[PATCH 4.19 68/98] Drivers: hv: vmbus: Fix virt_to_hvpfn() for X86_PAE

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Dexuan Cui <decui@microsoft.com>

commit a9fc4340aee041dd186d1fb8f1b5d1e9caf28212 upstream.

In the case of X86_PAE, unsigned long is u32, but the physical address type
should be u64. Due to the bug here, the netvsc driver can not load
successfully, and sometimes the VM can panic due to memory corruption (the
hypervisor writes data to the wrong location).

Fixes: 6ba34171bcbd ("Drivers: hv: vmbus: Remove use of slow_virt_to_phys()")
Cc: stable@vger.kernel.org
Cc: Michael Kelley <mikelley@microsoft.com>
Reported-and-tested-by: Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by:  Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hv/channel.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -38,7 +38,7 @@
 
 static unsigned long virt_to_hvpfn(void *addr)
 {
-	unsigned long paddr;
+	phys_addr_t paddr;
 
 	if (is_vmalloc_addr(addr))
 		paddr = page_to_phys(vmalloc_to_page(addr)) +