From: <dan.j.williams@intel.com>
To: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
Kees Cook <kees@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
Ira Weiny <ira.weiny@intel.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Len Brown <lenb@kernel.org>
Cc: <nvdimm@lists.linux.dev>, <linux-acpi@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
<linux-hardening@vger.kernel.org>
Subject: Re: [PATCH v4][for-next/hardening] acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings
Date: Wed, 25 Jun 2025 18:03:13 -0700 [thread overview]
Message-ID: <685c9c515ffd8_1608bd1004d@dwillia2-xfh.jf.intel.com.notmuch> (raw)
In-Reply-To: <aFxtOLs6Yv_uzgt4@kspp>
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 <dan.j.williams@intel.com>
> Tested-by: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> 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 = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_GET_SECURITY_STATE,
> .nd_family = NVDIMM_FAMILY_INTEL,
> @@ -120,10 +119,9 @@ static unsigned long intel_security_flags(struct nvdimm *nvdimm,
> static int intel_security_freeze(struct nvdimm *nvdimm)
> {
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_freeze_lock cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_freeze_lock cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_FREEZE_LOCK,
> .nd_family = NVDIMM_FAMILY_INTEL,
> @@ -153,10 +151,9 @@ static int intel_security_change_key(struct nvdimm *nvdimm,
> unsigned int cmd = ptype == NVDIMM_MASTER ?
> NVDIMM_INTEL_SET_MASTER_PASSPHRASE :
> NVDIMM_INTEL_SET_PASSPHRASE;
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_set_passphrase cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_set_passphrase cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_family = NVDIMM_FAMILY_INTEL,
> .nd_size_in = ND_INTEL_PASSPHRASE_SIZE * 2,
> @@ -195,10 +192,9 @@ static int __maybe_unused intel_security_unlock(struct nvdimm *nvdimm,
> const struct nvdimm_key_data *key_data)
> {
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_unlock_unit cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_unlock_unit cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_UNLOCK_UNIT,
> .nd_family = NVDIMM_FAMILY_INTEL,
> @@ -234,10 +230,9 @@ static int intel_security_disable(struct nvdimm *nvdimm,
> {
> int rc;
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_disable_passphrase cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_disable_passphrase cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_DISABLE_PASSPHRASE,
> .nd_family = NVDIMM_FAMILY_INTEL,
> @@ -277,10 +272,9 @@ static int __maybe_unused intel_security_erase(struct nvdimm *nvdimm,
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> unsigned int cmd = ptype == NVDIMM_MASTER ?
> NVDIMM_INTEL_MASTER_SECURE_ERASE : NVDIMM_INTEL_SECURE_ERASE;
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_secure_erase cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_secure_erase cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_family = NVDIMM_FAMILY_INTEL,
> .nd_size_in = ND_INTEL_PASSPHRASE_SIZE,
> @@ -318,10 +312,9 @@ static int __maybe_unused intel_security_query_overwrite(struct nvdimm *nvdimm)
> {
> int rc;
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_query_overwrite cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_query_overwrite cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_QUERY_OVERWRITE,
> .nd_family = NVDIMM_FAMILY_INTEL,
> @@ -354,10 +347,9 @@ static int __maybe_unused intel_security_overwrite(struct nvdimm *nvdimm,
> {
> int rc;
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_overwrite cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_overwrite cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_OVERWRITE,
> .nd_family = NVDIMM_FAMILY_INTEL,
> @@ -407,10 +399,9 @@ const struct nvdimm_security_ops *intel_security_ops = &__intel_security_ops;
> static int intel_bus_fwa_businfo(struct nvdimm_bus_descriptor *nd_desc,
> struct nd_intel_bus_fw_activate_businfo *info)
> {
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_bus_fw_activate_businfo cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_bus_fw_activate_businfo cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_BUS_INTEL_FW_ACTIVATE_BUSINFO,
> .nd_family = NVDIMM_BUS_FAMILY_INTEL,
> @@ -518,10 +509,9 @@ static enum nvdimm_fwa_capability intel_bus_fwa_capability(
> static int intel_bus_fwa_activate(struct nvdimm_bus_descriptor *nd_desc)
> {
> struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_bus_fw_activate cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_bus_fw_activate cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_BUS_INTEL_FW_ACTIVATE,
> .nd_family = NVDIMM_BUS_FAMILY_INTEL,
> @@ -582,10 +572,9 @@ const struct nvdimm_bus_fw_ops *intel_bus_fw_ops = &__intel_bus_fw_ops;
> static int intel_fwa_dimminfo(struct nvdimm *nvdimm,
> struct nd_intel_fw_activate_dimminfo *info)
> {
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_fw_activate_dimminfo cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_fw_activate_dimminfo cmd;
> + ) nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_FW_ACTIVATE_DIMMINFO,
> .nd_family = NVDIMM_FAMILY_INTEL,
> @@ -688,10 +677,9 @@ static int intel_fwa_arm(struct nvdimm *nvdimm, enum nvdimm_fwa_trigger arm)
> {
> struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
> struct acpi_nfit_desc *acpi_desc = nfit_mem->acpi_desc;
> - struct {
> - struct nd_cmd_pkg pkg;
> - struct nd_intel_fw_activate_arm cmd;
> - } nd_cmd = {
> + TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
> + struct nd_intel_fw_activate_arm cmd;
> + ) nd_cmd = {
The regression is here.
