This is a regression fix.
Before, to fix erratum AVR31, the following commit:
522e664644 ("x86/apic: Disable I/O APIC before shutdown of the local APIC")
... moved the lapic_shutdown() call to after disable_IO_APIC() in the reboot
and kexec/kdump code paths.
This introduced the following regression: disable_IO_APIC() not only clears
the IO-APIC, but it also restores boot IRQ mode by setting the
LAPIC/APIC/IMCR, calling lapic_shutdown() after disable_IO_APIC() will
disable LAPIC and ruin the possible virtual wire mode setting which
the code has been trying to do all along.
The consequence is that a KVM guest kernel always prints the warning below
during kexec/kdump as the kernel boots up:
[ 0.001000] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/apic/apic.c:1467 setup_local_APIC+0x228/0x330
[ ........]
[ 0.001000] Call Trace:
[ 0.001000] apic_bsp_setup+0x56/0x74
[ 0.001000] x86_late_time_init+0x11/0x16
[ 0.001000] start_kernel+0x3c9/0x486
[ 0.001000] secondary_startup_64+0xa5/0xb0
[ ........]
[ 0.001000] masked ExtINT on CPU#0
To fix this, just call clear_IO_APIC() to stop the IO-APIC where
disable_IO_APIC() was called, and call restore_boot_irq_mode() to
restore boot IRQ mode before a reboot or a kexec/kdump jump.
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: douly.fnst@cn.fujitsu.com
Cc: joro@8bytes.org
Cc: prarit@redhat.com
Cc: stable@vger.kernel.org
Cc: uobergfe@redhat.com
Fixes: commit 522e664644 ("x86/apic: Disable I/O APIC before shutdown of the local APIC")
Link: http://lkml.kernel.org/r/20180214054656.3780-4-bhe@redhat.com
[ Rewrote the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trying to reboot via real mode fails with PCID on: long mode cannot
be exited while CR4.PCIDE is set. (No, I have no idea why, but the
SDM and actual CPUs are in agreement here.) The result is a GPF and
a hang instead of a reboot.
I didn't catch this in testing because neither my computer nor my VM
reboots this way. I can trigger it with reboot=bios, though.
Fixes: 660da7c922 ("x86/mm: Enable CR4.PCIDE on supported systems")
Reported-and-tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/f1e7d965998018450a7a70c2823873686a8b21c0.1507524746.git.luto@kernel.org
... and __initconst if applicable.
Based on similar work for an older kernel in the Grsecurity patch.
[JD: fix toshiba-wmi build]
[JD: add htcpen]
[JD: move __initconst where checkscript wants it]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
kexec and reboot have both code to invalidate IDT. Create a common function
and use it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.600953282@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When EFI runtime services are disabled, for example by the "noefi"
kernel cmdline parameter, the reboot_type could still be set to
BOOT_EFI causing reboot to fail.
Fix this by checking if EFI runtime services are enabled.
Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170724122248.24006-1-sassmann@kpanic.de
[ Fixed 'not disabled' double negation. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for an objtool rewrite which will have broader checks,
whitelist functions and files which cause problems because they do
unusual things with the stack.
These whitelists serve as a TODO list for which functions and files
don't yet have undwarf unwinder coverage. Eventually most of the
whitelists can be removed in favor of manual CFI hint annotations or
objtool improvements.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/7f934a5d707a574bda33ea282e9478e627fb1829.1498659915.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When we are about to kexec a crash kernel and right then and there a
broadcasted MCE fires while we're still in the first kernel and while
the other CPUs remain in a holding pattern, the #MC handler of the
first kernel will timeout and then panic due to never completing MCE
synchronization.
Handle this in a similar way as to when the CPUs are offlined when that
broadcasted MCE happens.
[ Boris: rewrote commit message and comments. ]
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: kexec@lists.infradead.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1487857012-9059-1-git-send-email-xlpang@redhat.com
Link: http://lkml.kernel.org/r/20170313095019.19351-1-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The reboot quirk for ASUS EeeBook X205TA contains a typo in
DMI_PRODUCT_NAME, improperly referring to X205TAW instead of
X205TA, which prevents the quirk from being triggered. The
model X205TAW already has a reboot quirk of its own.
This fix simply removes the inappropriate final letter W.
