Intel's MCA implementation broadcasts MCEs to all CPUs on the
node. This poses a problem for offlined CPUs which cannot
participate in the rendezvous process:
Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler
Kernel Offset: disabled
Rebooting in 100 seconds..
More specifically, Linux does a soft offline of a CPU when
writing a 0 to /sys/devices/system/cpu/cpuX/online, which
doesn't prevent the #MC exception from being broadcasted to that
CPU.
Ensure that offline CPUs don't participate in the MCE rendezvous
and clear the RIP valid status bit so that a second MCE won't
cause a shutdown.
Without the patch, mce_start() will increment mce_callin and
wait for all CPUs. Offlined CPUs should avoid participating in
the rendezvous process altogether.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
[ Massage commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
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>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1449742346-21470-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull perf fixes from Ingo Molnar:
"This tree includes four core perf fixes for misc bugs, three fixes to
x86 PMU drivers, and two updates to old email addresses"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Do not send exit event twice
perf/x86/intel: Fix INTEL_FLAGS_UEVENT_CONSTRAINT_DATALA_NA macro
perf/x86/intel: Make L1D_PEND_MISS.FB_FULL not constrained on Haswell
perf: Fix PERF_EVENT_IOC_PERIOD deadlock
treewide: Remove old email address
perf/x86: Fix LBR call stack save/restore
perf: Update email address in MAINTAINERS
perf/core: Robustify the perf_cgroup_from_task() RCU checks
perf/core: Fix RCU problem with cgroup context switching code
Pull x86 fixes from Thoma Gleixner:
"Another round of fixes for x86:
- Move the initialization of the microcode driver to late_initcall to
make sure everything that init function needs is available.
- Make sure that lockdep knows about interrupts being off in the
entry code before calling into c-code.
- Undo the cpu hotplug init delay regression.
- Use the proper conditionals in the mpx instruction decoder.
- Fixup restart_syscall for x32 tasks.
- Fix the hugepage regression on PAE kernels which was introduced
with the latest PAT changes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/signal: Fix restart_syscall number for x32 tasks
x86/mpx: Fix instruction decoder condition
x86/mm: Fix regression with huge pages on PAE
x86 smpboot: Re-enable init_udelay=0 by default on modern CPUs
x86/entry/64: Fix irqflag tracing wrt context tracking
x86/microcode: Initialize the driver late when facilities are up
when memory hotplug enabled system is booted with less
than 4GB of RAM and then later more RAM is hotplugged
32-bit devices stop functioning with following error:
nommu_map_single: overflow 327b4f8c0+1522 of device mask ffffffff
the reason for this is that if x86_64 system were booted
with RAM less than 4GB, it doesn't enable SWIOTLB and
when memory is hotplugged beyond MAX_DMA32_PFN, devices
that expect 32-bit addresses can't handle 64-bit addresses.
Fix it by tracking max possible PFN when parsing
memory affinity structures from SRAT ACPI table and
enable SWIOTLB if there is hotpluggable memory
regions beyond MAX_DMA32_PFN.
It fixes KVM guests when they use emulated devices
(reproduces with ata_piix, e1000 and usb devices,
RHBZ: 1275941, 1275977, 1271527)
It also fixes the HyperV, VMWare with emulated devices
which are affected by this issue as well.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: fujita.tomonori@lab.ntt.co.jp
Cc: konrad.wilk@oracle.com
Cc: pbonzini@redhat.com
Cc: revers@redhat.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1449234426-273049-3-git-send-email-imammedo@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When restarting a syscall with regs->ax == -ERESTART_RESTARTBLOCK,
regs->ax is assigned to a restart_syscall number. For x32 tasks, this
syscall number must have __X32_SYSCALL_BIT set, otherwise it will be
an x86_64 syscall number instead of a valid x32 syscall number. This
issue has been there since the introduction of x32.
Reported-by: strace/tests/restart_syscall.test
Reported-and-tested-by: Elvira Khabirova <lineprinter0@gmail.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Elvira Khabirova <lineprinter0@gmail.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20151130215436.GA25996@altlinux.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Calling set_memory_rw() and set_memory_ro() for every iteration of the
loop in klp_write_object_relocations() is messy, inefficient, and
error-prone.
Change all the read-only pages to read-write before the loop and convert
them back to read-only again afterwards.
Suggested-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.
It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
'range_new' doesn't seem to be used after init. It is only passed
to memset(), sum_ranges(), memcmp() and x86_get_mtrr_mem_range(), the
latter of which also only passes it on to various *range*
library functions.
