Patch "random: add interrupt callback to VMBus IRQ handler" has been added to the 4.7-stable tree

Patch "random: add interrupt callback to VMBus IRQ handler" has been added to the 4.7-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    random: add interrupt callback to VMBus IRQ handler

to the 4.7-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:
     random-add-interrupt-callback-to-vmbus-irq-handler.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 4b44f2d18a330565227a7348844493c59366171e Mon Sep 17 00:00:00 2001
From: Stephan Mueller <smueller@chronox.de>
Date: Mon, 2 May 2016 02:14:34 -0400
Subject: random: add interrupt callback to VMBus IRQ handler

From: Stephan Mueller <smueller@chronox.de>

commit 4b44f2d18a330565227a7348844493c59366171e upstream.

The Hyper-V Linux Integration Services use the VMBus implementation for
communication with the Hypervisor. VMBus registers its own interrupt
handler that completely bypasses the common Linux interrupt handling.
This implies that the interrupt entropy collector is not triggered.

This patch adds the interrupt entropy collection callback into the VMBus
interrupt handler function.

Signed-off-by: Stephan Mueller <stephan.mueller@atsec.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/char/random.c  |    1 +
 drivers/hv/vmbus_drv.c |    3 +++
 2 files changed, 4 insertions(+)

--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -949,6 +949,7 @@ void add_interrupt_randomness(int irq, i
 	/* award one bit for the contents of the fast pool */
 	credit_entropy_bits(r, credit + 1);
 }
+EXPORT_SYMBOL_GPL(add_interrupt_randomness);
 
 #ifdef CONFIG_BLOCK
 void add_disk_randomness(struct gendisk *disk)
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -42,6 +42,7 @@
 #include <linux/screen_info.h>
 #include <linux/kdebug.h>
 #include <linux/efi.h>
+#include <linux/random.h>
 #include "hyperv_vmbus.h"
 
 static struct acpi_device  *hv_acpi_dev;
@@ -806,6 +807,8 @@ static void vmbus_isr(void)
 		else
 			tasklet_schedule(hv_context.msg_dpc[cpu]);
 	}
+
+	add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
 }
 
 


Patches currently in stable-queue which might be from smueller@chronox.de are

queue-4.7/random-add-interrupt-callback-to-vmbus-irq-handler.patch