Hi Kees, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 467f8165a2b0e6accf3d0dd9c8089b1dbde29f7f commit: cdf8a76fda4ae3b53c5a09e5a8c79e27b7b65d68 ubsan: move cc-option tests into Kconfig date: 5 days ago config: powerpc-randconfig-r002-20201220 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project cee1e7d14f4628d6174b33640d502bff3b54ae45) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cdf8a76fda4ae3b53c5a09e5a8c79e27b7b65d68 git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout cdf8a76fda4ae3b53c5a09e5a8c79e27b7b65d68 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:156:1: note: expanded from here __do_insw ^ arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw' #define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/filemap.c:20: In file included from include/linux/kernel_stat.h:9: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:160:1: note: expanded from here __do_insl ^ arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl' #define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/filemap.c:20: In file included from include/linux/kernel_stat.h:9: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:164:1: note: expanded from here __do_outsb ^ arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb' #define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/filemap.c:20: In file included from include/linux/kernel_stat.h:9: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:168:1: note: expanded from here __do_outsw ^ arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw' #define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from mm/filemap.c:20: In file included from include/linux/kernel_stat.h:9: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:172:1: note: expanded from here __do_outsl ^ arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl' #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ mm/filemap.c:830:14: warning: no previous prototype for function '__add_to_page_cache_locked' [-Wmissing-prototypes] noinline int __add_to_page_cache_locked(struct page *page, ^ mm/filemap.c:830:10: note: declare 'static' if the function is not intended to be used outside of this translation unit noinline int __add_to_page_cache_locked(struct page *page, ^ static >> mm/filemap.c:2439:9: warning: stack frame size of 2096 bytes in function 'generic_file_buffered_read' [-Wframe-larger-than=] ssize_t generic_file_buffered_read(struct kiocb *iocb, ^ 14 warnings generated. -- In file included from kernel/debug/gdbstub.c:35: In file included from include/linux/serial_core.h:13: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:45:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insw, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:85:1: note: expanded from here __do_insw ^ arch/powerpc/include/asm/io.h:542:56: note: expanded from macro '__do_insw' #define __do_insw(p, b, n) readsw((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from kernel/debug/gdbstub.c:35: In file included from include/linux/serial_core.h:13: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:47:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(insl, (unsigned long p, void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:89:1: note: expanded from here __do_insl ^ arch/powerpc/include/asm/io.h:543:56: note: expanded from macro '__do_insl' #define __do_insl(p, b, n) readsl((PCI_IO_ADDR)_IO_BASE+(p), (b), (n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from kernel/debug/gdbstub.c:35: In file included from include/linux/serial_core.h:13: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:49:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:93:1: note: expanded from here __do_outsb ^ arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb' #define __do_outsb(p, b, n) writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from kernel/debug/gdbstub.c:35: In file included