[PATCH 3.18 46/50] vfio-pci: use 32-bit comparisons for register address for gcc-4.5

From	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups	linux.kernel
Subject	[PATCH 3.18 46/50] vfio-pci: use 32-bit comparisons for register address for gcc-4.5
Date	2017-08-05 01:40 +0200
Message-ID	<uaUmf-5dC-23@gated-at.bofh.it> (permalink)
References	<uaUcy-5a1-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <arnd@arndb.de>


[ Upstream commit 45e869714489431625c569d21fc952428d761476 ]

Using ancient compilers (gcc-4.5 or older) on ARM, we get a link
failure with the vfio-pci driver:

ERROR: "__aeabi_lcmp" [drivers/vfio/pci/vfio-pci.ko] undefined!

The reason is that the compiler tries to do a comparison of
a 64-bit range. This changes it to convert to a 32-bit number
explicitly first, as newer compilers do for themselves.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/vfio/pci/vfio_pci_rdwr.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -190,7 +190,10 @@ ssize_t vfio_pci_vga_rw(struct vfio_pci_
 	if (!vdev->has_vga)
 		return -EINVAL;
 
-	switch (pos) {
+	if (pos > 0xbfffful)
+		return -EINVAL;
+
+	switch ((u32)pos) {
 	case 0xa0000 ... 0xbffff:
 		count = min(count, (size_t)(0xc0000 - pos));
 		iomem = ioremap_nocache(0xa0000, 0xbffff - 0xa0000 + 1);

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[PATCH 3.18 46/50] vfio-pci: use 32-bit comparisons for register address for gcc-4.5 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-05 01:40 +0200

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