The .discard/.discard.* sections are used to generate intermediate
results for the assembler (effectively "test assembly".) The output
is waste and should not be retained.
Cc: Stefani Seibold <stefani@seibold.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-psizrnant8x3nrhbgvq2vekr@git.kernel.org
The size of the reserved memory for a 32 bit vdso must be the size of the
32 bit vDSO in pages + HPET page + VVAR page.
One page is not enough for this. Grrrr.... silly copy and paste bug,
was right in previous patch.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/1395592694-20571-1-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This replaces a decent amount of incomprehensible and buggy code
with much more straightforward code. It also brings the 32-bit vdso
more in line with the 64-bit vdsos, so maybe someday they can share
even more code.
This wastes a small amount of kernel .data and .text space, but it
avoids a couple of allocations on startup, so it should be more or
less a wash memory-wise.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/b8093933fad09ce181edb08a61dcd5d2592e9814.1395352498.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
For the 32-bit VDSO, match the 64-bit VDSO in:
1. Disable the stack protector.
2. Use -fno-omit-frame-pointer for user space debugging sanity.
3. Use -foptimize-sibling-calls like the 64-bit VDSO does.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-13-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
By coincidence, the VVAR page is at the end of an ELF segment. As a
result, if it ends up being a partial page, the kernel loader will
leave garbage behind at the end of the vvar page. Zero-pad it to a
full page to fix this issue.
This has probably been broken since the VVAR page was introduced.
On QEMU, if you dump the run-time contents of the VVAR page, you can
find entertaining strings from seabios left behind.
It's remotely possible that this is a security bug -- conceivably
there's some BIOS out there that leaves something sensitive in the
few K of memory that is exposed to userspace.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-12-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch add the VDSO time support for the IA32 Emulation Layer.
Due the nature of the kernel headers and the LP64 compiler where the
size of a long and a pointer differs against a 32 bit compiler, there
is some type hacking necessary for optimal performance.
The vsyscall_gtod_data struture must be a rearranged to serve 32- and
64-bit code access at the same time:
- The seqcount_t was replaced by an unsigned, this makes the
vsyscall_gtod_data intedepend of kernel configuration and internal functions.
- All kernel internal structures are replaced by fix size elements
which works for 32- and 64-bit access
- The inner struct clock was removed to pack the whole struct.
The "unsigned seq" would be handled by functions derivated from seqcount_t.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-11-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch add the time support for 32 bit a VDSO to a 32 bit kernel.
For 32 bit programs running on a 32 bit kernel, the same mechanism is
used as for 64 bit programs running on a 64 bit kernel.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-10-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch cleans up the __vdso_gettimeofday() function a little.
It kicks out an unneeded ret local variable and makes the code faster
if only the timezone is needed (an admittedly rare case.)
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-7-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
There a currently more than 30 users of the gtod macro, so replace the
last VVAR(vsyscall_gtod_data) by gtod macro.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-6-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch is a small code cleanup for the __vdso_clock_gettime() function.
It removes the unneeded return values from do_monotonic_coarse() and
do_realtime_coarse() and add a fallback label for doing the kernel
gettimeofday() system call.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-5-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This intermediate patch revamps the vclock_gettime.c by moving some functions
around. It is only for spliting purpose, to make whole the 32 bit vdso timer
patch easier to review.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-4-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch move the vsyscall_gtod_data handling out of vsyscall_64.c
into an additonal file vsyscall_gtod.c to make the functionality
available for x86 32 bit kernel.
It also adds a new vsyscall_32.c which setup the VVAR page.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-2-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Checkin
b0b49f2673 x86, vdso: Remove compat vdso support
... removed the VDSO from the fixmap, and thus FIX_VDSO; remove a
stray reference in Xen.
Found by Fengguang Wu's test robot.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Link: http://lkml.kernel.org/r/4bb4690899106eb11430b1186d5cc66ca9d1660c.1394751608.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The compat vDSO is a complicated hack that's needed to maintain
compatibility with a small range of glibc versions.
This removes it and replaces it with a much simpler hack: a config
option to disable the 32-bit vDSO by default.
This also changes the default value of CONFIG_COMPAT_VDSO to n --
users configuring kernels from scratch almost certainly want that
choice.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/4bb4690899106eb11430b1186d5cc66ca9d1660c.1394751608.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
It's an enum, not a #define, you can't use it in asm files.