from include/linux/serial_core.h:13: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:51:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:97:1: note: expanded from here __do_outsw ^ arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw' #define __do_outsw(p, b, n) writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ In file included from kernel/debug/gdbstub.c:35: In file included from include/linux/serial_core.h:13: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:10: In file included from arch/powerpc/include/asm/hardirq.h:6: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: In file included from arch/powerpc/include/asm/io.h:604: arch/powerpc/include/asm/io-defs.h:53:1: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET' __do_##name al; \ ^~~~~~~~~~~~~~ <scratch space>:101:1: note: expanded from here __do_outsl ^ arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl' #define __do_outsl(p, b, n) writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n)) ~~~~~~~~~~~~~~~~~~~~~^ >> kernel/debug/gdbstub.c:957:5: warning: stack frame size of 2192 bytes in function 'gdb_serial_stub' [-Wframe-larger-than=] int gdb_serial_stub(struct kgdb_state *ks) ^ 13 warnings generated. vim +/generic_file_buffered_read +2439 mm/filemap.c 06c0444290cecf0 Kent Overstreet 2020-12-14 2422 723ef24b9b379e5 Kent Overstreet 2020-12-14 2423 /** 723ef24b9b379e5 Kent Overstreet 2020-12-14 2424 * generic_file_buffered_read - generic file read routine 723ef24b9b379e5 Kent Overstreet 2020-12-14 2425 * @iocb: the iocb to read 723ef24b9b379e5 Kent Overstreet 2020-12-14 2426 * @iter: data destination 723ef24b9b379e5 Kent Overstreet 2020-12-14 2427 * @written: already copied 723ef24b9b379e5 Kent Overstreet 2020-12-14 2428 * 723ef24b9b379e5 Kent Overstreet 2020-12-14 2429 * This is a generic file read routine, and uses the 723ef24b9b379e5 Kent Overstreet 2020-12-14 2430 * mapping->a_ops->readpage() function for the actual low-level stuff. 723ef24b9b379e5 Kent Overstreet 2020-12-14 2431 * 723ef24b9b379e5 Kent Overstreet 2020-12-14 2432 * This is really ugly. But the goto's actually try to clarify some 723ef24b9b379e5 Kent Overstreet 2020-12-14 2433 * of the logic when it comes to error handling etc. 723ef24b9b379e5 Kent Overstreet 2020-12-14 2434 * 723ef24b9b379e5 Kent Overstreet 2020-12-14 2435 * Return: 723ef24b9b379e5 Kent Overstreet 2020-12-14 2436 * * total number of bytes copied, including those the were already @written 723ef24b9b379e5 Kent Overstreet 2020-12-14 2437 * * negative error code if nothing was copied 723ef24b9b379e5 Kent Overstreet 2020-12-14 2438 */ 723ef24b9b379e5 Kent Overstreet 2020-12-14 @2439 ssize_t generic_file_buffered_read(struct kiocb *iocb, 723ef24b9b379e5 Kent Overstreet 2020-12-14 2440 struct iov_iter *iter, ssize_t written) 723ef24b9b379e5 Kent Overstreet 2020-12-14 2441 { 723ef24b9b379e5 Kent Overstreet 2020-12-14 2442 struct file *filp = iocb->ki_filp; 06c0444290cecf0 Kent Overstreet 2020-12-14 2443 struct file_ra_state *ra = &filp->f_ra; 723ef24b9b379e5 Kent Overstreet 2020-12-14 2444 struct address_space *mapping = filp->f_mapping; 723ef24b9b379e5 Kent Overstreet 2020-12-14 2445 struct inode *inode = mapping->host; 06c0444290cecf0 Kent Overstreet 2020-12-14 2446 struct page *pages_onstack[PAGEVEC_SIZE], **pages = NULL; 06c0444290cecf0 Kent Overstreet 2020-12-14 2447 unsigned int nr_pages = min_t(unsigned int, 512, 06c0444290cecf0 Kent Overstreet 2020-12-14 2448 ((iocb->ki_pos + iter->count + PAGE_SIZE - 1) >> PAGE_SHIFT) - 06c0444290cecf0 Kent Overstreet 2020-12-14 2449 (iocb->ki_pos >> PAGE_SHIFT)); 06c0444290cecf0 Kent Overstreet 2020-12-14 2450 int i, pg_nr, error = 0; 06c0444290cecf0 Kent Overstreet 2020-12-14 2451 bool writably_mapped; 06c0444290cecf0 Kent Overstreet 2020-12-14 2452 loff_t isize, end_offset; 723ef24b9b379e5 Kent Overstreet 2020-12-14 2453 723ef24b9b379e5 Kent Overstreet 2020-12-14 