From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>,
Paul Gortmaker <paul.gortmaker@windriver.com>,
<stable-rt@vger.kernel.org>
Subject: [PATCH RT 05/22] net/core: protect users of napi_alloc_cache against reentrance
Date: Wed, 02 Mar 2016 10:09:04 -0500 [thread overview]
Message-ID: <20160302151111.049865653@goodmis.org> (raw)
In-Reply-To: 20160302150859.204542604@goodmis.org
[-- Attachment #1: 0005-net-core-protect-users-of-napi_alloc_cache-against-r.patch --]
[-- Type: text/plain, Size: 1657 bytes --]
4.1.15-rt18-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
On -RT the code running in BH can not be moved to another CPU so CPU
local variable remain local. However the code can be preempted
and another task may enter BH accessing the same CPU using the same
napi_alloc_cache variable.
This patch ensures that each user of napi_alloc_cache uses a local lock.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
net/core/skbuff.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 36c138197f37..df293d45e0cd 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -358,6 +358,7 @@ struct netdev_alloc_cache {
static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache);
static DEFINE_PER_CPU(struct netdev_alloc_cache, napi_alloc_cache);
static DEFINE_LOCAL_IRQ_LOCK(netdev_alloc_lock);
+static DEFINE_LOCAL_IRQ_LOCK(napi_alloc_cache_lock);
static struct page *__page_frag_refill(struct netdev_alloc_cache *nc,
gfp_t gfp_mask)
@@ -456,7 +457,12 @@ EXPORT_SYMBOL(netdev_alloc_frag);
static void *__napi_alloc_frag(unsigned int fragsz, gfp_t gfp_mask)
{
- return __alloc_page_frag(&napi_alloc_cache, fragsz, gfp_mask);
+ void *data;
+
+ local_lock(napi_alloc_cache_lock);
+ data = __alloc_page_frag(&napi_alloc_cache, fragsz, gfp_mask);
+ local_unlock(napi_alloc_cache_lock);
+ return data;
}
void *napi_alloc_frag(unsigned int fragsz)
--
2.7.0
next prev parent reply other threads:[~2016-03-02 15:11 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-02 15:08 [PATCH RT 00/22] Linux 4.1.15-rt18-rc1 Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 01/22] sched: reset tasks lockless wake-queues on fork() Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 02/22] ptrace: dont open IRQs in ptrace_freeze_traced() too early Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 03/22] net: move xmit_recursion to per-task variable on -RT Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 04/22] kernel/softirq: use cond_resched_rcu_qs() on -RT as well (run_ksoftirqd()) Steven Rostedt
2016-03-02 15:09 ` Steven Rostedt [this message]
2016-03-02 15:09 ` [PATCH RT 06/22] preempt-lazy: Add the lazy-preemption check to preempt_schedule() Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 07/22] softirq: split timer softirqs out of ksoftirqd Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 08/22] net: provide a way to delegate processing a softirq to ksoftirqd Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 09/22] latencyhist: disable jump-labels Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 10/22] arm64: replace read_lock to rcu lock in call_step_hook Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 11/22] kernel: migrate_disable() do fastpath in atomic & irqs-off Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 12/22] kernel: softirq: unlock with irqs on Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 13/22] kernel/stop_machine: partly revert "stop_machine: Use raw spinlocks" Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 14/22] tick/broadcast: Make broadcast hrtimer irqsafe Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 15/22] sched,rt: __always_inline preemptible_lazy() Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 16/22] drm,radeon,i915: Use preempt_disable/enable_rt() where recommended Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 17/22] drm,i915: Use local_lock/unlock_irq() in intel_pipe_update_start/end() Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 18/22] trace: Use rcuidle version for preemptoff_hist trace point Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 19/22] f2fs: Mutex cant be used by down_write_nest_lock() Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 20/22] rcu/torture: Comment out rcu_bh ops on PREEMPT_RT_FULL Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 21/22] kernel: sched: Fix preempt_disable_ip recodring for preempt_disable() Steven Rostedt
2016-03-02 15:09 ` [PATCH RT 22/22] Linux 4.1.15-rt18-rc1 Steven Rostedt
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