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Peter Zijlstra 42f3bdc5dd x86/events/intel/ds: Use the proper cache flush method for mapping ds buffers
Thomas reported the following warning:

 BUG: using smp_processor_id() in preemptible [00000000] code: ovsdb-server/4498
 caller is native_flush_tlb_single+0x57/0xc0
 native_flush_tlb_single+0x57/0xc0
 __set_pte_vaddr+0x2d/0x40
 set_pte_vaddr+0x2f/0x40
 cea_set_pte+0x30/0x40
 ds_update_cea.constprop.4+0x4d/0x70
 reserve_ds_buffers+0x159/0x410
 x86_reserve_hardware+0x150/0x160
 x86_pmu_event_init+0x3e/0x1f0
 perf_try_init_event+0x69/0x80
 perf_event_alloc+0x652/0x740
 SyS_perf_event_open+0x3f6/0xd60
 do_syscall_64+0x5c/0x190

set_pte_vaddr is used to map the ds buffers into the cpu entry area, but
there are two problems with that:

 1) The resulting flush is not supposed to be called in preemptible context

 2) The cpu entry area is supposed to be per CPU, but the debug store
    buffers are mapped for all CPUs so these mappings need to be flushed
    globally.

Add the necessary preemption protection across the mapping code and flush
TLBs globally.

Fixes: c1961a4631 ("x86/events/intel/ds: Map debug buffers in cpu_entry_area")
Reported-by: Thomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180104170712.GB3040@hirez.programming.kicks-ass.net
2018-01-05 00:39:58 +01:00
arch x86/events/intel/ds: Use the proper cache flush method for mapping ds buffers 2018-01-05 00:39:58 +01:00
block License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 2017-11-06 09:05:03 -08:00
Documentation x86/kaslr: Fix the vaddr_end mess 2018-01-05 00:39:57 +01:00
drivers locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-17 13:57:15 +01:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-17 13:57:15 +01:00
include x86/mm/pti: Add infrastructure for page table isolation 2017-12-23 21:12:59 +01:00
init x86/mm/pti: Add infrastructure for page table isolation 2017-12-23 21:12:59 +01:00
ipc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kernel arch, mm: Allow arch_dup_mmap() to fail 2017-12-22 20:13:01 +01:00
lib Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
mm locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-17 13:57:15 +01:00
net vlan: fix a use-after-free in vlan_device_event() 2017-11-11 19:35:32 +09:00
samples License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
scripts Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
security x86/pti: Enable PTI by default 2018-01-03 15:57:58 +01:00
sound sound fixes for 4.14 2017-11-09 09:58:11 -08:00
tools x86/ldt: Make the LDT mapping RO 2017-12-23 21:13:01 +01:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt Fixes for interrupt controller emulation in ARM/ARM64 and x86, plus a one-liner 2017-11-04 11:44:55 -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 to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2017-11-09 18:26:51 -08:00
Makefile Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

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.