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Add the necessary changes to do_machine_check() to be able to
process MCEs signaled as local MCEs. Typically, only recoverable
errors (SRAR type) will be Signaled as LMCE. The architecture
does not restrict to only those errors, however.
When errors are signaled as LMCE, there is no need for the MCE
handler to perform rendezvous with other logical processors
unlike earlier processors that would broadcast machine check
errors.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.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: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1433436928-31903-17-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Initialize and prepare for handling LMCEs. Add a boot-time
option to disable LMCEs.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
[ Simplify stuff, align statements for better readability, reflow comments; kill
unused lmce_clear(); save us an MSR write if LMCE is already enabled. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.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: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1433436928-31903-16-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- early_idt_handlers[] fix that fixes the build with bleeding edge
tooling
- build warning fix on GCC 5.1
- vm86 fix plus self-test to make it harder to break it again"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm/irq: Stop relying on magic JMP behavior for early_idt_handlers
x86/asm/entry/32, selftests: Add a selftest for kernel entries from VM86 mode
x86/boot: Add CONFIG_PARAVIRT_SPINLOCKS quirk to arch/x86/boot/compressed/misc.h
x86/asm/entry/32: Really make user_mode() work correctly for VM86 mode
Pull perf fixes from Ingo Molnar:
"The biggest chunk of the changes are two regression fixes: a HT
workaround fix and an event-group scheduling fix. It's been verified
with 5 days of fuzzer testing.
Other fixes:
- eBPF fix
- a BIOS breakage detection fix
- PMU driver fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/pt: Fix a refactoring bug
perf/x86: Tweak broken BIOS rules during check_hw_exists()
perf/x86/intel/pt: Untangle pt_buffer_reset_markers()
perf: Disallow sparse AUX allocations for non-SG PMUs in overwrite mode
perf/x86: Improve HT workaround GP counter constraint
perf/x86: Fix event/group validation
perf: Fix race in BPF program unregister
Deobfuscate the 'found' logic, it can be replaced with a simple:
if (!pa_data)
return;
and 'found' can be eliminated.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
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: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1433398729-8314-1-git-send-email-weiyang@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 066450be41 ("perf/x86/intel/pt: Clean up the control flow
in pt_pmu_hw_init()") changed attribute initialization so that
only the first attribute gets initialized using
sysfs_attr_init(), which upsets lockdep.
This patch fixes the glitch so that all allocated attributes are
properly initialized thus fixing the lockdep warning reported by
Tvrtko and Imre.
Reported-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reported-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: <linux-kernel@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The vsyscall code is entry code too, so move it to arch/x86/entry/vsyscall/.
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'v4.1-rc6' into drm-next
Linux 4.1-rc6
backmerge 4.1-rc6 as some of the later pull reqs are based on newer bases
and I'd prefer to do the fixup myself.
Create a new directory hierarchy for the low level x86 entry code:
arch/x86/entry/*
This will host all the low level glue that is currently scattered
all across arch/x86/.
Start with entry_64.S and entry_32.S.
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Nothing in <asm/io.h> uses anything from <linux/vmalloc.h>, so
remove it from there and fix up the resulting build problems
triggered on x86 {64|32}-bit {def|allmod|allno}configs.
The breakages were triggering in places where x86 builds relied
on vmalloc() facilities but did not include <linux/vmalloc.h>
explicitly and relied on the implicit inclusion via <asm/io.h>.
Also add:
- <linux/init.h> to <linux/io.h>
- <asm/pgtable_types> to <asm/io.h>
... which were two other implicit header file dependencies.
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[ Tidied up the changelog. ]
Acked-by: David Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Colin Cross <ccross@android.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Suma Ramars <sramars@cisco.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We did try trimming whitespace surrounding the 'model name'
field in /proc/cpuinfo since reportedly some userspace uses it
in string comparisons and there were discrepancies:
[thetango@prarit ~]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g'
______1_model_name :_AMD_Opteron(TM)_Processor_6272
_____63_model_name :_AMD_Opteron(TM)_Processor_6272_________________
However, there were issues with overlapping buffers, string
sizes and non-byte-sized copies in the previous proposed
solutions; see Link tags below for the whole farce.
