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-rw-r--r--kernel/bpf/cgroup.c59
-rw-r--r--kernel/bpf/syscall.c20
-rw-r--r--kernel/cgroup.c9
-rw-r--r--kernel/time/tick-sched.c14
-rw-r--r--kernel/time/tick-sched.h2
5 files changed, 68 insertions, 36 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index a515f7b007c6..da0f53690295 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -52,6 +52,7 @@ void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent)
e = rcu_dereference_protected(parent->bpf.effective[type],
lockdep_is_held(&cgroup_mutex));
rcu_assign_pointer(cgrp->bpf.effective[type], e);
+ cgrp->bpf.disallow_override[type] = parent->bpf.disallow_override[type];
}
}
@@ -82,30 +83,63 @@ void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent)
*
* Must be called with cgroup_mutex held.
*/
-void __cgroup_bpf_update(struct cgroup *cgrp,
- struct cgroup *parent,
- struct bpf_prog *prog,
- enum bpf_attach_type type)
+int __cgroup_bpf_update(struct cgroup *cgrp, struct cgroup *parent,
+ struct bpf_prog *prog, enum bpf_attach_type type,
+ bool new_overridable)
{
- struct bpf_prog *old_prog, *effective;
+ struct bpf_prog *old_prog, *effective = NULL;
struct cgroup_subsys_state *pos;
+ bool overridable = true;
- old_prog = xchg(cgrp->bpf.prog + type, prog);
+ if (parent) {
+ overridable = !parent->bpf.disallow_override[type];
+ effective = rcu_dereference_protected(parent->bpf.effective[type],
+ lockdep_is_held(&cgroup_mutex));
+ }
+
+ if (prog && effective && !overridable)
+ /* if parent has non-overridable prog attached, disallow
+ * attaching new programs to descendent cgroup
+ */
+ return -EPERM;
+
+ if (prog && effective && overridable != new_overridable)
+ /* if parent has overridable prog attached, only
+ * allow overridable programs in descendent cgroup
+ */
+ return -EPERM;
- effective = (!prog && parent) ?
- rcu_dereference_protected(parent->bpf.effective[type],
- lockdep_is_held(&cgroup_mutex)) :
- prog;
+ old_prog = cgrp->bpf.prog[type];
+
+ if (prog) {
+ overridable = new_overridable;
+ effective = prog;
+ if (old_prog &&
+ cgrp->bpf.disallow_override[type] == new_overridable)
+ /* disallow attaching non-overridable on top
+ * of existing overridable in this cgroup
+ * and vice versa
+ */
+ return -EPERM;
+ }
+
+ if (!prog && !old_prog)
+ /* report error when trying to detach and nothing is attached */
+ return -ENOENT;
+
+ cgrp->bpf.prog[type] = prog;
css_for_each_descendant_pre(pos, &cgrp->self) {
struct cgroup *desc = container_of(pos, struct cgroup, self);
/* skip the subtree if the descendant has its own program */
- if (desc->bpf.prog[type] && desc != cgrp)
+ if (desc->bpf.prog[type] && desc != cgrp) {
pos = css_rightmost_descendant(pos);
- else
+ } else {
rcu_assign_pointer(desc->bpf.effective[type],
effective);
+ desc->bpf.disallow_override[type] = !overridable;
+ }
}
if (prog)
@@ -115,6 +149,7 @@ void __cgroup_bpf_update(struct cgroup *cgrp,
bpf_prog_put(old_prog);
static_branch_dec(&cgroup_bpf_enabled_key);
}
+ return 0;
}
/**
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 19b6129eab23..bbb016adbaeb 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -920,13 +920,14 @@ static int bpf_obj_get(const union bpf_attr *attr)
#ifdef CONFIG_CGROUP_BPF
-#define BPF_PROG_ATTACH_LAST_FIELD attach_type
+#define BPF_PROG_ATTACH_LAST_FIELD attach_flags
static int bpf_prog_attach(const union bpf_attr *attr)
{
+ enum bpf_prog_type ptype;
struct bpf_prog *prog;
struct cgroup *cgrp;
- enum bpf_prog_type ptype;
+ int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
@@ -934,6 +935,9 @@ static int bpf_prog_attach(const union bpf_attr *attr)
if (CHECK_ATTR(BPF_PROG_ATTACH))
return -EINVAL;
+ if (attr->attach_flags & ~BPF_F_ALLOW_OVERRIDE)
+ return -EINVAL;
+
