There's no need for the *_MASK flags (TF_MASK, IF_MASK, etc), found in
processor.h (both _32 and _64). They have a one-to-one mapping with the
EFLAGS value. This patch removes the definitions, and use the already
existent X86_EFLAGS_ version when applicable.

[ roland@redhat.com: KVM build fixes. ]
Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This requires making die() return a value, making its callers honor
this (and be prepared that it may return), and making oops_end() have
two additional parameters.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Export math_state_restore symbol, so it can be used for hypervisors.
They are commonly loaded as modules (lguest being an example).
Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Acked-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This changes size-specific register names (eip/rip, esp/rsp, etc.) to
generic names in the thread and tss structures.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We have a lot of code which differs only by the naming of specific
members of structures that contain registers.  In order to enable
additional unifications, this patch drops the e- or r- size prefix
from the register names in struct pt_regs, and drops the x- prefixes
for segment registers on the 32-bit side.

This patch also performs the equivalent renames in some additional
places that might be candidates for unification in the future.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This implements user-mode step-until-branch on x86 using the BTF bit
in MSR_IA32_DEBUGCTLMSR.  It's just like single-step, only less so.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This changes the single-step support to use a new thread_info flag
TIF_FORCED_TF instead of the PT_DTRACE flag in task_struct.ptrace.
This keeps arch implementation uses out of this non-arch field.

This changes the ptrace access to eflags to mask TF and maintain
the TIF_FORCED_TF flag directly if userland sets TF, instead of
relying on ptrace_signal_deliver.  The 64-bit and 32-bit kernels
are harmonized on this same behavior.  The ptrace_signal_deliver
approach works now, but this change makes the low-level register
access code reliable when called from different contexts than a
ptrace stop, which will be possible in the future.

The 64-bit do_debug exception handler is also changed not to clear TF
from user-mode registers.  This matches the 32-bit kernel's behavior.
Signed-off-by: NRoland McGrath <roland@redhat.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>

On Sat, 2007-12-29 at 18:06 +0100, Marcin Slusarz wrote:
> Hi
> Today I've got this (while i was upgrading my gentoo box):
>
> WARNING: at kernel/lockdep.c:2658 check_flags()
> Pid: 21680, comm: conftest Not tainted 2.6.24-rc6 #63
>
> Call Trace:
>  [<ffffffff80253457>] check_flags+0x1c7/0x1d0
>  [<ffffffff80257217>] lock_acquire+0x57/0xc0
>  [<ffffffff8024d5c0>] __atomic_notifier_call_chain+0x60/0xd0
>  [<ffffffff8024d641>] atomic_notifier_call_chain+0x11/0x20
>  [<ffffffff8024d67e>] notify_die+0x2e/0x30
>  [<ffffffff8020da0a>] do_divide_error+0x5a/0xa0
>  [<ffffffff80522bdd>] trace_hardirqs_on_thunk+0x35/0x3a
>  [<ffffffff80255b89>] trace_hardirqs_on+0xd9/0x180
>  [<ffffffff80522bdd>] trace_hardirqs_on_thunk+0x35/0x3a
>  [<ffffffff80523c2d>] error_exit+0x0/0xa9
>
> possible reason: unannotated irqs-off.
> irq event stamp: 4693
> hardirqs last  enabled at (4693): [<ffffffff80522bdd>] trace_hardirqs_on_thunk+0x35/0x3a
> hardirqs last disabled at (4692): [<ffffffff80522c17>] trace_hardirqs_off_thunk+0x35/0x37
> softirqs last  enabled at (3546): [<ffffffff80238343>] __do_softirq+0xb3/0xd0
> softirqs last disabled at (3521): [<ffffffff8020c97c>] call_softirq+0x1c/0x30

more early fixups for notify_die()..
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ensure the hardirq state is consistent before using locks. Use the rare
trace_hardirqs_fixup() because the trap can happen in any context.

resolves this rare lockdep warning:

