diff options
| author | David Rientjes <rientjes@google.com> | 2008-06-05 12:57:11 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-06-10 12:26:16 +0200 |
| commit | 9985b0bab332289f14837eff3c6e0bcc658b58f7 (patch) | |
| tree | 8c4bcbc4348c473b14644dc4d371a45c0dabda53 /kernel | |
| parent | 7def2be1dc679984f4c4fb3ef19a8a081b2454ec (diff) | |
| download | kernel_samsung_tuna-9985b0bab332289f14837eff3c6e0bcc658b58f7.zip kernel_samsung_tuna-9985b0bab332289f14837eff3c6e0bcc658b58f7.tar.gz kernel_samsung_tuna-9985b0bab332289f14837eff3c6e0bcc658b58f7.tar.bz2 | |
sched: prevent bound kthreads from changing cpus_allowed
Kthreads that have called kthread_bind() are bound to specific cpus, so
other tasks should not be able to change their cpus_allowed from under
them. Otherwise, it is possible to move kthreads, such as the migration
or software watchdog threads, so they are not allowed access to the cpu
they work on.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpuset.c | 14 | ||||
| -rw-r--r-- | kernel/kthread.c | 1 | ||||
| -rw-r--r-- | kernel/sched.c | 6 |
3 files changed, 20 insertions, 1 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 6090d18..b84354f 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1190,6 +1190,15 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) return -ENOSPC; + if (tsk->flags & PF_THREAD_BOUND) { + cpumask_t mask; + + mutex_lock(&callback_mutex); + mask = cs->cpus_allowed; + mutex_unlock(&callback_mutex); + if (!cpus_equal(tsk->cpus_allowed, mask)) + return -EINVAL; + } return security_task_setscheduler(tsk, 0, NULL); } @@ -1203,11 +1212,14 @@ static void cpuset_attach(struct cgroup_subsys *ss, struct mm_struct *mm; struct cpuset *cs = cgroup_cs(cont); struct cpuset *oldcs = cgroup_cs(oldcont); + int err; mutex_lock(&callback_mutex); guarantee_online_cpus(cs, &cpus); - set_cpus_allowed_ptr(tsk, &cpus); + err = set_cpus_allowed_ptr(tsk, &cpus); mutex_unlock(&callback_mutex); + if (err) + return; from = oldcs->mems_allowed; to = cs->mems_allowed; diff --git a/kernel/kthread.c b/kernel/kthread.c index bd1b9ea..97747cd 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -180,6 +180,7 @@ void kthread_bind(struct task_struct *k, unsigned int cpu) set_task_cpu(k, cpu); k->cpus_allowed = cpumask_of_cpu(cpu); k->rt.nr_cpus_allowed = 1; + k->flags |= PF_THREAD_BOUND; } EXPORT_SYMBOL(kthread_bind); diff --git a/kernel/sched.c b/kernel/sched.c index e9c24a1..164fe7f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5563,6 +5563,12 @@ int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask) goto out; } + if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && + !cpus_equal(p->cpus_allowed, *new_mask))) { + ret = -EINVAL; + goto out; + } + if (p->sched_class->set_cpus_allowed) p->sched_class->set_cpus_allowed(p, new_mask); else { |