Impact: extend nmi_shootdown_cpus() with a callback

The reboot code will use a different function on crash_nmi_callback().
Adding a function pointer parameter to nmi_shootdown_cpus() for that.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

For the kdump-specific code that was living on nmi_shootdown_cpus().
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

This variable will be moved to non-kdump-specific code.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

The NMI CPU-halting code will be used on non-kdump cases, also
(e.g. emergency_reboot when virtualization is enabled).
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch a llows machine_crash_shutdown to
be replaced, just like any of the other functions
in machine_ops
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

take them out of the x86_64-only asm/mach_apic.h
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

we should also add hpet_disable() for kdump.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

X86_32 build fix to commit 62a31a03Signed-off-by: NMike Galbraith <efault@gmx.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Most of contents in crash are same.
Signed-off-by: NHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch moves the die notifier handling to common code.  Previous
various architectures had exactly the same code for it.  Note that the new
code is compiled unconditionally, this should be understood as an appel to
the other architecture maintainer to implement support for it aswell (aka
sprinkling a notify_die or two in the proper place)

arm had a notifiy_die that did something totally different, I renamed it to
arm_notify_die as part of the patch and made it static to the file it's
declared and used at.  avr32 used to pass slightly less information through
this interface and I brought it into line with the other architectures.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix vmalloc_sync_all bustage]
[bryan.wu@analog.com: fix vmalloc_sync_all in nommu]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The elf note saving code is currently duplicated over several
architectures.  This cleanup patch simply adds code to a common file and
then replaces the arch-specific code with calls to the newly added code.

The only drawback with this approach is that s390 doesn't fully support
kexec-on-panic which for that arch leads to introduction of unused code.
Signed-off-by: NMagnus Damm <magnus@valinux.co.jp>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Re-implement smp_send_nmi_allbutself() so that calls to smp_processor_id
(through send_IPI_allbutself) can be replaced with safe_smp_processor_id
without affecting other parts of the kernel (as suggested by Eric Biederman).
Signed-off-by: NFernando Vazquez <fernando@intellilink.co.jp>
Looks-reasonable-to: Andi Kleen <ak@muc.de>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Substitute "smp_processor_id" with the stack overflow-safe
"safe_smp_processor_id" in the reboot path to the second kernel.

[akpm@osdl.org: build fix]
Signed-off-by: NFernando Vazquez <fernando@intellilink.co.jp>
Looks-reasonable-to: Andi Kleen <ak@muc.de>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

After a crash we should wait for NMI IPI event and not for external NMI or
NMI watchdog tick.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Removes the un/set_nmi_callback and reserve/release_lapic_nmi functions as
they are no longer needed.  The various subsystems are modified to register
with the die_notifier instead.

Also includes compile fixes by Andrew Morton.
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

This patch removes the foolish assumption that SMP implied local apics.
That assumption is not-true on the Voyager subarch.  This makes that
dependency explicit, and allows the code to build.

What gets disabled is just an optimization to get better crash dumps so the
support should work if there is a kernel that will initialization on the
voyager subarch under those harsh conditions.

Hopefully we can figure out how to initialize apics in init_IRQ and remove
the need to disable io_apics and this dependency.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

x86_64 and i386 behave inconsistently when sending an IPI on vector 2
(NMI_VECTOR).  Make both behave the same, so IPI 2 is sent as NMI.

The crash code was abusing send_IPI_allbutself() by passing a code
instead of a vector, it only worked because crash knew about the
internal code of send_IPI_allbutself().  Change crash to use NMI_VECTOR
instead, and remove the comment about how crash was abusing the function.

This patch is a pre-requisite for fixing the problem where sending an
IPI as NMI would reboot some Dell Xeon systems.  I cannot fix that
problem while crash continus to abuse send_IPI_allbutself().

It also removes the inconsistency between i386 and x86_64 for
NMI_VECTOR.  That will simplify all the RAS code that needs to bring
all the cpus to a clean stop, even when one or more cpus are spinning
disabled.
Signed-off-by: NKeith Owens <kaos@sgi.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In a testament to the utter simplicity and logic of the English
language ;-), I found a single correct use - in kernel/panic.c - and
10-15 incorrect ones.
Signed-Off-By: NLee Revell <rlrevell@joe-job.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Add cpu_relax() to infinite loops in crash.c and doublefault.c.  This is
the safest change.
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kexec: grammar fix for crash_save_this_cpu()
Signed-Off-By: NHorms <horms@verge.net.au>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

>commit 76381fee
>Author: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
>Date:   Thu Jun 23 00:08:46 2005 -0700
>
>    [PATCH] xen: x86_64: use more usermode macro
>
>    Make use of the user_mode macro where it's possible.  This is useful for Xen
>    because it will need only to redefine only the macro to a hypervisor call.

I am of the opinion that the above changeset is incomplete, i.e.  it missed
converting some previous uses of user_mode to user_mode_vm.  While most of
them could be considered just cosmetical, at least the one in die_nmi
doesn't appear to be.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Cc: Zachary Amsden <zach@vmware.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- If system panics then cpu register states are captured through funciton
  crash_get_current_regs().  This is not a inline function hence a stack frame
  is pushed on to the stack and then cpu register state is captured.  Later
  this frame is popped and new frames are pushed (machine_kexec).

- In theory this is not very right as we are capturing register states for a
  frame and that frame is no more valid.  This seems to have created back
  trace problems for ppc64.

