include/linux/efi.h:1101:34: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access

From: kernel test robot <lkp@intel.com>
To: Chester Lin <clin@suse.com>
Cc: kbuild-all@lists.01.org, clang-built-linux@googlegroups.com,
	linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>
Subject: include/linux/efi.h:1101:34: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access
Date: Wed, 10 Mar 2021 13:41:41 +0800	[thread overview]
Message-ID: <202103101334.y2cQeyjh-lkp@intel.com> (raw)

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   05a59d79793d482f628a31753c671f2e92178a21
commit: e1ac4b2406d94eddce8ac2c5ab4235f6075a9602 efi: generalize efi_get_secureboot
date:   4 months ago
config: x86_64-randconfig-a016-20210308 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project cd9a69289c7825d54450cb6829fef2c8e0f1963a)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e1ac4b2406d94eddce8ac2c5ab4235f6075a9602
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout e1ac4b2406d94eddce8ac2c5ab4235f6075a9602
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from drivers/firmware/dmi_scan.c:8:
>> include/linux/efi.h:1101:34: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access [-Walign-mismatch]
           status = get_var(L"SecureBoot", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size,
                                           ^
   include/linux/efi.h:1109:24: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access [-Walign-mismatch]
           get_var(L"SetupMode", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size, &setupmode);
                                 ^
   2 warnings generated.
--
   In file included from init/main.c:50:
>> include/linux/efi.h:1101:34: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access [-Walign-mismatch]
           status = get_var(L"SecureBoot", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size,
                                           ^
   include/linux/efi.h:1109:24: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access [-Walign-mismatch]
           get_var(L"SetupMode", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size, &setupmode);
                                 ^
   init/main.c:766:20: warning: no previous prototype for function 'mem_encrypt_init' [-Wmissing-prototypes]
   void __init __weak mem_encrypt_init(void) { }
                      ^
   init/main.c:766:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void __init __weak mem_encrypt_init(void) { }
   ^
   static 
   3 warnings generated.
--
   In file included from arch/x86/mm/ioremap.c:18:
>> include/linux/efi.h:1101:34: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access [-Walign-mismatch]
           status = get_var(L"SecureBoot", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size,
                                           ^
   include/linux/efi.h:1109:24: warning: passing 1-byte aligned argument to 4-byte aligned parameter 2 of 'get_var' may result in an unaligned pointer access [-Walign-mismatch]
           get_var(L"SetupMode", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size, &setupmode);
                                 ^
   arch/x86/mm/ioremap.c:737:17: warning: no previous prototype for function 'early_memremap_pgprot_adjust' [-Wmissing-prototypes]
   pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
                   ^
   arch/x86/mm/ioremap.c:737:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
   ^
   static 
   3 warnings generated.

vim +/get_var +1101 include/linux/efi.h

  1092	
  1093	static inline
  1094	enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t *get_var)
  1095	{
  1096		u8 secboot, setupmode = 0;
  1097		efi_status_t status;
  1098		unsigned long size;
  1099	
  1100		size = sizeof(secboot);
> 1101		status = get_var(L"SecureBoot", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size,
  1102				 &secboot);
  1103		if (status == EFI_NOT_FOUND)
  1104			return efi_secureboot_mode_disabled;
  1105		if (status != EFI_SUCCESS)
  1106			return efi_secureboot_mode_unknown;
  1107	
  1108		size = sizeof(setupmode);
  1109		get_var(L"SetupMode", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size, &setupmode);
  1110		if (secboot == 0 || setupmode == 1)
  1111			return efi_secureboot_mode_disabled;
  1112		return efi_secureboot_mode_enabled;
  1113	}
  1114	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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