linux-kernel - [PATCH] efi: fix -Wmissing-variable-declarations warning

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Message-ID: <20230829-missingvardecl-efi-v1-1-13d055a55176@google.com>
Date:   Tue, 29 Aug 2023 22:54:17 +0000
From:   Justin Stitt <justinstitt@...gle.com>
To:     Ard Biesheuvel <ardb@...nel.org>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>,
        Nathan Chancellor <nathan@...nel.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Tom Rix <trix@...hat.com>
Cc:     linux-efi@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        linux-kernel@...r.kernel.org, llvm@...ts.linux.dev,
        Justin Stitt <justinstitt@...gle.com>
Subject: [PATCH] efi: fix -Wmissing-variable-declarations warning

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 variables are not externally declared anywhere (AFAIK) so let's
add the static keyword and ensure we follow the ODR.

Link: https://github.com/ClangBuiltLinux/linux/issues/1920
Signed-off-by: Justin Stitt <justinstitt@...gle.com>
---
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);
---
Note: build-tested.
---
 arch/x86/platform/efi/efi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index e9f99c56f3ce..30c354c52ad4 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -931,9 +931,9 @@ EFI_ATTR_SHOW(fw_vendor);
 EFI_ATTR_SHOW(runtime);
 EFI_ATTR_SHOW(config_table);
 
-struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
-struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
-struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
+static struct kobj_attribute efi_attr_fw_vendor = __ATTR_RO(fw_vendor);
+static struct kobj_attribute efi_attr_runtime = __ATTR_RO(runtime);
+static struct kobj_attribute efi_attr_config_table = __ATTR_RO(config_table);
 
 umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
 {

---
base-commit: 706a741595047797872e669b3101429ab8d378ef
change-id: 20230829-missingvardecl-efi-59306aacfed4

Best regards,
--
Justin Stitt <justinstitt@...gle.com>