MISRA R16.6 states that "Every switch statement shall have at least two
switch-clauses". There are only 3 violations left on x86 (zero on ARM).
One of them is only a violation depending on the kconfig configuration.
So deviate it instead with a SAF comment.
Two of them are deliberate to enable future additions. Deviate them as
such.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
MISRA C Rule 20.7 states:
"Expressions resulting from the expansion of macro parameters shall
be enclosed in parentheses".
Document the behaviour of ECLAIR with respect to the CPP extension
that allows variable macro arguments to be named.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Rule 11.8 states as following: "A cast shall not remove any `const' or
`volatile' qualification from the type pointed to by a pointer".
Function `__hvm_copy' in `xen/arch/x86/hvm/hvm.c' is a double-use
function, where the parameter needs to not be const because it can be
set for write or not. As it was decided a new const-only function will
lead to more developer confusion than it's worth, this violation is
addressed by deviating the function.
All cases of casting away const-ness are accompanied with a comment
explaining why it is safe given the other flags passed in; such comment is used
by the deviation in order to match the appropriate function call.
No functional change.
Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Rename all instances of ECLAIR MISRA C:2012 service identifiers,
identified by the prefix MC3R1, to use the prefix MC3A2, which
refers to MISRA C:2012 Amendment 2 guidelines.
This update is motivated by the need to upgrade ECLAIR GitLab runners
that use the new naming scheme for MISRA C:2012 Amendment 2 guidelines.
Changes to the docs/misra directory are needed in order to keep
comment-based deviation up to date.
Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Currently the identifiers characters limit is arbitrarily set to 40. It
causes a few violations as we have some identifiers longer than 40.
Increase the limit to another rather arbitrary limit of 63. Thanks to
this change, we remove a few violations, getting us one step closer to
marking Rules 5.2 and 5.4 as clean.
The ECLAIR configuration is already using 63, so this change matches
the rules.rst documentation with the ECLAIR behavior.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Reviewed-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The Xen community is already informally following both rules. Let's make
it explicit. Both rules have zero violations, only cautions. While we
want to go down to zero cautions in time, adding both rules to rules.rst
enables us to immediately make both rules gating in the ECLAIR job part
of gitlab-ci.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
MISRA C:2012 Rule 20.7 states that "Expressions resulting from the
expansion of macro parameters shall be enclosed in parentheses".
The rational of the rule is that if a macro argument expands to an
expression, there may be problems related to operator precedence, e.g.,
define M(A, B) A * B
M(1+1, 2+2) will expand to: 1+1 * 2+2
Update ECLAIR configuration to tag as 'safe' the expansions of macro
arguments surrounded tokens '{', '}' and ';', since in their presence
problems related to operator precedence can not occur.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
MISRA C Rule 18.2 states: "Subtraction between pointers shall
only be applied to pointers that address elements of the same array".
Subtractions between pointer where at least one symbol is a
symbol defined by the linker are safe and thus deviated, because
the compiler cannot exploit the undefined behaviour that would
arise from violating the rules in this case.
To create an ECLAIR configuration that contains the list of
linker-defined symbols, the script "linker-symbols.sh" is used
after a build of xen (without static analysis) is performed.
The generated file "linker_symbols.ecl" is then used as part of the
static analysis configuration.
Additional changes to the ECLAIR integration are:
- perform a build of xen without static analysis during prepare.sh
- run the scripts to generated ECL configuration during the prepare.sh,
rather than analysis.sh
- export ECLAIR_PROJECT_ROOT earlier, to allow such generation
Additionally, the macro page_to_mfn performs a subtraction that is safe,
so its uses are deviated.
No functional changes.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Prior to bd1664db7b ("xen/bitops: Introduce a multiple_bits_set() helper")
the definition of {COMPILE,RUNTIME}_CHECK was fully compliant with respect
to MISRA C Rule 20.7:
"Expressions resulting from the expansion of macro parameters shall be
enclosed in parentheses."
However, to allow testing function-like macros, parentheses on the "fn"
parameter were removed and thus new violations of the rule have been
introduced. Given the usefulness of this functionality,
it is deemed ok to deviate these two macros for this rule, because
their scope of (direct) usage is limited to just the file where they
are defined, and the possibility of misuses is unlikely.
No functional change.
Fixes: bd1664db7b ("xen/bitops: Introduce a multiple_bits_set() helper")
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Update ECLAIR configuration to deviate more cases where an
unintentional fallthrough cannot happen.
