commit b0b6e86846093c5f8820386bc01515f857dd8faa upstream.
cpu_llc_id (Last Level Cache ID) derivation on AMD Fam17h has an
underflow bug when extracting the socket_id value. It starts from 0
so subtracting 1 from it will result in an invalid value. This breaks
scheduling topology later on since the cpu_llc_id will be incorrect.
For example, the the cpu_llc_id of the *other* CPU in the loops in
set_cpu_sibling_map() underflows and we're generating the funniest
thread_siblings masks and then when I run 8 threads of nbench, they get
spread around the LLC domains in a very strange pattern which doesn't
give you the normal scheduling spread one would expect for performance.
Other things like EDAC use cpu_llc_id so they will be b0rked too.
So, the APIC ID is preset in APICx020 for bits 3 and above: they contain
the core complex, node and socket IDs.
The LLC is at the core complex level so we can find a unique cpu_llc_id
by right shifting the APICID by 3 because then the least significant bit
will be the Core Complex ID.
Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
[ Cleaned up and extended the commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 3849e91f57 ("x86/AMD: Fix last level cache topology for AMD Fam17h systems")
Link: http://lkml.kernel.org/r/20161108083506.rvqb5h4chrcptj7d@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 548acf19234dbda5a52d5a8e7e205af46e9da840 upstream.
Huge amounts of help from Andy Lutomirski and Borislav Petkov to
produce this. Andy provided the inspiration to add classes to the
exception table with a clever bit-squeezing trick, Boris pointed
out how much cleaner it would all be if we just had a new field.
Linus Torvalds blessed the expansion with:
' I'd rather not be clever in order to save just a tiny amount of space
in the exception table, which isn't really criticial for anybody. '
The third field is another relative function pointer, this one to a
handler that executes the actions.
We start out with three handlers:
1: Legacy - just jumps the to fixup IP
2: Fault - provide the trap number in %ax to the fixup code
3: Cleaned up legacy for the uaccess error hack
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
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/f6af78fcbd348cf4939875cfda9c19689b5e50b8.1455732970.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d721b02fd00bf133580f431b82ef37f3b746dfb2 upstream.
Looks like the TSEG lives just above TOUD, stolen comes after TSEG.
The spec seems somewhat self-contradictory in places, in the ESMRAMC
register desctription it says:
TSEG Size:
10=(TOUD + 512 KB) to TOUD
11 =(TOUD + 1 MB) to TOUD
so that agrees with TSEG being at TOUD. But the example given
elsehwere in the spec says:
TOUD equals 62.5 MB = 03E7FFFFh
TSEG selected as 512 KB in size,
Graphics local memory selected as 1 MB in size
General System RAM available in system = 62.5 MB
General system RAM range00000000h to 03E7FFFFh
TSEG address range03F80000h to 03FFFFFFh
TSEG pre-allocated from03F80000h to 03FFFFFFh
Graphics local memory pre-allocated from03E80000h to 03F7FFFFh
so here we have TSEG above stolen.
Real world evidence agrees with the TOUD->TSEG->stolen order however, so
let's fix up the code to account for the TSEG size.
Cc: Taketo Kabe <fdporg@vega.pgw.jp>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Fixes: 0ad98c74e0 ("drm/i915: Determine the stolen memory base address on gen2")
Fixes: a4dff76924 ("x86/gpu: Add Intel graphics stolen memory quirk for gen2 platforms")
Reported-by: Taketo Kabe <fdporg@vega.pgw.jp>
Tested-by: Taketo Kabe <fdporg@vega.pgw.jp>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96473
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470653919-27251-1-git-send-email-ville.syrjala@linux.intel.com
Link: http://download.intel.com/design/chipsets/datashts/25251405.pdf
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 23446cb66c073b827779e5eb3dec301623299b32 upstream.
Commit:
917db484dc6a ("x86/boot: Fix kdump, cleanup aborted E820_PRAM max_pfn manipulation")
... fixed up the broken manipulations of max_pfn in the presence of
E820_PRAM ranges.
However, it also broke the sanitize_e820_map() support for not merging
E820_PRAM ranges.
Re-introduce the enabling to keep resource boundaries between
consecutive defined ranges. Otherwise, for example, an environment that
boots with memmap=2G!8G,2G!10G will end up with a single 4G /dev/pmem0
device instead of a /dev/pmem0 and /dev/pmem1 device 2G in size.
Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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: Jeff Moyer <jmoyer@redhat.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: Zhang Yi <yizhan@redhat.com>
Cc: linux-nvdimm@lists.01.org
Fixes: 917db484dc6a ("x86/boot: Fix kdump, cleanup aborted E820_PRAM max_pfn manipulation")
Link: http://lkml.kernel.org/r/147629530854.10618.10383744751594021268.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 72b4f6a5e903b071f2a7c4eb1418cbe4eefdc344 upstream.
On x86_32, when an interrupt happens from kernel space, SS and SP aren't
pushed and the existing stack is used. So pt_regs is effectively two
words shorter, and the previous stack pointer is normally the memory
after the shortened pt_regs, aka '®s->sp'.
But in the rare case where the interrupt hits right after the stack
pointer has been changed to point to an empty stack, like for example
when call_on_stack() is used, the address immediately after the
shortened pt_regs is no longer on the stack. In that case, instead of
'®s->sp', the previous stack pointer should be retrieved from the
beginning of the current stack page.
kernel_stack_pointer() wants to do that, but it forgets to dereference
the pointer. So instead of returning a pointer to the previous stack,
it returns a pointer to the beginning of the current stack.
