On 2024-04-29 17:58, Jan Beulich wrote:
On 29.04.2024 17:45, Alessandro Zucchelli wrote:
Change #ifdef CONFIG_MEM_ACCESS by OR-ing defined(CONFIG_ARM),
allowing asm/mem_access.h to be included in all ARM build
configurations.
This is to address the violation of MISRA C: 2012 Rule 8.4 which
states:
"A compatible declaration shall be visible when an object or function
with external linkage is defined". Functions p2m_mem_access_check
and p2m_mem_access_check_and_get_page when CONFIG_MEM_ACCESS is not
defined in ARM builds don't have visible declarations in the file
containing their definitions.
Signed-off-by: Alessandro Zucchelli <alessandro.zucche...@bugseng.com>
---
xen/include/xen/mem_access.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/xen/include/xen/mem_access.h
b/xen/include/xen/mem_access.h
index 87d93b31f6..ec0630677d 100644
--- a/xen/include/xen/mem_access.h
+++ b/xen/include/xen/mem_access.h
@@ -33,7 +33,7 @@
*/
struct vm_event_st;
-#ifdef CONFIG_MEM_ACCESS
+#if defined(CONFIG_MEM_ACCESS) || defined(CONFIG_ARM)
#include <asm/mem_access.h>
#endif
This doesn't look quite right. If Arm supports mem-access, why would it
not set MEM_ACCESS=y? Whereas if it's only stubs that Arm supplies,
then
those would better move here, thus eliminating the need for a per-arch
stub header (see what was e.g. done for numa.h). This way RISC-V and
PPC
(and whatever is to come) would then be taken care of as well.
ARM does support mem-access, so I don't think this is akin to the
changes done to handle numa.h.
ARM also allows users to set MEM_ACCESS=n (e.g.
xen/arch/arm/configs/tiny64_defconfig) and builds just fine; however,
the implementation file mem_access.c is compiled unconditionally in
ARM's makefile, hence why the violation was spotted.
This is a bit unusual, so I was also hoping to get some feedback from
mem-access maintainers as to why this discrepancy from x86 exists. I
probably should have also included some ARM maintainers as well, so I'm
going to loop them in now.
An alternative option I think is to make the compilation of arm's
mem_access.c conditional on CONFIG_MEM_ACCESS (as for x86/mm and
common).
--
Alessandro Zucchelli, B.Sc.
Software Engineer, BUGSENG (https://bugseng.com)
