lib/tests/overflow_kunit.c:637:13-14: WARNING: array_size is used later (line 644) to compute the same size

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
CC: linux-kernel@vger.kernel.org
TO: Kees Cook <kees@kernel.org>
CC: David Gow <davidgow@google.com>
CC: Rae Moar <rmoar@google.com>

Hi Kees,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   4856ebd997159f198e3177e515bda01143727463
commit: db6fe4d61ece24193eb4d94a82d967501d53358c lib: Move KUnit tests into tests/ subdirectory
date:   3 months ago
:::::: branch date: 3 hours ago
:::::: commit date: 3 months ago
config: x86_64-randconfig-104-20250524 (https://download.01.org/0day-ci/archive/20250524/202505240949.oKaaAeZq-lkp@intel.com/config)
compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Julia Lawall <julia.lawall@inria.fr>
| Closes: https://lore.kernel.org/r/202505240949.oKaaAeZq-lkp@intel.com/

cocci warnings: (new ones prefixed by >>)
>> lib/tests/overflow_kunit.c:637:13-14: WARNING: array_size is used later (line 644) to compute the same size
--
>> lib/tests/overflow_kunit.c:295:14-19: Unneeded variable: "index". Return "0" on line 297

vim +637 lib/tests/overflow_kunit.c

ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  621  
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  622  #define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
617f55e20743fc lib/overflow_kunit.c Kees Cook 2022-02-16  623  static void test_ ## func (struct kunit *test, void *arg)		\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  624  {									\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  625  	volatile size_t a = TEST_SIZE;					\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  626  	volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1;			\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  627  	void *ptr;							\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  628  									\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  629  	/* Tiny allocation test. */					\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  630  	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
617f55e20743fc lib/overflow_kunit.c Kees Cook 2022-02-16  631  	KUNIT_ASSERT_NOT_ERR_OR_NULL_MSG(test, ptr,			\
617f55e20743fc lib/overflow_kunit.c Kees Cook 2022-02-16  632  			    #func " failed regular allocation?!\n");	\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  633  	free ## want_arg (free_func, arg, ptr);				\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  634  									\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  635  	/* Wrapped allocation test. */					\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  636  	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10 @637  							  a * b);	\
617f55e20743fc lib/overflow_kunit.c Kees Cook 2022-02-16  638  	KUNIT_ASSERT_NOT_ERR_OR_NULL_MSG(test, ptr,			\
617f55e20743fc lib/overflow_kunit.c Kees Cook 2022-02-16  639  			    #func " unexpectedly failed bad wrapping?!\n"); \
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  640  	free ## want_arg (free_func, arg, ptr);				\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  641  									\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  642  	/* Saturated allocation test. */				\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  643  	ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg,	\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10 @644  						   array_size(a, b));	\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  645  	if (ptr) {							\
617f55e20743fc lib/overflow_kunit.c Kees Cook 2022-02-16  646  		KUNIT_FAIL(test, #func " missed saturation!\n");	\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  647  		free ## want_arg (free_func, arg, ptr);			\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  648  	}								\
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  649  }
ca90800a91ba72 lib/test_overflow.c  Kees Cook 2018-05-10  650  

:::::: The code at line 637 was first introduced by commit
:::::: ca90800a91ba723d78ded634d037c1d2df8b54d6 test_overflow: Add memory allocation overflow tests

:::::: TO: Kees Cook <keescook@chromium.org>
:::::: CC: Kees Cook <keescook@chromium.org>

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