Re: [PATCH v3 2/3] x86/modules: Increase randomization for modules

From: kbuild test robot <lkp@intel.com>
To: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: kbuild-all@01.org, tglx@linutronix.de, mingo@redhat.com,
	hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, kernel-hardening@lists.openwall.com,
	daniel@iogearbox.net, jannh@google.com, keescook@chromium.org,
	kristen@linux.intel.com, dave.hansen@intel.com,
	arjan@linux.intel.com,
	Rick Edgecombe <rick.p.edgecombe@intel.com>
Subject: Re: [PATCH v3 2/3] x86/modules: Increase randomization for modules
Date: Thu, 16 Aug 2018 15:15:02 +0800	[thread overview]
Message-ID: <201808161516.1Wjg2efl%fengguang.wu@intel.com> (raw)
In-Reply-To: <1534365020-18943-3-git-send-email-rick.p.edgecombe@intel.com>

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Hi Rick,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on v4.18 next-20180815]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Rick-Edgecombe/KASLR-feature-to-randomize-each-loadable-module/20180816-120750
config: um-x86_64_defconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=um SUBARCH=x86_64

Note: the linux-review/Rick-Edgecombe/KASLR-feature-to-randomize-each-loadable-module/20180816-120750 HEAD 7eff11788897c8579f53bc7043f854794dbad25f builds fine.
      It only hurts bisectibility.

All error/warnings (new ones prefixed by >>):

   arch/x86/um/../kernel/module.c: In function 'kaslr_randomize_each_module':
>> arch/x86/um/../kernel/module.c:53:9: error: implicit declaration of function 'kaslr_enabled' [-Werror=implicit-function-declaration]
     return kaslr_enabled()
            ^~~~~~~~~~~~~
   arch/x86/um/../kernel/module.c: In function 'get_modules_rand_len':
>> arch/x86/um/../kernel/module.c:68:9: error: 'MODULES_RAND_LEN' undeclared (first use in this function); did you mean 'MODULE_NAME_LEN'?
     return MODULES_RAND_LEN;
            ^~~~~~~~~~~~~~~~
            MODULE_NAME_LEN
   arch/x86/um/../kernel/module.c:68:9: note: each undeclared identifier is reported only once for each function it appears in
>> arch/x86/um/../kernel/module.c:69:1: warning: control reaches end of non-void function [-Wreturn-type]
    }
    ^
   cc1: some warnings being treated as errors

vim +/kaslr_enabled +53 arch/x86/um/../kernel/module.c

    50	
    51	static inline int kaslr_randomize_each_module(void)
    52	{
  > 53		return kaslr_enabled()
    54				&& IS_ENABLED(CONFIG_RANDOMIZE_BASE)
    55				&& IS_ENABLED(CONFIG_X86_64);
    56	}
    57	
    58	static inline int kaslr_randomize_base(void)
    59	{
    60		return kaslr_enabled()
    61				&& IS_ENABLED(CONFIG_RANDOMIZE_BASE)
    62				&& !IS_ENABLED(CONFIG_X86_64);
    63	}
    64	
    65	#ifdef CONFIG_X86_64
    66	static inline const unsigned long get_modules_rand_len(void)
    67	{
  > 68		return MODULES_RAND_LEN;
  > 69	}
    70	#else
    71	static inline const unsigned long get_modules_rand_len(void)
    72	{
    73		BUILD_BUG();
    74		return 0;
    75	}
    76	#endif
    77	

---
0-DAY kernel test infrastructure                Open Source Technology Center
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