2454 if (unlikely(iocb->ki_pos >= inode->i_sb->s_maxbytes)) 723ef24b9b379e5 Kent Overstreet 2020-12-14 2455 return 0; 723ef24b9b379e5 Kent Overstreet 2020-12-14 2456 iov_iter_truncate(iter, inode->i_sb->s_maxbytes); 723ef24b9b379e5 Kent Overstreet 2020-12-14 2457 06c0444290cecf0 Kent Overstreet 2020-12-14 2458 if (nr_pages > ARRAY_SIZE(pages_onstack)) 06c0444290cecf0 Kent Overstreet 2020-12-14 2459 pages = kmalloc_array(nr_pages, sizeof(void *), GFP_KERNEL); 06c0444290cecf0 Kent Overstreet 2020-12-14 2460 06c0444290cecf0 Kent Overstreet 2020-12-14 2461 if (!pages) { 06c0444290cecf0 Kent Overstreet 2020-12-14 2462 pages = pages_onstack; 06c0444290cecf0 Kent Overstreet 2020-12-14 2463 nr_pages = min_t(unsigned int, nr_pages, ARRAY_SIZE(pages_onstack)); 06c0444290cecf0 Kent Overstreet 2020-12-14 2464 } 06c0444290cecf0 Kent Overstreet 2020-12-14 2465 06c0444290cecf0 Kent Overstreet 2020-12-14 2466 do { 06c0444290cecf0 Kent Overstreet 2020-12-14 2467 cond_resched(); 723ef24b9b379e5 Kent Overstreet 2020-12-14 2468 ^1da177e4c3f415 Linus Torvalds 2005-04-16 2469 /* 723ef24b9b379e5 Kent Overstreet 2020-12-14 2470 * If we've already successfully copied some data, then we 723ef24b9b379e5 Kent Overstreet 2020-12-14 2471 * can no longer safely return -EIOCBQUEUED. Hence mark 723ef24b9b379e5 Kent Overstreet 2020-12-14 2472 * an async read NOWAIT at that point. ^1da177e4c3f415 Linus Torvalds 2005-04-16 2473 */ 06c0444290cecf0 Kent Overstreet 2020-12-14 2474 if ((iocb->ki_flags & IOCB_WAITQ) && written) 723ef24b9b379e5 Kent Overstreet 2020-12-14 2475 iocb->ki_flags |= IOCB_NOWAIT; ^1da177e4c3f415 Linus Torvalds 2005-04-16 2476 06c0444290cecf0 Kent Overstreet 2020-12-14 2477 i = 0; 06c0444290cecf0 Kent Overstreet 2020-12-14 2478 pg_nr = generic_file_buffered_read_get_pages(iocb, iter, 06c0444290cecf0 Kent Overstreet 2020-12-14 2479 pages, nr_pages); 06c0444290cecf0 Kent Overstreet 2020-12-14 2480 if (pg_nr < 0) { 06c0444290cecf0 Kent Overstreet 2020-12-14 2481 error = pg_nr; 06c0444290cecf0 Kent Overstreet 2020-12-14 2482 break; 723ef24b9b379e5 Kent Overstreet 2020-12-14 2483 } ^1da177e4c3f415 Linus Torvalds 2005-04-16 2484 ^1da177e4c3f415 Linus Torvalds 2005-04-16 2485 /* 06c0444290cecf0 Kent Overstreet 2020-12-14 2486 * i_size must be checked after we know the pages are Uptodate. 06c0444290cecf0 Kent Overstreet 2020-12-14 2487 * 06c0444290cecf0 Kent Overstreet 2020-12-14 2488 * Checking i_size after the check allows us to calculate 06c0444290cecf0 Kent Overstreet 2020-12-14 2489 * the correct value for "nr", which means the zero-filled 06c0444290cecf0 Kent Overstreet 2020-12-14 2490 * part of the page is not copied back to userspace (unless 06c0444290cecf0 Kent Overstreet 2020-12-14 2491 * another truncate extends the file - this is desired though). ^1da177e4c3f415 Linus Torvalds 2005-04-16 2492 */ 06c0444290cecf0 Kent Overstreet 2020-12-14 2493 isize = i_size_read(inode); 06c0444290cecf0 Kent Overstreet 2020-12-14 2494 if (unlikely(iocb->ki_pos >= isize)) 06c0444290cecf0 Kent Overstreet 2020-12-14 2495 goto put_pages; 723ef24b9b379e5 Kent Overstreet 2020-12-14 2496 06c0444290cecf0 Kent Overstreet 2020-12-14 2497 end_offset = min_t(loff_t, isize, iocb->ki_pos + iter->count); 723ef24b9b379e5 Kent Overstreet 2020-12-14 2498 06c0444290cecf0 Kent Overstreet 2020-12-14 2499 while ((iocb->ki_pos >> PAGE_SHIFT) + pg_nr > 06c0444290cecf0 Kent Overstreet 2020-12-14 2500 (end_offset + PAGE_SIZE - 1) >> PAGE_SHIFT) 06c0444290cecf0 Kent Overstreet 2020-12-14 2501 put_page(pages[--pg_nr]); 723ef24b9b379e5 Kent Overstreet 2020-12-14 2502 06c0444290cecf0 Kent Overstreet 2020-12-14 2503 /* 06c0444290cecf0 Kent Overstreet 2020-12-14 2504 * Once we start copying data, we don't want to be touching any 06c0444290cecf0 Kent Overstreet 2020-12-14 2505 * cachelines that might be contended: 06c0444290cecf0 Kent Overstreet 2020-12-14 2506 */ 06c0444290cecf0 Kent Overstreet 