Tag Rule 16.3 as clean for arm.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add MISRA C rules 13.2 and 18.2 to rules.rst. Both rules have zero
violations reported by Eclair but they have some cautions. We accept
both rules and for now we'll enable scanning for them in Eclair but only
violations will cause the Gitlab CI job to fail (cautions will not.)
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
In practice, we are already following R18.6 and we have zero violations
reported by ECLAIR (there are some cautions being reported.)
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
As discussed during the last MISRA C meeting, add Rule 12.2 to the list
of MISRA C rules we accept, together with an explanation that we use gcc
-fsanitize=undefined to check for violations.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
This patch adds a bunch of rules to rules.rst that are uncontroversial
and have zero violations in Xen. As such, they have been approved for
adoption.
All the ones that regard the standard library have the link to the
existing footnote in the notes.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Add deviation comments to address violations of
MISRA C:2012 Directive 4.10 ("Precautions shall be taken in order
to prevent the contents of a header file being included more than
once").
Inclusion guards must appear at the beginning of the headers
(comments are permitted anywhere).
This patch adds deviation comments using the format specified
in docs/misra/safe.json for headers with just the direct
inclusion guard before the inclusion guard since they are
safe and not supposed to comply with the directive.
Note that with SAF-10-safe in place, failures to have proper guards later
in the header files will not be reported
Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com>
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
This patch modifies deviations for Directive 4.10:
"Precautions shall be taken in order to prevent the contents of
a header file being included more than once"
This patch avoids the file-based deviation for empty headers, and
replaces it with a comment-based one using the format specified in
docs/misra/safe.json.
Generated headers are not generally safe against multi-inclusions,
whether a header is safe depends on the nature of the generated code
in the header. For that reason, this patch drops the deviation for
generated headers.
Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com>
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Some headers, under specific circumstances (documented in a comment at
the beginning of the file), explicitly do not have strict inclusion
guards: the caller is responsible for including them correctly.
These files are not supposed to comply with Directive 4.10:
"Precautions shall be taken in order to prevent the contents of a header
file being included more than once"
This patch adds deviation cooments for headers that avoid guards.
Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Signed-off-by: Alessandro Zucchelli <alessandro.zucchelli@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Update ECLAIR configuration to take into account the deviations
agreed during the MISRA meetings.
While doing this, remove the obsolete "Set [123]" comments.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
MISRA C Rule 20.7 states: "Expressions resulting from the expansion
of macro parameters shall be enclosed in parentheses".
The local helpers GRP2 and XADD in the x86 emulator use their first
argument as the constant expression for a case label. This pattern
is deviated project-wide, because it is very unlikely to induce
developer confusion and result in the wrong control flow being
carried out.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
MISRA C Rule 20.7 states: "Expressions resulting from the expansion
of macro parameters shall be enclosed in parentheses".
The helper macro bitmap_switch has parameters that cannot be parenthesized
in order to comply with the rule, as that would break its functionality.
Moreover, the risk of misuse due developer confusion is deemed not
substantial enough to warrant a more involved refactor, thus the macro
is deviated for this rule.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Rule 13.6 states that "The operand of the `sizeof' operator shall not
contain any expression which has potential side effects".
Define service B.UNEVALEFF as an extension of Rule 13.6 to
check for unevalued side effects also for typeof and alignof operators.
Update ECLAIR configuration to deviate uses of BUILD_BUG_ON and
alternative_v?call[0-9] for both Rule 13.6 and B.UNEVALEFF.
Add service B.UNEVALEFF to the accepted.ecl guidelines to check
"violations" in the weekly analysis.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>
MISRA C Rule 5.5 states that "Identifiers shall be distinct from macro
names".
Update ECLAIR configuration to deviate:
- macros expanding to their own name;
- clashes between macros and non-callable entities;
- clashes related to the selection of specific implementations of string
handling functions.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
MISRA C Rule 20.12 states: "A macro parameter used as an operand to
the # or ## operators, which is itself subject to further macro replacement,
shall only be used as an operand to these operators".
In this case, builds where CONFIG_COMPAT=y the fpu_ctxt
macro is used both as a regular macro argument and as an operand for
stringification in the expansion of CHECK_FIELD_.