Introduced in commit 5fa10196bd ("x86: Ignore NMIs that come in during
early boot"), and sadly I didn't compile-test things like I should have
before pushing out.
My weak excuse is that the x86 tree generally doesn't introduce stupid
things like this (and the ARM pull afterwards doesn't cause me to do a
compile-test either, since I don't cross-compile).
Cc: Don Zickus <dzickus@redhat.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don Zickus reports:
A customer generated an external NMI using their iLO to test kdump
worked. Unfortunately, the machine hung. Disabling the nmi_watchdog
made things work.
I speculated the external NMI fired, caused the machine to panic (as
expected) and the perf NMI from the watchdog came in and was latched.
My guess was this somehow caused the hang.
----
It appears that the latched NMI stays latched until the early page
table generation on 64 bits, which causes exceptions to happen which
end in IRET, which re-enable NMI. Therefore, ignore NMIs that come in
during early execution, until we have proper exception handling.
Reported-and-tested-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1394221143-29713-1-git-send-email-dzickus@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.5+, older with some backport effort
Building on commit 0ac09f9f8c ("x86, trace: Fix CR2 corruption when
tracing page faults") this patch addresses another few issues:
- Now that read_cr2() is lifted into trace_do_page_fault(), we should
pass the address to trace_page_fault_entries() to avoid it
re-reading a potentially changed cr2.
- Put both trace_do_page_fault() and trace_page_fault_entries() under
CONFIG_TRACING.
- Mark both fault entry functions {,trace_}do_page_fault() as notrace
to avoid getting __mcount or other function entry trace callbacks
before we've observed CR2.
- Mark __do_page_fault() as noinline to guarantee the function tracer
does get to see the fault.
Cc: <jolsa@redhat.com>
Cc: <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140306145300.GO9987@twins.programming.kicks-ass.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The trace_do_page_fault function trigger tracepoint
and then handles the actual page fault.
This could lead to error if the tracepoint caused page
fault. The original cr2 value gets lost and the original
page fault handler kills current process with SIGSEGV.
This happens if you record page faults with callchain
data, the user part of it will cause tracepoint handler
to page fault:
# perf record -g -e exceptions:page_fault_user ls
Fixing this by saving the original cr2 value
and using it after tracepoint handler is done.
v2: Moving the cr2 read before exception_enter, because
it could trigger tracepoint as well.
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1402211701380.6395@vincent-weaver-1.um.maine.edu
Link: http://lkml.kernel.org/r/20140228160526.GD1133@krava.brq.redhat.com
causes a crash during boot - Borislav Petkov
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=YIab
-----END PGP SIGNATURE-----
Merge tag 'efi-urgent' into x86/urgent
* Disable the new EFI 1:1 virtual mapping for SGI UV because using it
causes a crash during boot - Borislav Petkov
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Alex reported hitting the following BUG after the EFI 1:1 virtual
mapping work was merged,
kernel BUG at arch/x86/mm/init_64.c:351!
invalid opcode: 0000 [#1] SMP
Call Trace:
[<ffffffff818aa71d>] init_extra_mapping_uc+0x13/0x15
[<ffffffff818a5e20>] uv_system_init+0x22b/0x124b
[<ffffffff8108b886>] ? clockevents_register_device+0x138/0x13d
[<ffffffff81028dbb>] ? setup_APIC_timer+0xc5/0xc7
[<ffffffff8108b620>] ? clockevent_delta2ns+0xb/0xd
[<ffffffff818a3a92>] ? setup_boot_APIC_clock+0x4a8/0x4b7
[<ffffffff8153d955>] ? printk+0x72/0x74
[<ffffffff818a1757>] native_smp_prepare_cpus+0x389/0x3d6
[<ffffffff818957bc>] kernel_init_freeable+0xb7/0x1fb
[<ffffffff81535530>] ? rest_init+0x74/0x74
[<ffffffff81535539>] kernel_init+0x9/0xff
[<ffffffff81541dfc>] ret_from_fork+0x7c/0xb0
[<ffffffff81535530>] ? rest_init+0x74/0x74
Getting this thing to work with the new mapping scheme would need more
work, so automatically switch to the old memmap layout for SGI UV.
