa->fsx_xflags = xflags; if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE) @@ -48,11 +46,9 @@ EXPORT_SYMBOL(fileattr_fill_xflags); * @flags: FS_*_FL flags * * Set ->flags, ->flags_valid and ->fsx_xflags (translated flags). - * All other fields are zeroed. */ void fileattr_fill_flags(struct file_kattr *fa, u32 flags) { - memset(fa, 0, sizeof(*fa)); fa->flags_valid = true; fa->flags = flags; if (fa->flags & FS_SYNC_FL) @@ -325,7 +321,7 @@ int ioctl_setflags(struct file *file, unsigned int __user *argp) { struct mnt_idmap *idmap = file_mnt_idmap(file); struct dentry *dentry = file->f_path.dentry; - struct file_kattr fa; + struct file_kattr fa = {}; unsigned int flags; int err; @@ -357,7 +353,7 @@ int ioctl_fssetxattr(struct file *file, void __user *argp) { struct mnt_idmap *idmap = file_mnt_idmap(file); struct dentry *dentry = file->f_path.dentry; - struct file_kattr fa; + struct file_kattr fa = {}; int err; err = copy_fsxattr_from_user(&fa, argp); @@ -431,7 +427,7 @@ SYSCALL_DEFINE5(file_setattr, int, dfd, const char __user *, filename, struct path filepath __free(path_put) = {}; unsigned int lookup_flags = 0; struct file_attr fattr; - struct file_kattr fa; + struct file_kattr fa = {}; int error; BUILD_BUG_ON(sizeof(struct file_attr) < FILE_ATTR_SIZE_VER0); diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index 46e234863644..ed9b4846c05f 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -517,7 +517,7 @@ xfs_ioc_fsgetxattra( xfs_inode_t *ip, void __user *arg) { - struct file_kattr fa; + struct file_kattr fa = {}; xfs_ilock(ip, XFS_ILOCK_SHARED); xfs_fill_fsxattr(ip, XFS_ATTR_FORK, &fa); -- 2.53.0 _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