Note that it's probably outside of kernel_stack_pointer()'s scope to be
switching stacks at all. The x86_64 version of this function doesn't do
it, and it would be better for the caller to do it if necessary. But
that's a patch for another day. This just fixes the original intent.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.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: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 0788aa6a23 ("x86: Prepare removal of previous_esp from i386 thread_info structure")
Link: http://lkml.kernel.org/r/472453d6e9f6a2d4ab16aaed4935f43117111566.1471535549.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit db91aa793ff984ac048e199ea1c54202543952fe upstream.
When a CPU is about to be offlined we call fixup_irqs() that resets IRQ
affinities related to the CPU in question. The same thing is also done when
the system is suspended to S-states like S3 (mem).
For each IRQ we try to complete any on-going move regardless whether the
IRQ is actually part of x86_vector_domain. For each IRQ descriptor we fetch
its chip_data, assume it is of type struct apic_chip_data and manipulate it
by clearing old_domain mask etc. For irq_chips that are not part of the
x86_vector_domain, like those created by various GPIO drivers, will find
their chip_data being changed unexpectly.
Below is an example where GPIO chip owned by pinctrl-sunrisepoint.c gets
corrupted after resume:
# cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 360-511, parent: platform/INT344B:00, INT344B:00:
gpio-511 ( |sysfs ) in hi
# rtcwake -s10 -mmem
<10 seconds passes>
# cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 360-511, parent: platform/INT344B:00, INT344B:00:
gpio-511 ( |sysfs ) in ?
Note '?' in the output. It means the struct gpio_chip ->get function is
NULL whereas before suspend it was there.
Fix this by first checking that the IRQ belongs to x86_vector_domain before
we try to use the chip_data as struct apic_chip_data.
Reported-and-tested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: http://lkml.kernel.org/r/20161003101708.34795-1-mika.westerberg@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 917db484dc6a69969d317b3e57add4208a8d9d42 upstream.
In commit:
ec776ef6bb ("x86/mm: Add support for the non-standard protected e820 type")
Christoph references the original patch I wrote implementing pmem support.
The intent of the 'max_pfn' changes in that commit were to enable persistent
memory ranges to be covered by the struct page memmap by default.
However, that approach was abandoned when Christoph ported the patches [1], and
that functionality has since been replaced by devm_memremap_pages().
In the meantime, this max_pfn manipulation is confusing kdump [2] that
assumes that everything covered by the max_pfn is "System RAM". This
results in kdump hanging or crashing.
[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-March/000348.html
[2]: https://bugzilla.redhat.com/show_bug.cgi?id=1351098
So fix it.
Reported-by: Zhang Yi <yizhan@redhat.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Zhang Yi <yizhan@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-nvdimm@lists.01.org
Fixes: ec776ef6bb ("x86/mm: Add support for the non-standard protected e820 type")
Link: http://lkml.kernel.org/r/147448744538.34910.11287693517367139607.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 05fb3c199bb09f5b85de56cc3ede194ac95c5e1f upstream.
Otherwise arch_task_struct_size == 0 and we die. While we're at it,
set X86_FEATURE_ALWAYS, too.
Reported-by: David Saggiorato <david@saggiorato.net>
Tested-by: David Saggiorato <david@saggiorato.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.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>
Fixes: aaeb5c01c5b ("x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86")
Link: http://lkml.kernel.org/r/8de723afbf0811071185039f9088733188b606c9.1475103911.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d1992996753132e2dafe955cccb2fb0714d3cfc4 upstream.
AMD F12h machines have an erratum which can cause DIV/IDIV to behave
unpredictably. The workaround is to set MSRC001_1029[31] but sometimes
there is no BIOS update containing that workaround so let's do it
ourselves unconditionally. It is simple enough.
[ Borislav: Wrote commit message. ]
Signed-off-by: Emanuel Czirai <icanrealizeum@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Yaowu Xu <yaowu@google.com>
Link: http://lkml.kernel.org/r/20160902053550.18097-1-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 15301a570754c7af60335d094dd2d1808b0641a5 upstream.
Łukasz Daniluk reported that on a RHEL kernel that his machine would lock up
after enabling function tracer. I asked him to bisect the functions within
available_filter_functions, which he did and it came down to three:
_paravirt_nop(), _paravirt_ident_32() and _paravirt_ident_64()
It was found that this is only an issue when noreplace-paravirt is added
to the kernel command line.
This means that those functions are most likely called within critical
sections of the funtion tracer, and must not be traced.
In newer kenels _paravirt_nop() is defined within gcc asm(), and is no
longer an issue. But both _paravirt_ident_{32,64}() causes the
following splat when they are traced:
mm/pgtable-generic.c:33: bad pmd ffff8800d2435150(0000000001d00054)
mm/pgtable-generic.c:33: bad pmd ffff8800d3624190(0000000001d00070)
mm/pgtable-generic.c:33: bad pmd ffff8800d36a5110(0000000001d00054)
mm/pgtable-generic.c:33: bad pmd ffff880118eb1450(0000000001d00054)
NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [systemd-journal:469]
Modules linked in: e1000e
CPU: 2 PID: 469 Comm: systemd-journal Not tainted 4.6.0-rc4-test+ #513
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012
task: ffff880118f740c0 ti: ffff8800d4aec000 task.ti: ffff8800d4aec000
RIP: 0010:[<ffffffff81134148>] [<ffffffff81134148>] queued_spin_lock_slowpath+0x118/0x1a0
RSP: 0018:ffff8800d4aefb90 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88011eb16d40
RDX: ffffffff82485760 RSI: 000000001f288820 RDI: ffffea0000008030
RBP: ffff8800d4aefb90 R08: 00000000000c0000 R09: 0000000000000000
R10: ffffffff821c8e0e R11: 0000000000000000 R12: ffff880000200fb8
R13: 00007f7a4e3f7000 R14: ffffea000303f600 R15: ffff8800d4b562e0
FS: 00007f7a4e3d7840(0000) GS:ffff88011eb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7a4e3f7000 CR3: 00000000d3e71000 CR4: 00000000001406e0
Call Trace:
_raw_spin_lock+0x27/0x30
handle_pte_fault+0x13db/0x16b0
handle_mm_fault+0x312/0x670
__do_page_fault+0x1b1/0x4e0
do_page_fault+0x22/0x30
page_fault+0x28/0x30
__vfs_read+0x28/0xe0
vfs_read+0x86/0x130
SyS_read+0x46/0xa0
entry_SYSCALL_64_fastpath+0x1e/0xa8
Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 40 6d 01 00 48 03 14 c5 80 6a 5d 82 48 89 0a 8b 41 08 85 c0 75 09 f3 90 8b 41 08 <85> c0 74 f7 4c 8b 09 4d 85 c9 74 08 41 0f 18 09 eb 02 f3 90 8b
Reported-by: Łukasz Daniluk <lukasz.daniluk@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This removes the CONFIG_DEBUG_RODATA option and makes it always enabled.