Acked-by: Russ Anderson <rja@sgi.com>
Cc: Alex Thorlton <athorlton@sgi.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Pull perf fixes from Ingo Molnar:
"Misc fixes, most of them on the tooling side"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix strict alias issue for find_first_bit
perf tools: fix BFD detection on opensuse
perf: Fix hotplug splat
perf/x86: Fix event scheduling
perf symbols: Destroy unused symsrcs
perf annotate: Check availability of annotate when processing samples
Pull x86 fixes from Peter Anvin:
"The VMCOREINFO patch I'll pushing for this release to avoid having a
release with kASLR and but without that information.
I was hoping to include the FPU patches from Suresh, but ran into a
problem (see other thread); will try to make them happen next week"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, kaslr: add missed "static" declarations
x86, kaslr: export offset in VMCOREINFO ELF notes
virtualization on Intel is broken in 3.13 and fixed by this
pull request.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)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=zQTn
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Three x86 fixes and one for ARM/ARM64.
In particular, nested virtualization on Intel is broken in 3.13 and
fixed by this pull request"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm, vmx: Really fix lazy FPU on nested guest
kvm: x86: fix emulator buffer overflow (CVE-2014-0049)
arm/arm64: KVM: detect CPU reset on CPU_PM_EXIT
KVM: MMU: drop read-only large sptes when creating lower level sptes
Commit e504c9098e (kvm, vmx: Fix lazy FPU on nested guest, 2013-11-13)
highlighted a real problem, but the fix was subtly wrong.
nested_read_cr0 is the CR0 as read by L2, but here we want to look at
the CR0 value reflecting L1's setup. In other words, L2 might think
that TS=0 (so nested_read_cr0 has the bit clear); but if L1 is actually
running it with TS=1, we should inject the fault into L1.
The effective value of CR0 in L2 is contained in vmcs12->guest_cr0, use
it.
Fixes: e504c9098e
Reported-by: Kashyap Chamarty <kchamart@redhat.com>
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Tested-by: Kashyap Chamarty <kchamart@redhat.com>
Tested-by: Anthoine Bourgeois <bourgeois@bertin.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The problem occurs when the guest performs a pusha with the stack
address pointing to an mmio address (or an invalid guest physical
address) to start with, but then extending into an ordinary guest
physical address. When doing repeated emulated pushes
emulator_read_write sets mmio_needed to 1 on the first one. On a
later push when the stack points to regular memory,
mmio_nr_fragments is set to 0, but mmio_is_needed is not set to 0.
As a result, KVM exits to userspace, and then returns to
complete_emulated_mmio. In complete_emulated_mmio
vcpu->mmio_cur_fragment is incremented. The termination condition of
vcpu->mmio_cur_fragment == vcpu->mmio_nr_fragments is never achieved.
The code bounces back and fourth to userspace incrementing
mmio_cur_fragment past it's buffer. If the guest does nothing else it
eventually leads to a a crash on a memcpy from invalid memory address.
However if a guest code can cause the vm to be destroyed in another
vcpu with excellent timing, then kvm_clear_async_pf_completion_queue
can be used by the guest to control the data that's pointed to by the
call to cancel_work_item, which can be used to gain execution.
Fixes: f78146b0f9
Signed-off-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org (3.5+)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Vince "Super Tester" Weaver reported a new round of syscall fuzzing (Trinity) failures,
with perf WARN_ON()s triggering. He also provided traces of the failures.
This is I think the relevant bit:
> pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_disable: x86_pmu_disable
> pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_state: Events: {
> pec_1076_warn-2804 [000] d... 147.926156: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null))
> pec_1076_warn-2804 [000] d... 147.926158: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926159: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926160: x86_pmu_state: n_events: 1, n_added: 0, n_txn: 1
> pec_1076_warn-2804 [000] d... 147.926161: x86_pmu_state: Assignment: {
> pec_1076_warn-2804 [000] d... 147.926162: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926163: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926166: collect_events: Adding event: 1 (ffff880119ec8800)
So we add the insn:p event (fd[23]).
At this point we should have:
n_events = 2, n_added = 1, n_txn = 1
> pec_1076_warn-2804 [000] d... 147.926170: collect_events: Adding event: 0 (ffff8800c9e01800)
> pec_1076_warn-2804 [000] d... 147.926172: collect_events: Adding event: 4 (ffff8800cbab2c00)
We try and add the {BP,cycles,br_insn} group (fd[3], fd[4], fd[15]).
