[lkml]   [2006]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    Patch in this message
    SubjectRe: [PATCH -mm] fs.h: ifdef security fields
    On Sat, Aug 05, 2006 at 11:25:49PM -0500, Serge E. Hallyn wrote:
    > Quoting Alexey Dobriyan (
    > > [BSD security levels are deleted in -mm, assuming this below]
    > >
    > > The only user of i_security, f_security, s_security fields is SELinux,
    > > so ifdef them with CONFIG_SECURITY_SELINUX. Following Stephen Smalley's
    > The SLIM security module, which is trying to get upstream, uses at least
    > i_security and f_security.

    OK, see it.

    > The Argus module supposedly being submitted "soon" which is used in
    > their LSPP product, surely must use them all.

    If they're going to use struct fown_struct::security, they'll just
    re-add it. Preferably under different name, so grepping for it won't be

    > Maybe you still want to make these CONFIG_SECURITY_SELINUX until the
    > other modules are upstreamed, but I just wanted to make sure you knew
    > other modules, trying to get upstream, are using them.
    > Personally I'd say these are a core part of the LSM framework, and if
    > you don't want LSM, compile it out.

    That's what I'm trying to do. This time for real. ;-)

    > But since I realize that using only
    > capabilities must be a pretty common case, how about just adding a
    > config option CONFIG_SECURITY_OBJFIELDS, which is auto-enabled with
    > SELINUX and default off, which hides these fields instead?

    Ahh, this is getting more and more complex, so I'll just put it under
    CONFIG_SECURITY and leave it.

    > Patch should be trivial, and I can aim to send one tomorrow.

    No need.
    [PATCH] fs.h: ifdef security fields

    [assuming BSD security levels are deleted]
    The only user of i_security, f_security, s_security fields is SELinux,
    however, quite a few security modules are trying to get into kernel.
    So, wrap them under CONFIG_SECURITY. Adding config option for each
    security field is likely an overkill.

    Following Stephen Smalley's suggestion, i_security initialization is
    moved to security_inode_alloc() to not clutter core code with ifdefs
    and make alloc_inode() codepath tiny little bit smaller and faster.

    The user of (highly greppable) struct fown_struct::security field is
    still to be found. I've checked every "fown_struct" and every "f_owner"
    occurence. Additionally it's removal doesn't break i386 allmodconfig

    struct inode, struct file, struct super_block, struct fown_struct
    become smaller.

    P.S. Combined with two reiserfs inode shrinking patches sent to
    linux-fsdevel, I can finally suck 12 reiserfs inodes into one page.


    -ext2_inode_cache 388 10
    +ext2_inode_cache 384 10
    -inode_cache 280 14
    +inode_cache 276 14
    -proc_inode_cache 296 13
    +proc_inode_cache 292 13
    -reiser_inode_cache 336 11
    +reiser_inode_cache 332 12 <=
    -shmem_inode_cache 372 10
    +shmem_inode_cache 368 10

    Signed-off-by: Alexey Dobriyan <>

    fs/inode.c | 1 -
    include/linux/fs.h | 8 ++++++--
    include/linux/security.h | 1 +
    3 files changed, 7 insertions(+), 3 deletions(-)

    --- a/fs/inode.c
    +++ b/fs/inode.c
    @@ -133,7 +133,6 @@ #endif
    inode->i_bdev = NULL;
    inode->i_cdev = NULL;
    inode->i_rdev = 0;
    - inode->i_security = NULL;
    inode->dirtied_when = 0;
    if (security_inode_alloc(inode)) {
    if (inode->i_sb->s_op->destroy_inode)
    --- a/include/linux/fs.h
    +++ b/include/linux/fs.h
    @@ -552,7 +552,9 @@ struct inode {
    unsigned int i_flags;

    atomic_t i_writecount;
    void *i_security;
    union {
    void *generic_ip;
    } u;
    @@ -645,7 +647,6 @@ struct fown_struct {
    rwlock_t lock; /* protects pid, uid, euid fields */
    int pid; /* pid or -pgrp where SIGIO should be sent */
    uid_t uid, euid; /* uid/euid of process setting the owner */
    - void *security;
    int signum; /* posix.1b rt signal to be delivered on IO */

    @@ -688,8 +689,9 @@ struct file {
    struct file_ra_state f_ra;

    unsigned long f_version;
    void *f_security;
    /* needed for tty driver, and maybe others */
    void *private_data;

    @@ -877,7 +879,9 @@ struct super_block {
    int s_syncing;
    int s_need_sync_fs;
    atomic_t s_active;
    void *s_security;
    struct xattr_handler **s_xattr;

    struct list_head s_inodes; /* all inodes */
    --- a/include/linux/security.h
    +++ b/include/linux/security.h
    @@ -1549,6 +1549,7 @@ static inline void security_sb_post_pivo

    static inline int security_inode_alloc (struct inode *inode)
    + inode->i_security = NULL;
    return security_ops->inode_alloc_security (inode);

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2006-08-06 07:27    [W:0.028 / U:44.728 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site