This simplifies the code and also makes it clearer that read-only mapped
memory is just as fundamental a security feature in kernel-space as it is
in user-space.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1455748879-21872-4-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Bug: 31660652
Change-Id: I3e79c7c4ead79a81c1445f1b3dd28003517faf18
(cherry picked from commit 9ccaf77cf05915f51231d158abfd5448aedde758)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
commit 2e63ad4bd5dd583871e6602f9d398b9322d358d9 upstream.
native_smp_prepare_cpus
-> default_setup_apic_routing
-> enable_IR_x2apic
-> irq_remapping_prepare
-> intel_prepare_irq_remapping
-> intel_setup_irq_remapping
So IR table is setup even if "noapic" boot parameter is added. As a result we
crash later when the interrupt affinity is set due to a half initialized
remapping infrastructure.
Prevent remap initialization when IOAPIC is disabled.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>
Link: http://lkml.kernel.org/r/1471954039-3942-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1e2ae9ec072f3b7887f456426bc2cf23b80f661a ]
Generation2 instances don't support reporting the NMI status on port 0x61,
read from there returns 'ff' and we end up reporting nonsensical PCI
error (as there is no PCI bus in these instances) on all NMIs:
NMI: PCI system error (SERR) for reason ff on CPU 0.
Dazed and confused, but trying to continue
Fix the issue by overriding x86_platform.get_nmi_reason. Use 'booted on
EFI' flag to detect Gen2 instances.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Cathy Avery <cavery@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: devel@linuxdriverproject.org
Link: http://lkml.kernel.org/r/1460728232-31433-1-git-send-email-vkuznets@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a223c1c7ab4cc64537dc4b911f760d851683768a ]
Currently CQM (cache quality of service monitoring) is grouping all
events belonging to same PID to use one RMID. However its not counting
all of these different events. Hence we end up with a count of zero
for all events other than the group leader.
The patch tries to address the issue by keeping a flag in the
perf_event.hw which has other CQM related fields. The field is updated
at event creation and during grouping.
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
[peterz: Changed hw_perf_event::is_group_event to an int]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: fenghua.yu@intel.com
Cc: h.peter.anvin@intel.com
Cc: ravi.v.shankar@intel.com
Cc: vikas.shivappa@intel.com
Link: http://lkml.kernel.org/r/1457652732-4499-2-git-send-email-vikas.shivappa@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 68187872c76a96ed4db7bfb064272591f02e208b upstream.
Since instruction decoder now supports EVEX-encoded instructions, two fixes
are needed to correctly handle them in uprobes.
Extended bits for MODRM.rm field need to be sanitized just like we do it
for VEX3, to avoid encoding wrong register for register-relative access.
EVEX has _two_ extended bits: b and x. Theoretically, EVEX.x should be
ignored by the CPU (since GPRs go only up to 15, not 31), but let's be
paranoid here: proper encoding for register-relative access
should have EVEX.x = 1.
Secondly, we should fetch vex.vvvv for EVEX too.
This is now super easy because instruction decoder populates
vex_prefix.bytes[2] for all flavors of (e)vex encodings, even for VEX2.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
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: linux-kernel@vger.kernel.org
Fixes: 8a764a875f ("x86/asm/decoder: Create artificial 3rd byte for 2-byte VEX")
Link: http://lkml.kernel.org/r/20160811154521.20469-1-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ad025a73f0e9344ac73ffe1b74c184033e08e7d5 upstream.
get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled.
This results in calling pat_init() on BSP only since APs do not call
pat_init() when MTRR is disabled. This inconsistency between BSP
and APs leads to undefined behavior.
Make BSP's calling condition to pat_init() consistent with AP's,
mtrr_ap_init() and mtrr_aps_init().
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-6-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit edfe63ec97ed8d4496225f7ba54c9ce4207c5431 upstream.
A Xorg failure on qemu32 was reported as a regression [1] caused by
commit 9cd25aac1f ("x86/mm/pat: Emulate PAT when it is disabled").
This patch fixes the Xorg crash.
Negative effects of this regression were the following two failures [2]
in Xorg on QEMU with QEMU CPU model "qemu32" (-cpu qemu32), which were
triggered by the fact that its virtual CPU does not support MTRRs.