Fixes: 90b28ded88 ("x86/reboot/quirks: Add ASUS EeeBook X205TA reboot quirk")
Signed-off-by: Matjaz Hegedic <matjaz.hegedic@gmail.com>
Link: http://lkml.kernel.org/r/1489064417-7445-1-git-send-email-matjaz.hegedic@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Without the parameter reboot=a, ASUS EeeBook X205TA/W will hang
when it should reboot. This adds the appropriate quirk, thus
fixing the problem.
Signed-off-by: Matjaz Hegedic <matjaz.hegedic@gmail.com>
Link: http://lkml.kernel.org/r/1488737804-20681-1-git-send-email-matjaz.hegedic@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Without the parameter reboot=a, ASUS EeeBook X205TA will hang when it should reboot.
This adds the appropriate quirk, thus fixing the problem.
Signed-off-by: Matjaz Hegedic <matjaz.hegedic@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Guided by grsecurity's analogous __read_only markings in arch/x86,
this applies several uses of __ro_after_init to structures that are
only updated during __init, and const for some structures that are
never updated. Additionally extends __init markings to some functions
that are only used during __init, and cleans up some missing C99 style
static initializers.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Link: http://lkml.kernel.org/r/20160808232906.GA29731@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 header cleanups from Ingo Molnar:
"This tree is a cleanup of the x86 tree reducing spurious uses of
module.h - which should improve build performance a bit"
* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads
x86/apic: Remove duplicated include from probe_64.c
x86/ce4100: Remove duplicated include from ce4100.c
x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t
x86/platform: Delete extraneous MODULE_* tags fromm ts5500
x86: Audit and remove any remaining unnecessary uses of module.h
x86/kvm: Audit and remove any unnecessary uses of module.h
x86/xen: Audit and remove any unnecessary uses of module.h
x86/platform: Audit and remove any unnecessary uses of module.h
x86/lib: Audit and remove any unnecessary uses of module.h
x86/kernel: Audit and remove any unnecessary uses of module.h
x86/mm: Audit and remove any unnecessary uses of module.h
x86: Don't use module.h just for AUTHOR / LICENSE tags
Dell Optiplex 7450 AIO works with BOOT_ACPI; however, the quirk for
"OptiPlex 745" changes its boot method to BOOT_BIOS and causes 7450 AIO
hangs when rebooting; as a result, 7450 AIO is appended to overwrite
BOOT_BIOS by BOOT_ACPI in order not to break the original 745 series
Signed-off-by: Alex Hung <alex.hung@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig. The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.
Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed. Build testing
revealed some implicit header usage that was fixed up accordingly.
Note that some bool/obj-y instances remain since module.h is
the header for some exception table entry stuff, and for things
like __init_or_module (code that is tossed when MODULES=n).
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If an EFI capsule has been sent to the firmware we must match the type
of EFI reset against that required by the capsule to ensure it is
processed correctly.
Force an EFI reboot if a capsule is pending for the next reset.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kweh Hock Leong <hock.leong.kweh@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: joeyli <jlee@suse.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-29-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Without the reboot=pci method, the iMac 10,1 simply
hangs after printing "Restarting system" at the point
when it should reboot. This fixes it.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
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: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1450466646-26663-1-git-send-email-mario.kleiner.de@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now, multiple CPUs can receive an external NMI simultaneously by
specifying the "apic_extnmi=all" command line parameter. When we take
a crash dump by using external NMI with this option, we fail to save
registers into the crash dump. This happens as follows:
CPU 0 CPU 1
================================ =============================
receive an external NMI
default_do_nmi() receive an external NMI
spin_lock(&nmi_reason_lock) default_do_nmi()
io_check_error() spin_lock(&nmi_reason_lock)
panic() busy loop
...
kdump_nmi_shootdown_cpus()
issue NMI IPI -----------> blocked until IRET
busy loop...
Here, since CPU 1 is in NMI context, an additional NMI from CPU 0
remains unhandled until CPU 1 IRETs. However, CPU 1 will never execute
IRET so the NMI is not handled and the callback function to save
registers is never called.