switch (attr->attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
@@ -956,10 +960,13 @@ static int bpf_prog_attach(const union bpf_attr *attr)
return PTR_ERR(cgrp);
}
- cgroup_bpf_update(cgrp, prog, attr->attach_type);
+ ret = cgroup_bpf_update(cgrp, prog, attr->attach_type,
+ attr->attach_flags & BPF_F_ALLOW_OVERRIDE);
+ if (ret)
+ bpf_prog_put(prog);
cgroup_put(cgrp);
- return 0;
+ return ret;
}
#define BPF_PROG_DETACH_LAST_FIELD attach_type
@@ -967,6 +974,7 @@ static int bpf_prog_attach(const union bpf_attr *attr)
static int bpf_prog_detach(const union bpf_attr *attr)
{
struct cgroup *cgrp;
+ int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
@@ -982,7 +990,7 @@ static int bpf_prog_detach(const union bpf_attr *attr)
if (IS_ERR(cgrp))
return PTR_ERR(cgrp);
- cgroup_bpf_update(cgrp, NULL, attr->attach_type);
+ ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false);
cgroup_put(cgrp);
break;
@@ -990,7 +998,7 @@ static int bpf_prog_detach(const union bpf_attr *attr)
return -EINVAL;
}
- return 0;
+ return ret;
}
#endif /* CONFIG_CGROUP_BPF */
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 688dd02af985..53bbca7c4859 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -6498,15 +6498,16 @@ static __init int cgroup_namespaces_init(void)
subsys_initcall(cgroup_namespaces_init);
#ifdef CONFIG_CGROUP_BPF
-void cgroup_bpf_update(struct cgroup *cgrp,
- struct bpf_prog *prog,
- enum bpf_attach_type type)
+int cgroup_bpf_update(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, bool overridable)
{
struct cgroup *parent = cgroup_parent(cgrp);
+ int ret;
mutex_lock(&cgroup_mutex);
- __cgroup_bpf_update(cgrp, parent, prog, type);
+ ret = __cgroup_bpf_update(cgrp, parent, prog, type, overridable);
mutex_unlock(&cgroup_mutex);
+ return ret;
}
#endif /* CONFIG_CGROUP_BPF */
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index fc6f740d0277..2c115fdab397 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -725,11 +725,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
*/
if (delta == 0) {
tick_nohz_restart(ts, now);
- /*
- * Make sure next tick stop doesn't get fooled by past
- * clock deadline
- */
- ts->next_tick = 0;
goto out;
}
}
@@ -772,7 +767,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
tick = expires;
/* Skip reprogram of event if its not changed */
- if (ts->tick_stopped && (expires == ts->next_tick))
+ if (ts->tick_stopped && (expires == dev->next_event))
goto out;
/*
@@ -792,8 +787,6 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
trace_tick_stop(1, TICK_DEP_MASK_NONE);
}
- ts->next_tick = tick;
-
/*
* If the expiration time == KTIME_MAX, then we simply stop
* the tick timer.
@@ -809,10 +802,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
else
tick_program_event(tick, 1);
out:
- /*
- * Update the estimated sleep length until the next timer
- * (not only the tick).
- */
+ /* Update the estimated sleep length */
ts->sleep_length = ktime_sub(dev->next_event, now);
return tick;
}
diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h
index 075444e3d48e..bf38226e5c17 100644
--- a/kernel/time/tick-sched.h
+++ b/kernel/time/tick-sched.h
@@ -27,7 +27,6 @@ enum tick_nohz_mode {
* timer is modified for nohz sleeps. This is necessary
* to resume the tick timer operation in the timeline
* when the CPU returns from nohz sleep.
- * @next_tick: Next tick to be fired when in dynticks mode.
* @tick_stopped: Indicator that the idle tick has been stopped
* @idle_jiffies: jiffies at the entry to idle for idle time accounting
* @idle_calls: Total number of idle calls
@@ -45,7 +44,6 @@ struct tick_sched {
unsigned long check_clocks;
enum tick_nohz_mode nohz_mode;
ktime_t last_tick;
- ktime_t next_tick;
int inidle;
int tick_stopped;
unsigned long idle_jiffies;
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