On 2024-04-25 11:40, Federico Serafini wrote:
On 25/04/24 02:06, Stefano Stabellini wrote:
On Tue, 23 Apr 2024, Federico Serafini wrote:
From: Simone Ballarin <simone.balla...@bugseng.com>
Introduce accepted_guidelines.sh: a script to autogenerate the
configuration file accepted.ecl from docs/misra/rules.rst which
enables
all accepted guidelines.
Introduce monitored.ecl: a manual selection of accepted guidelines
which are clean or almost clean, it is intended to be used for the
analyses triggered by commits.
Reorganize tagging.ecl:
-Remove "accepted" tags: keeping track of accepted guidelines
tagging
them as "accepted" in the configuration file tagging.ecl is no
longer needed since docs/rules.rst is keeping track of them.
-Tag more guidelines as clean.
Reorganize eclair pipelines:
- Set1, Set2, Set3 are now obsolete: remove the corresponding
pipelines and ecl files.
- Amend scheduled eclair pipeline to use accepted.ecl.
- Amend triggered eclair pipeline to use monitored.ecl.
Rename and improve action_check_clean_regressions.sh to print a
diagnostic in case a commit introduces a violation of a clean
guideline.
An example of diagnostic is the following:
Failure: 13 regressions found for clean guidelines
service MC3R1.R8.2: (required) Function types shall be in
prototype form with named parameters:
violation: 13
Signed-off-by: Simone Ballarin <simone.balla...@bugseng.com>
Signed-off-by: Federico Serafini <federico.seraf...@bugseng.com>
Signed-off-by: Alessandro Zucchelli
<alessandro.zucche...@bugseng.com>
Fantastic work, thank you!
Reviewed-by: Stefano Stabellini <sstabell...@kernel.org>
Is this patch safe to commit now? Or would it cause gitlab-ci
breakage?
Yes, it is safe because the ECLAIR analysis is still allowed to fail.
Committing this patch wouldn't break the CI but it will highlight some
regressions with the orange badge and the following messages:
arm:
Failure: 5 regressions found for clean guidelines
service MC3R1.R1.1: (required) The program shall contain no
violations of the standard C syntax and constraints, and shall not
exceed the implementation's translation limits:
violation: 5
+Cc ARM maintainers, Luca Fancellu
after some investigation on these regressions on R1.1, there are some
concerns with the current code:
2209c1e35b479dff8ed3d3161001ffdefa0a704e introduced the struct
struct membanks {
unsigned int nr_banks;
unsigned int max_banks;
struct membank bank[];
};
with a flexible array member at the end; this is well-defined in C99,
but what is non-standard (a GNU extension) is having this struct as a
member to another struct/union in a position other than the last.
This is still supported by GNU (albeit reliance on this is undocumented
for Xen), but what is concerning here is the following (taken from [1]):
"A structure containing a C99 flexible array member, or a union
containing such a structure, is not the last field of another structure,
for example:
struct flex { int length; char data[]; };
struct mid_flex { int m; struct flex flex_data; int n; };
In the above, accessing a member of the array mid_flex.flex_data.data[]
might have undefined behavior. Compilers do not handle such a case
consistently. Any code relying on this case should be modified to ensure
that flexible array members only end up at the ends of structures.
Please use the warning option -Wflex-array-member-not-at-end to identify
all such cases in the source code and modify them. This extension is now
deprecated."
It looks like this option, and the corresponding deprecation of the
extension, will be available starting from GCC 14, so this might impact
future compiler updates for Xen builds.
Linux is also concerned about this (see [2]), so I think the changes in
struct layout introduced by the series [3] should be reviewed to
determine whether this change was deliberate or happened as a byproduct.
If this is determined not to be a legitimate concern, then this can be
documented as an use of the GNU extension.
See [4] for the findings.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://lkml.org/lkml/2024/4/11/1293
[3]
https://lore.kernel.org/xen-devel/20240418073652.3622828-1-luca.fance...@arm.com/
[4]
https://saas.eclairit.com:3787/fs/var/local/eclair/xen-project.ecdf/xen-project/xen/ECLAIR_normal/staging/ARM64/6713015426/PROJECT.ecd;/by_service/MC3R1.R1.1.html
Thanks,
Nicola
x86:
Failure: 2 regressions found for clean guidelines
service MC3R1.R8.2: (required) Function types shall be in prototype
form with named parameters:
violation: 2
(George just sent a patch to address the regressions of Rule 8.2.)
--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)