To solve this issue, we check if the IPI for crash dumping was issued
while waiting for nmi_reason_lock to be released, and if so, call its
callback function directly. If the IPI is not issued (e.g. kdump is
disabled), the actual behavior doesn't change.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: kexec@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20151210065245.4587.39316.stgit@softrs
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Currently, kdump_nmi_shootdown_cpus(), a subroutine of crash_kexec(),
sends an NMI IPI to CPUs which haven't called panic() to stop them,
save their register information and do some cleanups for crash dumping.
However, if such a CPU is infinitely looping in NMI context, we fail to
save its register information into the crash dump.
For example, this can happen when unknown NMIs are broadcast to all
CPUs as follows:
CPU 0 CPU 1
=========================== ==========================
receive an unknown NMI
unknown_nmi_error()
panic() receive an unknown NMI
spin_trylock(&panic_lock) unknown_nmi_error()
crash_kexec() panic()
spin_trylock(&panic_lock)
panic_smp_self_stop()
infinite loop
kdump_nmi_shootdown_cpus()
issue NMI IPI -----------> blocked until IRET
infinite loop...
Here, since CPU 1 is in NMI context, the second NMI from CPU 0 is
blocked until CPU 1 executes IRET. However, CPU 1 never executes IRET,
so the NMI is not handled and the callback function to save registers is
never called.
In practice, this can happen on some servers which broadcast NMIs to all
CPUs when the NMI button is pushed.
To save registers in this case, we need to:
a) Return from NMI handler instead of looping infinitely
or
b) Call the callback function directly from the infinite loop
Inherently, a) is risky because NMI is also used to prevent corrupted
data from being propagated to devices. So, we chose b).
This patch does the following:
1. Move the infinite looping of CPUs which haven't called panic() in NMI
context (actually done by panic_smp_self_stop()) outside of panic() to
enable us to refer pt_regs. Please note that panic_smp_self_stop() is
still used for normal context.
2. Call a callback of kdump_nmi_shootdown_cpus() directly to save
registers and do some cleanups after setting waiting_for_crash_ipi which
is used for counting down the number of CPUs which handled the callback
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Javi Merino <javi.merino@arm.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: kexec@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: lkml <linux-kernel@vger.kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/20151210014628.25437.75256.stgit@softrs
[ Cleanup comments, fixup formatting. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There are two kexec load syscalls, kexec_load another and kexec_file_load.
kexec_file_load has been splited as kernel/kexec_file.c. In this patch I
split kexec_load syscall code to kernel/kexec.c.
And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.
The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use
kexec_load syscall can bypass the checking.
Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.
Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig. Also updated general kernel code with to
kexec_load syscall.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ASRock Q1900DC-ITX mainboard (Baytrail-D) hangs randomly in
both BIOS and UEFI mode while rebooting unless reboot=pci is
used. Add a quirk to reboot via the pci method.
The problem is very intermittent and hard to debug, it might succeed
rebooting just fine 40 times in a row - but fails half a dozen times
the next day. It seems to be slightly less common in BIOS CSM mode
than native UEFI (with the CSM disabled), but it does happen in either
mode. Since I've started testing this patch in late january, rebooting
has been 100% reliable.
Most of the time it already hangs during POST, but occasionally it
might even make it through the bootloader and the kernel might even
start booting, but then hangs before the mode switch. The same symptoms
occur with grub-efi, gummiboot and grub-pc, just as well as (at least)
kernel 3.16-3.19 and 4.0-rc6 (I haven't tried older kernels than 3.16).
Upgrading to the most current mainboard firmware of the ASRock
Q1900DC-ITX, version 1.20, does not improve the situation.
( Searching the web seems to suggest that other Bay Trail-D mainboards
might be affected as well. )
--
Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Cc: <stable@vger.kernel.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/20150330224427.0fb58e42@mir
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Clean up code by moving IOAPIC related declarations from hw_irq.h into
io_apic.h.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Aubrey <aubrey.li@linux.intel.com>
Cc: Ryan Desfosses <ryan@desfo.org>
Cc: Quentin Lambert <lambert.quentin@gmail.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: http://lkml.kernel.org/r/1414397531-28254-14-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
It appears that the BayTrail-T class of hardware requires EFI in order
to powerdown and reboot and no other reliable method exists.
This quirk is generally applicable to all hardware that has the ACPI
Hardware Reduced bit set, since usually ACPI would be the preferred
method.
