Re: [PATCH 4/7] minmax: Simplify signedness check

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

:::::: 
:::::: Manual check reason: "low confidence static check first_new_problem: arch/arm64/kvm/hyp/nvhe/page_alloc.c:121:21: sparse: sparse: bad integer constant expression"
:::::: 

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <03601661326c4efba4e618ead15fa0e2@AcuMS.aculab.com>
References: <03601661326c4efba4e618ead15fa0e2@AcuMS.aculab.com>
TO: David Laight <David.Laight@ACULAB.COM>
TO: "'linux-kernel@vger.kernel.org'" <linux-kernel@vger.kernel.org>
TO: "'Linus Torvalds'" <torvalds@linuxfoundation.org>
CC: "'Matthew Wilcox (Oracle)'" <willy@infradead.org>
CC: "'Christoph Hellwig'" <hch@infradead.org>
CC: "'Andrew Morton'" <akpm@linux-foundation.org>
CC: Linux Memory Management List <linux-mm@kvack.org>
CC: "'Andy Shevchenko'" <andriy.shevchenko@linux.intel.com>
CC: "'Dan Carpenter'" <dan.carpenter@linaro.org>
CC: "'Arnd Bergmann'" <arnd@kernel.org>
CC: "'Jason@zx2c4.com'" <Jason@zx2c4.com>
CC: "'pedro.falcato@gmail.com'" <pedro.falcato@gmail.com>
CC: "'Mateusz Guzik'" <mjguzik@gmail.com>

Hi David,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linux/master]
[also build test WARNING on linus/master v6.10 next-20240725]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/David-Laight/minmax-Put-all-the-clamp-definitions-together/20240724-224832
base:   linux/master
patch link:    https://lore.kernel.org/r/03601661326c4efba4e618ead15fa0e2%40AcuMS.aculab.com
patch subject: [PATCH 4/7] minmax: Simplify signedness check
:::::: branch date: 29 hours ago
:::::: commit date: 29 hours ago
config: arm64-randconfig-r132-20240725 (https://download.01.org/0day-ci/archive/20240726/202407260319.rmgaXdIl-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 14.1.0
reproduce: (https://download.01.org/0day-ci/archive/20240726/202407260319.rmgaXdIl-lkp@intel.com/reproduce)

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>
| Closes: https://lore.kernel.org/r/202407260319.rmgaXdIl-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> arch/arm64/kvm/hyp/nvhe/page_alloc.c:121:21: sparse: sparse: bad integer constant expression
>> arch/arm64/kvm/hyp/nvhe/page_alloc.c:121:21: sparse: sparse: static assertion failed: "min(p, buddy) signedness error, fix types or consider umin() before min_t()"

vim +121 arch/arm64/kvm/hyp/nvhe/page_alloc.c

914cde58a03cc5 Quentin Perret     2021-06-08   92  
8e17c66249e9ea Quentin Perret     2021-03-19   93  static void __hyp_attach_page(struct hyp_pool *pool,
8e17c66249e9ea Quentin Perret     2021-03-19   94  			      struct hyp_page *p)
8e17c66249e9ea Quentin Perret     2021-03-19   95  {
72a5bc0f153ce8 Quentin Perret     2022-11-10   96  	phys_addr_t phys = hyp_page_to_phys(p);
87ec0606733e1a Quentin Perret     2021-06-08   97  	unsigned short order = p->order;
8e17c66249e9ea Quentin Perret     2021-03-19   98  	struct hyp_page *buddy;
8e17c66249e9ea Quentin Perret     2021-03-19   99  
8e17c66249e9ea Quentin Perret     2021-03-19  100  	memset(hyp_page_to_virt(p), 0, PAGE_SIZE << p->order);
8e17c66249e9ea Quentin Perret     2021-03-19  101  
72a5bc0f153ce8 Quentin Perret     2022-11-10  102  	/* Skip coalescing for 'external' pages being freed into the pool. */
72a5bc0f153ce8 Quentin Perret     2022-11-10  103  	if (phys < pool->range_start || phys >= pool->range_end)
72a5bc0f153ce8 Quentin Perret     2022-11-10  104  		goto insert;
72a5bc0f153ce8 Quentin Perret     2022-11-10  105  
8e17c66249e9ea Quentin Perret     2021-03-19  106  	/*
8e17c66249e9ea Quentin Perret     2021-03-19  107  	 * Only the first struct hyp_page of a high-order page (otherwise known
8e17c66249e9ea Quentin Perret     2021-03-19  108  	 * as the 'head') should have p->order set. The non-head pages should
8e17c66249e9ea Quentin Perret     2021-03-19  109  	 * have p->order = HYP_NO_ORDER. Here @p may no longer be the head
21ea457842759a Julia Lawall       2022-03-18  110  	 * after coalescing, so make sure to mark it HYP_NO_ORDER proactively.
8e17c66249e9ea Quentin Perret     2021-03-19  111  	 */
8e17c66249e9ea Quentin Perret     2021-03-19  112  	p->order = HYP_NO_ORDER;
23baf831a32c04 Kirill A. Shutemov 2023-03-15  113  	for (; (order + 1) <= pool->max_order; order++) {
8e17c66249e9ea Quentin Perret     2021-03-19  114  		buddy = __find_buddy_avail(pool, p, order);
8e17c66249e9ea Quentin Perret     2021-03-19  115  		if (!buddy)
8e17c66249e9ea Quentin Perret     2021-03-19  116  			break;
8e17c66249e9ea Quentin Perret     2021-03-19  117  
21ea457842759a Julia Lawall       2022-03-18  118  		/* Take the buddy out of its list, and coalesce with @p */
914cde58a03cc5 Quentin Perret     2021-06-08  119  		page_remove_from_list(buddy);
8e17c66249e9ea Quentin Perret     2021-03-19  120  		buddy->order = HYP_NO_ORDER;
8e17c66249e9ea Quentin Perret     2021-03-19 @121  		p = min(p, buddy);
8e17c66249e9ea Quentin Perret     2021-03-19  122  	}
8e17c66249e9ea Quentin Perret     2021-03-19  123  
72a5bc0f153ce8 Quentin Perret     2022-11-10  124  insert:
8e17c66249e9ea Quentin Perret     2021-03-19  125  	/* Mark the new head, and insert it */
8e17c66249e9ea Quentin Perret     2021-03-19  126  	p->order = order;
914cde58a03cc5 Quentin Perret     2021-06-08  127  	page_add_to_list(p, &pool->free_area[order]);
8e17c66249e9ea Quentin Perret     2021-03-19  128  }
8e17c66249e9ea Quentin Perret     2021-03-19  129  

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