| Message ID | Z618ILbAR8YAvTkd@kspp |
|---|---|
| State | New |
| Headers | show |
| Series | [next] UAPI: ndctl / acpi: intel: Avoid multiple -Wflex-array-member-not-at-end warnings | expand |
On Thu, Feb 13, 2025 at 02:25:27PM -0800, Alison Schofield wrote: > On Thu, Feb 13, 2025 at 03:29:12PM +1030, 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. > > > > So, in order to avoid ending up with flexible-array members in the > > middle of other structs, we use the `__struct_group()` helper to > > separate the flexible array from the rest of the members in the > > flexible structure. We then use the newly created tagged `struct > > nd_cmd_pkg_hdr` to replace the type of the objects causing trouble > > (`pkg`) in multiple structs. > > > > So, with these changes, fix the following warnings: > > > > 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] > > One sample warning is good. > > How about adding a comment on why the usage of __struct_group() here > means this doesn't break userspace. > > snip > > > diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h > > index 73516e263627..34c11644d5d7 100644 > > --- a/include/uapi/linux/ndctl.h > > +++ b/include/uapi/linux/ndctl.h > > FWIW: In a patch like this where reviewers likely want to see > the header file change first, put it first in the diff. > (git diff.orderfile) TIL about diff.orderfile! :) Just for my own education, what do you have as the contents for your orderfile? Is it just simply: *.h ? > > > > @@ -227,12 +227,15 @@ enum ars_masks { > > */ > > > > struct nd_cmd_pkg { > > - __u64 nd_family; /* family of commands */ > > - __u64 nd_command; > > - __u32 nd_size_in; /* INPUT: size of input args */ > > - __u32 nd_size_out; /* INPUT: size of payload */ > > - __u32 nd_reserved2[9]; /* reserved must be zero */ > > - __u32 nd_fw_size; /* OUTPUT: size fw wants to return */ > > + /* New members MUST be added within the __struct_group() macro below. */ > > + __struct_group(nd_cmd_pkg_hdr, __hdr, /* no attrs */, > > + __u64 nd_family; /* family of commands */ > > + __u64 nd_command; > > + __u32 nd_size_in; /* INPUT: size of input args */ > > + __u32 nd_size_out; /* INPUT: size of payload */ > > + __u32 nd_reserved2[9]; /* reserved must be zero */ > > + __u32 nd_fw_size; /* OUTPUT: size fw wants to return */ > > + ); > > unsigned char nd_payload[]; /* Contents of call */ > > }; Gustavo, any updates on this patch? I'm skimming through patchwork to check on stalled patches...
On Mon, Apr 07, 2025 at 11:11:08AM -0700, Kees Cook wrote: > On Thu, Feb 13, 2025 at 02:25:27PM -0800, Alison Schofield wrote: > > On Thu, Feb 13, 2025 at 03:29:12PM +1030, 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. > > > > > > So, in order to avoid ending up with flexible-array members in the > > > middle of other structs, we use the `__struct_group()` helper to > > > separate the flexible array from the rest of the members in the > > > flexible structure. We then use the newly created tagged `struct > > > nd_cmd_pkg_hdr` to replace the type of the objects causing trouble > > > (`pkg`) in multiple structs. > > > > > > So, with these changes, fix the following warnings: > > > > > > 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] > > > > One sample warning is good. > > > > How about adding a comment on why the usage of __struct_group() here > > means this doesn't break userspace. > > > > snip > > > > > diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h > > > index 73516e263627..34c11644d5d7 100644 > > > --- a/include/uapi/linux/ndctl.h > > > +++ b/include/uapi/linux/ndctl.h > > > > FWIW: In a patch like this where reviewers likely want to see > > the header file change first, put it first in the diff. > > (git diff.orderfile) > > TIL about diff.orderfile! :) Just for my own education, what do you have > as the contents for your orderfile? Is it just simply: > > *.h > > ? I've updated my local environment to use this, to see how well it ends up behaving: Kconfig */Kconfig */Kconfig.* Makefile */Makefile */Makefile.* scripts/* Documentation/* *.h *.S *.c tools/testing/* https://github.com/kees/kernel-tools/commit/909db155b5cd36832d10d7d9932d7b51b46388aa -Kees