So, instead of diddling with this more, let's simply extend what
was there originally with trimming any present trailing
whitespace. Final result is really simple and obvious.
Testing with the most insane model IDs qemu can generate, looks
good:
.model_id = " My funny model ID CPU ",
______4_model_name :_My_funny_model_ID_CPU
.model_id = "My funny model ID CPU ",
______4_model_name :_My_funny_model_ID_CPU
.model_id = " My funny model ID CPU",
______4_model_name :_My_funny_model_ID_CPU
.model_id = " ",
______4_model_name :__
.model_id = "",
______4_model_name :_15/02
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Igor Mammedov <imammedo@redhat.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/1432050210-32036-1-git-send-email-prarit@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
retint_kernel doesn't require %rcx to be pointing to thread info
(anymore?), and the code on the two alternative paths is - not
really surprisingly - identical.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
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/556C664F020000780007FB64@mail.emea.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The early_idt_handlers asm code generates an array of entry
points spaced nine bytes apart. It's not really clear from that
code or from the places that reference it what's going on, and
the code only works in the first place because GAS never
generates two-byte JMP instructions when jumping to global
labels.
Clean up the code to generate the correct array stride (member size)
explicitly. This should be considerably more robust against
screw-ups, as GAS will warn if a .fill directive has a negative
count. Using '. =' to advance would have been even more robust
(it would generate an actual error if it tried to move
backwards), but it would pad with nulls, confusing anyone who
tries to disassemble the code. The new scheme should be much
clearer to future readers.
While we're at it, improve the comments and rename the array and
common code.
Binutils may start relaxing jumps to non-weak labels. If so,
this change will fix our build, and we may need to backport this
change.
Before, on x86_64:
0000000000000000 <early_idt_handlers>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 00 00 00 00 jmpq 9 <early_idt_handlers+0x9>
5: R_X86_64_PC32 early_idt_handler-0x4
...
48: 66 90 xchg %ax,%ax
4a: 6a 08 pushq $0x8
4c: e9 00 00 00 00 jmpq 51 <early_idt_handlers+0x51>
4d: R_X86_64_PC32 early_idt_handler-0x4
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: e9 00 00 00 00 jmpq 120 <early_idt_handler>
11c: R_X86_64_PC32 early_idt_handler-0x4
After:
0000000000000000 <early_idt_handler_array>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 14 01 00 00 jmpq 11d <early_idt_handler_common>
...
48: 6a 08 pushq $0x8
4a: e9 d1 00 00 00 jmpq 120 <early_idt_handler_common>
4f: cc int3
50: cc int3
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: eb 03 jmp 120 <early_idt_handler_common>
11d: cc int3
11e: cc int3
11f: cc int3
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Binutils <binutils@sourceware.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/ac027962af343b0c599cbfcf50b945ad2ef3d7a8.1432336324.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull RCU changes from Paul E. McKenney:
- Initialization/Kconfig updates: hide most Kconfig options from unsuspecting users.
There's now a single high level configuration option:
*
* RCU Subsystem
*
Make expert-level adjustments to RCU configuration (RCU_EXPERT) [N/y/?] (NEW)
Which if answered in the negative, leaves us with a single interactive
configuration option:
Offload RCU callback processing from boot-selected CPUs (RCU_NOCB_CPU) [N/y/?] (NEW)
All the rest of the RCU options are configured automatically.
- Remove all uses of RCU-protected array indexes: replace the
rcu_[access|dereference]_index_check() APIs with READ_ONCE() and rcu_lockdep_assert().
- RCU CPU-hotplug cleanups.
- Updates to Tiny RCU: a race fix and further code shrinkage.
- RCU torture-testing updates: fixes, speedups, cleanups and
documentation updates.
- Miscellaneous fixes.
- Documentation updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
So the dwarf2 annotations in low level assembly code have
become an increasing hindrance: unreadable, messy macros
mixed into some of the most security sensitive code paths
of the Linux kernel.
These debug info annotations don't even buy the upstream
kernel anything: dwarf driven stack unwinding has caused
problems in the past so it's out of tree, and the upstream
kernel only uses the much more robust framepointers based
stack unwinding method.
