Re: [PATCH] iommu/ipmmu-vmsa: Add missing 'U' in IMTTLBR0_TTBR_MASK for shifted constant

[Julien Grall <julien@xxxxxxx>]

Hi,

On 05/07/2023 23:55, Stefano Stabellini wrote:
> On Tue, 4 Jul 2023, Oleksandr Tyshchenko wrote:
> > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> >
> > With enabling both CONFIG_UBSAN and CONFIG_IPMMU_VMSA I have got the following
> > splat when an IOMMU driver tried to setup page tables:
> >
> > (XEN) ipmmu: /soc/iommu@e67b0000: d1: Set IPMMU context 1 (pgd 0x77fe90000)
> > (XEN) 
> > ================================================================================
> > (XEN) UBSAN: Undefined behaviour in drivers/passthrough/arm/ipmmu-vmsa.c:558:51
> > (XEN) left shift of 1048575 by 12 places cannot be represented in type 'int'
> > (XEN) Xen WARN at common/ubsan/ubsan.c:172
> > (XEN) ---[ Xen-4.18-unstable  arm64  debug=y ubsan=y  Tainted:      S ]----
> > ...
> >
> > This points to shifted constant in IMTTLBR0_TTBR_MASK. Fix that by adding
> > missing 'U' to it.
> >
> > This should also address MISRA Rule 7.2:
> >
> > A "u" or "U" suffix shall be applied to all integer constants that
> > are represented in an unsigned type.
> >
> > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
This is now committed.

Cheers,

--
Julien Grall