linux-kernel - [deller-parisc:for-next-maybe 1/1] mm/usercopy.c:134:2: warning: this 'if' clause does not guard...

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Date:   Wed, 1 Dec 2021 11:11:46 +0800
From:   kernel test robot <lkp@...el.com>
To:     Helge Deller <deller@....de>
Cc:     kbuild-all@...ts.01.org, linux-kernel@...r.kernel.org
Subject: [deller-parisc:for-next-maybe 1/1] mm/usercopy.c:134:2: warning:
 this 'if' clause does not guard...

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git for-next-maybe
head:   4d7b3620412d727e09bf0eef942be42da363260d
commit: 4d7b3620412d727e09bf0eef942be42da363260d [1/1] usercopy: Do not fail if memory is from the init section
config: i386-randconfig-r033-20211129 (https://download.01.org/0day-ci/archive/20211201/202112011144.adv9Pf3v-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/commit/?id=4d7b3620412d727e09bf0eef942be42da363260d
        git remote add deller-parisc https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git
        git fetch --no-tags deller-parisc for-next-maybe
        git checkout 4d7b3620412d727e09bf0eef942be42da363260d
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

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

All warnings (new ones prefixed by >>):

   mm/usercopy.c: In function 'check_kernel_text_object':
   mm/usercopy.c:134:56: error: expected ')' before 'return'
     134 |  if (inside_init_area(ptr, n, __init_begin, __init_end)
         |     ~                                                  ^
         |                                                        )
     135 |   return;
         |   ~~~~~~                                                
>> mm/usercopy.c:134:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
     134 |  if (inside_init_area(ptr, n, __init_begin, __init_end)
         |  ^~
   mm/usercopy.c:324: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
     324 | late_initcall(set_hardened_usercopy);
         | 
   mm/usercopy.c:324:1: error: expected declaration or statement at end of input
     324 | late_initcall(set_hardened_usercopy);
         | ^~~~~~~~~~~~~
   mm/usercopy.c:131:32: warning: unused variable 'texthigh_linear' [-Wunused-variable]
     131 |  unsigned long textlow_linear, texthigh_linear;
         |                                ^~~~~~~~~~~~~~~
   mm/usercopy.c:131:16: warning: unused variable 'textlow_linear' [-Wunused-variable]
     131 |  unsigned long textlow_linear, texthigh_linear;
         |                ^~~~~~~~~~~~~~
   mm/usercopy.c:130:16: warning: unused variable 'texthigh' [-Wunused-variable]
     130 |  unsigned long texthigh = (unsigned long)_etext;
         |                ^~~~~~~~
   mm/usercopy.c:129:16: warning: unused variable 'textlow' [-Wunused-variable]
     129 |  unsigned long textlow = (unsigned long)_stext;
         |                ^~~~~~~
   At top level:
   mm/usercopy.c:103:13: warning: 'overlaps' defined but not used [-Wunused-function]
     103 | static bool overlaps(const unsigned long ptr, unsigned long n,
         |             ^~~~~~~~
   mm/usercopy.c:34:21: warning: 'check_stack_object' defined but not used [-Wunused-function]
      34 | static noinline int check_stack_object(const void *obj, unsigned long len)
         |                     ^~~~~~~~~~~~~~~~~~


vim +/if +134 mm/usercopy.c

   124	
   125	/* Is this address range in the kernel text area? */
   126	static inline void check_kernel_text_object(const unsigned long ptr,
   127						    unsigned long n, bool to_user)
   128	{
   129		unsigned long textlow = (unsigned long)_stext;
   130		unsigned long texthigh = (unsigned long)_etext;
   131		unsigned long textlow_linear, texthigh_linear;
   132	
   133		/* Ok if inside the former init sections */
 > 134		if (inside_init_area(ptr, n, __init_begin, __init_end)
   135			return;
   136		if (inside_init_area(ptr, n, _sinittext, _einittext)
   137			return;
   138	
   139		if (overlaps(ptr, n, textlow, texthigh))
   140			usercopy_abort("kernel text", NULL, to_user, ptr - textlow, n);
   141	
   142		/*
   143		 * Some architectures have virtual memory mappings with a secondary
   144		 * mapping of the kernel text, i.e. there is more than one virtual
   145		 * kernel address that points to the kernel image. It is usually
   146		 * when there is a separate linear physical memory mapping, in that
   147		 * __pa() is not just the reverse of __va(). This can be detected
   148		 * and checked:
   149		 */
   150		textlow_linear = (unsigned long)lm_alias(textlow);
   151		/* No different mapping: we're done. */
   152		if (textlow_linear == textlow)
   153			return;
   154	
   155		/* Check the secondary mapping... */
   156		texthigh_linear = (unsigned long)lm_alias(texthigh);
   157		if (overlaps(ptr, n, textlow_linear, texthigh_linear))
   158			usercopy_abort("linear kernel text", NULL, to_user,
   159				       ptr - textlow_linear, n);
   160	}
   161	

---
0-DAY CI Kernel Test Service, Intel Corporation
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