On Wed, Jun 25, 2025 at 03:42:16PM -0600, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
>
> Use the new TRAILING_OVERLAP() helper to fix a dozen instances of
> the following type of warning:
>
> drivers/acpi/nfit/intel.c:692:35: warning: structure containing a flexible
> array member is not at the end of another structure
> [-Wflex-array-member-not-at-end]
>
> Acked-by: Dan Williams <[email protected]>
> Tested-by: Dan Williams <[email protected]>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
> This patch should go through:
> https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/
> (for-next/hardening)
>
> Changes in v4:
> - Use the new TRAILING_OVERLAP() helper.
>
> Changes in v3:
> - Use union instead of DEFINE_RAW_FLEX().
> - Link: https://lore.kernel.org/linux-hardening/aEneid7gdAZr1_kR@kspp/
>
> Changes in v2:
> - Use DEFINE_RAW_FLEX() instead of __struct_group().
> - Link: https://lore.kernel.org/linux-hardening/Z-QpUcxFCRByYcTA@kspp/
>
> v1:
> - Link: https://lore.kernel.org/linux-hardening/Z618ILbAR8YAvTkd@kspp/
>
> drivers/acpi/nfit/intel.c | 84 +++++++++++++++++----------------------
> 1 file changed, 36 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/acpi/nfit/intel.c b/drivers/acpi/nfit/intel.c
> index 3902759abcba..d0b72e906428 100644
> --- a/drivers/acpi/nfit/intel.c
> +++ b/drivers/acpi/nfit/intel.c
> @@ -55,10 +55,9 @@ static unsigned long intel_security_flags(struct nvdimm
> *nvdimm,
> {
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> unsigned long security_flags = 0;
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_get_security_state cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_get_security_state cmd;
> + ) nd_cmd = {
If you wanted, these could be even further minimized to this, leaving
the trailing object indentation unchanged:
- struct {
- struct nd_cmd_pkg pkg;
+ TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
struct nd_intel_get_security_state cmd;
- } nd_cmd = {
+ ) nd_cmd = {
--
Kees Cook