In addition to that there's a steady, slow bitrot going
on with these annotations, requiring frequent fixups.
There's no tooling and no functionality upstream that
keeps it correct.
So burn down the sick forest, allowing new, healthier growth:
27 files changed, 350 insertions(+), 1101 deletions(-)
Someone who has the willingness and time to do this
properly can attempt to reintroduce dwarf debuginfo in x86
assembly code plus dwarf unwinding from first principles,
with the following conditions:
- it should be maximally readable, and maximally low-key to
'ordinary' code reading and maintenance.
- find a build time method to insert dwarf annotations
automatically in the most common cases, for pop/push
instructions that manipulate the stack pointer. This could
be done for example via a preprocessing step that just
looks for common patterns - plus special annotations for
the few cases where we want to depart from the default.
We have hundreds of CFI annotations, so automating most of
that makes sense.
- it should come with build tooling checks that ensure that
CFI annotations are sensible. We've seen such efforts from
the framepointer side, and there's no reason it couldn't be
done on the dwarf side.
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: Frédéric Weisbecker <fweisbec@gmail.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.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>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If you try to enable NOHZ_FULL on a guest today, you'll get
the following error when the guest tries to deactivate the
scheduler tick:
WARNING: CPU: 3 PID: 2182 at kernel/time/tick-sched.c:192 can_stop_full_tick+0xb9/0x290()
NO_HZ FULL will not work with unstable sched clock
CPU: 3 PID: 2182 Comm: kworker/3:1 Not tainted 4.0.0-10545-gb9bb6fb #204
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Workqueue: events flush_to_ldisc
ffffffff8162a0c7 ffff88011f583e88 ffffffff814e6ba0 0000000000000002
ffff88011f583ed8 ffff88011f583ec8 ffffffff8104d095 ffff88011f583eb8
0000000000000000 0000000000000003 0000000000000001 0000000000000001
Call Trace:
<IRQ> [<ffffffff814e6ba0>] dump_stack+0x4f/0x7b
[<ffffffff8104d095>] warn_slowpath_common+0x85/0xc0
[<ffffffff8104d146>] warn_slowpath_fmt+0x46/0x50
[<ffffffff810bd2a9>] can_stop_full_tick+0xb9/0x290
[<ffffffff810bd9ed>] tick_nohz_irq_exit+0x8d/0xb0
[<ffffffff810511c5>] irq_exit+0xc5/0x130
[<ffffffff814f180a>] smp_apic_timer_interrupt+0x4a/0x60
[<ffffffff814eff5e>] apic_timer_interrupt+0x6e/0x80
<EOI> [<ffffffff814ee5d1>] ? _raw_spin_unlock_irqrestore+0x31/0x60
[<ffffffff8108bbc8>] __wake_up+0x48/0x60
[<ffffffff8134836c>] n_tty_receive_buf_common+0x49c/0xba0
[<ffffffff8134a6bf>] ? tty_ldisc_ref+0x1f/0x70
[<ffffffff81348a84>] n_tty_receive_buf2+0x14/0x20
[<ffffffff8134b390>] flush_to_ldisc+0xe0/0x120
[<ffffffff81064d05>] process_one_work+0x1d5/0x540
[<ffffffff81064c81>] ? process_one_work+0x151/0x540
[<ffffffff81065191>] worker_thread+0x121/0x470
[<ffffffff81065070>] ? process_one_work+0x540/0x540
[<ffffffff8106b4df>] kthread+0xef/0x110
[<ffffffff8106b3f0>] ? __kthread_parkme+0xa0/0xa0
[<ffffffff814ef4f2>] ret_from_fork+0x42/0x70
[<ffffffff8106b3f0>] ? __kthread_parkme+0xa0/0xa0
---[ end trace 06e3507544a38866 ]---
However, it turns out that kvmclock does provide a stable
sched_clock callback. So, let the scheduler know this which
in turn makes NOHZ_FULL work in the guest.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
ACPI 6.0 formalizes e820-type-7 and efi-type-14 as persistent memory.
Mark it "reserved" and allow it to be claimed by a persistent memory
device driver.