Cc: Len Brown <len.brown@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Implement efi_reboot(), which is really just a wrapper around the
EfiResetSystem() EFI runtime service, but it does at least allow us to
funnel all callers through a single location.
It also simplifies the callsites since users no longer need to check to
see whether EFI_RUNTIME_SERVICES are enabled.
Cc: Tony Luck <tony.luck@intel.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Steve reported a reboot hang and bisected it back to this commit:
a4f1987e4c x86, reboot: Add EFI and CF9 reboot methods into the default list
He heroically tested all reboot methods and found the following:
reboot=t # triple fault ok
reboot=k # keyboard ctrl FAIL
reboot=b # BIOS ok
reboot=a # ACPI FAIL
reboot=e # EFI FAIL [system has no EFI]
reboot=p # PCI 0xcf9 FAIL
And I think it's pretty obvious that we should only try PCI 0xcf9 as a
last resort - if at all.
The other observation is that (on this box) we should never try
the PCI reboot method, but close with either the 'triple fault'
or the 'BIOS' (terminal!) reboot methods.
Thirdly, CF9_COND is a total misnomer - it should be something like
CF9_SAFE or CF9_CAREFUL, and 'CF9' should be 'CF9_FORCE' ...
So this patch fixes the worst problems:
- it orders the actual reboot logic to follow the reboot ordering
pattern - it was in a pretty random order before for no good
reason.
- it fixes the CF9 misnomers and uses BOOT_CF9_FORCE and
BOOT_CF9_SAFE flags to make the code more obvious.
- it tries the BIOS reboot method before the PCI reboot method.
(Since 'BIOS' is a terminal reboot method resulting in a hang
if it does not work, this is essentially equivalent to removing
the PCI reboot method from the default reboot chain.)
- just for the miraculous possibility of terminal (resulting
in hang) reboot methods of triple fault or BIOS returning
without having done their job, there's an ordering between
them as well.
Reported-and-bisected-and-tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Aubrey <aubrey.li@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Link: http://lkml.kernel.org/r/20140404064120.GB11877@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Only CF9_COND is appropriate for inclusion in the default chain, not
CF9; the latter will poke that register unconditionally, whereas
CF9_COND will at least look for PCI configuration method #1 or #2
first (a weak check, but better than nothing.)
CF9 should be used for explicit system configuration (command line or
DMI) only.
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Link: http://lkml.kernel.org/r/53130A46.1010801@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Reboot is the last service linux OS provides to the end user. We are
supposed to make this function more robust than today. This patch adds
all of the known reboot methods into the default attempt list. The
machines requiring reboot=efi or reboot=p or reboot=bios get a chance
to reboot automatically now.
If there is a new reboot method emerged, we are supposed to add it to
the default list as well, instead of adding the endless dmidecode entry.
If one method required is in the default list in this patch but the
machine reboot still hangs, that means some methods ahead of the
required method cause the system hangs, then reboot the machine by
passing reboot= arguments and submit the reboot dmidecode table quirk.
We are supposed to remove the reboot dmidecode table from the kernel,
but to be safe, we keep it. This patch prevents us from adding more.
If you happened to have a machine listed in the reboot dmidecode
table and this patch makes reboot work on your machine, please submit
a patch to remove the quirk.
The default reboot order with this patch is now:
ACPI > KBD > ACPI > KBD > EFI > CF9_COND > BIOS
Because BIOS and TRIPLE are mutually exclusive (either will either
work or hang the machine) that method is not included.
[ hpa: as with any changes to the reboot order, this patch will have
to be monitored carefully for regressions. ]
Signed-off-by: Aubrey Li <aubrey.li@intel.com>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Link: http://lkml.kernel.org/r/53130A46.1010801@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Since erratum AVR31 in "Intel Atom Processor C2000 Product Family
Specification Update" is now published, I added a justification
comment for disabling IO APIC before Local APIC, as changed in commit:
522e664644 x86/apic: Disable I/O APIC before shutdown of the local APIC
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1386202069-51515-1-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 reboot changes from Ingo Molnar:
"Misc changes - the only one with functional impact should be commit
16c21ae5ca ("reboot: Allow specifying warm/cold reset for CF9 boot
type") which extends cold/warm reboot handling to the 0xCF9 reboot
method"
* 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/reboot: Correct pr_info() log message in the set_bios/pci/kbd_reboot()
x86/reboot: Sort reboot DMI quirks by vendor
x86/reboot: Remove the duplicate C6100 entry in the reboot quirks list
reboot: Allow specifying warm/cold reset for CF9 boot type
In reboot and crash path, when we shut down the local APIC, the I/O APIC is
still active. This may cause issues because external interrupts
can still come in and disturb the local APIC during shutdown process.