WARNING: at kernel/lockdep.c:2658 check_flags()
 [<c013571e>] check_flags+0x90/0x140
 [<c0138a69>] lock_release+0x4b/0x1d0
 [<c0507fea>] notifier_call_chain+0x2a/0x47
 [<c050806b>] __atomic_notifier_call_chain+0x64/0x6d
 [<c0508007>] __atomic_notifier_call_chain+0x0/0x6d
 [<c050808b>] atomic_notifier_call_chain+0x17/0x1a
 [<c0131802>] notify_die+0x30/0x34
 [<c0506b09>] do_debug+0x3e/0xd4
 [<c050658f>] debug_stack_correct+0x27/0x2c
 [<c04be389>] tcp_rcv_established+0x1/0x620
 [<c04c38c2>] tcp_v4_do_rcv+0x2b/0x313
 [<c04c56b6>] tcp_v4_rcv+0x467/0x85d
 [<c0505ff2>] _spin_lock_nested+0x27/0x32
 [<c04c5a4d>] tcp_v4_rcv+0x7fe/0x85d
 [<c04c560e>] tcp_v4_rcv+0x3bf/0x85d
 [<c04adbb5>] ip_local_deliver_finish+0x11b/0x1b0
 [<c04adac8>] ip_local_deliver_finish+0x2e/0x1b0
 [<c04ada7b>] ip_rcv_finish+0x27b/0x29a
 [<c04961e5>] netif_receive_skb+0xfb/0x2a6
 [<c04add0f>] ip_rcv+0x0/0x1fb
 [<c0496354>] netif_receive_skb+0x26a/0x2a6
 [<c04961e5>] netif_receive_skb+0xfb/0x2a6
 [<c049872e>] process_backlog+0x7f/0xc6
 [<c04983ba>] net_rx_action+0xb9/0x1ac
 [<c0498348>] net_rx_action+0x47/0x1ac
 [<c01376cb>] trace_hardirqs_on+0x118/0x16b
 [<c01225e2>] __do_softirq+0x49/0xa2
 [<c010595f>] do_softirq+0x60/0xdd
 [<c0506300>] _spin_unlock_irq+0x20/0x2c
 [<c0103e4f>] restore_nocheck+0x12/0x15
 [<c01440e1>] handle_fasteoi_irq+0x0/0x9b
 [<c0105a70>] do_IRQ+0x94/0xaa
 [<c0506300>] _spin_unlock_irq+0x20/0x2c
 [<c0104832>] common_interrupt+0x2e/0x34
 [<c0114703>] native_safe_halt+0x2/0x3
 [<c0102c01>] default_idle+0x44/0x65
 [<c010257f>] cpu_idle+0x42/0x50
 [<c076ea09>] start_kernel+0x26b/0x270
 [<c076e317>] unknown_bootoption+0x0/0x196
 =======================
irq event stamp: 559190
hardirqs last  enabled at (559190): [<c0507316>] kprobe_exceptions_notify+0x299/0x305
hardirqs last disabled at (559189): [<c05067bf>] do_int3+0x1d/0x95
softirqs last  enabled at (559172): [<c010595f>] do_softirq+0x60/0xdd
softirqs last disabled at (559181): [<c010595f>] do_softirq+0x60/0xdd
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

today, all oopses contain a version number of the kernel, which is nice
because the people who actually do bother to read the oops get this
vital bit of information always without having to ask the reporter in
another round trip.

However, WARN_ON() and many other dump_stack() users right now lack this
information; the patch below adds this. This information is essential
for getting people to use their time effectively when looking at these
things; in addition, it's essential for tools that try to collect
statistics about defects.

Please consider, since its so simple and important for long term kernel
quality processes.

The code is identical between 32/64 bit; a lot of this code should be
unified over time, the patch keeps the identical-ness intact.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Ensure we fixup the IRQ state before we hit any locking code.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Spelling fixes in arch/x86_64/.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Don't want any lockdep or other fragile machinery to run during oopses.
Use raw spinlocks directly for oops locking.
Also disables irq flag tracing there.

[ tglx: arch/x86 adaptation ]
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

.. as they're never written to.