This definition is in addition to the Linux kernel's existing type-12
definition that was recently added in support of shipping platforms with
NVDIMM support that predate ACPI 6.0 (which now classifies type-12 as
OEM reserved).
Note, /proc/iomem can be consulted for differentiating legacy
"Persistent Memory (legacy)" E820_PRAM vs standard "Persistent Memory"
E820_PMEM.
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Because mce is arch-specific x86 code, there is little or no
performance benefit of using rcu_dereference_index_check() over using
smp_load_acquire(). It also turns out that mce is the only place that
array-index-based RCU is used, and it would be convenient to drop
this portion of the RCU API.
This patch therefore changes rcu_dereference_index_check() uses to
smp_load_acquire(), but keeping the lockdep diagnostics, and also
changes rcu_access_index() uses to READ_ONCE().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: linux-edac@vger.kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <bp@suse.de>
The former duplicate the functionalities of the latter but are
neither documented nor arch-independent.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: http://lkml.kernel.org/r/1432645896-12588-9-git-send-email-bgolaszewski@baylibre.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We use pat_enabled in x86-specific code to see if PAT is enabled
or not but we're granting full access to it even though readers
do not need to set it. If, for instance, we granted access to it
to modules later they then could override the variable
setting... no bueno.
This renames pat_enabled to a new static variable __pat_enabled.
Folks are redirected to use pat_enabled() now.
Code that sets this can only be internal to pat.c. Apart from
the early kernel parameter "nopat" to disable PAT, we also have
a few cases that disable it later and make use of a helper
pat_disable(). It is wrapped under an ifdef but since that code
cannot run unless PAT was enabled its not required to wrap it
with ifdefs, unwrap that. Likewise, since "nopat" doesn't really
change non-PAT systems just remove that ifdef as well.
Although we could add and use an early_param_off(), these
helpers don't use __read_mostly but we want to keep
__read_mostly for __pat_enabled as this is a hot path -- upon
boot, for instance, a simple guest may see ~4k accesses to
pat_enabled(). Since __read_mostly early boot params are not
that common we don't add a helper for them just yet.
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kyle McMartin <kyle@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430425520-22275-3-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-13-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It is possible to enable CONFIG_MTRR and CONFIG_X86_PAT and end
up with a system with MTRR functionality disabled but PAT
functionality enabled. This can happen, for instance, when the
Xen hypervisor is used where MTRRs are not supported but PAT is.
This can happen on Linux as of commit
47591df50512 ("xen: Support Xen pv-domains using PAT")
by Juergen, introduced in v3.19.
Technically, we should assume the proper CPU bits would be set
to disable MTRRs but we can't always rely on this. At least on
the Xen Hypervisor, for instance, only X86_FEATURE_MTRR was
disabled as of Xen 4.4 through Xen commit 586ab6a [0], but not
X86_FEATURE_K6_MTRR, X86_FEATURE_CENTAUR_MCR, or
X86_FEATURE_CYRIX_ARR for instance.
Roger Pau Monné has clarified though that although this is
technically true we will never support PVH on these CPU types so
Xen has no need to disable these bits on those systems. As per
Roger, AMD K6, Centaur and VIA chips don't have the necessary
hardware extensions to allow running PVH guests [1].
As per Toshi it is also possible for the BIOS to disable MTRR
support, in such cases get_mtrr_state() would update the MTRR
state as per the BIOS, we need to propagate this information as
well.
x86 MTRR code relies on quite a bit of checks for mtrr_if being
set to check to see if MTRRs did get set up. Instead, lets
provide a generic getter for that. This also adds a few checks
where they were not before which could potentially safeguard
ourselves against incorrect usage of MTRR where this was not
desirable.
Where possible match error codes as if MTRRs were disabled on
arch/x86/include/asm/mtrr.h.
Lastly, since disabling MTRRs can happen at run time and we
could end up with PAT enabled, best record now in our logs when
MTRRs are disabled.
