For 4KB pages, x86 CPU has 2 or 1 level TLB, first level is data TLB and
instruction TLB, second level is shared TLB for both data and instructions.
For hupe page TLB, usually there is just one level and seperated by 2MB/4MB
and 1GB.
Although each levels TLB size is important for performance tuning, but for
genernal and rude optimizing, last level TLB entry number is suitable. And
in fact, last level TLB always has the biggest entry number.
This patch will get the biggest TLB entry number and use it in furture TLB
optimizing.
Accroding Borislav's suggestion, except tlb_ll[i/d]_* array, other
function and data will be released after system boot up.
For all kinds of x86 vendor friendly, vendor specific code was moved to its
specific files.
Signed-off-by: Alex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/1340845344-27557-2-git-send-email-alex.shi@intel.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add "read-mostly" qualifier to the following variables in
smp.h:
- cpu_sibling_map
- cpu_core_map
- cpu_llc_shared_map
- cpu_llc_id
- cpu_number
- x86_cpu_to_apicid
- x86_bios_cpu_apicid
- x86_cpu_to_logical_apicid
As long as all the variables above are only written during the
initialization, this change is meant to prevent the false
sharing. More specifically, on vSMP Foundation platform
x86_cpu_to_apicid shared the same internode_cache_line with
frequently written lapic_events.
From the analysis of the first 33 per_cpu variables out of 219
(memories they describe, to be more specific) the 8 have read_mostly
nature (tlb_vector_offset, cpu_loops_per_jiffy, xen_debug_irq, etc.)
and 25 are frequently written (irq_stack_union, gdt_page,
exception_stacks, idt_desc, etc.).
Assuming that the spread of the rest of the per_cpu variables is
similar, identifying the read mostly memories will make more sense
in terms of long-term code maintenance comparing to identifying
frequently written memories.
Signed-off-by: Vlad Zolotarov <vlad@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Cc: Shai Fultheim (Shai@ScaleMP.com) <Shai@scalemp.com>
Cc: ido@wizery.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1719258.EYKzE4Zbq5@vlad
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some read-mostly per-cpu data may need to be declared or defined
early, so it can be initialized and accessed before per_cpu
areas are allocated.
Only the data that resides in the per_cpu areas should be
read-mostly, as there is little benefit in optimizing cache
lines on initialization.
Signed-off-by: Ido Yariv <ido@wizery.com>
[ Added the missing declarations in !SMP code. ]
Signed-off-by: Vlad Zolotarov <vlad@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/46188571.ddB8aVQYWo@vlad
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/nmi: Fix section mismatch warnings on 32-bit
x86/uv: Fix UV2 BAU legacy mode
x86/mm: Only add extra pages count for the first memory range during pre-allocation early page table space
x86, efi stub: Add .reloc section back into image
x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs
x86/reboot: Fix a warning message triggered by stop_other_cpus()
x86/intel/moorestown: Change intel_scu_devices_create() to __devinit
x86/numa: Set numa_nodes_parsed at acpi_numa_memory_affinity_init()
x86/gart: Fix kmemleak warning
x86: mce: Add the dropped timer interval init back
x86/mce: Fix the MCE poll timer logic
Pull perf fixes from Ingo Molnar:
"A bit larger than what I'd wish for - half of it is due to hw driver
updates to Intel Ivy-Bridge which info got recently released,
cycles:pp should work there now too, amongst other things. (but we
are generally making exceptions for hardware enablement of this type.)
There are also callchain fixes in it - responding to mostly
theoretical (but valid) concerns. The tooling side sports perf.data
endianness/portability fixes which did not make it for the merge
window - and various other fixes as well."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
perf/x86: Check user address explicitly in copy_from_user_nmi()
perf/x86: Check if user fp is valid
perf: Limit callchains to 127
perf/x86: Allow multiple stacks
perf/x86: Update SNB PEBS constraints
perf/x86: Enable/Add IvyBridge hardware support
perf/x86: Implement cycles:p for SNB/IVB
perf/x86: Fix Intel shared extra MSR allocation
x86/decoder: Fix bsr/bsf/jmpe decoding with operand-size prefix
perf: Remove duplicate invocation on perf_event_for_each
perf uprobes: Remove unnecessary check before strlist__delete
perf symbols: Check for valid dso before creating map
perf evsel: Fix 32 bit values endianity swap for sample_id_all header
perf session: Handle endianity swap on sample_id_all header data
perf symbols: Handle different endians properly during symbol load
perf evlist: Pass third argument to ioctl explicitly
perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP
perf tools: Make --version show kernel version instead of pull req tag
perf tools: Check if callchain is corrupted
perf callchain: Make callchain cursors TLS
...
