[linux-next:master 1011/2056] mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces)

[linux-next:master 1011/2056] mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces)

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   e922ba281a8d84f640d8c8e18a385d032c19e185
commit: 1d313cb53d95b8d1527173bda7174e920f5a195a [1011/2056] mm/gup: disallow FOLL_LONGTERM GUP-fast writing to file-backed mappings
config: loongarch-randconfig-s042-20230514 (https://download.01.org/0day-ci/archive/20230514/202305140954.06aQsI9r-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 12.1.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=1d313cb53d95b8d1527173bda7174e920f5a195a
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout 1d313cb53d95b8d1527173bda7174e920f5a195a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=loongarch olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=loongarch SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305140954.06aQsI9r-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got unsigned int [noderef] __percpu *
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got unsigned int [noderef] __percpu *
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got unsigned int [noderef] __percpu *
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got unsigned int [noderef] __percpu *
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got int [noderef] __percpu *
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got int [noderef] __percpu *
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got int [noderef] __percpu *
>> mm/gup.c:2430:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
   mm/gup.c:2430:9: sparse:     expected void *ptr
   mm/gup.c:2430:9: sparse:     got int [noderef] __percpu *

vim +2430 mm/gup.c

  2382	
  2383	/*
  2384	 * Used in the GUP-fast path to determine whether a pin is permitted for a
  2385	 * specific folio.
  2386	 *
  2387	 * This call assumes the caller has pinned the folio, that the lowest page table
  2388	 * level still points to this folio, and that interrupts have been disabled.
  2389	 *
  2390	 * Writing to pinned file-backed dirty tracked folios is inherently problematic
  2391	 * (see comment describing the writable_file_mapping_allowed() function). We
  2392	 * therefore try to avoid the most egregious case of a long-term mapping doing
  2393	 * so.
  2394	 *
  2395	 * This function cannot be as thorough as that one as the VMA is not available
  2396	 * in the fast path, so instead we whitelist known good cases and if in doubt,
  2397	 * fall back to the slow path.
  2398	 */
  2399	static bool folio_fast_pin_allowed(struct folio *folio, unsigned int flags)
  2400	{
  2401		struct address_space *mapping;
  2402		unsigned long mapping_flags;
  2403	
  2404		/*
  2405		 * If we aren't pinning then no problematic write can occur. A long term
  2406		 * pin is the most egregious case so this is the one we disallow.
  2407		 */
  2408		if ((flags & (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE)) !=
  2409		    (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE))
  2410			return true;
  2411	
  2412		/* The folio is pinned, so we can safely access folio fields. */
  2413	
  2414		if (WARN_ON_ONCE(folio_test_slab(folio)))
  2415			return false;
  2416	
  2417		/* hugetlb mappings do not require dirty-tracking. */
  2418		if (folio_test_hugetlb(folio))
  2419			return true;
  2420	
  2421		/*
  2422		 * GUP-fast disables IRQs. When IRQS are disabled, RCU grace periods
  2423		 * cannot proceed, which means no actions performed under RCU can
  2424		 * proceed either.
  2425		 *
  2426		 * inodes and thus their mappings are freed under RCU, which means the
  2427		 * mapping cannot be freed beneath us and thus we can safely dereference
  2428		 * it.
  2429		 */
> 2430		lockdep_assert_irqs_disabled();
  2431	
  2432		/*
  2433		 * However, there may be operations which _alter_ the mapping, so ensure
  2434		 * we read it once and only once.
  2435		 */
  2436		mapping = READ_ONCE(folio->mapping);
  2437	
  2438		/*
  2439		 * The mapping may have been truncated, in any case we cannot determine
  2440		 * if this mapping is safe - fall back to slow path to determine how to
  2441		 * proceed.
  2442		 */
  2443		if (!mapping)
  2444			return false;
  2445	
  2446		/* Anonymous folios pose no problem. */
  2447		mapping_flags = (unsigned long)mapping & PAGE_MAPPING_FLAGS;
  2448		if (mapping_flags)
  2449			return mapping_flags & PAGE_MAPPING_ANON;
  2450	
  2451		/*
  2452		 * At this point, we know the mapping is non-null and points to an
  2453		 * address_space object. The only remaining whitelisted file system is
  2454		 * shmem.
  2455		 */
  2456		return shmem_mapping(mapping);
  2457	}
  2458	

-- 
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