On 2024-12-19 09:49, Jan Beulich wrote:
On 18.12.2024 15:25, Alessandro Zucchelli wrote:
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.zucche...@bugseng.com>
---
--- 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$))))"}
-doc_end
+-doc_begin="Function __hvm_copy in xen/arch/x86/hvm/hvm.c is a
double-use
+function, where the parameter needs to not be const because it can be
set for
+write or not"
+-config=MC3A2.R11.8,reports+={safe,"any_area(any_loc(text(^.*__hvm_copy.*HVMCOPY_to_guest
doesn't modify.*$)))"}
This is probably good enough for now, yet still: It constrains
re-formatting
that we may want to do on such function calls. Personally I'd consider
it
entirely unexpected if I ended up (re)introducing a violation just by
re-
formatting one of those function calls to
return __hvm_copy(
(void *)buf /* HVMCOPY_to_guest doesn't modify */,
addr, size, current, HVMCOPY_to_guest | HVMCOPY_linear,
PFEC_page_present | PFEC_write_access | pfec, pfinfo);
yet aiui the pattern above would have this effect (I don't think .*
matches
newlines; instead I expect such regex-es to be applied to individual
lines
only). Thoughts anyone?
Hi Jan,
we can simply drop the "__hvm_copy" part from the regex. The regex can
be made multiline, or alternatively we can apply the search to a range
of lines. By default it searches on the same location mentioned by the
report, which in this case is the line containing __hvm_copy (range
defaults to 0..0). However I would leave it either as is or without the
__hvm_copy prefix.
--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)