It was reported that compiling for 32-bit caused a bunch of
section mismatch warnings:
VDSOSYM arch/x86/vdso/vdso32-syms.lds
LD arch/x86/vdso/built-in.o
LD arch/x86/built-in.o
WARNING: arch/x86/built-in.o(.data+0x5af0): Section mismatch in
reference from the variable test_nmi_ipi_callback_na.10451 to
the function .init.text:test_nmi_ipi_callback() [...]
WARNING: arch/x86/built-in.o(.data+0x5b04): Section mismatch in
reference from the variable nmi_unk_cb_na.10399 to the function
.init.text:nmi_unk_cb() The variable nmi_unk_cb_na.10399
references the function __init nmi_unk_cb() [...]
Both of these are attributed to the internal representation of
the nmiaction struct created during register_nmi_handler. The
reason for this is that those structs are not defined in the
init section whereas the rest of the code in nmi_selftest.c is.
To resolve this, I created a new #define,
register_nmi_handler_initonly, that tags the struct as
__initdata to resolve the mismatch. This #define should only be
used in rare situations where the register/unregister is called
during init of the kernel.
Big thanks to Jan Beulich for decoding this for me as I didn't
have a clue what was going on.
Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Tested-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1338991542-23000-1-git-send-email-dzickus@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SGI Altix UV2 BAU (Broadcast Assist Unit) as used for
tlb-shootdown (selective broadcast mode) always uses UV2
broadcast descriptor format. There is no need to clear the
'legacy' (UV1) mode, because the hardware always uses UV2 mode
for selective broadcast.
But the BIOS uses general broadcast and legacy mode, and the
hardware pays attention to the legacy mode bit for general
broadcast. So the kernel must not clear that mode bit.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/E1SccoO-0002Lh-Cb@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Robin found this regression:
| I just tried to boot an 8TB system. It fails very early in boot with:
| Kernel panic - not syncing: Cannot find space for the kernel page tables
git bisect commit 722bc6b167.
A git revert of that commit does boot past that point on the 8TB
configuration.
That commit will add up extra pages for all memory range even
above 4g.
Try to limit that extra page count adding to first entry only.
Bisected-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/CAE9FiQUj3wyzQxtq9yzBNc9u220p8JZ1FYHG7t%3DMOzJ%3D9BZMYA@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some UEFI firmware will not load a .efi with a .reloc section
with a size of 0.
Therefore, we create a .efi image with 4 main areas and 3 sections.
1. PE/COFF file header
2. .setup section (covers all setup code following the first sector)
3. .reloc section (contains 1 dummy reloc entry, created in build.c)
4. .text section (covers the remaining kernel image)
To make room for the new .setup section data, the header
bugger_off_msg had to be shortened.
Reported-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Link: http://lkml.kernel.org/r/1339085121-12760-1-git-send-email-jordan.l.justen@intel.com
Tested-by: Lee G Rosenbaum <lee.g.rosenbaum@intel.com>
Tested-by: Henrik Rydberg <rydberg@euromail.se>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Without this patch, applications with two different stack
regions (eg: native stack vs JIT stack) get truncated
callchains even when RBP chaining is present. GDB shows proper
stack traces and the frame pointer chaining is intact.
This patch disables the (fp < RSP) check, hoping that other checks
in the code save the day for us. In our limited testing, this
didn't seem to break anything.
In the long term, we could potentially have userspace advise
the kernel on the range of valid stack addresses, so we don't
spend a lot of time unwinding from bogus addresses.
Signed-off-by: Arun Sharma <asharma@fb.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1334961696-19580-2-git-send-email-asharma@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Afaict there's no need to (incompletely) iterate the
MEM_UOPS_RETIRED.* umask state.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1338884803.28282.153.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Implement rudimentary IVB perf support. The SDM states its identical
to SNB with exception of the exact event tables, but a quick look
suggests they're similar enough.
Also mark SNB-EP as broken for now.
Requested-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338884803.28282.153.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that there's finally a chip with working PEBS (IvyBridge), we can
enable the hardware and implement cycles:p for SNB/IVB.
Cc: Stephane Eranian <eranian@google.com>
Requested-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338884803.28282.153.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Zheng Yan reported that event group validation can wreck event state
when Intel extra_reg allocation changes event state.
