On Wed, Aug 30, 2023 at 10:54 AM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > On Wed, 30 Aug 2023 at 19:51, Justin Stitt <justinstitt@xxxxxxxxxx> wrote: > > > > When building x86/defconfig with Clang-18 I encounter the following warnings: > > | arch/x86/platform/efi/efi.c:934:23: warning: no previous extern declaration for non-static variable 'efi_attr_fw_vendor' [-Wmissing-variable-declarations] > > | 934 | struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor); > > | arch/x86/platform/efi/efi.c:935:23: warning: no previous extern declaration for non-static variable 'efi_attr_runtime' [-Wmissing-variable-declarations] > > | 935 | struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime); > > | arch/x86/platform/efi/efi.c:936:23: warning: no previous extern declaration for non-static variable 'efi_attr_config_table' [-Wmissing-variable-declarations] > > | 936 | struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table); > > > > These symbols are declared extern in drivers/firmware/efi/efi.c. Move > > the declarations to linux/efi.h to resolve these warnings. > > > > Also, trim a trailing space from efi_set_variable_t typedef. > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/1920 > > Suggested-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > > Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> > > Thanks, I'll take this as a fix. > > > --- > > Changes in v2: > > - Don't use static. Instead move symbols to header file (thanks Ard) > > - Remove duplicated warnings output from b4 (thanks Ard) > > - Link to v1: https://lore.kernel.org/r/20230829-missingvardecl-efi-v1-1-13d055a55176@xxxxxxxxxx > > --- > > Note: build-tested. > > > > Also, a question: Why does the compiler warn at all? The extern > > declarations _do_ exist as Ard points out [1]. > > > > [1]: https://lore.kernel.org/all/CAMj1kXE_xs+wWno4G4U+6CFCOwO7JWcmNv4et5=W=ZRrQatWnQ@xxxxxxxxxxxxxx/ > > Those declarations are not observed by the compiler when building .c > files other than drivers/firmware/efi/efi.c, so they essentially don't > exist when compiling arch/x86/platform/efi/efi.c. I see, the linker is resolving these later then? > > > > --- > > drivers/firmware/efi/efi.c | 3 --- > > include/linux/efi.h | 6 +++++- > > 2 files changed, 5 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c > > index 1599f1176842..7b4e59ccf09e 100644 > > --- a/drivers/firmware/efi/efi.c > > +++ b/drivers/firmware/efi/efi.c > > @@ -161,9 +161,6 @@ static ssize_t fw_platform_size_show(struct kobject *kobj, > > return sprintf(buf, "%d\n", efi_enabled(EFI_64BIT) ? 64 : 32); > > } > > > > -extern __weak struct kobj_attribute efi_attr_fw_vendor; > > -extern __weak struct kobj_attribute efi_attr_runtime; > > -extern __weak struct kobj_attribute efi_attr_config_table; > > static struct kobj_attribute efi_attr_fw_platform_size = > > __ATTR_RO(fw_platform_size); > > > > diff --git a/include/linux/efi.h b/include/linux/efi.h > > index ab088c662e88..32f7ca60b0e9 100644 > > --- a/include/linux/efi.h > > +++ b/include/linux/efi.h > > @@ -287,7 +287,7 @@ typedef efi_status_t efi_get_variable_t (efi_char16_t *name, efi_guid_t *vendor, > > unsigned long *data_size, void *data); > > typedef efi_status_t efi_get_next_variable_t (unsigned long *name_size, efi_char16_t *name, > > efi_guid_t *vendor); > > -typedef efi_status_t efi_set_variable_t (efi_char16_t *name, efi_guid_t *vendor, > > +typedef efi_status_t efi_set_variable_t (efi_char16_t *name, efi_guid_t *vendor, > > u32 attr, unsigned long data_size, > > void *data); > > typedef efi_status_t efi_get_next_high_mono_count_t (u32 *count); > > @@ -632,6 +632,10 @@ typedef struct { > > > > extern unsigned long __ro_after_init efi_rng_seed; /* RNG Seed table */ > > > > +extern __weak struct kobj_attribute efi_attr_fw_vendor; > > +extern __weak struct kobj_attribute efi_attr_runtime; > > +extern __weak struct kobj_attribute efi_attr_config_table; > > + > > /* > > * All runtime access to EFI goes through this structure: > > */ > > > > --- > > base-commit: 706a741595047797872e669b3101429ab8d378ef > > change-id: 20230829-missingvardecl-efi-59306aacfed4 > > > > Best regards, > > -- > > Justin Stitt <justinstitt@xxxxxxxxxx> > >
