[Ocfs2-devel] [PATCH 22/30] ocfs2: Handles missing export should_remove_suid()

[Joel Becker]

On Thu, Dec 20, 2007 at 03:29:39PM -0800, Sunil Mushran wrote:
> Commits 01de85e057328ecbef36e108673b1e81059d54c1 and
> d23a147bb6e8d467e8df73b6589888717da3b9ce in mainline added and exported
> symbol should_remove_suid(). This patch allows one to build ocfs2 with
> kernels having/not having these changes.
> 

This should go in kapi-compat/include/should-remove-suid.h and play the
same tricks as we did above.

[should-remove-suid.h]
#ifdef NO_SHOULD_REMOVE_SUID
int should_remove_suid()
{
...
}
#endif

[Makefile]
ifdef NO_SHOULD_REMOVE_SUID
CPPFLAGS_file.o += -DNO_SHOULD_REMOVE_SUID
endif

> Signed-off-by: Sunil Mushran <sunil.mushran at oracle.com>
> ---
>  configure.in      |    5 +++++
>  fs/ocfs2/Makefile |    4 ++++
>  fs/ocfs2/file.c   |   30 ++++++++++++++++++++++++++++++
>  3 files changed, 39 insertions(+), 0 deletions(-)
> 
> diff --git a/configure.in b/configure.in
> index 39fb02b..472e01a 100644
> --- a/configure.in
> +++ b/configure.in
> @@ -257,6 +257,11 @@ OCFS2_CHECK_KERNEL([MNT_RELATIME in mount.h], mount.h,
>    , relatime_compat_header="mount.h", [^#define MNT_RELATIME])
>  KAPI_COMPAT_HEADERS="$KAPI_COMPAT_HEADERS $relatime_compat_header"
>  
> +SHOULD_REMOVE_SUID=
> +OCFS2_CHECK_KERNEL([should_remove_suid() in fs.h], fs.h,
> +  SHOULD_REMOVE_SUID=yes, , [should_remove_suid()])
> +AC_SUBST(SHOULD_REMOVE_SUID)
> +
>  # using -include has two advantages:
>  #  the source doesn't need to know to include compat headers
>  #  the compat header file names don't go through the search path
> diff --git a/fs/ocfs2/Makefile b/fs/ocfs2/Makefile
> index 3cc7c74..a80a9fc 100644
> --- a/fs/ocfs2/Makefile
> +++ b/fs/ocfs2/Makefile
> @@ -53,6 +53,10 @@ ifdef SPLICE_HEADER
>  EXTRA_CFLAGS += -DSPLICE_HEADER
>  endif
>  
> +ifdef SHOULD_REMOVE_SUID
> +EXTRA_CFLAGS += -DSHOULD_REMOVE_SUID
> +endif
> +
>  #
>  # Since SUBDIRS means something to kbuild, define them safely.  Do not
>  # include trailing slashes.
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 1c179fc..cee10ae 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1593,6 +1593,36 @@ out:
>  	return ret;
>  }
>  
> +#ifndef SHOULD_REMOVE_SUID
> +/*
> + * The logic we want is
> + *
> + *	if suid or (sgid and xgrp)
> + *		remove privs
> + */
> +int should_remove_suid(struct dentry *dentry)
> +{
> +	mode_t mode = dentry->d_inode->i_mode;
> +	int kill = 0;
> +
> +	/* suid always must be killed */
> +	if (unlikely(mode & S_ISUID))
> +		kill = ATTR_KILL_SUID;
> +
> +	/*
> +	 * sgid without any exec bits is just a mandatory locking mark; leave
> +	 * it alone.  If some exec bits are set, it's a real sgid; kill it.
> +	 */
> +	if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
> +		kill |= ATTR_KILL_SGID;
> +
> +	if (unlikely(kill && !capable(CAP_FSETID)))
> +		return kill;
> +
> +	return 0;
> +}
> +#endif
> +
>  /*
>   * Parts of this function taken from xfs_change_file_space()
>   */
> -- 
> 1.5.2.5
> 
> 
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Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127