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@xxxxxxxxx/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@xxxxxxxxx> | Link: https://lore.kernel.org/oe-kbuild-all/202305140954.06aQsI9r-lkp@xxxxxxxxx/ 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 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests
