[v2 064/115] sysctl: sysctl_head_grab defaults to root header on NULL
From: Lucian Adrian Grijincu <hidden>
Date: 2011-05-08 22:51:36
Also in:
lkml
Subsystem:
filesystems (vfs and infrastructure), proc filesystem, proc sysctl, the rest · Maintainers:
Alexander Viro, Christian Brauner, Kees Cook, Joel Granados, Linus Torvalds
The code that could send NULL to sysctl_head_grab is grab_header
because for the root sysctl directory ('/proc/sys/')
PROC_I(inode)->sysctl is NULL.
For it we used to return root_table_header indirectly through a call
to sysctl_head_next(NULL). Now we default to the root header here.
The BUG() has not been triggered until now so we can assume no one
else is sending NULL here.
Signed-off-by: Lucian Adrian Grijincu <redacted>
---
fs/proc/proc_sysctl.c | 5 +----
kernel/sysctl.c | 2 +-
2 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index d1640bc..93962b0 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c@@ -64,10 +64,7 @@ static struct ctl_table *find_in_table(struct ctl_table *p, struct qstr *name) static struct ctl_table_header *grab_header(struct inode *inode) { - if (PROC_I(inode)->sysctl) - return sysctl_head_grab(PROC_I(inode)->sysctl); - else - return sysctl_head_next(NULL); + return sysctl_head_grab(PROC_I(inode)->sysctl); } static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 0450d3d..8b56695 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c@@ -1554,7 +1554,7 @@ void sysctl_head_put(struct ctl_table_header *head) struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) { if (!head) - BUG(); + head = &root_table_header; spin_lock(&sysctl_lock); if (!use_table(head)) head = ERR_PTR(-ENOENT);
--
1.7.5.134.g1c08b