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Re: [Qemu-trivial] [PATCH 00/12] Avoid shifting left into sign bit
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-trivial] [PATCH 00/12] Avoid shifting left into sign bit |
Date: |
Tue, 11 Mar 2014 00:00:35 +0200 |
On Mon, Mar 10, 2014 at 07:10:36PM +0000, Peter Maydell wrote:
> This is a set of patches which silence clang -fsanitize=undefined
> warnings about shifting left into the sign bit of a signed value.
> Typically this is the result of "1 << 31" and similar constructs;
> the fix is to add a "U" suffix to the 1 so that we do unsigned
> arithmetic rather than signed arithmetic.
>
> Since these patches are very minor changes to a fairly
> wide ranging set of files, it seems easiest to send these
> through the -trivial queue. Happy to split the series up
> if people disagree.
I'm fine with this for pci and pc bits.
> Mostly I think these warnings are not particularly exciting
> (even the adversarial optimizations preferred by modern
> compilers will probably not break "1 << 31") but there are
> a lot of them, the fix is pretty trivial, and getting rid of
> them allows us to see the interesting sanitizer warnings more
> clearly.
>
> My method here has been just to look at the warnings produced
> during a 'make check' run; no doubt actually running a guest
> for various platforms would identify more of these.
>
> thanks
> -- PMM
>
> Peter Maydell (12):
> target-i386: Avoid shifting left into sign bit
> hw/intc/apic.c: Use uint32_t for mask word in foreach_apic
> hw/pci/pci_host.c: Avoid shifting left into sign bit
> hw/i386/acpi_build.c: Avoid shifting left into sign bit
> target-mips: Avoid shifting left into sign bit
> hw/usb/hcd-ohci.c: Avoid shifting left into sign bit
> hw/intc/openpic: Avoid shifting left into sign bit
> hw/ppc: Avoid shifting left into sign bit
> tests/libqos/pci-pc: Avoid shifting left into sign bit
> hw/intc/slavio_intctl: Avoid shifting left into sign bit
> hw/intc/xilinx_intc: Avoid shifting left into sign bit
> hw/pci-host/apb.c: Avoid shifting left into sign bit
>
> hw/i386/acpi-build.c | 2 +-
> hw/intc/apic.c | 5 +++--
> hw/intc/openpic.c | 4 ++--
> hw/intc/slavio_intctl.c | 2 +-
> hw/intc/xilinx_intc.c | 3 ++-
> hw/pci-host/apb.c | 2 +-
> hw/pci/pci_host.c | 3 ++-
> hw/ppc/ppc.c | 2 +-
> hw/ppc/ppc440_bamboo.c | 4 ++--
> hw/ppc/ppc4xx_devs.c | 2 +-
> hw/ppc/ppc_booke.c | 4 ++--
> hw/ppc/virtex_ml507.c | 4 ++--
> hw/usb/hcd-ohci.c | 6 +++---
> target-i386/cpu.h | 8 ++++----
> target-mips/cpu.h | 2 +-
> target-mips/helper.c | 8 ++++----
> target-mips/op_helper.c | 2 +-
> target-mips/translate_init.c | 22 +++++++++++-----------
> tests/libqos/pci-pc.c | 12 ++++++------
> 19 files changed, 50 insertions(+), 47 deletions(-)
>
> --
> 1.9.0
>
- Re: [Qemu-trivial] [PATCH 04/12] hw/i386/acpi_build.c: Avoid shifting left into sign bit, (continued)
- [Qemu-trivial] [PATCH 11/12] hw/intc/xilinx_intc: Avoid shifting left into sign bit, Peter Maydell, 2014/03/10
- [Qemu-trivial] [PATCH 07/12] hw/intc/openpic: Avoid shifting left into sign bit, Peter Maydell, 2014/03/10
- [Qemu-trivial] [PATCH 09/12] tests/libqos/pci-pc: Avoid shifting left into sign bit, Peter Maydell, 2014/03/10
- [Qemu-trivial] [PATCH 01/12] target-i386: Avoid shifting left into sign bit, Peter Maydell, 2014/03/10
- [Qemu-trivial] [PATCH 10/12] hw/intc/slavio_intctl: Avoid shifting left into sign bit, Peter Maydell, 2014/03/10
- [Qemu-trivial] [PATCH 02/12] hw/intc/apic.c: Use uint32_t for mask word in foreach_apic, Peter Maydell, 2014/03/10
- Re: [Qemu-trivial] [PATCH 00/12] Avoid shifting left into sign bit,
Michael S. Tsirkin <=