To quiet external interrupts, disable I/O APIC before shutdown local APIC.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1382578212-4677-1-git-send-email-fenghua.yu@intel.com
Cc: <stable@kernel.org>
[ I suppose the 'issue' is a hang during shutdown. It's a fine change nevertheless. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Two entries for the same system type were added, with two different vendor
names: 'Dell' and 'Dell, Inc.'.
Since a prefix match is being used by the DMI parsing code, we can eliminate
the latter as redundant.
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Masoud Sharbiani <msharbiani@twitter.com>
Cc: holt@sgi.com
Link: http://lkml.kernel.org/r/1380216643-4683-1-git-send-email-masoud.sharbiani@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In current implementation for reboot type CF9 and CF9_COND,
warm and cold reset are not differentiated, and both are
performed by writing 0x06 to port 0xCF9.
This commit will differentiate warm and cold reset:
For warm reset, write 0x06 to port 0xCF9;
For cold reset, write 0x0E to port 0xCF9.
[ hpa: This meaning of "cold" and "warm" reset is different from other
reboot types use, where "warm" means "bypass BIOS POST". It is also
not entirely clear that it actually solves any actual problem. However,
it would seem fairly harmless to offer this additional option.
Also note that we do not mask bit 3 in the "warm reset" case. This
preserves the behavior on existing systems, including ones quirked
to use CF9. It seems reasonable that on any system where the
warm/cold distinction actually matters that bit 3 would be read as
zero. ]
From: Liu Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Li Fei <fei.li@intel.com>
Link: http://lkml.kernel.org/r/1377072837.24556.2.camel@fli24-HP-Compaq-8100-Elite-CMT-PC
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This seems to have been copied from the Optiplex 990 entry
above, but somoene forgot to change the ident text.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Link: http://lkml.kernel.org/r/20130925001344.GA13554@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge together the unicore32, arm, and x86 reboot= command line
parameter handling.
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prepare for the moving the parsing of reboot= to the generic kernel code
by making reboot_mode into a more generic form.
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Miguel Boton <mboton.lkml@gmail.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.
The immediate motivation for this patch is the bug report at,
https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,
https://bugzilla.kernel.org/show_bug.cgi?id=47121
details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,
if (!efi_enabled)
hasn't been a sufficient condition for quite some time.
Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.
For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).
This patch is a prereq for the samsung-laptop fix patch.
Cc: David Airlie <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Remove the quirk for the SBC FITPC. It seems ot have been
required when the default was kbd reboot, but no longer required
now that the default is acpi reboot. Furthermore, BIOS reboot no
longer works for this board as of 2.6.39 or any of the 3.x
kernels.
Signed-off-by: David Hooper <dave@beermex.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/20121002142635.17403.59959.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86/reboot changes from Ingo Molnar:
"Now that the revampted x86 real-mode trampoline code is upstream and
seems to be working well, we can extend the 64-bit reboot code to be
as capable as the 32-bit one."
* 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86-64, reboot: Be more paranoid in 64-bit reboot=bios
x86, reboot: Drop redundant write of reboot_mode
x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64
Pull debug-for-linus git tree from Ingo Molnar.
Fix up trivial conflict in arch/x86/kernel/cpu/perf_event_intel.c due to
a printk() having changed to a pr_info() differently in the two branches.
* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Move call to print_modules() out of show_regs()
x86/mm: Mark free_initrd_mem() as __init
x86/microcode: Mark microcode_id[] as __initconst
x86/nmi: Clean up register_nmi_handler() usage
x86: Save cr2 in NMI in case NMIs take a page fault (for i386)
x86: Remove cmpxchg from i386 NMI nesting code
x86: Save cr2 in NMI in case NMIs take a page fault
x86/debug: Add KERN_<LEVEL> to bare printks, convert printks to pr_<level>
We write reboot_mode to BIOS location 0x472 in
native_machine_emergency_restart() (reboot.c:542) already, there is no
need to then write it again in machine_real_restart().
