This is a note to let you know that I've just added the patch titled
irqchip/gic-v3: Use wmb() instead of smb_wmb() in gic_raise_softirq()
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
irqchip-gic-v3-use-wmb-instead-of-smb_wmb-in-gic_raise_softirq.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 21ec30c0ef5234fb1039cc7c7737d885bf875a9e Mon Sep 17 00:00:00 2001
From: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
Date: Wed, 31 Jan 2018 18:03:42 -0600
Subject: irqchip/gic-v3: Use wmb() instead of smb_wmb() in gic_raise_softirq()
From: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
commit 21ec30c0ef5234fb1039cc7c7737d885bf875a9e upstream.
A DMB instruction can be used to ensure the relative order of only
memory accesses before and after the barrier. Since writes to system
registers are not memory operations, barrier DMB is not sufficient
for observability of memory accesses that occur before ICC_SGI1R_EL1
writes.
A DSB instruction ensures that no instructions that appear in program
order after the DSB instruction, can execute until the DSB instruction
has completed.
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Will Deacon <will.deacon@xxxxxxx>,
Signed-off-by: Shanker Donthineni <shankerd@xxxxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/irqchip/irq-gic-v3.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -604,7 +604,7 @@ static void gic_raise_softirq(const stru
* Ensure that stores to Normal memory are visible to the
* other CPUs before issuing the IPI.
*/
- smp_wmb();
+ wmb();
for_each_cpu(cpu, mask) {
unsigned long cluster_id = cpu_logical_map(cpu) & ~0xffUL;
Patches currently in stable-queue which might be from shankerd@xxxxxxxxxxxxxx are
queue-4.4/irqchip-gic-v3-use-wmb-instead-of-smb_wmb-in-gic_raise_softirq.patch