#1. copy_process() failed in the check in reserve_pfn_range()
copy_process
copy_mm
dup_mm
dup_mmap
copy_page_range
track_pfn_copy
reserve_pfn_range
A WC map request was tracked as WC in memtype, which set a PTE as
UC (pgprot) per __cachemode2pte_tbl[]. This led to this error in
reserve_pfn_range() called from track_pfn_copy(), which obtained
a pgprot from a PTE. It converts pgprot to page_cache_mode, which
does not necessarily result in the original page_cache_mode since
__cachemode2pte_tbl[] redirects multiple types to UC.
#2. error path in copy_process() then hit WARN_ON_ONCE in
untrack_pfn().
x86/PAT: Xorg:509 map pfn expected mapping type uncached-
minus for [mem 0xfd000000-0xfdffffff], got write-combining
Call Trace:
dump_stack
warn_slowpath_common
? untrack_pfn
? untrack_pfn
warn_slowpath_null
untrack_pfn
? __kunmap_atomic
unmap_single_vma
? pagevec_move_tail_fn
unmap_vmas
exit_mmap
mmput
copy_process.part.47
_do_fork
SyS_clone
do_syscall_32_irqs_on
entry_INT80_32
These negative effects are caused by two separate bugs, but they
can be addressed in separate patches. Fixing the pat_init() issue
described below addresses the root cause, and avoids Xorg to hit
these cases.
When the CPU does not support MTRRs, MTRR does not call pat_init(),
which leaves PAT enabled without initializing PAT. This pat_init()
issue is a long-standing issue, but manifested as issue #1 (and then
hit issue #2) with the above-mentioned commit because the memtype
now tracks cache attribute with 'page_cache_mode'.
This pat_init() issue existed before the commit, but we used pgprot
in memtype. Hence, we did not have issue #1 before. But WC request
resulted in WT in effect because WC pgrot is actually WT when PAT
is not initialized. This is not how it was designed to work. When
PAT is set to disable properly, WC is converted to UC. The use of
WT can result in a system crash if the target range does not support
WT. Fortunately, nobody ran into such issue before.
To fix this pat_init() issue, PAT code has been enhanced to provide
pat_disable() interface. Call this interface when MTRRs are disabled.
By setting PAT to disable properly, PAT bypasses the memtype check,
and avoids issue #1.
[1]: https://lkml.org/lkml/2016/3/3/828
[2]: https://lkml.org/lkml/2016/3/4/775
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-5-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1424a09a9e1839285e948d4ea9fdfca26c9a2086 upstream.
This patch fixes broken PEBS support on Intel Atom and Core2
due to wrong pointer arithmetic in intel_pmu_drain_pebs_core().
The get_next_pebs_record_by_bit() was called on PEBS format fmt0
which does not use the pebs_record_nhm layout.
Signed-off-by: Stephane Eranian <eranian@google.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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kan.liang@intel.com
Fixes: 21509084f9 ("perf/x86/intel: Handle multiple records in the PEBS buffer")
Link: http://lkml.kernel.org/r/1449182000-31524-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 749d088b8e7f4b9826ede02b9a043e417fa84aa1 upstream.
Protocol for the "version" fields is: hypervisor raises it (making it
uneven) before it starts updating the fields and raises it again (making
it even) when it is done. Thus the guest can make sure the time values
it got are consistent by checking the version before and after reading
them.
Add CPU barries after getting version value just like what function
vread_pvclock does, because all of callees in this function is inline.
Fixes: 502dfeff23
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit abb2bafd295fe962bbadc329dbfb2146457283ac upstream.
The EFI firmware on Macs contains a full-fledged network stack for
downloading OS X images from osrecovery.apple.com. Unfortunately
on Macs introduced 2011 and 2012, EFI brings up the Broadcom 4331
wireless card on every boot and leaves it enabled even after
ExitBootServices has been called. The card continues to assert its IRQ
line, causing spurious interrupts if the IRQ is shared. It also corrupts
memory by DMAing received packets, allowing for remote code execution
over the air. This only stops when a driver is loaded for the wireless
card, which may be never if the driver is not installed or blacklisted.
The issue seems to be constrained to the Broadcom 4331. Chris Milsted
has verified that the newer Broadcom 4360 built into the MacBookPro11,3
(2013/2014) does not exhibit this behaviour. The chances that Apple will
ever supply a firmware fix for the older machines appear to be zero.
The solution is to reset the card on boot by writing to a reset bit in
its mmio space. This must be done as an early quirk and not as a plain
vanilla PCI quirk to successfully combat memory corruption by DMAed
packets: Matthew Garrett found out in 2012 that the packets are written
to EfiBootServicesData memory (http://mjg59.dreamwidth.org/11235.html).
This type of memory is made available to the page allocator by
efi_free_boot_services(). Plain vanilla PCI quirks run much later, in
subsys initcall level. In-between a time window would be open for memory
corruption. Random crashes occurring in this time window and attributed
to DMAed packets have indeed been observed in the wild by Chris
Bainbridge.
When Matthew Garrett analyzed the memory corruption issue in 2012, he
sought to fix it with a grub quirk which transitions the card to D3hot:
http://git.savannah.gnu.org/cgit/grub.git/commit/?id=9d34bb85da56
This approach does not help users with other bootloaders and while it
may prevent DMAed packets, it does not cure the spurious interrupts
emanating from the card. Unfortunately the card's mmio space is
inaccessible in D3hot, so to reset it, we have to undo the effect of
Matthew's grub patch and transition the card back to D0.
Note that the quirk takes a few shortcuts to reduce the amount of code:
The size of BAR 0 and the location of the PM capability is identical
on all affected machines and therefore hardcoded. Only the address of
BAR 0 differs between models. Also, it is assumed that the BCMA core
currently mapped is the 802.11 core. The EFI driver seems to always take
care of this.
Michael Büsch, Bjorn Helgaas and Matt Fleming contributed feedback
towards finding the best solution to this problem.
