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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: David Miller <davem@davemloft.net>,
	bpf@vger.kernel.org, netdev@vger.kernel.org,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Sebastian Sewior <bigeasy@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Clark Williams <williams@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Ingo Molnar <mingo@kernel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Vinicius Costa Gomes <vinicius.gomes@intel.com>,
	Jakub Kicinski <kuba@kernel.org>
Subject: [patch V2 13/20] bpf: Use migrate_disable/enable in array macros and cgroup/lirc code.
Date: Thu, 20 Feb 2020 21:45:30 +0100	[thread overview]
Message-ID: <20200220204618.611167433@linutronix.de> (raw)
In-Reply-To: 20200220204517.863202864@linutronix.de

From: David Miller <davem@davemloft.net>

Replace the preemption disable/enable with migrate_disable/enable() to
reflect the actual requirement and to allow PREEMPT_RT to substitute it
with an actual migration disable mechanism which does not disable
preemption.

Including the code paths that go via __bpf_prog_run_save_cb().

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 include/linux/bpf.h    |    8 ++++----
 include/linux/filter.h |    5 +++--
 2 files changed, 7 insertions(+), 6 deletions(-)

--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -885,7 +885,7 @@ int bpf_prog_array_copy(struct bpf_prog_
 		struct bpf_prog *_prog;			\
 		struct bpf_prog_array *_array;		\
 		u32 _ret = 1;				\
-		preempt_disable();			\
+		migrate_disable();			\
 		rcu_read_lock();			\
 		_array = rcu_dereference(array);	\
 		if (unlikely(check_non_null && !_array))\
@@ -898,7 +898,7 @@ int bpf_prog_array_copy(struct bpf_prog_
 		}					\
 _out:							\
 		rcu_read_unlock();			\
-		preempt_enable();			\
+		migrate_enable();			\
 		_ret;					\
 	 })
 
@@ -932,7 +932,7 @@ int bpf_prog_array_copy(struct bpf_prog_
 		u32 ret;				\
 		u32 _ret = 1;				\
 		u32 _cn = 0;				\
-		preempt_disable();			\
+		migrate_disable();			\
 		rcu_read_lock();			\
 		_array = rcu_dereference(array);	\
 		_item = &_array->items[0];		\
@@ -944,7 +944,7 @@ int bpf_prog_array_copy(struct bpf_prog_
 			_item++;			\
 		}					\
 		rcu_read_unlock();			\
-		preempt_enable();			\
+		migrate_enable();			\
 		if (_ret)				\
 			_ret = (_cn ? NET_XMIT_CN : NET_XMIT_SUCCESS);	\
 		else					\
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -677,6 +677,7 @@ static inline u8 *bpf_skb_cb(struct sk_b
 	return qdisc_skb_cb(skb)->data;
 }
 
+/* Must be invoked with migration disabled */
 static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog,
 					 struct sk_buff *skb)
 {
@@ -702,9 +703,9 @@ static inline u32 bpf_prog_run_save_cb(c
 {
 	u32 res;
 
-	preempt_disable();
+	migrate_disable();
 	res = __bpf_prog_run_save_cb(prog, skb);
-	preempt_enable();
+	migrate_enable();
 	return res;
 }
 


  parent reply	other threads:[~2020-02-20 20:57 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-20 20:45 [patch V2 00/20] bpf: Make BPF and PREEMPT_RT co-exist Thomas Gleixner
2020-02-20 20:45 ` [patch V2 01/20] bpf: Enforce preallocation for all instrumentation programs Thomas Gleixner
2020-02-22  4:29   ` Alexei Starovoitov
2020-02-22  8:40     ` Thomas Gleixner
2020-02-23 22:40       ` Alexei Starovoitov
2020-02-22 16:44   ` kbuild test robot
2020-02-22 16:44     ` kbuild test robot
2020-02-20 20:45 ` [patch V2 02/20] bpf: Update locking comment in hashtab code Thomas Gleixner
2020-02-20 20:45 ` [patch V2 03/20] bpf/tracing: Remove redundant preempt_disable() in __bpf_trace_run() Thomas Gleixner
2020-02-20 20:45 ` [patch V2 04/20] perf/bpf: Remove preempt disable around BPF invocation Thomas Gleixner
2020-02-20 20:45 ` [patch V2 05/20] bpf: Remove recursion prevention from rcu free callback Thomas Gleixner
2020-02-20 20:45 ` [patch V2 06/20] bpf: Dont iterate over possible CPUs with interrupts disabled Thomas Gleixner
2020-02-20 20:45 ` [patch V2 07/20] bpf: Provide bpf_prog_run_pin_on_cpu() helper Thomas Gleixner
2020-02-20 20:45 ` [patch V2 08/20] bpf: Replace cant_sleep() with cant_migrate() Thomas Gleixner
2020-02-20 20:45 ` [patch V2 09/20] bpf: Use bpf_prog_run_pin_on_cpu() at simple call sites Thomas Gleixner
2020-02-20 20:45 ` [patch V2 10/20] trace/bpf: Use migrate disable in trace_call_bpf() Thomas Gleixner
2020-02-20 20:45 ` [patch V2 11/20] bpf/tests: Use migrate disable instead of preempt disable Thomas Gleixner
2020-02-20 20:45 ` [patch V2 12/20] bpf: Use migrate_disable/enabe() in trampoline code Thomas Gleixner
2020-02-20 20:45 ` Thomas Gleixner [this message]
2020-02-20 20:45 ` [patch V2 14/20] bpf: Use migrate_disable() in hashtab code Thomas Gleixner
2020-02-20 20:45 ` [patch V2 15/20] bpf: Provide recursion prevention helpers Thomas Gleixner
2020-02-20 20:45 ` [patch V2 16/20] bpf: Replace open coded recursion prevention Thomas Gleixner
2020-02-20 20:45 ` [patch V2 17/20] bpf: Factor out hashtab bucket lock operations Thomas Gleixner
2020-02-20 20:45 ` [patch V2 18/20] bpf: Prepare hashtab locking for PREEMPT_RT Thomas Gleixner
2020-02-20 20:45 ` [patch V2 19/20] bpf, lpm: Make locking RT friendly Thomas Gleixner
2020-02-20 20:45 ` [patch V2 20/20] bpf/stackmap: Dont trylock mmap_sem with PREEMPT_RT and interrupts disabled Thomas Gleixner

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