proc: Clear the pieces of proc_inode that proc_evict_inode cares about

[ Upstream commit 71448011ea2a1cd36d8f5cbdab0ed716c454d565 ]

This just keeps everything tidier, and allows for using flags like
SLAB_TYPESAFE_BY_RCU where slabs are not always cleared before reuse.
I don't see reuse without reinitializing happening with the proc_inode
but I had a false alarm while reworking flushing of proc dentries and
indoes when a process dies that caused me to tidy this up.

The code is a little easier to follow and reason about this
way so I figured the changes might as well be kept.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Stable-dep-of: b969f9614885 ("fix proc_sys_compare() handling of in-lookup dentries")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Eric W. Biederman 2020-02-20 11:17:28 -06:00 • committed by Greg Kroah-Hartman
commit 42e9cf27c0

View file

@ -33,21 +33,27 @@ static void proc_evict_inode(struct inode *inode)
{
struct proc_dir_entry *de;
struct ctl_table_header *head;
struct proc_inode *ei = PROC_I(inode);
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
/* Stop tracking associated processes */
put_pid(PROC_I(inode)->pid);
if (ei->pid) {
put_pid(ei->pid);
ei->pid = NULL;
}
/* Let go of any associated proc directory entry */
de = PDE(inode);
if (de)
de = ei->pde;
if (de) {
pde_put(de);
ei->pde = NULL;
}
head = PROC_I(inode)->sysctl;
head = ei->sysctl;
if (head) {
RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
RCU_INIT_POINTER(ei->sysctl, NULL);
proc_sys_evict_inode(inode, head);
}
}