This means nothing gets written there for MRR_APM, but the APM call is
a poweroff call and doesn't use this memory location.
Link: http://lkml.kernel.org/n/tip-3i0pfh44c1e3jv5lab0cf7sc@git.kernel.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
With the revamped realmode trampoline code, it is trivial to extend
support for reboot=bios to x86-64. Furthermore, while we are at it,
remove the restriction that only we can only override the reboot CPU
on 32 bits.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
When rebooting our 24 CPU Westmere servers with 3.4-rc6, we
always see this warning msg:
Restarting system.
machine restart
------------[ cut here ]------------
WARNING: at arch/x86/kernel/smp.c:125
native_smp_send_reschedule+0x74/0xa7() Hardware name: X8DTN
Modules linked in: igb [last unloaded: scsi_wait_scan]
Pid: 1, comm: systemd-shutdow Not tainted 3.4.0-rc6+ #22
Call Trace:
<IRQ> [<ffffffff8102a41f>] warn_slowpath_common+0x7e/0x96
[<ffffffff8102a44c>] warn_slowpath_null+0x15/0x17
[<ffffffff81018cf7>] native_smp_send_reschedule+0x74/0xa7
[<ffffffff810561c1>] trigger_load_balance+0x279/0x2a6
[<ffffffff81050112>] scheduler_tick+0xe0/0xe9
[<ffffffff81036768>] update_process_times+0x60/0x70
[<ffffffff81062f2f>] tick_sched_timer+0x68/0x92
[<ffffffff81046e33>] __run_hrtimer+0xb3/0x13c
[<ffffffff81062ec7>] ? tick_nohz_handler+0xd0/0xd0
[<ffffffff810474f2>] hrtimer_interrupt+0xdb/0x198
[<ffffffff81019a35>] smp_apic_timer_interrupt+0x81/0x94
[<ffffffff81655187>] apic_timer_interrupt+0x67/0x70
<EOI> [<ffffffff8101a3c4>] ? default_send_IPI_mask_allbutself_phys+0xb4/0xc4
[<ffffffff8101c680>] physflat_send_IPI_allbutself+0x12/0x14
[<ffffffff81018db4>] native_nmi_stop_other_cpus+0x8a/0xd6
[<ffffffff810188ba>] native_machine_shutdown+0x50/0x67
[<ffffffff81018926>] machine_shutdown+0xa/0xc
[<ffffffff8101897e>] native_machine_restart+0x20/0x32
[<ffffffff810189b0>] machine_restart+0xa/0xc
[<ffffffff8103b196>] kernel_restart+0x47/0x4c
[<ffffffff8103b2e6>] sys_reboot+0x13e/0x17c
[<ffffffff8164e436>] ? _raw_spin_unlock_bh+0x10/0x12
[<ffffffff810fcac9>] ? bdi_queue_work+0xcf/0xd8
[<ffffffff810fe82f>] ? __bdi_start_writeback+0xae/0xb7
[<ffffffff810e0d64>] ? iterate_supers+0xa3/0xb7
[<ffffffff816547a2>] system_call_fastpath+0x16/0x1b
---[ end trace 320af5cb1cb60c5b ]---
The root cause seems to be the
default_send_IPI_mask_allbutself_phys() takes quite some time (I
measured it could be several ms) to complete sending NMIs to all
the other 23 CPUs, and for HZ=250/1000 system, the time is long
enough for a timer interrupt to happen, which will in turn
trigger to kick load balance to a stopped CPU and cause this
warning in native_smp_send_reschedule().
So disabling the local irq before stop_other_cpu() can fix this
problem (tested 25 times reboot ok), and it is fine as there
should be nobody caring the timer interrupt in such reboot
stage.
The latest 3.4 kernel slightly changes this behavior by sending
REBOOT_VECTOR first and only send NMI_VECTOR if the REBOOT_VCTOR
fails, and this patch is still needed to prevent the problem.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120530231541.4c13433a@feng-i7
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Baoquan He