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Aneesh Kumar K.V fc5c2f4a55 powerpc/mm/hash64: Zero PGD pages on allocation
On powerpc we allocate page table pages from slab caches of different
sizes. Currently we have a constructor that zeroes out the objects when
we allocate them for the first time.

We expect the objects to be zeroed out when we free the the object
back to slab cache. This happens in the unmap path. For hugetlb pages
we call huge_pte_get_and_clear() to do that.

With the current configuration of page table size, both PUD and PGD
level tables are allocated from the same slab cache. At the PUD level,
we use the second half of the table to store the slot information. But
we never clear that when unmapping.

When such a freed object is then allocated for a PGD page, the second
half of the page table page will not be zeroed as expected. This
results in a kernel crash.

Fix it by always clearing PGD pages when they're allocated.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Change log wording and formatting, add whitespace]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13 22:37:48 +11:00
Documentation linux-watchdog 4.16-rc1 merge window tag 2018-02-07 11:54:34 -08:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
arch powerpc/mm/hash64: Zero PGD pages on allocation 2018-02-13 22:37:48 +11:00
block for-linus-20180204 2018-02-04 11:16:35 -08:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-01-31 14:22:45 -08:00
drivers ocxl: fix signed comparison with less than zero 2018-02-08 23:56:11 +11:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs iversion.h related cleanup for v4.16 2018-02-07 14:25:22 -08:00
include iversion.h related cleanup for v4.16 2018-02-07 14:25:22 -08:00
init membarrier: Provide core serializing command, *_SYNC_CORE 2018-02-05 21:35:03 +01:00
ipc ipc/mqueue.c: have RT tasks queue in by priority in wq_add() 2018-02-06 18:32:46 -08:00
kernel Modules updates for v4.16 2018-02-07 14:29:34 -08:00
lib Merge branch 'akpm' (patches from Andrew) 2018-02-06 22:15:42 -08:00
mm Merge branch 'akpm' (patches from Andrew) 2018-02-06 22:15:42 -08:00
net seq_file: Introduce DEFINE_SHOW_ATTRIBUTE() helper macro 2018-02-07 12:50:21 +02:00
samples sample/bpf: fix erspan metadata 2018-02-06 11:32:49 -05:00
scripts Modules updates for v4.16 2018-02-07 14:29:34 -08:00
security iversion.h related cleanup for v4.16 2018-02-07 14:25:22 -08:00
sound ASoC: Updates for v4.16 2018-02-07 12:11:09 -08:00
tools Merge branch 'akpm' (patches from Andrew) 2018-02-06 22:15:42 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt Currently, hardened usercopy performs dynamic bounds checking on slab 2018-02-03 16:25:42 -08:00
.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 scripts/package: snap-pkg target 2017-12-13 00:00:18 +09:00
.mailmap mailmap: update Mark Yao's email address 2018-01-04 16:45:09 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Modules updates for v4.16 2018-02-07 14:29:34 -08:00
Makefile Makefile: introduce CONFIG_CC_STACKPROTECTOR_AUTO 2018-02-06 18:32:44 -08:00
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.