These events are 0:cycles and 4:br_insn, the BP event isn't x86_pmu so
that's not visible.
group_sched_in()
pmu->start_txn() /* nop - BP pmu */
event_sched_in()
event->pmu->add()
So here we should end up with:
0: n_events = 3, n_added = 2, n_txn = 2
4: n_events = 4, n_added = 3, n_txn = 3
But seeing the below state on x86_pmu_enable(), the must have failed,
because the 0 and 4 events aren't there anymore.
Looking at group_sched_in(), since the BP is the leader, its
event_sched_in() must have succeeded, for otherwise we would not have
seen the sibling adds.
But since neither 0 or 4 are in the below state; their event_sched_in()
must have failed; but I don't see why, the complete state: 0,0,1:p,4
fits perfectly fine on a core2.
However, since we try and schedule 4 it means the 0 event must have
succeeded! Therefore the 4 event must have failed, its failure will
have put group_sched_in() into the fail path, which will call:
event_sched_out()
event->pmu->del()
on 0 and the BP event.
Now x86_pmu_del() will reduce n_events; but it will not reduce n_added;
giving what we see below:
n_event = 2, n_added = 2, n_txn = 2
> pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_enable: x86_pmu_enable
> pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_state: Events: {
> pec_1076_warn-2804 [000] d... 147.926179: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null))
> pec_1076_warn-2804 [000] d... 147.926181: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926182: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: n_events: 2, n_added: 2, n_txn: 2
> pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: Assignment: {
> pec_1076_warn-2804 [000] d... 147.926186: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800)
> pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: 1->0 tag: 1 config: 1 (ffff880119ec8800)
> pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: }
> pec_1076_warn-2804 [000] d... 147.926190: x86_pmu_enable: S0: hwc->idx: 33, hwc->last_cpu: 0, hwc->last_tag: 1 hwc->state: 0
So the problem is that x86_pmu_del(), when called from a
group_sched_in() that fails (for whatever reason), and without x86_pmu
TXN support (because the leader is !x86_pmu), will corrupt the n_added
state.
Reported-and-Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20140221150312.GF3104@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Read-only large sptes can be created due to read-only faults as
follows:
- QEMU pagetable entry that maps guest memory is read-only
due to COW.
- Guest read faults such memory, COW is not broken, because
it is a read-only fault.
- Enable dirty logging, large spte not nuked because it is read-only.
- Write-fault on such memory causes guest to loop endlessly
(which must go down to level 1 because dirty logging is enabled).
Fix by dropping large spte when necessary.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Include kASLR offset in VMCOREINFO ELF notes to assist in debugging.
[ hpa: pushing this for v3.14 to avoid having a kernel version with
kASLR where we can't debug output. ]
Signed-off-by: Eugene Surovegin <surovegin@google.com>
Link: http://lkml.kernel.org/r/20140123173120.GA25474@www.outflux.net
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 fixes from Thomas Gleixner:
- a bugfix which prevents a divide by 0 panic when the newly introduced
try_msr_calibrate_tsc() fails
- enablement of the Baytrail platform to utilize the newfangled msr
based calibration
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: tsc: Add missing Baytrail frequency to the table
x86, tsc: Fallback to normal calibration if fast MSR calibration fails
This patch updates the CBOX PMU filters mapping tables for SNB-EP
and IVT (model 45 and 62 respectively).
The NID umask always comes in addition to another umask.
When set, the NID filter is applied.
The current mapping tables were missing some code/umask
combinations to account for the NID umask. This patch
fixes that.
Cc: mingo@elte.hu
Cc: ak@linux.intel.com
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140219131018.GA24475@quad
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The current code simply assumes Intel Arch PerfMon v2+ to have
the IA32_PERF_CAPABILITIES MSR; the SDM specifies that we should check
CPUID[1].ECX[15] (aka, FEATURE_PDCM) instead.
This was found by KVM which implements v2+ but didn't provide the
capabilities MSR. Change the code to DTRT; KVM will also implement the
MSR and return 0.
Cc: pbonzini@redhat.com
Reported-by: "Michael S. Tsirkin" <mst@redhat.com>
Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140203132903.GI8874@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When using BTS on Core i7-4*, I get the below kernel warning.
$ perf record -c 1 -e branches:u ls
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317893] Uhhuh. NMI received for unknown reason 31 on CPU 2.
