Minimal supplement to upstream Kernel Self Protection Project changes. Features already provided by SELinux + Yama and archs other than multiarch arm64 / x86_64 aren't in scope. Only tags have stable history. Shared IRC channel with KSPP: irc.libera.chat #linux-hardening
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NeilBrown 4bc034d353 Revert "MD: fix lock contention for flush bios"
This reverts commit 5a409b4f56.

This patch has two problems.

1/ it make multiple calls to submit_bio() from inside a make_request_fn.
 The bios thus submitted will be queued on current->bio_list and not
 submitted immediately.  As the bios are allocated from a mempool,
 this can theoretically result in a deadlock - all the pool of requests
 could be in various ->bio_list queues and a subsequent mempool_alloc
 could block waiting for one of them to be released.

2/ It aims to handle a case when there are many concurrent flush requests.
  It handles this by submitting many requests in parallel - all of which
  are identical and so most of which do nothing useful.
  It would be more efficient to just send one lower-level request, but
  allow that to satisfy multiple upper-level requests.

Fixes: 5a409b4f56 ("MD: fix lock contention for flush bios")
Cc: <stable@vger.kernel.org> # v4.19+
Tested-by: Xiao Ni <xni@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01 12:11:48 -06:00
arch A collection of x86 and ARM bugfixes, and some improvements to documentation. 2019-03-31 08:55:59 -07:00
block block: don't check if adjacent bvecs in one bio can be mergeable 2019-04-01 12:11:48 -06:00
certs kexec, KEYS: Make use of platform keyring for signature verify 2019-02-04 17:34:07 -05:00
crypto lib/lzo: separate lzo-rle from lzo 2019-03-07 18:32:03 -08:00
Documentation doc, block, bfq: add information on bfq execution time 2019-04-01 08:15:40 -06:00
drivers Revert "MD: fix lock contention for flush bios" 2019-04-01 12:11:48 -06:00
fs Merge branch 'akpm' (patches from Andrew) 2019-03-29 16:02:28 -07:00
include block: put the same page when adding it to bio 2019-04-01 12:11:34 -06:00
init init/main: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
ipc Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 14:08:19 -07:00
kernel Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-31 08:22:12 -07:00
lib for-linus-20190329 2019-03-29 14:43:07 -07:00
LICENSES LICENSES: Add GCC runtime library exception text 2019-01-16 14:54:15 -07:00
mm mm/migrate.c: add missing flush_dcache_page for non-mapped page migrate 2019-03-29 10:01:37 -07:00
net A patch to avoid choking on multipage bvecs in the messenger and 2019-03-29 14:41:09 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-11 08:54:01 -07:00
scripts Merge branch 'akpm' (patches from Andrew) 2019-03-29 16:02:28 -07:00
security LSM: Revive CONFIG_DEFAULT_SECURITY_* for "make oldconfig" 2019-03-29 14:08:49 -07:00
sound sound fixes for 5.1-rc3 2019-03-29 14:53:33 -07:00
tools A collection of x86 and ARM bugfixes, and some improvements to documentation. 2019-03-31 08:55:59 -07:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt KVM/ARM fixes for 5.1 2019-03-28 19:07:30 +01:00
.clang-format Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-03-12 13:43:42 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap mailmap: add Changbin Du 2019-03-29 10:01:37 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-31 07:48:58 -07:00
Makefile Linux 5.1-rc3 2019-03-31 14:39:29 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.