From da53be12bbb4fabbe2e9f6f908de0cf478b5161d Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 May 2013 15:22:44 -0700 Subject: Don't pass inode to ->d_hash() and ->d_compare() Instances either don't look at it at all (the majority of cases) or only want it to find the superblock (which can be had as dentry->d_sb). A few cases that want more are actually safe with dentry->d_inode - the only precaution needed is the check that it hadn't been replaced with NULL by rmdir() or by overwriting rename(), which case should be simply treated as cache miss. Signed-off-by: Linus Torvalds Signed-off-by: Al Viro --- fs/proc/proc_sysctl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'fs/proc') diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index f3a570e7c257..71290463a1d3 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -796,15 +796,16 @@ static int sysctl_is_seen(struct ctl_table_header *p) return res; } -static int proc_sys_compare(const struct dentry *parent, - const struct inode *pinode, - const struct dentry *dentry, const struct inode *inode, +static int proc_sys_compare(const struct dentry *parent, const struct dentry *dentry, unsigned int len, const char *str, const struct qstr *name) { struct ctl_table_header *head; + struct inode *inode; + /* Although proc doesn't have negative dentries, rcu-walk means * that inode here can be NULL */ /* AV: can it, indeed? */ + inode = ACCESS_ONCE(dentry->d_inode); if (!inode) return 1; if (name->len != len) -- cgit v1.2.3