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317920] Do you have a strange power saving mode enabled?
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317945] Dazed and confused, but trying to continue
Make intel_pmu_handle_irq() take the full exit path when returning early.
Cc: eranian@google.com
Cc: peterz@infradead.org
Cc: mingo@kernel.org
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392425048-5309-1-git-send-email-andi@firstfloor.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull DMA-mapping fixes from Marek Szyprowski:
"This contains fixes for incorrect atomic test in dma-mapping subsystem
for ARM and x86 architecture"
* 'fixes-for-v3.14' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
x86: dma-mapping: fix GFP_ATOMIC macro usage
ARM: dma-mapping: fix GFP_ATOMIC macro usage
Intel Baytrail is based on Silvermont core so MSR_FSB_FREQ[2:0] == 0 means
that the CPU reference clock runs at 83.3MHz. Add this missing frequency to
the table.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1392810750-18660-2-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we cannot calibrate TSC via MSR based calibration
try_msr_calibrate_tsc() stores zero to fast_calibrate and returns that
to the caller. This value gets then propagated further to clockevents
code resulting division by zero oops like the one below:
divide error: 0000 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 3.13.0+ #47
task: ffff880075508000 ti: ffff880075506000 task.ti: ffff880075506000
RIP: 0010:[<ffffffff810aec14>] [<ffffffff810aec14>] clockevents_config.part.3+0x24/0xa0
RSP: 0000:ffff880075507e58 EFLAGS: 00010246
RAX: ffffffffffffffff RBX: ffff880079c0cd80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffffffffff
RBP: ffff880075507e70 R08: 0000000000000001 R09: 00000000000000be
R10: 00000000000000bd R11: 0000000000000003 R12: 000000000000b008
R13: 0000000000000008 R14: 000000000000b010 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff880079c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff880079fff000 CR3: 0000000001c0b000 CR4: 00000000001006f0
Stack:
ffff880079c0cd80 000000000000b008 0000000000000008 ffff880075507e88
ffffffff810aecb0 ffff880079c0cd80 ffff880075507e98 ffffffff81030168
ffff880075507ed8 ffffffff81d1104f 00000000000000c3 0000000000000000
Call Trace:
[<ffffffff810aecb0>] clockevents_config_and_register+0x20/0x30
[<ffffffff81030168>] setup_APIC_timer+0xc8/0xd0
[<ffffffff81d1104f>] setup_boot_APIC_clock+0x4cc/0x4d8
[<ffffffff81d0f5de>] native_smp_prepare_cpus+0x3dd/0x3f0
[<ffffffff81d02ee9>] kernel_init_freeable+0xc3/0x205
[<ffffffff8177c910>] ? rest_init+0x90/0x90
[<ffffffff8177c91e>] kernel_init+0xe/0x120
[<ffffffff8178deec>] ret_from_fork+0x7c/0xb0
[<ffffffff8177c910>] ? rest_init+0x90/0x90
Prevent this from happening by:
1) Modifying try_msr_calibrate_tsc() to return calibration value or zero
if it fails.
2) Check this return value in native_calibrate_tsc() and in case of zero
fallback to use normal non-MSR based calibration.
[mw: Added subject and changelog]
Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bin Gao <bin.gao@linux.intel.com>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1392810750-18660-1-git-send-email-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The first is a fix for the way the ring buffer stores timestamps.
After a restructure of the code was done, the ring buffer timestamp
logic missed the fact that the first event on a sub buffer is to have
a zero delta, as the full timestamp is stored on the sub buffer itself.
But because the delta was not cleared to zero, the timestamp for that
event will be calculated as the real timestamp + the delta from the
last timestamp. This can skew the timestamps of the events and
have them say they happened when they didn't really happen. That's bad.
The second fix is for modifying the function graph caller site.
When the stop machine was removed from updating the function tracing
code, it missed updating the function graph call site location.
It is still modified as if it is being done via stop machine. But it's not.