> .pkg = {
> .nd_command = NVDIMM_INTEL_FW_ACTIVATE_ARM,
> .nd_family = NVDIMM_FAMILY_INTEL,
So the full context is this:
union {
struct nd_cmd_pkg pkg;
struct {
u8 _offset_to_fam[offsetof(struct nd_cmd_pkg, nd_payload)];
struct nd_intel_fw_activate_arm cmd;
};
} nd_cmd = {
.pkg = {
.nd_command = NVDIMM_INTEL_FW_ACTIVATE_ARM,
.nd_family = NVDIMM_FAMILY_INTEL,
.nd_size_in = sizeof(nd_cmd.cmd.activate_arm),
.nd_size_out =
sizeof(struct nd_intel_fw_activate_arm),
.nd_fw_size =
sizeof(struct nd_intel_fw_activate_arm),
},
.cmd = {
.activate_arm = arm == NVDIMM_FWA_ARM
? ND_INTEL_DIMM_FWA_ARM
: ND_INTEL_DIMM_FWA_DISARM,
},
};
The problem is that the designated initialization of .cmd zeroes out the
.pkg portion of the union. This incremental change works, and with it
folded you can keep my Acked-by and Tested-by on v5.
You might want to remind folks about this designated initializer trap in
the kdoc for TRAILING_OVERLAP().
-- 8< --
diff --git a/drivers/acpi/nfit/intel.c b/drivers/acpi/nfit/intel.c
index c88647428715..c63284ce9a87 100644
--- a/drivers/acpi/nfit/intel.c
+++ b/drivers/acpi/nfit/intel.c
@@ -511,29 +511,27 @@ static int intel_bus_fwa_activate(struct nvdimm_bus_descriptor *nd_desc)
struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
struct nd_intel_bus_fw_activate cmd;
- ) nd_cmd = {
- .pkg = {
- .nd_command = NVDIMM_BUS_INTEL_FW_ACTIVATE,
- .nd_family = NVDIMM_BUS_FAMILY_INTEL,
- .nd_size_in = sizeof(nd_cmd.cmd.iodev_state),
- .nd_size_out =
- sizeof(struct nd_intel_bus_fw_activate),
- .nd_fw_size =
- sizeof(struct nd_intel_bus_fw_activate),
- },
+ ) nd_cmd;
+ int rc;
+
+ nd_cmd.pkg = (struct nd_cmd_pkg) {
+ .nd_command = NVDIMM_BUS_INTEL_FW_ACTIVATE,
+ .nd_family = NVDIMM_BUS_FAMILY_INTEL,
+ .nd_size_in = sizeof(nd_cmd.cmd.iodev_state),
+ .nd_size_out = sizeof(struct nd_intel_bus_fw_activate),
+ .nd_fw_size = sizeof(struct nd_intel_bus_fw_activate),
+ };
+ nd_cmd.cmd = (struct nd_intel_bus_fw_activate) {
/*
* Even though activate is run from a suspended context,
* for safety, still ask platform firmware to force
* quiesce devices by default. Let a module
* parameter override that policy.
*/
- .cmd = {
- .iodev_state = acpi_desc->fwa_noidle
- ? ND_INTEL_BUS_FWA_IODEV_OS_IDLE
- : ND_INTEL_BUS_FWA_IODEV_FORCE_IDLE,
- },
+ .iodev_state = acpi_desc->fwa_noidle ?
+ ND_INTEL_BUS_FWA_IODEV_OS_IDLE :
+ ND_INTEL_BUS_FWA_IODEV_FORCE_IDLE,
};
- int rc;
switch (intel_bus_fwa_state(nd_desc)) {
case NVDIMM_FWA_ARMED:
@@ -679,24 +677,22 @@ static int intel_fwa_arm(struct nvdimm *nvdimm, enum nvdimm_fwa_trigger arm)
struct acpi_nfit_desc *acpi_desc = nfit_mem->acpi_desc;
TRAILING_OVERLAP(struct nd_cmd_pkg, pkg, nd_payload,
struct nd_intel_fw_activate_arm cmd;
- ) nd_cmd = {
- .pkg = {
- .nd_command = NVDIMM_INTEL_FW_ACTIVATE_ARM,
- .nd_family = NVDIMM_FAMILY_INTEL,
- .nd_size_in = sizeof(nd_cmd.cmd.activate_arm),
- .nd_size_out =
- sizeof(struct nd_intel_fw_activate_arm),
- .nd_fw_size =
- sizeof(struct nd_intel_fw_activate_arm),
- },
- .cmd = {
- .activate_arm = arm == NVDIMM_FWA_ARM
- ? ND_INTEL_DIMM_FWA_ARM
- : ND_INTEL_DIMM_FWA_DISARM,
- },
- };
+ ) nd_cmd;
int rc;
+ nd_cmd.pkg = (struct nd_cmd_pkg) {
+ .nd_command = NVDIMM_INTEL_FW_ACTIVATE_ARM,
+ .nd_family = NVDIMM_FAMILY_INTEL,
+ .nd_size_in = sizeof(nd_cmd.cmd.activate_arm),
+ .nd_size_out = sizeof(struct nd_intel_fw_activate_arm),
+ .nd_fw_size = sizeof(struct nd_intel_fw_activate_arm),
+ };
+ nd_cmd.cmd = (struct nd_intel_fw_activate_arm) {
+ .activate_arm = arm == NVDIMM_FWA_ARM ?
+ ND_INTEL_DIMM_FWA_ARM :
+ ND_INTEL_DIMM_FWA_DISARM,
+ };
+
switch (intel_fwa_state(nvdimm)) {
case NVDIMM_FWA_INVALID:
return -ENXIO;
next prev parent reply other threads:[~2025-06-26 1:03 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-25 21:42 [PATCH v4][for-next/hardening] acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings Gustavo A. R. Silva
2025-06-26 0:17 ` dan.j.williams
2025-06-26 1:03 ` dan.j.williams [this message]
2025-06-27 15:52 ` Kees Cook
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