Re: [RFC PATCH 0/4] fix some issues related to MISRA C:2012 Rule 9.1

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

For the record, as I mentioned during the call today, I asked to
postpone the 9.1 work for later, because it is going to take a lot of
work and discussions to figure out a good way forward for all these
cases. There are at least 3-5 different sub-classes for this issues. So
I think it would be better for the Xen community to make more progress
with other rules and violations fixes first.


On Fri, 14 Jul 2023, Nicola Vetrini wrote:
> This patch series is aimed at discussing different categories of
> patterns concerning local variables that are possibly not
> initialized in all code paths, which results in hard-to-prove
> correctness. The main categories are as follows:
> 
> 1. Variables initialized by passing a pointer to them to a function.
>    Many such functions are coupled with error handling which results
>        in the variable not being initialized.
> 
> 2. Some variables are used in switch statements and the control flow
>    ensures that all code paths do initialize them, but due to the
>        presence of goto statements, the flow is harder to follow.
> 
> I emphasize that, as far as I can tell, the code is already
> compliant with the rule, but there is room for improvement, especially
> on the side of allowing automatic checks to be more effective.
> 
> Nicola Vetrini (4):
>   xen/arm: justify or initialize conditionally uninitialized variables
>   xen/arm64: bitops: justify uninitialized variable inside a macro
>   xen/arm: initialize conditionally uninitialized local variables
>   xen/arm: initialize conditionally uninitialized local variables
> 
>  docs/misra/safe.json                        | 24 +++++++++++++++
>  xen/arch/arm/arm64/lib/bitops.c             |  3 ++
>  xen/arch/arm/arm64/lib/find_next_bit.c      |  1 +
>  xen/arch/arm/bootfdt.c                      |  6 ++++
>  xen/arch/arm/cpuerrata.c                    |  6 ++--
>  xen/arch/arm/decode.c                       |  2 ++
>  xen/arch/arm/dm.c                           |  2 +-
>  xen/arch/arm/domain_build.c                 | 29 ++++++++++++++----
>  xen/arch/arm/domctl.c                       |  8 ++---
>  xen/arch/arm/efi/efi-boot.h                 |  6 ++--
>  xen/arch/arm/gic-v3-its.c                   |  9 +++---
>  xen/arch/arm/gic-v3-lpi.c                   | 17 ++++++-----
>  xen/arch/arm/guest_walk.c                   | 12 ++++----
>  xen/arch/arm/include/asm/guest_atomics.h    |  3 ++
>  xen/arch/arm/include/asm/p2m.h              | 10 ++++---
>  xen/arch/arm/mm.c                           |  1 +
>  xen/arch/arm/p2m.c                          | 33 ++++++++++++---------
>  xen/arch/arm/platforms/xilinx-zynqmp-eemi.c | 10 ++-----
>  xen/arch/arm/psci.c                         | 10 +++----
>  xen/drivers/char/pl011.c                    |  2 +-
>  20 files changed, 129 insertions(+), 65 deletions(-)
> 
> --
> 2.34.1
>