This can lead to a GPF and kernel crash if the function graph call site
happens to lie between cache lines and one CPU is executing it while
another CPU is doing the update. It would be a very hard condition to
hit, but the result is sever enough to have it fixed ASAP.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.15 (GNU/Linux)
iQEcBAABAgAGBQJS/2leAAoJEKQekfcNnQGu7nYH/AltUO19AgM2sFLOLM7Q0dp4
Lg7vE8CLKtFq0fjtv/ri//fJ56Lr+/WNHiiD06aIrgnMVBbWynS0m0RO+9bhFl8/
rELiUpXTTruqljmlT2T5lPxk+ZKgtLbxK8hNywU99eLgkTwyaOwrSUol30E8pw41
UwtKg4OAn1LbjQ8/sddVynGlFDNRdqFiGTIDvhHqI6F6/QlaEX81EeZbLThDU4D/
l86fMuIdw5pb+efa29Rr0s7O4Xol7SJgnSMVgd0OYADRFmp4sg+MKxuJAUjPsHk7
9vvbylOb4w5H6lo5h7kUee3w7kG+FjYVoEx+Sqq9936+KlwtN0kbiNvl0DkrXnY=
=kUmM
-----END PGP SIGNATURE-----
Merge tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull twi tracing fixes from Steven Rostedt:
"Two urgent fixes in the tracing utility.
The first is a fix for the way the ring buffer stores timestamps.
After a restructure of the code was done, the ring buffer timestamp
logic missed the fact that the first event on a sub buffer is to have
a zero delta, as the full timestamp is stored on the sub buffer
itself. But because the delta was not cleared to zero, the timestamp
for that event will be calculated as the real timestamp + the delta
from the last timestamp. This can skew the timestamps of the events
and have them say they happened when they didn't really happen.
That's bad.
The second fix is for modifying the function graph caller site. When
the stop machine was removed from updating the function tracing code,
it missed updating the function graph call site location. It is still
modified as if it is being done via stop machine. But it's not. This
can lead to a GPF and kernel crash if the function graph call site
happens to lie between cache lines and one CPU is executing it while
another CPU is doing the update. It would be a very hard condition to
hit, but the result is severe enough to have it fixed ASAP"
* tag 'trace-fixes-v3.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace/x86: Use breakpoints for converting function graph caller
ring-buffer: Fix first commit on sub-buffer having non-zero delta
Pull x86 EFI fixes from Peter Anvin:
"A few more EFI-related fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/efi: Check status field to validate BGRT header
x86/efi: Fix 32-bit fallout
There have been reports of EFI crashes since -rc1. The following two
commits fix known issues.
* Fix boot failure on 32-bit EFI due to the recent EFI memmap changes
merged during the merge window - Borislav Petkov
* Avoid a crash during efi_bgrt_init() by detecting invalid BGRT
headers based on the 'status' field.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 fixes from Peter Anvin:
"A collection of small fixes:
- There still seem to be problems with asm goto which requires the
empty asm hack.
- If SMAP is disabled at compile time, don't enable it nor try to
interpret a page fault as an SMAP violation.
- Fix a case of unbounded recursion while tracing"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, smap: smap_violation() is bogus if CONFIG_X86_SMAP is off
x86, smap: Don't enable SMAP if CONFIG_X86_SMAP is disabled
compiler/gcc4: Make quirk for asm_volatile_goto() unconditional
x86: Use preempt_disable_notrace() in cycles_2_ns()
Madper reported seeing the following crash,
BUG: unable to handle kernel paging request at ffffffffff340003
IP: [<ffffffff81d85ba4>] efi_bgrt_init+0x9d/0x133
Call Trace:
[<ffffffff81d8525d>] efi_late_init+0x9/0xb
[<ffffffff81d68f59>] start_kernel+0x436/0x450
[<ffffffff81d6892c>] ? repair_env_string+0x5c/0x5c
[<ffffffff81d68120>] ? early_idt_handlers+0x120/0x120
[<ffffffff81d685de>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81d6871e>] x86_64_start_kernel+0x13e/0x14d
This is caused because the layout of the ACPI BGRT header on this system
doesn't match the definition from the ACPI spec, and so we get a bogus
physical address when dereferencing ->image_address in efi_bgrt_init().
Luckily the status field in the BGRT header clearly marks it as invalid,
so we can check that field and skip BGRT initialisation.
Reported-by: Madper Xie <cxie@redhat.com>
Suggested-by: Toshi Kani <toshi.kani@hp.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
We do not enable the new efi memmap on 32-bit and thus we need to run
runtime_code_page_mkexec() unconditionally there. Fix that.
Reported-and-tested-by: Lejun Zhu <lejun.zhu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