So mark it __initdata to free up an extra page after init.
Its contents are wiped at every call to mtrr_calc_range_state(),
so it being static is not about preserving state between calls,
but simply to avoid a 4k+ stack frame. While there, add a
comment explaining this and why it's safe.
We could also mark nr_range_new as __initdata, but since it's
just a single int and also doesn't carry state between calls (it
is unconditionally assigned to before it is read), we might as
well make it an ordinary automatic variable.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
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>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/1449002691-20783-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If there are no persistent memory ranges present then don't bother
creating the platform device. Otherwise, it loads the full libnvdimm
sub-system only to discover no resources present.
Reported-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
x86_init_rdrand() was added with 2 goals:
1. Sanity check that the built-in-self-test circuit on the Digital
Random Number Generator (DRNG) is not complaining. As RDRAND
HW self-checks on every invocation, this goal is achieved
by simply invoking RDRAND and checking its return code.
2. Force a full re-seed of the random number generator.
This was done out of paranoia to benefit the most un-sophisticated
DRNG implementation conceivable in the architecture,
an implementation that does not exist, and unlikely ever will.
This worst-case full-re-seed is achieved by invoking
a 64-bit RDRAND 8192 times.
Unfortunately, this worst-case re-seed costs O(1,000us).
Magnifying this cost, it is done from identify_cpu(), which is the
synchronous critical path to bring a processor on-line -- repeated
for every logical processor in the system at boot and resume from S3.
As it is very expensive, and of highly dubious value, we delete the
worst-case re-seed from the kernel.
We keep the 1st goal -- sanity check the hardware, and mark it absent
if it complains.
This change reduces the cost of x86_init_rdrand() by a factor of 1,000x,
to O(1us) from O(1,000us).
Signed-off-by: Len Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/058618cc56ec6611171427ad7205e37e377aa8d4.1439738240.git.len.brown@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When an anomaly is found while modifying function code, ftrace_bug() is
called which disables the function tracing infrastructure and reports
information about what failed. If the code that is to be replaced does not
match what is expected, then actual code is shown. Currently there is no
arch generic way to show what was expected.
Add a new variable pointer calld ftrace_expected that the arch code can set
to point to what it expected so that ftrace_bug() can report the actual text
as well as the text that was expected to be there.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Saving and restoring lapic vectors in lapic_suspend() and
lapic_resume() is not consistent: the thmr vector saving is
guarded by a different config option than the restore part. The
cmci vector isn't handled at all.
Those inconsistencies are not very critical, as the missing cmci
vector will be set via mce resume handling, the wrong config
option used for restoring the thmr vector can't be configured
differently than the one which should be used.
Nevertheless correct the thmr vector restore and add cmci vector
handling.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1448276364-31334-1-git-send-email-jgross@suse.com
[ Minor code edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
So sparse rightfully complains that the u64 MSR value we're
writing into the STAR MSR, i.e. 0xc0000081, is being truncated:
./arch/x86/include/asm/msr.h:193:36: warning: cast truncates
bits from constant value (23001000000000 becomes 0)
because the actual value doesn't fit into the unsigned 32-bit
quantity which are the @low and @high wrmsrl() parameters.
This is not a problem, practically, because gcc is actually
being smart enough here and does the right thing:
.loc 3 87 0
xorl %esi, %esi # we needz a 32-bit zero
movl $2293776, %edx # 0x00230010 == (__USER32_CS << 16) | __KERNEL_CS go into the high bits
movl $-1073741695, %ecx # MSR_STAR, i.e., 0xc0000081
movl %esi, %eax # low order 32 bits in the MSR which are 0
#APP
# 87 "./arch/x86/include/asm/msr.h" 1
wrmsr
More specifically, MSR_STAR[31:0] is being set to 0. That field
is reserved on Intel and on AMD it is 32-bit SYSCALL Target EIP.
I'd strongly guess because Intel doesn't have SYSCALL in
compat/legacy mode and we're using SYSENTER and INT80 there. And
for compat syscalls in long mode we use CSTAR.
So let's fix the sparse warning by writing SYSRET and SYSCALL CS
and SS into the high 32-bit half of STAR and 0 in the low half
explicitly.
[ Actually, if we had to be precise, we would have to read what's in
STAR[31:0] and write it back unchanged on Intel and write 0 on AMD. I
guess the current writing to 0 is still ok since Intel can apparently
stomach it. ]
The resulting code is identical to what we have above:
.loc 3 87 0
xorl %esi, %esi # tmp104
movl $2293776, %eax #, tmp103
movl $-1073741695, %ecx #, tmp102
movl %esi, %edx # tmp104, tmp104
...
wrmsr
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1448273546-2567-6-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We used to have a special ring buffer for deferred errors that
was used to mark problem pages. We replaced that with a generic
pool. Then later converted mce_log() to also use the same pool.
