[PATCH 2/2] fs: move file_remove_suid() to fs/inode.c

From: Cong Wang
Date: Tue May 15 2012 - 02:58:22 EST


From: Cong Wang <xiyou.wangcong@xxxxxxxxx>

file_remove_suid() is a generic function operates on struct file,
it almost has no relations with file mapping, so move it to fs/inode.c.

Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
---
fs/inode.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
mm/filemap.c | 65 ----------------------------------------------------------
2 files changed, 65 insertions(+), 65 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index 9f4f5fe..1f9627d 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1524,6 +1524,71 @@ void touch_atime(struct path *path)
}
EXPORT_SYMBOL(touch_atime);

+/*
+ * The logic we want is
+ *
+ * if suid or (sgid and xgrp)
+ * remove privs
+ */
+int should_remove_suid(struct dentry *dentry)
+{
+ umode_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) && S_ISREG(mode)))
+ return kill;
+
+ return 0;
+}
+EXPORT_SYMBOL(should_remove_suid);
+
+static int __remove_suid(struct dentry *dentry, int kill)
+{
+ struct iattr newattrs;
+
+ newattrs.ia_valid = ATTR_FORCE | kill;
+ return notify_change(dentry, &newattrs);
+}
+
+int file_remove_suid(struct file *file)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ int killsuid;
+ int killpriv;
+ int error = 0;
+
+ /* Fast path for nothing security related */
+ if (IS_NOSEC(inode))
+ return 0;
+
+ killsuid = should_remove_suid(dentry);
+ killpriv = security_inode_need_killpriv(dentry);
+
+ if (killpriv < 0)
+ return killpriv;
+ if (killpriv)
+ error = security_inode_killpriv(dentry);
+ if (!error && killsuid)
+ error = __remove_suid(dentry, killsuid);
+ if (!error && (inode->i_sb->s_flags & MS_NOSEC))
+ inode->i_flags |= S_NOSEC;
+
+ return error;
+}
+EXPORT_SYMBOL(file_remove_suid);
+
/**
* file_update_time - update mtime and ctime time
* @file: file accessed
diff --git a/mm/filemap.c b/mm/filemap.c
index 64b48f9..b70e777 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1899,71 +1899,6 @@ struct page *read_cache_page(struct address_space *mapping,
}
EXPORT_SYMBOL(read_cache_page);

-/*
- * The logic we want is
- *
- * if suid or (sgid and xgrp)
- * remove privs
- */
-int should_remove_suid(struct dentry *dentry)
-{
- umode_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) && S_ISREG(mode)))
- return kill;
-
- return 0;
-}
-EXPORT_SYMBOL(should_remove_suid);
-
-static int __remove_suid(struct dentry *dentry, int kill)
-{
- struct iattr newattrs;
-
- newattrs.ia_valid = ATTR_FORCE | kill;
- return notify_change(dentry, &newattrs);
-}
-
-int file_remove_suid(struct file *file)
-{
- struct dentry *dentry = file->f_path.dentry;
- struct inode *inode = dentry->d_inode;
- int killsuid;
- int killpriv;
- int error = 0;
-
- /* Fast path for nothing security related */
- if (IS_NOSEC(inode))
- return 0;
-
- killsuid = should_remove_suid(dentry);
- killpriv = security_inode_need_killpriv(dentry);
-
- if (killpriv < 0)
- return killpriv;
- if (killpriv)
- error = security_inode_killpriv(dentry);
- if (!error && killsuid)
- error = __remove_suid(dentry, killsuid);
- if (!error && (inode->i_sb->s_flags & MS_NOSEC))
- inode->i_flags |= S_NOSEC;
-
- return error;
-}
-EXPORT_SYMBOL(file_remove_suid);
-
static size_t __iovec_copy_from_user_inatomic(char *vaddr,
const struct iovec *iov, size_t base, size_t bytes)
{
--
1.7.7.6

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