The following should be a comprehensive list of affected models:
iMac13,1 2012 21.5" [Root Port 00:1c.3 = 8086:1e16]
iMac13,2 2012 27" [Root Port 00:1c.3 = 8086:1e16]
Macmini5,1 2011 i5 2.3 GHz [Root Port 00:1c.1 = 8086:1c12]
Macmini5,2 2011 i5 2.5 GHz [Root Port 00:1c.1 = 8086:1c12]
Macmini5,3 2011 i7 2.0 GHz [Root Port 00:1c.1 = 8086:1c12]
Macmini6,1 2012 i5 2.5 GHz [Root Port 00:1c.1 = 8086:1e12]
Macmini6,2 2012 i7 2.3 GHz [Root Port 00:1c.1 = 8086:1e12]
MacBookPro8,1 2011 13" [Root Port 00:1c.1 = 8086:1c12]
MacBookPro8,2 2011 15" [Root Port 00:1c.1 = 8086:1c12]
MacBookPro8,3 2011 17" [Root Port 00:1c.1 = 8086:1c12]
MacBookPro9,1 2012 15" [Root Port 00:1c.1 = 8086:1e12]
MacBookPro9,2 2012 13" [Root Port 00:1c.1 = 8086:1e12]
MacBookPro10,1 2012 15" [Root Port 00:1c.1 = 8086:1e12]
MacBookPro10,2 2012 13" [Root Port 00:1c.1 = 8086:1e12]
For posterity, spurious interrupts caused by the Broadcom 4331 wireless
card resulted in splats like this (stacktrace omitted):
irq 17: nobody cared (try booting with the "irqpoll" option)
handlers:
[<ffffffff81374370>] pcie_isr
[<ffffffffc0704550>] sdhci_irq [sdhci] threaded [<ffffffffc07013c0>] sdhci_thread_irq [sdhci]
[<ffffffffc0a0b960>] azx_interrupt [snd_hda_codec]
Disabling IRQ #17
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79301
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111781
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=728916
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=895951#c16
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1009819
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1098621
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1149632#c5
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1279130
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1332732
Tested-by: Konstantin Simanov <k.simanov@stlk.ru> # [MacBookPro8,1]
Tested-by: Lukas Wunner <lukas@wunner.de> # [MacBookPro9,1]
Tested-by: Bryan Paradis <bryan.paradis@gmail.com> # [MacBookPro9,2]
Tested-by: Andrew Worsley <amworsley@gmail.com> # [MacBookPro10,1]
Tested-by: Chris Bainbridge <chris.bainbridge@gmail.com> # [MacBookPro10,2]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris Milsted <cmilsted@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Michael Buesch <m@bues.ch>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: b43-dev@lists.infradead.org
Cc: linux-pci@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Link: http://lkml.kernel.org/r/48d0972ac82a53d460e5fce77a07b2560db95203.1465690253.git.lukas@wunner.de
[ Did minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 850c321027c2e31d0afc71588974719a4b565550 upstream.
We used to scan secondary buses until the following commit that
was applied in 2009:
8659c406ad ("x86: only scan the root bus in early PCI quirks")
which commit constrained early quirks to the root bus only. Its
motivation was to prevent application of the nvidia_bugs quirk
on secondary buses.
We're about to add a quirk to reset the Broadcom 4331 wireless card on
2011/2012 Macs, which is located on a secondary bus behind a PCIe root
port. To facilitate that, reintroduce scanning of secondary buses.
The commit message of 8659c406ad notes that scanning only the root bus
"saves quite some unnecessary scanning work". The algorithm used prior
to 8659c406ad was particularly time consuming because it scanned
buses 0 to 31 brute force. To avoid lengthening boot time, employ a
recursive strategy which only scans buses that are actually reachable
from the root bus.
Yinghai Lu pointed out that the secondary bus number read from a
bridge's config space may be invalid, in particular a value of 0 would
cause an infinite loop. The PCI core goes beyond that and recurses to a
child bus only if its bus number is greater than the parent bus number
(see pci_scan_bridge()). Since the root bus is numbered 0, this implies
that secondary buses may not be 0. Do the same on early scanning.
If this algorithm is found to significantly impact boot time or cause
infinite loops on broken hardware, it would be possible to limit its
recursion depth: The Broadcom 4331 quirk applies at depth 1, all others
at depth 0, so the bus need not be scanned deeper than that for now. An
alternative approach would be to revert to scanning only the root bus,
and apply the Broadcom 4331 quirk to the root ports 8086:1c12, 8086:1e12
and 8086:1e16. Apple always positioned the card behind either of these
three ports. The quirk would then check presence of the card in slot 0
below the root port and do its deed.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
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: 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: Yinghai Lu <yinghai@kernel.org>
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/f0daa70dac1a9b2483abdb31887173eb6ab77bdf.1465690253.git.lukas@wunner.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 447d29d1d3aed839e74c2401ef63387780ac51ed upstream.
Since the following commit:
8659c406ad ("x86: only scan the root bus in early PCI quirks")
... early quirks are only applied to devices on the root bus.
The motivation was to prevent application of the nvidia_bugs quirk on
secondary buses.
We're about to reintroduce scanning of secondary buses for a quirk to
reset the Broadcom 4331 wireless card on 2011/2012 Macs. To prevent
regressions, open code the requirement to apply nvidia_bugs only on the
root bus.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
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: 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: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/4d5477c1d76b2f0387a780f2142bbcdd9fee869b.1465690253.git.lukas@wunner.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6d6f2833bfbf296101f9f085e10488aef2601ba5 upstream.
Jim reported:
UBSAN: Undefined behaviour in arch/x86/events/intel/core.c:3708:12
shift exponent 35 is too large for 32-bit type 'long unsigned int'
The use of 'unsigned long' type obviously is not correct here, make it
'unsigned long long' instead.
