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Reinette Chatre 80b71c340f x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence
The user triggers the creation of a pseudo-locked region when writing
the requested schemata to the schemata resctrl file. The pseudo-locking
of a region is required to be done on a CPU that is associated with the
cache on which the pseudo-locked region will reside. In order to run the
locking code on a specific CPU, the needed CPU has to be selected and
ensured to remain online during the entire locking sequence.

At this time, the cpu_hotplug_lock is not taken during the pseudo-lock
region creation and it is thus possible for a CPU to be selected to run
the pseudo-locking code and then that CPU to go offline before the
thread is able to run on it.

Fix this by ensuring that the cpu_hotplug_lock is taken while the CPU on
which code has to run needs to be controlled. Since the cpu_hotplug_lock
is always taken before rdtgroup_mutex the lock order is maintained.

Fixes: e0bdfe8e36 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: gavin.hindman@intel.com
Cc: jithu.joseph@intel.com
Cc: stable <stable@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/b7b17432a80f95a1fa21a1698ba643014f58ad31.1544476425.git.reinette.chatre@intel.com
2018-12-11 21:59:01 +01:00
Documentation Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-01 12:35:48 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
arch x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence 2018-12-11 21:59:01 +01:00
block block: fix single range discard merge 2018-11-30 10:07:57 -07:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: user - Zeroize whole structure given to user space 2018-11-09 17:35:43 +08:00
drivers ARM: SoC fixes 2018-12-02 12:19:44 -08:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs for-linus-20181201 2018-12-01 11:36:32 -08:00
include ARM: SoC fixes 2018-12-02 12:19:44 -08:00
init initramfs: clean old path before creating a hardlink 2018-11-30 14:56:14 -08:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-01 12:35:48 -08:00
lib debugobjects: avoid recursive calls with kmemleak 2018-11-30 14:56:14 -08:00
mm mm/khugepaged: fix the xas_create_range() error path 2018-11-30 14:56:15 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2018-11-28 11:02:45 -08:00
samples VFIO updates for v4.20 2018-10-31 11:01:38 -07:00
scripts Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-01 12:35:48 -08:00
security selinux/stable-4.20 PR 20181129 2018-11-29 10:15:06 -08:00
sound ALSA: usb-audio: Add vendor and product name for Dell WD19 Dock 2018-11-28 10:59:49 +01:00
tools Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-01 12:35:48 -08:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks" 2018-10-26 16:25:19 -07:00
.clang-format page cache: Convert find_get_pages_contig to XArray 2018-10-21 10:46:34 -04:00
.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 updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap mailmap: Update email for Punit Agrawal 2018-11-05 10:02:11 +00:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: change Sparse's maintainer 2018-11-25 09:17:43 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS ARM: SoC fixes 2018-12-02 12:19:44 -08:00
Makefile Linux 4.20-rc5 2018-12-02 15:07:55 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.