[0] ~/devel/xen (git::stable-4.5)$ git describe --contains 586ab6a 4.4.0-rc1~18
[1] http://lists.xenproject.org/archives/html/xen-devel/2015-03/msg03460.html
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: bhelgaas@google.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: konrad.wilk@oracle.com
Cc: venkatesh.pallipadi@intel.com
Cc: ville.syrjala@linux.intel.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1426893517-2511-3-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-12-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is only one user but since we're going to bury MTRR next
out of access to drivers, expose this last piece of API to
drivers in a general fashion only needing io.h for access to
helpers.
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Abhilash Kesavan <a.kesavan@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Cristian Stoica <cristian.stoica@freescale.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: dri-devel@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1429722736-4473-1-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-11-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As part of the effort to phase out MTRR use document
write-combining MTRR effects on pages with different non-PAT
page attributes flags and different PAT entry values. Extend
arch_phys_wc_add() documentation to clarify power of two sizes /
boundary requirements as we phase out mtrr_add() use.
Lastly hint towards ioremap_uc() for corner cases on device
drivers working with devices with mixed regions where MTRR size
requirements would otherwise not enable write-combining
effective memory types.
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-fbdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1430343851-967-3-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-10-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds the argument 'uniform' to mtrr_type_lookup(),
which gets set to 1 when a given range is covered uniformly by
MTRRs, i.e. the range is fully covered by a single MTRR entry or
the default type.
Change pud_set_huge() and pmd_set_huge() to honor the 'uniform'
flag to see if it is safe to create a huge page mapping in the
range.
This allows them to create a huge page mapping in a range
covered by a single MTRR entry of any memory type. It also
detects a non-optimal request properly. They continue to check
with the WB type since it does not effectively change the
uniform mapping even if a request spans multiple MTRR entries.
pmd_set_huge() logs a warning message to a non-optimal request
so that driver writers will be aware of such a case. Drivers
should make a mapping request aligned to a single MTRR entry
when the range is covered by MTRRs.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
[ Realign, flesh out comments, improve warning message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: pebolle@tiscali.nl
Link: http://lkml.kernel.org/r/1431714237-880-7-git-send-email-toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1432628901-18044-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
MTRRs contain fixed and variable entries. mtrr_type_lookup() may
repeatedly call __mtrr_type_lookup() to handle a request that
overlaps with variable entries.
However, __mtrr_type_lookup() also handles the fixed entries,
which do not have to be repeated. Therefore, this patch creates
separate functions, mtrr_type_lookup_fixed() and
mtrr_type_lookup_variable(), to handle the fixed and variable
ranges respectively.
The patch also updates the function headers to clarify the
return values and output argument. It updates comments to
clarify that the repeating is necessary to handle overlaps with
the default type, since overlaps with multiple entries alone can
be handled without such repeating.
There is no functional change in this patch.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: pebolle@tiscali.nl
Link: http://lkml.kernel.org/r/1431714237-880-6-git-send-email-toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1432628901-18044-6-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
mtrr_type_lookup() returns verbatim 0xFF when MTRRs are
disabled. This patch defines MTRR_TYPE_INVALID to clarify the
meaning of this value, and documents its usage.
Document the return values of the kernel virtual address mapping
helpers pud_set_huge(), pmd_set_huge, pud_clear_huge() and
pmd_clear_huge().
There is no functional change in this patch.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: pebolle@tiscali.nl
Link: http://lkml.kernel.org/r/1431714237-880-5-git-send-email-toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1432628901-18044-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
'mtrr_state.enabled' contains the FE (fixed MTRRs enabled)
and E (MTRRs enabled) flags in MSR_MTRRdefType. Intel SDM,
section 11.11.2.1, defines these flags as follows:
- All MTRRs are disabled when the E flag is clear.
The FE flag has no affect when the E flag is clear.
- The default type is enabled when the E flag is set.
- MTRR variable ranges are enabled when the E flag is set.
- MTRR fixed ranges are enabled when both E and FE flags
are set.
MTRR state checks in __mtrr_type_lookup() do not match with SDM.
Hence, this patch makes the following changes:
- The current code detects MTRRs disabled when both E and
FE flags are clear in mtrr_state.enabled. Fix to detect
MTRRs disabled when the E flag is clear.
- The current code does not check if the FE bit is set in
mtrr_state.enabled when looking at the fixed entries.
