Re: [PATCH] ARM: ubsan: select ARCH_HAS_UBSAN_SANITIZE_ALL

[Florian Fainelli]

On 9/29/22 01:10, Kees Cook wrote:
> On Wed, Sep 28, 2022 at 05:33:14PM -0700, William Zhang wrote:
> > On 09/28/2022 04:06 PM, Florian Fainelli wrote:
> > > On 9/28/22 11:01, Kees Cook wrote:
> > > > On Wed, Sep 28, 2022 at 10:47:39AM -0700, Florian Fainelli wrote:
> > > > > From: Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx>
> > > > >
> > > > > To enable UBSAN on ARM, this patch enables ARCH_HAS_UBSAN_SANITIZE_ALL
> > > > > from arm confiuration. Basic kernel bootup test is passed on arm with
> > > > > CONFIG_UBSAN_SANITIZE_ALL enabled.
> > > > >
> > > > > Signed-off-by: Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx>
> > > > > [florian: rebased against v6.0-rc7]
> > > > > Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> > > >
> > > > Ah-ha, thanks for testing this. What devices did you check this on? I
> > > > know boot-up on arm32 can be very device-specific.
> > >
> > > This was tested on an ARCH_BRCMSTB system which is using an ARMv8 CPU
> > > booted in AArch32 mode, so virtually equivalent to armv7l. A raspberry
> > > Pi 4B is also happily booting with it.
> > >
> > > > Which UBSAN configs did you try?
> > >
> > > All CONFIG_UBSAN_* work with the exception of CONFIG_UBSAN_ALIGNMENT on
> > > my ARCH_BRCMSTB system, however it works fine on the Raspberry Pi 4B.
> > > Florian
> >
> > I also tested on a BCM63138 board (ARM A9) under ARCH_BCMBCA using the
> > multi_v7_defconfig with all the UBSAN configs enabled except UBSAN_ALIGNMENT
> > and board boots up fine. Turning on UBSAN_ALIGNMENT results in flood of
> > false positive misaligned-access warnings. This is fine as ARM supports
> > unaligned access.
> >
> > It did catch an out-of-band bug in mach-sunxi smp code.  I will submit a
> > separate patch to fix that bug.
>
> Yay! :) Move coverage is great. :)
>
> > Tested-by: William Zhang <william.zhang@xxxxxxxxxxxx>

Submitted to the patch tracker:

https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=9253/1
--
Florian