random: add interrupt callback to VMBus IRQ handler

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>

diff --git a/drivers/char/random.c b/drivers/char/random.c
index e5e1f1432e4d45495b2f689d4ed454c2cde1ba88..491a4dce13fef5962a9b07d6cef5c82fc3fc31d8 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -948,6 +948,7 @@ void add_interrupt_randomness(int irq, int irq_flags)
        /* 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)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index f19b6f7a467a6a8c14988da9a3817e2cea02c433..9b5440f6b3b4cb62d1f49e5974fe6f0d028a72de 100644 (file)
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -41,6 +41,7 @@
 #include <linux/ptrace.h>
 #include <linux/screen_info.h>
 #include <linux/kdebug.h>
+#include <linux/random.h>
 #include "hyperv_vmbus.h"
 
 static struct acpi_device  *hv_acpi_dev;
@@ -826,6 +827,8 @@ static void vmbus_isr(void)
                else
                        tasklet_schedule(&msg_dpc);
        }
+
+       add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
 }