[ tglx: arch/x86 adaptation ]
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Since the x86 merge, lots of files that referenced their own filenames
are no longer correct.  Rather than keep them up to date, just delete
them, as they add no real value.

Additionally:
- fix up comment formatting in scx200_32.c
- Remove a credit from myself in setup_64.c from a time when we had no SCM
- remove longwinded history from tsc_32.c which can be figured out from
  git.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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 makes the i386 behave the same way that x86_64 does when a
segfault happens.  A line gets printed to the kernel log so that tools
that need to check for failures can behave more uniformly between
debug.show_unhandled_signals sysctl variable to 0 (or by doing echo 0 >
/proc/sys/debug/exception-trace)

Also, all of the lines being printed are now using printk_ratelimit() to
deny the ability of DoS from a local user with a program like the
following:

main()
{
       while (1)
               if (!fork()) *(int *)0 = 0;
}

This new revision also includes the fix that Andrew did which got rid of
new sysctl that was added to the system in earlier versions of this.
Also, 'show-unhandled-signals' sysctl has been renamed back to the old
'exception-trace' to avoid breakage of people's scripts.

AK: Enabling by default for i386 will be likely controversal, but let's see what happens
AK: Really folks, before complaining just fix your segfaults
AK: I bet this will find a lot of silent issues
Signed-off-by: NMasoud Sharbiani <masouds@google.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
[ Personally, I've found the complaints useful on x86-64, so I'm all for
  this. That said, I wonder if we could do it more prettily..   -Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provides a way for NMI reported errors on x86 to notify the EDAC
subsystem pending ECC errors by writing to a software state variable.

Here's the reworked patch. I added an EDAC stub to the kernel so we can
have variables that are in the kernel even if EDAC is a module. I also
implemented the idea of using the chip driver to select error detection
mode via module parameter and eliminate the kernel compile option.
Please review/test. Thx!

Also, I only made changes to some of the chipset drivers since I am
unfamiliar with the other ones. We can add similar changes as we go.
Signed-off-by: NDave Jiang <djiang@mvista.com>
Signed-off-by: NDouglas Thompson <dougthompson@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On large memory configuration with not so fast CPUs the NMI watchdog is
triggered when memory addresses are being gathered and printed.  The code
paths for Alt-SysRq-t are sprinkled with touch_nmi_watchdog in various
places but not in this routine (or in the loop that utilizes this
function).  The patch has been tested for regression on large CPU+memory
configuration (128 logical CPUs + 224 GB) and 1,2,4,16-CPU sockets with
various memory sizes (1,2,4,6,20).

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If the kernel OOPSed or BUGed then it probably should be considered as
tainted.  Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel.  This saves a lot of time explaining oddities in the
calltraces.
Signed-off-by: NPavel Emelianov <xemul@openvz.org>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
[ Added parisc patch from Matthew Wilson  -Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current generic bug implementation has a call to dump_stack() in case a
WARN_ON(whatever) gets hit.  Since report_bug(), which calls dump_stack(),
gets called from an exception handler we can do better: just pass the
pt_regs structure to report_bug() and pass it to show_regs() in case of a
warning.  This will give more debug informations like register contents,
etc...  In addition this avoids some pointless lines that dump_stack()
emits, since it includes a stack backtrace of the exception handler which
is of no interest in case of a warning.  E.g.  on s390 the following lines
are currently always present in a stack backtrace if dump_stack() gets
called from report_bug():

 [<000000000001517a>] show_trace+0x92/0xe8)
 [<0000000000015270>] show_stack+0xa0/0xd0
 [<00000000000152ce>] dump_stack+0x2e/0x3c
 [<0000000000195450>] report_bug+0x98/0xf8
 [<0000000000016cc8>] illegal_op+0x1fc/0x21c
 [<00000000000227d6>] sysc_return+0x0/0x10
Acked-by: NJeremy Fitzhardinge <jeremy@goop.org>
Acked-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We don't want to see this:

>  BUG: using smp_processor_id() in preemptible [00000001] code: bash/3857
>  caller is oops_begin+0xb/0x6f
>
>  Call Trace:
>  [<ffffffff8020ab4d>] show_trace+0x34/0x4f
>  [<ffffffff8020ab7a>] dump_stack+0x12/0x17
>  [<ffffffff8030d92d>] debug_smp_processor_id+0xad/0xbc
>  [<ffffffff8042388f>] oops_begin+0xb/0x6f
>  [<ffffffff8042520b>] do_page_fault+0x66a/0x7c0
>  [<ffffffff804234bd>] error_exit+0x0/0x84
>

coming out when the kernel is trying to oops.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit f64da958.