diff --git a/drivers/acpi/nfit/intel.c b/drivers/acpi/nfit/intel.c index 3902759abcba..fe561ce0ddec 100644 --- a/drivers/acpi/nfit/intel.c +++ b/drivers/acpi/nfit/intel.c @@ -56,7 +56,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_get_security_state cmd; } nd_cmd = { .pkg = { @@ -121,7 +121,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_freeze_lock cmd; } nd_cmd = { .pkg = { @@ -154,7 +154,7 @@ static int intel_security_change_key(struct nvdimm *nvdimm, NVDIMM_INTEL_SET_MASTER_PASSPHRASE : NVDIMM_INTEL_SET_PASSPHRASE; struct { - struct nd_cmd_pkg pkg; + struct nd_cmd_pkg_hdr pkg; struct nd_intel_set_passphrase cmd; } nd_cmd = { .pkg = { @@ -196,7 +196,7 @@ static int __maybe_unused intel_security_unlock(struct nvdimm *nvdimm, { struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm); struct { - struct nd_cmd_pkg pkg; + struct nd_cmd_pkg_hdr pkg; struct nd_intel_unlock_unit cmd; } nd_cmd = { .pkg = { @@ -235,7 +235,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_disable_passphrase cmd; } nd_cmd = { .pkg = { @@ -278,7 +278,7 @@ static int __maybe_unused intel_security_erase(struct nvdimm *nvdimm, unsigned int cmd = ptype == NVDIMM_MASTER ? NVDIMM_INTEL_MASTER_SECURE_ERASE : NVDIMM_INTEL_SECURE_ERASE; struct { - struct nd_cmd_pkg pkg; + struct nd_cmd_pkg_hdr pkg; struct nd_intel_secure_erase cmd; } nd_cmd = { .pkg = { @@ -319,7 +319,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_query_overwrite cmd; } nd_cmd = { .pkg = { @@ -355,7 +355,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_overwrite cmd; } nd_cmd = { .pkg = { @@ -408,7 +408,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_bus_fw_activate_businfo cmd; } nd_cmd = { .pkg = { @@ -519,7 +519,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_bus_fw_activate cmd; } nd_cmd = { .pkg = { @@ -583,7 +583,7 @@ static int intel_fwa_dimminfo(struct nvdimm *nvdimm, struct nd_intel_fw_activate_dimminfo *info) { struct { - struct nd_cmd_pkg pkg; + struct nd_cmd_pkg_hdr pkg; struct nd_intel_fw_activate_dimminfo cmd; } nd_cmd = { .pkg = { @@ -689,7 +689,7 @@ 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_cmd_pkg_hdr pkg; struct nd_intel_fw_activate_arm cmd; } nd_cmd = { .pkg = { diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h index 73516e263627..34c11644d5d7 100644 --- a/include/uapi/linux/ndctl.h +++ b/include/uapi/linux/ndctl.h @@ -227,12 +227,15 @@ enum ars_masks { */ struct nd_cmd_pkg { - __u64 nd_family; /* family of commands */ - __u64 nd_command; - __u32 nd_size_in; /* INPUT: size of input args */ - __u32 nd_size_out; /* INPUT: size of payload */ - __u32 nd_reserved2[9]; /* reserved must be zero */ - __u32 nd_fw_size; /* OUTPUT: size fw wants to return */ + /* New members MUST be added within the __struct_group() macro below. */ + __struct_group(nd_cmd_pkg_hdr, __hdr, /* no attrs */, + __u64 nd_family; /* family of commands */ + __u64 nd_command; + __u32 nd_size_in; /* INPUT: size of input args */ + __u32 nd_size_out; /* INPUT: size of payload */ + __u32 nd_reserved2[9]; /* reserved must be zero */ + __u32 nd_fw_size; /* OUTPUT: size fw wants to return */ + ); unsigned char nd_payload[]; /* Contents of call */ };
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. So, in order to avoid ending up with flexible-array members in the middle of other structs, we use the `__struct_group()` helper to separate the flexible array from the rest of the members in the flexible structure. We then use the newly created tagged `struct nd_cmd_pkg_hdr` to replace the type of the objects causing trouble (`pkg`) in multiple structs. So, with these changes, fix the following warnings: 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] drivers/acpi/nfit/intel.c:59:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:586:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:522:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:411:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:358:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:322:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:281:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:238:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:199:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:157:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/acpi/nfit/intel.c:124:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/acpi/nfit/intel.c | 24 ++++++++++++------------ include/uapi/linux/ndctl.h | 15 +++++++++------ 2 files changed, 21 insertions(+), 18 deletions(-)