Fix to check the FE flag.
- The current code returns the default type when the E flag
is clear in mtrr_state.enabled. However, the default type
is UC when the E flag is clear. Remove the code as this
case is handled as MTRR disabled with the 1st change.
In addition, this patch defines the E and FE flags in
mtrr_state.enabled as follows.
- FE flag: MTRR_STATE_MTRR_FIXED_ENABLED
- E flag: MTRR_STATE_MTRR_ENABLED
print_mtrr_state() and x86_get_mtrr_mem_range() are also updated
accordingly.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: pebolle@tiscali.nl
Link: http://lkml.kernel.org/r/1431714237-880-4-git-send-email-toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1432628901-18044-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When an MTRR entry is inclusive to a requested range, i.e. the
start and end of the request are not within the MTRR entry range
but the range contains the MTRR entry entirely:
range_start ... [mtrr_start ... mtrr_end] ... range_end
__mtrr_type_lookup() ignores such a case because both
start_state and end_state are set to zero.
This bug can cause the following issues:
1) reserve_memtype() tracks an effective memory type in case
a request type is WB (ex. /dev/mem blindly uses WB). Missing
to track with its effective type causes a subsequent request
to map the same range with the effective type to fail.
2) pud_set_huge() and pmd_set_huge() check if a requested range
has any overlap with MTRRs. Missing to detect an overlap may
cause a performance penalty or undefined behavior.
This patch fixes the bug by adding a new flag, 'inclusive',
to detect the inclusive case. This case is then handled in
the same way as end_state:1 since the first region is the same.
With this fix, __mtrr_type_lookup() handles the inclusive case
properly.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
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: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: pebolle@tiscali.nl
Link: http://lkml.kernel.org/r/1431714237-880-3-git-send-email-toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1432628901-18044-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'v4.1-rc5' into x86/mm, to refresh the tree before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Using "mce=1,10000000" on the kernel cmdline to change the
monarch timeout does not work. The cause is that get_option()
does parse a subsequent comma in the option string and signals
that with a return value. So we don't need to check for a second
comma ourselves.
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.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: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1432120943-25028-1-git-send-email-xiexiuqi@huawei.com
Link: http://lkml.kernel.org/r/1432628901-18044-19-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When comparing the 'model name' field of each core in
/proc/cpuinfo it was noticed that there is a whitespace
difference between the cores' model names.
After some quick investigation it was noticed that the model
name fields were actually different -- processor 0's model name
field had trailing whitespace removed, while the other
processors did not.
Another way of seeing this behaviour is to convert spaces into
underscores in the output of /proc/cpuinfo,
[thetango@prarit ~]# grep "^model name" /proc/cpuinfo | uniq -c | sed 's/\ /_/g'
______1_model_name :_AMD_Opteron(TM)_Processor_6272
_____63_model_name :_AMD_Opteron(TM)_Processor_6272_________________
which shows the discrepancy.
This occurs because the kernel calls strim() on cpu 0's
x86_model_id field to output a pretty message to the console in
print_cpu_info(), and as a result strips the whitespace at the
end of the ->x86_model_id field.
But, the ->x86_model_id field should be the same for the all
identical CPUs in the box. Thus, we need to remove both leading
and trailing whitespace.
As a result, the print_cpu_info() output looks like
smpboot: CPU0: AMD Opteron(TM) Processor 6272 (fam: 15, model: 01, stepping: 02)
and the x86_model_id field is correct on all processors on AMD
platforms:
_____64_model_name :_AMD_Opteron(TM)_Processor_6272
Output is still correct on an Intel box:
____144_model_name :_Intel(R)_Xeon(R)_CPU_E7-8890_v3_@_2.50GHz
Signed-off-by: Prarit Bhargava <prarit@redhat.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: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Igor Mammedov <imammedo@redhat.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/1432050210-32036-1-git-send-email-prarit@redhat.com
Link: http://lkml.kernel.org/r/1432628901-18044-15-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
copy_kernel_to_xregs_booting() has a second parameter that is the mask
of xfeatures that should be copied - but this parameter is always -1.
