On Arm32, when CONFIG_PHYS_ADDR_T_32 is set, a build failure is observed:
common/device-tree/bootfdt.c: In function 'build_assertions':
./include/xen/macros.h:47:31: error: static assertion failed: "!(alignof(struct
membanks) != 8)"
47 | #define BUILD_BUG_ON(cond) ({ _Static_assert(!(cond), "!(" #cond ")");
})
| ^~~~~~~~~~~~~~
common/device-tree/bootfdt.c:31:5: note: in expansion of macro 'BUILD_BUG_ON'
31 | BUILD_BUG_ON(alignof(struct membanks) != 8);
When CONFIG_PHYS_ADDR_T_32 is set, paddr_t is defined as unsigned long,
therefore the struct membanks alignment is 4B and not 8B. The check is
there to ensure the struct membanks and struct membank, which is a
member of the former, are equally aligned. Therefore modify the check to
compare alignments obtained via alignof not to rely on hardcoded
values.
Fixes: 2209c1e35b47 ("xen/arm: Introduce a generic way to access memory bank
structures")
Signed-off-by: Michal Orzel <michal.or...@amd.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kuroc...@gmail.com>
---
Changes in v2:
- modify the check to test against alignment of struct membank
---
xen/common/device-tree/bootfdt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/xen/common/device-tree/bootfdt.c b/xen/common/device-tree/bootfdt.c
index 47386d4fffea..529c91e603ab 100644
--- a/xen/common/device-tree/bootfdt.c
+++ b/xen/common/device-tree/bootfdt.c
@@ -27,8 +27,8 @@ static void __init __maybe_unused build_assertions(void)
*/
BUILD_BUG_ON((offsetof(struct membanks, bank) !=
offsetof(struct meminfo, bank)));
- /* Ensure "struct membanks" is 8-byte aligned */
- BUILD_BUG_ON(alignof(struct membanks) != 8);
+ /* Ensure "struct membanks" and "struct membank" are equally aligned */
+ BUILD_BUG_ON(alignof(struct membanks) != alignof(struct membank));
}
static bool __init device_tree_node_is_available(const void *fdt, int node)
--
2.25.1