This is deviated using a SAF-x-safe comment.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
These files are used when debugging Xen, and are not meant to comply
with MISRA rules at the moment.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
The count_args_ macro violates Rule 20.7, but it can't be made
compliant with Rule 20.7 without breaking its functionality. Since
it's very unlikely for this macro to be misused, it is deviated.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
These rules are concerned with the use of facilities provided by the
C Standard Library (qsort, bsearch for rule 21.9, and those provided
by <time.h> for rule 21.10).
Xen provides in its source code its own implementation of some of these
functions and macros, therefore a justification is provided for allowing
uses of these functions in the project.
The rules are also marked as clean as a consequence.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Update ECLAIR configuration to take into account the deviations
agreed during MISRA meetings.
Amend an existing entry of Rule 14.4 in deviations-rst:
it is not a project-wide deviation.
Tag Rule 14.4 as clean for arm.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
MISRA C:2012 Rule 16.4 states that "Every switch statement shall have a
default label".
Update ECLAIR configuration to take into account the deviations
agreed during MISRA meetings.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Add a section for terms and definitions used by MISRA but expressed
in terms of the C specification.
Add a definition of "switch clause" to the newly-introduced section.
Link the first use of the term "switch clause" in the document to its
definition.
Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
MISRA C Rule 16.2 states:
"A switch label shall only be used when the most closely-enclosing
compound statement is the body of a switch statement".
The PROGRESS_VCPU local helper specifies a case that is directly
inside the compound statement of a for loop, hence violating the rule.
To avoid this, the construct is deviated with a text-based deviation.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
MISRA C Rule 16.2 states:
"A switch label shall only be used when the most closely-enclosing
compound statement is the body of a switch statement".
Since complying with this rule of the x86 emulator would lead to
a lot of code duplication, it is deemed better to exempt those
files for this guideline.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Xen makes assumptions about the size of integer types on the various
architectures. Document these assumptions.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Bertrand Marquis <bertrand.marquis@arm.com>
The Xen community wants to avoid using variadic functions except for
specific circumstances where it feels appropriate by strict code review.
Functions hypercall_create_continuation and hypercall_xlat_continuation
are internal helper functions made to break long running hypercalls into
multiple calls. They take a variable number of arguments depending on the
original hypercall they are trying to continue.
Add SAF deviations for the aforementioned functions.
Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
The Xen community wants to avoid using variadic functions except for
specific circumstances where it feels appropriate by strict code review.
Add deviation for printf()-like functions.
Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
These deviations deal with the following cases:
- macro arguments used directly as initializer list arguments;
- uses of the __config_enabled macro, that can't be brought
into compliance without breaking its functionality;
- exclude files that are out of scope (efi headers and cpu_idle);
- uses of alternative_{call,vcall}[0-9] macros.
The existing configuration for R20.7 is reordered so that it matches the
cases listed in its documentation comment.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
As agreed during MISRA C meetings, add Rule 13.6 to rules.rst, with a
note about extending the rule to alignof and typeof. Also take the
opportunity to remove an older and out of order entry for the same rule.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Update ECLAIR configuration of MISRA C:2012 Rule 8.3 to deviate
violations involving parameter name "unused" (with an optional
numeric suffix): it makes explicit the intention of not using such
parameter within the function.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Rule 20.4 states: "A macro shall not be defined with the same name
as a keyword".
Defining this macro with the same name as the inline keyword
allows for additionally checking that out-of-lined static inline
functions end up in the correct section while minimizing churn and
has a positive impact on the overall safety. See [1] for additional
context on the motivation of this deviation.
No functional change.
[1] https://lore.kernel.org/xen-devel/adaa6d55-266d-4df8-8967-9340080d17e4@citrix.com/
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Certain macros are allowed to violate the Rule, since their meaning and
intended use is well-known to all Xen developers.
Variadic macros that rely on the GCC extension for removing a trailing
comma when token pasting the variable argument are similarly
well-understood and therefore allowed.
No functional change.
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Update ECLAIR configuration to take into account the deviations
agreed during MISRA meetings.
Signed-off-by: Federico Serafini <federico.serafini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Commit 4cac80e226 broke the CI cppcheck jobs by adding an entry for
a rule 20.12 with "Severity" and "Summary" fields placed in reverse order.
This leads to an error as reported by convert_misra_doc.py:
No summary for rule 20.12
Fixes: 4cac80e226 ("docs/misra/rules.rst: add rule 16.6 and 20.12")
Signed-off-by: Michal Orzel <michal.orzel@amd.com>
Reviewed-by: Luca Fancellu <luca.fancellu@arm.com>
Stefano Stabellini