Reported-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Imre Palik <imrep@amazon.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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>
Fixes: 2c33645d36 ("perf/x86: Honor the architectural performance monitoring version")
Link: http://lkml.kernel.org/r/1462974711-10037-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Christopher <kevinc@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1ead852dd88779eda12cb09cc894a03d9abfe1ec upstream.
Fix boot crash that triggers if this driver is built into a kernel and
run on non-AMD systems.
AMD northbridges users call amd_cache_northbridges() and it returns
a negative value to signal that we weren't able to cache/detect any
northbridges on the system.
At least, it should do so as all its callers expect it to do so. But it
does return a negative value only when kmalloc() fails.
Fix it to return -ENODEV if there are no NBs cached as otherwise, amd_nb
users like amd64_edac, for example, which relies on it to know whether
it should load or not, gets loaded on systems like Intel Xeons where it
shouldn't.
Reported-and-tested-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
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/1466097230-5333-2-git-send-email-bp@alien8.de
Link: https://lkml.kernel.org/r/5761BEB0.9000807@cybernetics.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dcfc47248d3f7d28df6f531e6426b933de94370d upstream.
Fix kprobe_fault_handler() to clear the TF (trap flag) bit of
the flags register in the case of a fault fixup on single-stepping.
If we put a kprobe on the instruction which caused a
page fault (e.g. actual mov instructions in copy_user_*),
that fault happens on the single-stepping buffer. In this
case, kprobes resets running instance so that the CPU can
retry execution on the original ip address.
However, current code forgets to reset the TF bit. Since this
fault happens with TF bit set for enabling single-stepping,
when it retries, it causes a debug exception and kprobes
can not handle it because it already reset itself.
On the most of x86-64 platform, it can be easily reproduced
by using kprobe tracer. E.g.
# cd /sys/kernel/debug/tracing
# echo p copy_user_enhanced_fast_string+5 > kprobe_events
# echo 1 > events/kprobes/enable
And you'll see a kernel panic on do_debug(), since the debug
trap is not handled by kprobes.
To fix this problem, we just need to clear the TF bit when
resetting running kprobe.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
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: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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: systemtap@sourceware.org
Link: http://lkml.kernel.org/r/20160611140648.25885.37482.stgit@devbox
[ Updated the comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aaee8c3c5cce2d9107310dd9f3026b4f901d441c upstream.
Forcing in_interrupt() to return true if we're not in a bona fide
interrupt confuses the softirq code. This fixes warnings like:
NOHZ: local_softirq_pending 282
... which can happen when running things like selftests/x86.
This will change perf's static percpu buffer usage in IST context.
I think this is okay, and it's changing the behavior to match
historical (pre-4.0) behavior.
Signed-off-by: Andy Lutomirski <luto@kernel.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: 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>
Fixes: 9592747538 ("x86, traps: Track entry into and exit from IST context")
Link: http://lkml.kernel.org/r/cdc215f94d118d691d73df35275022331156fb45.1464130360.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab92b232ae05c382c3df0e3d6a5c6d16b639ac8c upstream.
Currently, the PT driver always sets the PMI bit one region (page) before
the STOP region so that we can wake up the consumer before we run out of
room in the buffer and have to disable the event. However, we also need
an interrupt in the last output region, so that we actually get to disable
the event (if no more room from new data is available at that point),
otherwise hardware just quietly refuses to start, but the event is
scheduled in and we end up losing trace data till the event gets removed.
For a cpu-wide event it is even worse since there may not be any
re-scheduling at all and no chance for the ring buffer code to notice
that its buffer is filled up and the event needs to be disabled (so that
the consumer can re-enable it when it finishes reading the data out). In
other words, all the trace data will be lost after the buffer gets filled
up.
This patch makes PT also generate a PMI when the last output region is
full.
Reported-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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: vince@deater.net
Link: http://lkml.kernel.org/r/1462886313-13660-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a21211672c9a1d730a39aa65d4a5b3414700adfb upstream.
There are several reports of freeze on enabling HWP (Hardware PStates)
feature on Skylake-based systems by the Intel P-states driver. The root
cause is identified as the HWP interrupts causing BIOS code to freeze.
HWP interrupts use the thermal LVT which can be handled by Linux
natively, but on the affected Skylake-based systems SMM will respond
to it by default. This is a problem for several reasons:
- On the affected systems the SMM thermal LVT handler is broken (it
will crash when invoked) and a BIOS update is necessary to fix it.
- With thermal interrupt handled in SMM we lose all of the reporting
features of the arch/x86/kernel/cpu/mcheck/therm_throt driver.
- Some thermal drivers like x86-package-temp depend on the thermal
threshold interrupts signaled via the thermal LVT.
- The HWP interrupts are useful for debugging and tuning
performance (if the kernel can handle them).
The native handling of thermal interrupts needs to be enabled
because of that.
This requires some way to tell SMM that the OS can handle thermal
interrupts. That can be done by using _OSC/_PDC in processor
scope very early during ACPI initialization.
The meaning of _OSC/_PDC bit 12 in processor scope is whether or
not the OS supports native handling of interrupts for Collaborative
Processor Performance Control (CPPC) notifications. Since on
HWP-capable systems CPPC is a firmware interface to HWP, setting
this bit effectively tells the firmware that the OS will handle
thermal interrupts natively going forward.
For details on _OSC/_PDC refer to:
http://www.intel.com/content/www/us/en/standards/processor-vendor-specific-acpi-specification.html
To implement the _OSC/_PDC handshake as described, introduce a new
function, acpi_early_processor_osc(), that walks the ACPI
namespace looking for ACPI processor objects and invokes _OSC for
them with bit 12 in the capabilities buffer set and terminates the
namespace walk on the first success.
Also modify intel_thermal_interrupt() to clear HWP status bits in
the HWP_STATUS MSR to acknowledge HWP interrupts (which prevents
them from firing continuously).
