Re: [Qemu-devel] [PULL 0/5] X86 patch queue, 2015-05-29

[Peter Maydell]

On 29 May 2015 at 19:04, Eduardo Habkost <address@hidden> wrote:
> The following changes since commit 2cc3bdbe2d3908f7a813d1c2d774cc2bf07746cd:
>
>   Merge remote-tracking branch 'remotes/armbru/tags/pull-block-2015-05-29' 
> into staging (2015-05-29 15:32:15 +0100)
>
> are available in the git repository at:
>
>   git://github.com/ehabkost/qemu.git tags/x86-pull-request
>
> for you to fetch changes up to d032544e08ed07c66afd45ca8a8420ca202fab75:
>
>   arch_init: Drop target-x86_64.conf (2015-05-29 14:46:32 -0300)
>
> ----------------------------------------------------------------
> X86 patch queue, 2015-05-29

Hi. I'm afraid this patchset provokes a lot of warnings from
clang's undefined-behaviour sanitizer when we run make check:

/home/petmay01/linaro/qemu-for-merges/hw/intc/apic_common.c:314:55:
runtime error: left shift of 1048575 by 12 places cannot be
represented in type 'int'

This is because this:
target-i386/cpu.h:#define MSR_IA32_APICBASE_BASE (0xfffff<<12)

is shifting a 1 into the sign bit of a signed integer. You need
to write 0xfffffU to force an unsigned shift here.

(The undef sanitizer is one of those things I don't really
expect submaintainers to run but which I have enabled for
my build process. At the moment we're almost clean for a
make check run, so I'm keen to avoid introducing new warnings.)

thanks
-- PMM