Andi Kleen is unhappy with the changes, and they really do not seem
worth it.  IPMI could use DIE_NMI_IPI instead of the new callback, even
though that ends up having its own set of problems too, mainly because
the IPMI code cannot really know the NMI was from IPMI or not.

Manually fix up conflicts in arch/x86_64/kernel/traps.c and
drivers/char/ipmi/ipmi_watchdog.c.

Cc: Andi Kleen <ak@suse.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Corey Minyard <minyard@acm.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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>

Convert over to the new NMI handling for getting IPMI watchdog timeouts via an
NMI.  This add config options to know if there is the ability to receive NMIs
and if it has an NMI post processing call.  Then it modifies the IPMI watchdog
to take advantage of this so that it can know if an NMI comes in.

It also adds testing that the IPMI NMI watchdog works.
Signed-off-by: NCorey Minyard <minyard@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAndi Kleen <ak@suse.de>

a userspace fault or a kernelspace fault which will result in the
immediate death of the process.  They should not be filled in as a
result of a kernelspace fault which can be fixed up.

Otherwise, if the process is handling SIGSEGV and examining the fault
information, this can result in the kernel space fault trashing the
previously stored fault information if it arrives between the
userspace fault happening and the SIGSEGV being delivered to the process.
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Acked-by: NJan Beulich <jbeulich@novell.com>
--
 arch/i386/kernel/traps.c   |   24 ++++++++++++++++++------
 arch/x86_64/kernel/traps.c |   30 +++++++++++++++++++++++-------
 2 files changed, 41 insertions(+), 13 deletions(-)

If caller passed the tsk, we should use it to validate a stack ptr.
Otherwise, sysrq-t and other debugging stuff doesn't work.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It has caused more problems than it ever really solved, and is
apparently not getting cleaned up and fixed.  We can put it back when
it's stable and isn't likely to make warning or bug events worse.

In the meantime, enable frame pointers for more readable stack traces.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This makes x86-64 use the generic BUG machinery.

The main advantage in using the generic BUG machinery for x86-64 is that
the inlined overhead of BUG is just the ud2a instruction; the file+line
information are no longer inlined into the instruction stream.  This
reduces cache pollution.
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Hugh Dickens <hugh@veritas.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This was added as a workaround for the fallback unwinder not supporting
unaligned stack pointers properly. But now it was fixed to do that,
so it's not needed anymore

Cc: mingo@elte.hu
Signed-off-by: NAndi Kleen <ak@suse.de>

Tighten the requirements on both input to and output from the Dwarf2
unwinder.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

We're already well protected against module unloads because module
unload uses stop_machine(). The only exception is NMIs, but other
users already risk lockless accesses here.

This avoids some hackery in lockdep and also a potential deadlock

This matches what i386 does.
Signed-off-by: NAndi Kleen <ak@suse.de>

Add sysctl for kstack_depth_to_print. This lets users change
the amount of raw stack data printed in dump_stack() without
having to reboot.
Signed-off-by: NChuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Instead of open coded __get_user
Signed-off-by: NAndi Kleen <ak@suse.de>

On modern systems RAM errors don't cause NMIs, but it's usually
caused by PCI SERR. Mention PCI instead of RAM in the printk.

Reported by r_hayashi@ctc-g.co.jp (Ryutaro Hayashi)

Cc:  r_hayashi@ctc-g.co.jp
Signed-off-by: NAndi Kleen <ak@suse.de>

Fix

BUG: using smp_processor_id() in preemptible [00000001] code:

in backtracer on preemptible debug kernels.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NAndi Kleen <ak@suse.de>