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Andy Lutomirski e50928d721 x86/fault: Fix SMAP #PF handling buglet for implicit supervisor accesses
Currently, if a user program somehow triggers an implicit supervisor
access to a user address (e.g. if the kernel somehow sets LDTR to a
user address), it will be incorrectly detected as a SMAP violation
if AC is clear and SMAP is enabled.  This is incorrect -- the error
has nothing to do with SMAP.  Fix the condition so that only
accesses with the hardware USER bit set are diagnosed as SMAP
violations.

With the logic fixed, an implicit supervisor access to a user address
will hit the code lower in the function that is intended to handle it
even if SMAP is enabled.  That logic is still a bit buggy, and later
patches will clean it up.

I *think* this code is still correct for WRUSS, and I've added a
comment to that effect.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/d1d1b2e66ef31f884dba172084486ea9423ddcdb.1542667307.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-20 08:44:29 +01:00
arch x86/fault: Fix SMAP #PF handling buglet for implicit supervisor accesses 2018-11-20 08:44:29 +01:00
block for-linus-20181109 2018-11-09 16:31:51 -06:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto KEYS: asym_tpm: Add support for the sign operation [ver #2] 2018-10-26 09:30:47 +01:00
Documentation Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-11-11 16:41:50 -06:00
drivers Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-11-11 17:09:48 -06:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs for-4.20-rc1-tag 2018-11-11 16:54:38 -06:00
include Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-11-11 16:41:50 -06:00
init memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-11-11 16:37:41 -06:00
lib lib/raid6: Fix arm64 test build 2018-11-06 17:12:44 +00:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
mm memory_hotplug: cond_resched in __remove_pages 2018-11-03 10:09:38 -07:00
net act_mirred: clear skb->tstamp on redirect 2018-11-11 10:21:31 -08:00
samples VFIO updates for v4.20 2018-10-31 11:01:38 -07:00
scripts builddeb: Fix inclusion of dtbs in debian package 2018-11-11 23:04:53 +09:00
security + Features/Improvements 2018-11-02 10:04:26 -07:00
sound ALSA: hda - Fix incorrect clearance of thinkpad_acpi hooks 2018-11-06 16:33:53 +01:00
tools perf/urgent improvements and fixes: 2018-11-06 20:03:11 +01:00
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 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
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 Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2018-11-10 06:57:34 -06:00
Makefile Linux 4.20-rc2 2018-11-11 17:12:31 -06:00
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.