- This patch fixes it up.  The very first thing it does after entering
  crash_kexec() is to capture the register states.  Anyway we don't want the
  back trace beyond crash_kexec().  crash_get_current_regs() has been made
  inline

- crash_setup_regs() is the top architecture dependent function which should
  be responsible for capturing the register states as well as to do some
  architecture dependent tricks.  For ex.  fixing up ss and esp for i386.
  crash_setup_regs() has also been made inline to ensure no new call frame is
  pushed onto stack.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- In case of system crash, current state of cpu registers is saved in memory
  in elf note format.  So far memory for storing elf notes was being allocated
  statically for NR_CPUS.

- This patch introduces dynamic allocation of memory for storing elf notes.
  It uses alloc_percpu() interface.  This should lead to better memory usage.

- Introduced based on Andi Kleen's and Eric W. Biederman's suggestions.

- This patch also moves memory allocation for elf notes from architecture
  dependent portion to architecture independent portion.  Now crash_notes is
  architecture independent.  The whole idea is that size of memory to be
  allocated per cpu (MAX_NOTE_BYTES) can be architecture dependent and
  allocation of this memory can be architecture independent.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

)

From: Vivek Goyal <vgoyal@in.ibm.com>

This patch fixes a minor bug based on Andi Kleen's suggestion.  asm's can't be
broken in this particular case, hence merging them.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

A patch by Eric was merged (f2b36db6)
and later on reverted back (1e4c85f9).

Along with above patch, another patch was posted and has been merged
(3d1675b4).  That patch was dependent on
the above patch and now it should also be reverted.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It is dangerous to shutdown the apics in machine_crash_shutdown.

With my previous patch to initialize apics in init_IRQ we should be able to
boot a kernel without this.  As long as we reinitialize the APICs we don't
care what state they were in during bootup.

This should make machine_crash_shutdown noticeably more reliable.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

	Most of these guys are simply not needed (pulled by other stuff
via asm-i386/hardirq.h).  One that is not entirely useless is hilarious -
arch/i386/oprofile/nmi_timer_int.c includes linux/irq.h... as a way to
get linux/errno.h
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some more assembler cleanups I noticed along the way.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Following patch provides purely cosmetic changes and corrects CodingStyle
  guide lines related certain issues like below in kexec related files

  o braces for one line "if" statements, "for" loops,
  o more than 80 column wide lines,
  o No space after "while", "for" and "switch" key words

o Changes:
  o take-2: Removed the extra tab before "case" key words.
  o take-3: Put operator at the end of line and space before "*/"
Signed-off-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Makes kexec_crashdump() take a pt_regs * as an argument.  This allows to
get exact register state at the point of the crash.  If we come from direct
panic assertion NULL will be passed and the current registers saved before
crashdump.

This hooks into two places:
die(): check the conditions under which we will panic when calling
do_exit and go there directly with the pt_regs that caused the fatal
fault.

die_nmi(): If we receive an NMI lockup while in the kernel use the
pt_regs and go directly to crash_kexec(). We're probably nested up badly
at this point so this might be the only chance to escape with proper
information.
Signed-off-by: NAlexander Nyberg <alexn@telia.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Problem: Kexec on panic hangs if first kernel is booted with nmi_watchdog
  command line parameter. This problem occurs because kexec crash shutdown
  code replaces the NMI callback handler. This handler saves the cpu register
  states and halts the cpu. If system is booted with nmi_watchdog parameter,
  then crashing cpu also runs this nmi handler and halts itself.

o This patch fixes the problem by keeping a track of crashing cpu and not
  executing the new nmi handler on crashing cpu.

o There is a dependence on smp_processor_id() function which might return
  insane value for cpu, if cpu field of thread_info is corrupted.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

CPU does not save ss and esp on stack if execution was already in kernel mode
at the time of NMI occurrence.  This leads to saving of erractic values for ss
and esp.  This patch fixes the issue.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

o Following patch exports kexec global variable "crash_notes" to user space
  through sysfs as kernel attribute in /sys/kernel.
Signed-off-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In the case of a crash/panic an architecture specific function
machine_crash_shutdown is called.  This patch adds to the x86 machine_crash
function the standard kernel code for shutting down apics.

Every line of code added to that function increases the risk that we will call
code after a kernel panic that is not safe.

This patch should not make it to the stable kernel without a being reviewed a
lot more.  It is unclear how much a hardned kernel can take when it comes to
misconfigured apics.  So since a normal kernel has problems this patch does a
clean shutdown.

It is my expectation this patch will be dropped from future generations of the
kexec work.  But for the moment it is a crutch to keep from breaking
everything.
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

After the kernel panics if we wish to generate an entire machine core file it
is very nice to know the register state at the time the machine crashed.

After long discussion it was realized that if you are going to be saving the
information anyway it is reasonable to store the information in a format that
it will be used and recognized in so the register state is stored in the
standard ELF note format.
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

One of the dangers when switching from one kernel to another is what happens
to all of the other cpus that were running in the crashed kernel.  In an
attempt to avoid that problem this patch adds a nmi handler and attempts to
shoot down the other cpus by sending them non maskable interrupts.

The code then waits for 1 second or until all known cpus have stopped running
and then jumps from the running kernel that has crashed to the kernel in
reserved memory.

The kernel spin loop is used for the delay as that should behave continue to
be safe even in after a crash.
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is the i386 implementation of kexec.
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>