[PATCH v2] misra: add deviation for MISRA C Rule R11.8.

[Alessandro Zucchelli <alessandro.zucchelli@xxxxxxxxxxx>]

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@xxxxxxxxxxx>
---
As this patch introduces a deviation for service MC3A2.R11.8, it
depends on the following patch and shall not be applied prior to its
application.
https://lore.kernel.org/xen-devel/cf13be4779f15620e94b99b3b91f9cb040319989.1733826952.git.alessandro.zucchelli@xxxxxxxxxxx/T/#u

Changes from V1:
The deviation has been refined to specify that every instance of casting away
const-ness is accompanied by a comment explaining why it is safe.
This comment is a requirement that has been incorporated into the text defining
the deviation.
---
 automation/eclair_analysis/ECLAIR/deviations.ecl | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/automation/eclair_analysis/ECLAIR/deviations.ecl 
b/automation/eclair_analysis/ECLAIR/deviations.ecl
index 2f58f29203..c9d06b44f4 100644
--- a/automation/eclair_analysis/ECLAIR/deviations.ecl
+++ b/automation/eclair_analysis/ECLAIR/deviations.ecl
@@ -393,6 +393,12 @@ Fixing this violation would require to increase code 
complexity and lower readab
 
-config=MC3R1.R11.8,reports+={safe,"any_area(any_loc(any_exp(macro(^container_of$))))"}
 -doc_end
 
+-doc_begin="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"
+-config=MC3A2.R11.8,reports+={safe,"any_area(any_loc(text(^.*__hvm_copy.*HVMCOPY_to_guest
 doesn't modify.*$)))"}
+-doc_end
+
 -doc_begin="This construct is used to check if the type is scalar, and for 
this purpose the use of 0 as a null pointer constant is deliberate."
 -config=MC3R1.R11.9,reports+={deliberate, 
"any_area(any_loc(any_exp(macro(^__ACCESS_ONCE$))))"
 }
-- 
2.43.0