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Subject & changelog, function rename ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c10fcb14c7afd6688c7b197a814358fecf244222 upstream.
The code for checking whether a BAR address range is valid will break
out of the loop when a start address of 0x0 is encountered.
This behaviour is wrong since by breaking out of the loop we may miss
the BAR that describes the EFI frame buffer in a later iteration.
Because of this bug I can't use video=efifb: boot parameter to get
efifb on my new ThinkPad E550 for my old linux system hard disk with
3.10 kernel. In 3.10, efifb is the only choice due to DRM/I915 not
supporting the GPU.
This patch also add a trivial optimization to break out after we find
the frame buffer address range without testing later BARs.
Signed-off-by: Wang YanQing <udknight@gmail.com>
[ Rewrote changelog. ]
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Peter Jones <pjones@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462454061-21561-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 886123fb3a8656699dff40afa0573df359abeb18 upstream.
Currently we read the tsc radio: ratio = (MSR_PLATFORM_INFO >> 8) & 0x1f;
Thus we get bit 8-12 of MSR_PLATFORM_INFO, however according to the SDM
(35.5), the ratio bits are bit 8-15.
Ignoring the upper bits can result in an incorrect tsc ratio, which causes the
TSC calibration and the Local APIC timer frequency to be incorrect.
Fix this problem by masking 0xff instead.
[ tglx: Massaged changelog ]
Fixes: 7da7c15613 "x86, tsc: Add static (MSR) TSC calibration on Intel Atom SoCs"
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Bin Gao <bin.gao@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/1462505619-5516-1-git-send-email-yu.c.chen@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1bdb8970392a68489b469c3a330a1adb5ef61beb upstream.
If x86_vector_alloc_irq() fails x86_vector_free_irqs() is invoked to cleanup
the already allocated vectors. This subsequently calls clear_vector_irq().
The failed irq has no vector assigned, which triggers the BUG_ON(!vector) in
clear_vector_irq().
We cannot suppress the call to x86_vector_free_irqs() for the failed
interrupt, because the other data related to this irq must be cleaned up as
well. So calling clear_vector_irq() with vector == 0 is legitimate.
Remove the BUG_ON and return if vector is zero,
[ tglx: Massaged changelog ]
Fixes: b5dc8e6c21 "x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors"
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a3125494cff084b098c80bb36fbe2061ffed9d52 upstream.
When we loop over all queued machine check error records to pass them
to the registered notifiers we use llist_for_each_entry(). But the loop
calls gen_pool_free() for the entry in the body of the loop - and then
the iterator looks at node->next after the free.
Use llist_for_each_entry_safe() instead.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Gong Chen <gong.chen@linux.intel.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/0205920@agluck-desk.sc.intel.com
Link: http://lkml.kernel.org/r/1459929916-12852-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e17dc65328057c00db7e1bfea249c8771a78b30b upstream.
Jiri reported some time ago that some entries in the PEBS data source table
in perf do not agree with the SDM. We investigated and the bits
changed for Sandy Bridge, but the SDM was not updated.
perf already implements the bits correctly for Sandy Bridge
and later. This patch patches it up for Nehalem and Westmere.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jolsa@kernel.org
Link: http://lkml.kernel.org/r/1456871124-15985-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e72daf3f4d764c47fb71c9bdc7f9c54a503825b1 upstream.
Using PAGE_SIZE buffers makes the WRMSR to PERF_GLOBAL_CTRL in
intel_pmu_enable_all() mysteriously hang on Core2. As a workaround, we
don't do this.
The hard lockup is easily triggered by running 'perf test attr'
repeatedly. Most of the time it gets stuck on sample session with
small periods.
# perf test attr -vv
14: struct perf_event_attr setup :
--- start ---
...
'PERF_TEST_ATTR=/tmp/tmpuEKz3B /usr/bin/perf record -o /tmp/tmpuEKz3B/perf.data -c 123 kill >/dev/null 2>&1' ret 1
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160301190352.GA8355@krava.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c3d266c8a9838cc141b69548bc3b1b18808ae8c4 upstream.
This patch tries to fix a PEBS warning found in my stress test. The
following perf command can easily trigger the pebs warning or spurious
NMI error on Skylake/Broadwell/Haswell platforms:
sudo perf record -e 'cpu/umask=0x04,event=0xc4/pp,cycles,branches,ref-cycles,cache-misses,cache-references' --call-graph fp -b -c1000 -a
Also the NMI watchdog must be enabled.
For this case, the events number is larger than counter number. So
perf has to do multiplexing.
In perf_mux_hrtimer_handler, it does perf_pmu_disable(), schedule out
old events, rotate_ctx, schedule in new events and finally
perf_pmu_enable().
If the old events include precise event, the MSR_IA32_PEBS_ENABLE
should be cleared when perf_pmu_disable(). The MSR_IA32_PEBS_ENABLE
should keep 0 until the perf_pmu_enable() is called and the new event is
precise event.
However, there is a corner case which could restore PEBS_ENABLE to
stale value during the above period. In perf_pmu_disable(), GLOBAL_CTRL
will be set to 0 to stop overflow and followed PMI. But there may be
pending PMI from an earlier overflow, which cannot be stopped. So even
GLOBAL_CTRL is cleared, the kernel still be possible to get PMI. At
the end of the PMI handler, __intel_pmu_enable_all() will be called,
which will restore the stale values if old events haven't scheduled
out.
Once the stale pebs value is set, it's impossible to be corrected if
the new events are non-precise. Because the pebs_enabled will be set
to 0. x86_pmu.enable_all() will ignore the MSR_IA32_PEBS_ENABLE
setting. As a result, the following NMI with stale PEBS_ENABLE
trigger pebs warning.
