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Tony Luck 40c36e2741 x86/mce: Fix incorrect "Machine check from unknown source" message
Some injection testing resulted in the following console log:

  mce: [Hardware Error]: CPU 22: Machine Check Exception: f Bank 1: bd80000000100134
  mce: [Hardware Error]: RIP 10:<ffffffffc05292dd> {pmem_do_bvec+0x11d/0x330 [nd_pmem]}
  mce: [Hardware Error]: TSC c51a63035d52 ADDR 3234bc4000 MISC 88
  mce: [Hardware Error]: PROCESSOR 0:50654 TIME 1526502199 SOCKET 0 APIC 38 microcode 2000043
  mce: [Hardware Error]: Run the above through 'mcelog --ascii'
  Kernel panic - not syncing: Machine check from unknown source

This confused everybody because the first line quite clearly shows
that we found a logged error in "Bank 1", while the last line says
"unknown source".

The problem is that the Linux code doesn't do the right thing
for a local machine check that results in a fatal error.

It turns out that we know very early in the handler whether the
machine check is fatal. The call to mce_no_way_out() has checked
all the banks for the CPU that took the local machine check. If
it says we must crash, we can do so right away with the right
messages.

We do scan all the banks again. This means that we might initially
not see a problem, but during the second scan find something fatal.
If this happens we print a slightly different message (so I can
see if it actually every happens).

[ bp: Remove unneeded severity assignment. ]

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: stable@vger.kernel.org # 4.2
Link: http://lkml.kernel.org/r/52e049a497e86fd0b71c529651def8871c804df0.1527283897.git.tony.luck@intel.com
2018-06-22 14:35:50 +02:00
arch x86/mce: Fix incorrect "Machine check from unknown source" message 2018-06-22 14:35:50 +02:00
block Merge branch 'hch.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:00:01 -07:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto Merge branch 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 13:57:43 -07:00
Documentation Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 21:34:39 -07:00
drivers Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-06-04 15:23:48 -07:00
include Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 21:02:18 -07:00
init init/main.c: include <linux/mem_encrypt.h> 2018-05-25 18:12:11 -07:00
ipc Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 21:02:18 -07:00
kernel Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 21:02:18 -07:00
lib Merge branch 'x86-dax-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 19:23:13 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
mm Merge branch 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 13:57:43 -07:00
net Merge branch 'work.aio-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 13:57:43 -07:00
samples x86/cpufeature: Guard asm_volatile_goto usage for BPF compilation 2018-05-13 21:49:14 +02:00
scripts There's been a fair amount of work in the docs tree this time around, 2018-06-04 12:34:27 -07:00
security Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-06-04 15:21:19 -07:00
sound ALSA: hda - Fix runtime PM 2018-05-24 20:16:47 +02:00
tools Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 17:14:22 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-06-04 15:23:48 -07:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig
.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 Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
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 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 16:40:11 -07:00
Makefile Linux 4.17 2018-06-03 14:15:21 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -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.
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.