Simplify the call site of this function, this also makes it more
similar to the function call signature of other copy_kernel_to*regs()
functions.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Bring the __copy_fpstate_to_fpregs() and copy_fpstate_to_fpregs() functions
in line with the parameter passing convention of other kernel-to-FPU-registers
copying functions: pass around an in-memory FPU register state pointer,
instead of struct fpu *.
NOTE: This patch also changes the assembly constraint of the FXSAVE-leak
workaround from 'fpu->fpregs_active' to 'fpstate' - but that is fine,
as we only need a valid memory address there for the FILDL instruction.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
None of the copy_kernel_to_*regs() FPU register copying functions are
supposed to fail, and all of them have debugging checks that enforce
this.
Remove their return values and simplify their call sites, which have
redundant error checks and error handling code paths.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Bring the __copy_fpstate_to_fpregs() and copy_fpstate_to_fpregs() functions
in line with the naming of other kernel-to-FPU-registers copying functions.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The copy_fpstate_to_fpregs() function is never supposed to fail,
so add a debugging check to its call site in fpu__restore().
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
fpu__activate_fpstate_write() is used before ptrace writes to the fpstate
context. Because it expects the modified registers to be reloaded on the
nexts context switch, it's only valid to call this function for stopped
child tasks.
- add a debugging check for this assumption
- remove code that only runs if the current task's FPU state needs
to be saved, which cannot occur here
- update comments to match the implementation
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remaining users of fpu__activate_fpstate() are all places that want to modify
FPU registers, rename the function to fpu__activate_fpstate_write() according
to this usage.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
fpu__activate_fpstate_read() is used before FPU registers are
read from the fpstate by ptrace and core dumping.
It's not necessary to unlazy non-current child tasks in this case,
since the reading of registers is non-destructive.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently fpu__activate_fpstate() is used for two distinct purposes:
- read access by ptrace and core dumping, where in the core dumping
case the current task's FPU state may be examined as well.
- write access by ptrace, which modifies FPU registers and expects
the modified registers to be reloaded on the next context switch.
Split out the reading side into fpu__activate_fpstate_read().
( Note that this is just a pure duplication of fpu__activate_fpstate()
for the time being, we'll optimize the new function in the next patch. )
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Bobby Powers reported the following FPU warning during ELF coredumping:
WARNING: CPU: 0 PID: 27452 at arch/x86/kernel/fpu/core.c:324 fpu__activate_stopped+0x8a/0xa0()
This warning unearthed an invalid assumption about fpu__activate_stopped()
that I added in:
67e97fc2ec57 ("x86/fpu: Rename init_fpu() to fpu__unlazy_stopped() and add debugging check")
the old init_fpu() function had an (intentional but obscure) side effect:
when FPU registers are accessed for the current task, for reading, then
it synchronized live in-register FPU state with the fpstate by saving it.
So fix this bug by saving the FPU if we are the current task. We'll
still warn in fpu__save() if this is called for not yet stopped
child tasks, so the debugging check is still preserved.
Also rename the function to fpu__activate_fpstate(), because it's not
exclusively used for stopped tasks, but for the current task as well.
( Note that this bug calls for a cleaner separation of access-for-read
and access-for-modification FPU methods, but we'll do that in separate
patches. )
Reported-by: Bobby Powers <bobbypowers@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is a 'pt' variable in the outer scope of pt_event_stop() with the same
type, we don't really need another one in the inner scope.
This patch removes the redundant variable declaration.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1432308626-18845-8-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Initially, we were trying to guard against scenarios where somebody
attaches to the system with a hardware debugger while PT is enabled
from software and pt_is_running() tries to make sure we handle this
better, but the truth is, there is still a race window no matter what
and people with hardware debuggers should really know what they are
doing anyway.
In other words, there is no point in keeping this one around, and
it's one RDMSR instructions fewer in the fast path.
The case when PT is enabled by the BIOS at boot time is handled
in the driver initialization path and doesn't use pt_is_running().
This patch gets rid of it.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1429622177-22843-6-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, the description of pt_buffer_reset_offsets() lacks information
about its calling constraints and ordering with regards to other buffer
management functions.
Add a clarification about when this function has to be called.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1429622177-22843-5-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
