Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
a1f459354a
struct list_lru_one l.nr_items could be accessed concurrently as noticed by KCSAN, BUG: KCSAN: data-race in list_lru_count_one / list_lru_isolate_move write to 0xffffa102789c4510 of 8 bytes by task 823 on cpu 39: list_lru_isolate_move+0xf9/0x130 list_lru_isolate_move at mm/list_lru.c:180 inode_lru_isolate+0x12b/0x2a0 __list_lru_walk_one+0x122/0x3d0 list_lru_walk_one+0x75/0xa0 prune_icache_sb+0x8b/0xc0 super_cache_scan+0x1b8/0x250 do_shrink_slab+0x256/0x6d0 shrink_slab+0x41b/0x4a0 shrink_node+0x35c/0xd80 balance_pgdat+0x652/0xd90 kswapd+0x396/0x8d0 kthread+0x1e0/0x200 ret_from_fork+0x27/0x50 read to 0xffffa102789c4510 of 8 bytes by task 6345 on cpu 56: list_lru_count_one+0x116/0x2f0 list_lru_count_one at mm/list_lru.c:193 super_cache_count+0xe8/0x170 do_shrink_slab+0x95/0x6d0 shrink_slab+0x41b/0x4a0 shrink_node+0x35c/0xd80 do_try_to_free_pages+0x1f7/0xa10 try_to_free_pages+0x26c/0x5e0 __alloc_pages_slowpath+0x458/0x1290 __alloc_pages_nodemask+0x3bb/0x450 alloc_pages_vma+0x8a/0x2c0 do_anonymous_page+0x170/0x700 __handle_mm_fault+0xc9f/0xd00 handle_mm_fault+0xfc/0x2f0 do_page_fault+0x263/0x6f9 page_fault+0x34/0x40 Reported by Kernel Concurrency Sanitizer on: CPU: 56 PID: 6345 Comm: oom01 Tainted: G W L 5.5.0-next-20200205+ #4 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 A shattered l.nr_items could affect the shrinker behaviour due to a data race. Fix it by adding READ_ONCE() for the read. Since the writes are aligned and up to word-size, assume those are safe from data races to avoid readability issues of writing WRITE_ONCE(var, var + val). Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Marco Elver <elver@google.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/1581114679-5488-1-git-send-email-cai@lca.pw Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.