2020-12-14 2507 writably_mapped = mapping_writably_mapped(mapping); 06c0444290cecf0 Kent Overstreet 2020-12-14 2508 06c0444290cecf0 Kent Overstreet 2020-12-14 2509 /* 06c0444290cecf0 Kent Overstreet 2020-12-14 2510 * When a sequential read accesses a page several times, only 06c0444290cecf0 Kent Overstreet 2020-12-14 2511 * mark it as accessed the first time. 06c0444290cecf0 Kent Overstreet 2020-12-14 2512 */ 06c0444290cecf0 Kent Overstreet 2020-12-14 2513 if (iocb->ki_pos >> PAGE_SHIFT != 06c0444290cecf0 Kent Overstreet 2020-12-14 2514 ra->prev_pos >> PAGE_SHIFT) 06c0444290cecf0 Kent Overstreet 2020-12-14 2515 mark_page_accessed(pages[0]); 06c0444290cecf0 Kent Overstreet 2020-12-14 2516 for (i = 1; i < pg_nr; i++) 06c0444290cecf0 Kent Overstreet 2020-12-14 2517 mark_page_accessed(pages[i]); 06c0444290cecf0 Kent Overstreet 2020-12-14 2518 06c0444290cecf0 Kent Overstreet 2020-12-14 2519 for (i = 0; i < pg_nr; i++) { 06c0444290cecf0 Kent Overstreet 2020-12-14 2520 unsigned int offset = iocb->ki_pos & ~PAGE_MASK; 06c0444290cecf0 Kent Overstreet 2020-12-14 2521 unsigned int bytes = min_t(loff_t, end_offset - iocb->ki_pos, 06c0444290cecf0 Kent Overstreet 2020-12-14 2522 PAGE_SIZE - offset); 06c0444290cecf0 Kent Overstreet 2020-12-14 2523 unsigned int copied; 06c0444290cecf0 Kent Overstreet 2020-12-14 2524 06c0444290cecf0 Kent Overstreet 2020-12-14 2525 /* 06c0444290cecf0 Kent Overstreet 2020-12-14 2526 * If users can be writing to this page using arbitrary 06c0444290cecf0 Kent Overstreet 2020-12-14 2527 * virtual addresses, take care about potential aliasing 06c0444290cecf0 Kent Overstreet 2020-12-14 2528 * before reading the page on the kernel side. 06c0444290cecf0 Kent Overstreet 2020-12-14 2529 */ 06c0444290cecf0 Kent Overstreet 2020-12-14 2530 if (writably_mapped) 06c0444290cecf0 Kent Overstreet 2020-12-14 2531 flush_dcache_page(pages[i]); 06c0444290cecf0 Kent Overstreet 2020-12-14 2532 06c0444290cecf0 Kent Overstreet 2020-12-14 2533 copied = copy_page_to_iter(pages[i], offset, bytes, iter); 06c0444290cecf0 Kent Overstreet 2020-12-14 2534 06c0444290cecf0 Kent Overstreet 2020-12-14 2535 written += copied; 06c0444290cecf0 Kent Overstreet 2020-12-14 2536 iocb->ki_pos += copied; 06c0444290cecf0 Kent Overstreet 2020-12-14 2537 ra->prev_pos = iocb->ki_pos; 06c0444290cecf0 Kent Overstreet 2020-12-14 2538 06c0444290cecf0 Kent Overstreet 2020-12-14 2539 if (copied < bytes) { 06c0444290cecf0 Kent Overstreet 2020-12-14 2540 error = -EFAULT; 06c0444290cecf0 Kent Overstreet 2020-12-14 2541 break; ^1da177e4c3f415 Linus Torvalds 2005-04-16 2542 } ^1da177e4c3f415 Linus Torvalds 2005-04-16 2543 } 06c0444290cecf0 Kent Overstreet 2020-12-14 2544 put_pages: 06c0444290cecf0 Kent Overstreet 2020-12-14 2545 for (i = 0; i < pg_nr; i++) 06c0444290cecf0 Kent Overstreet 2020-12-14 2546 put_page(pages[i]); 06c0444290cecf0 Kent Overstreet 2020-12-14 2547 } while (iov_iter_count(iter) && iocb->ki_pos < isize && !error); ^1da177e4c3f415 Linus Torvalds 2005-04-16 2548 ^1da177e4c3f415 Linus Torvalds 2005-04-16 2549 file_accessed(filp); 06c0444290cecf0 Kent Overstreet 2020-12-14 2550 06c0444290cecf0 Kent Overstreet 2020-12-14 2551 if (pages != pages_onstack) 06c0444290cecf0 Kent Overstreet 2020-12-14 2552 kfree(pages); 723ef24b9b379e5 Kent Overstreet 2020-12-14 2553 6e58e79db8a1622 Al Viro 2014-02-03 2554 return written ? written : error; ^1da177e4c3f415 Linus Torvalds 2005-04-16 2555 } d85dc2e116fdce7 Goldwyn Rodrigues 2019-08-30 2556 EXPORT_SYMBOL_GPL(generic_file_buffered_read); ^1da177e4c3f415 Linus Torvalds 2005-04-16 2557 :::::: The code at line 2439 was first introduced by commit :::::: 723ef24b9b379e59facc65de8c065c8b89d479cd mm/filemap/c: break generic_file_buffered_read up into multiple functions :::::: TO: Kent Overstreet <kent.overstreet@xxxxxxxxx> :::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
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