| Message ID | 20161216105634.235457-5-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 16 Dec 2016 11:56:25 +0100 Arnd Bergmann <arnd@arndb.de> wrote: > 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> > --- > drivers/vfio/pci/vfio_pci_rdwr.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c > index 5ffd1d9ad4bd..357243d76f10 100644 > --- a/drivers/vfio/pci/vfio_pci_rdwr.c > +++ b/drivers/vfio/pci/vfio_pci_rdwr.c > @@ -193,7 +193,10 @@ ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf, > 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); Acked-by: Alex Williamson <alex.williamson@redhat.com> Would you like me to pull this one patch in through the vfio tree? Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Friday, December 16, 2016 8:30:56 AM CET Alex Williamson wrote: > > Acked-by: Alex Williamson <alex.williamson@redhat.com> > > Would you like me to pull this one patch in through the vfio tree? > Thanks, If you think the patch is appropriate, please merge it. I originally just posted this as illustration to raise the question of whether we actually want to support gcc-4.5, from the feedback so far it does seem like the answer is yes, and we will need it. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c index 5ffd1d9ad4bd..357243d76f10 100644 --- a/drivers/vfio/pci/vfio_pci_rdwr.c +++ b/drivers/vfio/pci/vfio_pci_rdwr.c @@ -193,7 +193,10 @@ ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf, 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);
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> --- drivers/vfio/pci/vfio_pci_rdwr.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)