WSL2-Linux-Kernel

The source for the Linux kernel used in Windows Subsystem for Linux 2 (WSL2)

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Johannes Weiner b8c8a338f7 Revert "vmalloc: back off when the current task is killed" This reverts commits `5d17a73a2e` ("vmalloc: back off when the current task is killed") and `171012f561` ("mm: don't warn when vmalloc() fails due to a fatal signal"). Commit `5d17a73a2e` ("vmalloc: back off when the current task is killed") made all vmalloc allocations from a signal-killed task fail. We have seen crashes in the tty driver from this, where a killed task exiting tries to switch back to N_TTY, fails n_tty_open because of the vmalloc failing, and later crashes when dereferencing tty->disc_data. Arguably, relying on a vmalloc() call to succeed in order to properly exit a task is not the most robust way of doing things. There will be a follow-up patch to the tty code to fall back to the N_NULL ldisc. But the justification to make that vmalloc() call fail like this isn't convincing, either. The patch mentions an OOM victim exhausting the memory reserves and thus deadlocking the machine. But the OOM killer is only one, improbable source of fatal signals. It doesn't make sense to fail allocations preemptively with plenty of memory in most cases. The patch doesn't mention real-life instances where vmalloc sites would exhaust memory, which makes it sound more like a theoretical issue to begin with. But just in case, the OOM access to memory reserves has been restricted on the allocator side in `cd04ae1e2d` ("mm, oom: do not rely on TIF_MEMDIE for memory reserves access"), which should take care of any theoretical concerns on that front. Revert this patch, and the follow-up that suppresses the allocation warnings when we fail the allocations due to a signal. Link: http://lkml.kernel.org/r/20171004185906.GB2136@cmpxchg.org Fixes: `171012f561` ("mm: don't warn when vmalloc() fails due to a fatal signal") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alan Cox <alan@llwyncelyn.cymru> Cc: Christoph Hellwig <hch@lst.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2017-10-13 16:18:32 -07:00
Documentation	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2017-10-09 16:25:00 -07:00
arch	powerpc fixes for 4.14 #5	2017-10-13 11:39:28 -07:00
block	bio_copy_user_iov(): don't ignore ->iov_offset	2017-10-10 23:55:14 -04:00
certs	modsign: add markers to endif-statements in certs/Makefile	2017-07-14 11:01:37 +10:00
crypto	crypto: shash - Fix zero-length shash ahash digest crash	2017-10-11 00:34:07 +08:00
drivers	mm: only display online cpus of the numa node	2017-10-13 16:18:32 -07:00
firmware	firmware: Restore support for built-in firmware	2017-09-16 10:58:48 -07:00
fs	Changes since last update:	2017-10-12 14:51:13 -07:00
include	include/linux/of.h: provide of_n_{addr,size}_cells wrappers for !CONFIG_OF	2017-10-13 16:18:32 -07:00
init	Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2017-09-14 18:54:01 -07:00
ipc	fix a typo in put_compat_shm_info()	2017-09-25 20:41:46 -04:00
kernel	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching	2017-10-12 09:21:56 -07:00
lib	lib/Kconfig.debug: kernel hacking menu: runtime testing: keep tests together	2017-10-13 16:18:32 -07:00
mm	Revert "vmalloc: back off when the current task is killed"	2017-10-13 16:18:32 -07:00
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2017-10-09 16:25:00 -07:00
samples	media updates for v4.14-rc1	2017-09-07 12:53:14 -07:00
scripts	scripts/kallsyms.c: ignore symbol type 'n'	2017-10-13 16:18:32 -07:00
security	lsm: fix smack_inode_removexattr and xattr_getsecurity memleak	2017-10-04 18:03:15 +11:00
sound	ALSA: caiaq: Fix stray URB at probe error path	2017-10-11 17:01:18 +02:00
tools	userfaultfd: selftest: exercise -EEXIST only in background transfer	2017-10-13 16:18:32 -07:00
usr	ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk.	2017-07-06 16:24:30 -07:00
virt	Revert "KVM: Don't accept obviously wrong gsi values via KVM_IRQFD"	2017-09-19 08:37:17 +02:00
.cocciconfig	scripts: add Linux .cocciconfig for coccinelle	2016-07-22 12:13:39 +02:00
.get_maintainer.ignore	Add hch to .get_maintainer.ignore	2015-08-21 14:30:10 -07:00
.gitattributes	.gitattributes: set git diff driver for C source code files	2016-10-07 18:46:30 -07:00
.gitignore	kbuild: Add support to generate LLVM assembly files	2017-04-25 08:13:52 +09:00
.mailmap	Update James Hogan's email address	2017-10-04 17:11:53 -07:00
COPYING	…
CREDITS	selinux/stable-4.14 PR 20170831	2017-09-12 13:21:00 -07:00
Kbuild	kbuild: Consolidate header generation from ASM offset information	2017-04-13 05:43:37 +09:00
Kconfig	kbuild: migrate all arch to the kconfig mainmenu upgrade	2010-09-19 22:54:11 -04:00
MAINTAINERS	Another latent bug related to PCID, an out-of-bounds access,	2017-10-12 10:42:03 -07:00
Makefile	Linux 4.14-rc4	2017-10-08 20:53:29 -07:00
README	README: add a new README file, pointing to the Documentation/	2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.