As a result, we end up adding all deferred errors to the pool
twice.
Rearrange this code. Make sure to set the m.severity and
m.usable_addr fields for deferred errors. Then if flags and
mca_cfg.dont_log_ce mean we call mce_log() we are done, because
that will add this entry to the generic pool.
If we skipped mce_log(), then we still want to take action for
the deferred error, so add to the pool.
Change the name of the boolean "error_logged" to "error_seen",
we should set it whether of not we logged an error because the
return value from machine_check_poll() is used to decide whether
storms have subsided or not.
Reported-by: Gong Chen <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1448350880-5573-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The earlier constraint fix for Broadwell CYCLE_ACTIVITY.*
forced umask 8 to counter 2. For this it used UEVENT,
to match the complete umask.
The event list for Broadwell has an additional
STALLS_L1D_PENDIND event that uses umask 8, but also
sets other bits in the umask. The earlier strict umask match
didn't handle this case.
Add a new UBIT_EVENT constraint macro that only matches
the specified bits in the umask. Then use that macro
to handle CYCLE_ACTIVITY.* on Broadwell.
The documented event also uses cmask, but there's no
need to let the event scheduler know about the cmask,
as the scheduling restriction is only tied to the umask.
Reported-by: Grant Ayers <ayers@cs.stanford.edu>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1447719667-9998-1-git-send-email-andi@firstfloor.org
[ Filled in the missing email address of Grant Ayers - hopefully I got the right one. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With LBRv5 reading the extra LBR flags like mispredict, TSX, cycles is
not free anymore, as it has moved to a separate MSR.
For callstack mode we don't need any of this information; so we can
avoid the unnecessary MSR read. Add flags to the perf interface where
perf record can request not collecting this information.
Add branch_sample_type flags for CYCLES and FLAGS. It's a bit unusual
for branch_sample_types to be negative (disable), not positive (enable),
but since the legacy ABI reported the flags we need some form of
explicit disabling to avoid breaking the ABI.
After we have the flags the x86 perf code can keep track if any users
need the flags. If noone needs it the information is not collected.
This cuts down the cost of LBR callstack on Skylake significantly.
Profiling a kernel build with LBR call stack the average run time of
the PMI handler drops by 43%.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: jolsa@kernel.org
Link: http://lkml.kernel.org/r/1445366797-30894-2-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change the perf user stack walking to use the new
__copy_from_user_nmi(), and split each access into word sized transfer
sizes. This allows to inline the complete access and optimize it all
into a single load.
The main advantage is that this avoids the overhead of double page
faults. When normal copy_from_user() fails it reexecutes the copy to
compute an accurate number of non copied bytes. This leads to
executing the expensive page fault twice.
While walking stacks having a fault at some point is relatively common
(typically when some part of the program isn't compiled with frame
pointers), so this is a large overhead.
With the optimized copies we avoid this problem because they only do
all accesses once. And of course they're much faster too when the
access does not fault because they're just single instructions instead
of complex function calls.
While profiling a kernel build with -g, the patch brings down the
average time of the PMI handler from 966ns to 552ns (-43%).
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1445551641-13379-2-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linux 4.4-rc2
Backmerge to get at
commit 1b0e3a049e
Author: Imre Deak <imre.deak@intel.com>
Date: Thu Nov 5 23:04:11 2015 +0200
drm/i915/skl: disable display side power well support for now
so that we can proplery re-eanble skl power wells in -next.
Conflicts are just adjacent lines changed, except for intel_fbdev.c
where we need to interleave the changs. Nothing nefarious.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Pull x86 fixes from Thomas Gleixner:
"This update contains:
- MPX updates for handling 32bit processes
- A fix for a long standing bug in 32bit signal frame handling
related to FPU/XSAVE state
- Handle get_xsave_addr() correctly in KVM
- Fix SMAP check under paravirtualization
- Add a comment to the static function trace entry to avoid further
confusion about the difference to dynamic tracing"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Fix SMAP check in PVOPS environments
x86/ftrace: Add comment on static function tracing
x86/fpu: Fix get_xsave_addr() behavior under virtualization
x86/fpu: Fix 32-bit signal frame handling
x86/mpx: Fix 32-bit address space calculation
x86/mpx: Do proper get_user() when running 32-bit binaries on 64-bit kernels
