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authorOlof Johansson <olof@lixom.net>2013-07-12 19:59:39 +0200
committerOlof Johansson <olof@lixom.net>2013-07-12 19:59:39 +0200
commitf4b96f5e4ff8d86699c851c10245e102809b0331 (patch)
treef766102263bed71738431cabb4d4f6f086005cd8 /security/device_cgroup.c
parentARM: omap2: add select of TI_PRIV_EDMA (diff)
parentARM: OMAP2+: omap2plus_defconfig: Enable appended DTB support (diff)
downloadlinux-f4b96f5e4ff8d86699c851c10245e102809b0331.tar.xz
linux-f4b96f5e4ff8d86699c851c10245e102809b0331.zip
Merge tag 'omap-for-v3.11/fixes-for-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
Omap fixes and minor defconfig updates that would be good to get in before -rc1. * tag 'omap-for-v3.11/fixes-for-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: ARM: OMAP2+: omap2plus_defconfig: Enable appended DTB support ARM: OMAP2+: Enable TI_EDMA in omap2plus_defconfig ARM: OMAP2+: omap2plus_defconfig: enable DRA752 thermal support by default ARM: OMAP2+: omap2plus_defconfig: enable TI bandgap driver ARM: OMAP2+: devices: remove duplicated include from devices.c ARM: OMAP3: igep0020: Set DSS pins in correct mux mode. ARM: OMAP2+: N900: enable N900-specific drivers even if device tree is enabled ARM: OMAP2+: Cocci spatch "ptr_ret.spatch" ARM: OMAP2+: Remove obsolete Makefile line ARM: OMAP5: Enable Cortex A15 errata 798181 ARM: scu: provide inline dummy functions when SCU is not present ARM: OMAP4: sleep: build OMAP4 specific functions only for OMAP4 ARM: OMAP2+: timer: initialize before using oh_name Signed-off-by: Olof Johansson <olof@lixom.net> Add/move/change conflicts in arch/arm/mach-omap2/Kconfig resolved.
Diffstat (limited to 'security/device_cgroup.c')
-rw-r--r--security/device_cgroup.c56
1 files changed, 18 insertions, 38 deletions
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index dd0dc574d78d..e8aad69f0d69 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -49,8 +49,6 @@ struct dev_cgroup {
struct cgroup_subsys_state css;
struct list_head exceptions;
enum devcg_behavior behavior;
- /* temporary list for pending propagation operations */
- struct list_head propagate_pending;
};
static inline struct dev_cgroup *css_to_devcgroup(struct cgroup_subsys_state *s)
@@ -241,7 +239,6 @@ static struct cgroup_subsys_state *devcgroup_css_alloc(struct cgroup *cgroup)
if (!dev_cgroup)
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&dev_cgroup->exceptions);
- INIT_LIST_HEAD(&dev_cgroup->propagate_pending);
dev_cgroup->behavior = DEVCG_DEFAULT_NONE;
return &dev_cgroup->css;
@@ -445,34 +442,6 @@ static void revalidate_active_exceptions(struct dev_cgroup *devcg)
}
/**
- * get_online_devcg - walks the cgroup tree and fills a list with the online
- * groups
- * @root: cgroup used as starting point
- * @online: list that will be filled with online groups
- *
- * Must be called with devcgroup_mutex held. Grabs RCU lock.
- * Because devcgroup_mutex is held, no devcg will become online or offline
- * during the tree walk (see devcgroup_online, devcgroup_offline)
- * A separated list is needed because propagate_behavior() and
- * propagate_exception() need to allocate memory and can block.
- */
-static void get_online_devcg(struct cgroup *root, struct list_head *online)
-{
- struct cgroup *pos;
- struct dev_cgroup *devcg;
-
- lockdep_assert_held(&devcgroup_mutex);
-
- rcu_read_lock();
- cgroup_for_each_descendant_pre(pos, root) {
- devcg = cgroup_to_devcgroup(pos);
- if (is_devcg_online(devcg))
- list_add_tail(&devcg->propagate_pending, online);
- }
- rcu_read_unlock();
-}
-
-/**
* propagate_exception - propagates a new exception to the children
* @devcg_root: device cgroup that added a new exception
* @ex: new exception to be propagated
@@ -482,15 +451,24 @@ static void get_online_devcg(struct cgroup *root, struct list_head *online)
static int propagate_exception(struct dev_cgroup *devcg_root,
struct dev_exception_item *ex)
{
- struct cgroup *root = devcg_root->css.cgroup;
- struct dev_cgroup *devcg, *parent, *tmp;
+ struct cgroup *root = devcg_root->css.cgroup, *pos;
int rc = 0;
- LIST_HEAD(pending);
- get_online_devcg(root, &pending);
+ rcu_read_lock();
- list_for_each_entry_safe(devcg, tmp, &pending, propagate_pending) {
- parent = cgroup_to_devcgroup(devcg->css.cgroup->parent);
+ cgroup_for_each_descendant_pre(pos, root) {
+ struct dev_cgroup *devcg = cgroup_to_devcgroup(pos);
+
+ /*
+ * Because devcgroup_mutex is held, no devcg will become
+ * online or offline during the tree walk (see on/offline
+ * methods), and online ones are safe to access outside RCU
+ * read lock without bumping refcnt.
+ */
+ if (!is_devcg_online(devcg))
+ continue;
+
+ rcu_read_unlock();
/*
* in case both root's behavior and devcg is allow, a new
@@ -512,8 +490,10 @@ static int propagate_exception(struct dev_cgroup *devcg_root,
}
revalidate_active_exceptions(devcg);
- list_del_init(&devcg->propagate_pending);
+ rcu_read_lock();
}
+
+ rcu_read_unlock();
return rc;
}