The pending PMI after enabled=0 will become harmless if the NMI handler
does not change the state. This patch checks cpuc->enabled in pmi and
only restore the state when PMU is active.
Here is the dump:
Call Trace:
<NMI> [<ffffffff813c3a2e>] dump_stack+0x63/0x85
[<ffffffff810a46f2>] warn_slowpath_common+0x82/0xc0
[<ffffffff810a483a>] warn_slowpath_null+0x1a/0x20
[<ffffffff8100fe2e>] intel_pmu_drain_pebs_nhm+0x2be/0x320
[<ffffffff8100caa9>] intel_pmu_handle_irq+0x279/0x460
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
[<ffffffff811f290d>] ? vunmap_page_range+0x20d/0x330
[<ffffffff811f2f11>] ? unmap_kernel_range_noflush+0x11/0x20
[<ffffffff8148379f>] ? ghes_copy_tofrom_phys+0x10f/0x2a0
[<ffffffff814839c8>] ? ghes_read_estatus+0x98/0x170
[<ffffffff81005a7d>] perf_event_nmi_handler+0x2d/0x50
[<ffffffff810310b9>] nmi_handle+0x69/0x120
[<ffffffff810316f6>] default_do_nmi+0xe6/0x100
[<ffffffff810317f2>] do_nmi+0xe2/0x130
[<ffffffff817aea71>] end_repeat_nmi+0x1a/0x1e
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
[<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
<<EOE>> <IRQ> [<ffffffff81006df8>] ? x86_perf_event_set_period+0xd8/0x180
[<ffffffff81006eec>] x86_pmu_start+0x4c/0x100
[<ffffffff8100722d>] x86_pmu_enable+0x28d/0x300
[<ffffffff811994d7>] perf_pmu_enable.part.81+0x7/0x10
[<ffffffff8119cb70>] perf_mux_hrtimer_handler+0x200/0x280
[<ffffffff8119c970>] ? __perf_install_in_context+0xc0/0xc0
[<ffffffff8110f92d>] __hrtimer_run_queues+0xfd/0x280
[<ffffffff811100d8>] hrtimer_interrupt+0xa8/0x190
[<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0
[<ffffffff81051bd8>] local_apic_timer_interrupt+0x38/0x60
[<ffffffff817af01d>] smp_apic_timer_interrupt+0x3d/0x50
[<ffffffff817ad15c>] apic_timer_interrupt+0x8c/0xa0
<EOI> [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0
[<ffffffff81123de5>] ? smp_call_function_single+0xd5/0x130
[<ffffffff81123ddb>] ? smp_call_function_single+0xcb/0x130
[<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0
[<ffffffff8119765a>] event_function_call+0x10a/0x120
[<ffffffff8119c660>] ? ctx_resched+0x90/0x90
[<ffffffff811971e0>] ? cpu_clock_event_read+0x30/0x30
[<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60
[<ffffffff8119772b>] _perf_event_enable+0x5b/0x70
[<ffffffff81197388>] perf_event_for_each_child+0x38/0xa0
[<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60
[<ffffffff811a0ffd>] perf_ioctl+0x12d/0x3c0
[<ffffffff8134d855>] ? selinux_file_ioctl+0x95/0x1e0
[<ffffffff8124a3a1>] do_vfs_ioctl+0xa1/0x5a0
[<ffffffff81036d29>] ? sched_clock+0x9/0x10
[<ffffffff8124a919>] SyS_ioctl+0x79/0x90
[<ffffffff817ac4b2>] entry_SYSCALL_64_fastpath+0x1a/0xa4
---[ end trace aef202839fe9a71d ]---
Uhhuh. NMI received for unknown reason 2d on CPU 2.
Do you have a strange power saving mode enabled?
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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/1457046448-6184-1-git-send-email-kan.liang@intel.com
[ Fixed various typos and other small details. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8077eca079a212f26419c57226f28696b7100683 upstream.
This patch fixes an issue with the GLOBAL_OVERFLOW_STATUS bits on
Haswell, Broadwell and Skylake processors when using PEBS.
The SDM stipulates that when the PEBS iterrupt threshold is crossed,
an interrupt is posted and the kernel is interrupted. The kernel will
find GLOBAL_OVF_SATUS bit 62 set indicating there are PEBS records to
drain. But the bits corresponding to the actual counters should NOT be
set. The kernel follows the SDM and assumes that all PEBS events are
processed in the drain_pebs() callback. The kernel then checks for
remaining overflows on any other (non-PEBS) events and processes these
in the for_each_bit_set(&status) loop.
As it turns out, under certain conditions on HSW and later processors,
on PEBS buffer interrupt, bit 62 is set but the counter bits may be
set as well. In that case, the kernel drains PEBS and generates
SAMPLES with the EXACT tag, then it processes the counter bits, and
generates normal (non-EXACT) SAMPLES.
I ran into this problem by trying to understand why on HSW sampling on
a PEBS event was sometimes returning SAMPLES without the EXACT tag.
This should not happen on user level code because HSW has the
eventing_ip which always point to the instruction that caused the
event.
The workaround in this patch simply ensures that the bits for the
counters used for PEBS events are cleared after the PEBS buffer has
been drained. With this fix 100% of the PEBS samples on my user code
report the EXACT tag.
Before:
$ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase
$ perf report -D | fgrep SAMPLES
PERF_RECORD_SAMPLE(IP, 0x2): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y
\--- EXACT tag is missing
After:
$ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase
$ perf report -D | fgrep SAMPLES
PERF_RECORD_SAMPLE(IP, 0x4002): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y
\--- EXACT tag is set
The problem tends to appear more often when multiple PEBS events are used.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: namhyung@kernel.org
Link: http://lkml.kernel.org/r/1457034642-21837-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
