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Suren Baghdasaryan 982ae058b2 userfaultfd: fix move_pages_pte() splitting folio under RCU read lock
While testing the split PMD path with lockdep enabled I've got an "Invalid
wait context" error caused by split_huge_page_to_list() trying to lock
anon_vma->rwsem while inside RCU read section.  The issues is due to
move_pages_pte() calling split_folio() under RCU read lock.  Fix this by
unmapping the PTEs and exiting RCU read section before splitting the folio
and then retrying.  The same retry pattern is used when locking the folio
or anon_vma in this function.  After splitting the large folio we unlock
and release it because after the split the old folio might not be the one
that contains the src_addr.

Link: https://lkml.kernel.org/r/20240102233256.1077959-1-surenb@google.com
Fixes: adef440691 ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-05 10:17:43 -08:00
arch kasan/arm64: improve comments for KASAN_SHADOW_START/END 2023-12-29 11:58:43 -08:00
block fs: convert block_write_full_page to block_write_full_folio 2023-12-29 11:58:35 -08:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression in ahash and hides the Kconfig sub-options for the jitter RNG. 2023-11-09 17:04:58 -08:00
Documentation zswap: memcontrol: implement zswap writeback disabling 2023-12-29 20:22:11 -08:00
drivers list_lru: allow explicit memcg and NUMA node selection 2023-12-12 10:57:01 -08:00
fs buffer: fix unintended successful return 2024-01-05 10:17:43 -08:00
include zswap: memcontrol: implement zswap writeback disabling 2023-12-29 20:22:11 -08:00
init As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
io_uring io_uring: use mempool KASAN hook 2023-12-29 11:58:41 -08:00
ipc Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
kernel kernel/events/uprobes: page_remove_rmap() -> folio_remove_rmap_pte() 2023-12-29 11:58:53 -08:00
lib lib/stackdepot: add printk_deferred_enter/exit guards 2023-12-29 11:58:41 -08:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm userfaultfd: fix move_pages_pte() splitting folio under RCU read lock 2024-01-05 10:17:43 -08:00
net skbuff: use mempool KASAN hooks 2023-12-29 11:58:41 -08:00
rust Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
samples samples/cgroup: introduce memcg memory.events listener 2023-12-10 16:51:54 -08:00
scripts Merge branch 'master' into mm-hotfixes-stable 2023-12-06 17:03:50 -08:00
security + Features 2023-11-03 09:48:17 -10:00
sound ALSA: hda: Disable power-save on KONTRON SinglePC 2023-11-30 16:14:21 +01:00
tools selftests/mm: log run_vmtests.sh results in TAP format 2023-12-29 11:58:43 -08:00
usr arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: generate kernel.spec in rpmbuild/SPECS/ 2023-10-03 20:49:09 +09:00
.mailmap mailmap: add an old address for Naoya Horiguchi 2023-12-20 13:46:20 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: drop Antti Palosaari 2023-12-06 16:12:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS samples: introduce new samples subdir for cgroup 2023-12-10 16:51:54 -08:00
Makefile Linux 6.7-rc4 2023-12-03 18:52:56 +09:00
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.