Validation shouldn't change any persistent state. Cloning events in
validate_{event,group}() isn't really pretty either, so add a few
special cases to avoid modifying the event state.
The code is restructured to minimize the special case impact.
Reported-by: Zheng Yan <zheng.z.yan@linux.intel.com>
Acked-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338903031.28282.175.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 316ad24830 ("sched/x86: Rewrite set_cpu_sibling_map()")
broke the booted_cores accounting.
The problem is that the booted_cores accounting needs all the
sibling links set up. So restore the second loop and add a comment as
to why its needed.
On qemu booted with -smp sockets=1,cores=2,threads=2;
Before:
$ grep cores /proc/cpuinfo
cpu cores : 2
cpu cores : 1
cpu cores : 4
cpu cores : 3
With the patch:
$ grep cores /proc/cpuinfo
cpu cores : 2
cpu cores : 2
cpu cores : 2
cpu cores : 2
Reported-by: Prarit Bhargava <prarit@redhat.com>
Reported-by: Borislav Petkov <bp@amd64.org>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120531073738.GH7511@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In current Linux, percpu variable `vector_irq' is not cleared on
offlined cpus while disabling devices' irqs. If the cpu that has
the disabled irqs in vector_irq is hotplugged,
__setup_vector_irq() hits invalid irq vector and may crash.
This bug can be reproduced as following;
# echo 0 > /sys/devices/system/cpu/cpu7/online
# modprobe -r some_driver_using_interrupts # vector_irq@cpu7 uncleared
# echo 1 > /sys/devices/system/cpu/cpu7/online # kernel may crash
This patch fixes this bug by clearing vector_irq in
__clear_irq_vector() even if the cpu is offlined.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: ltc-kernel@ml.yrl.intra.hitachi.co.jp
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/4FC340BE.7080101@hitachi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When rebooting our 24 CPU Westmere servers with 3.4-rc6, we
always see this warning msg:
Restarting system.
machine restart
------------[ cut here ]------------
WARNING: at arch/x86/kernel/smp.c:125
native_smp_send_reschedule+0x74/0xa7() Hardware name: X8DTN
Modules linked in: igb [last unloaded: scsi_wait_scan]
Pid: 1, comm: systemd-shutdow Not tainted 3.4.0-rc6+ #22
Call Trace:
<IRQ> [<ffffffff8102a41f>] warn_slowpath_common+0x7e/0x96
[<ffffffff8102a44c>] warn_slowpath_null+0x15/0x17
[<ffffffff81018cf7>] native_smp_send_reschedule+0x74/0xa7
[<ffffffff810561c1>] trigger_load_balance+0x279/0x2a6
[<ffffffff81050112>] scheduler_tick+0xe0/0xe9
[<ffffffff81036768>] update_process_times+0x60/0x70
[<ffffffff81062f2f>] tick_sched_timer+0x68/0x92
[<ffffffff81046e33>] __run_hrtimer+0xb3/0x13c
[<ffffffff81062ec7>] ? tick_nohz_handler+0xd0/0xd0
[<ffffffff810474f2>] hrtimer_interrupt+0xdb/0x198
[<ffffffff81019a35>] smp_apic_timer_interrupt+0x81/0x94
[<ffffffff81655187>] apic_timer_interrupt+0x67/0x70
<EOI> [<ffffffff8101a3c4>] ? default_send_IPI_mask_allbutself_phys+0xb4/0xc4
[<ffffffff8101c680>] physflat_send_IPI_allbutself+0x12/0x14
[<ffffffff81018db4>] native_nmi_stop_other_cpus+0x8a/0xd6
[<ffffffff810188ba>] native_machine_shutdown+0x50/0x67
[<ffffffff81018926>] machine_shutdown+0xa/0xc
[<ffffffff8101897e>] native_machine_restart+0x20/0x32
[<ffffffff810189b0>] machine_restart+0xa/0xc
[<ffffffff8103b196>] kernel_restart+0x47/0x4c
[<ffffffff8103b2e6>] sys_reboot+0x13e/0x17c
[<ffffffff8164e436>] ? _raw_spin_unlock_bh+0x10/0x12
[<ffffffff810fcac9>] ? bdi_queue_work+0xcf/0xd8
[<ffffffff810fe82f>] ? __bdi_start_writeback+0xae/0xb7
[<ffffffff810e0d64>] ? iterate_supers+0xa3/0xb7
[<ffffffff816547a2>] system_call_fastpath+0x16/0x1b
---[ end trace 320af5cb1cb60c5b ]---
The root cause seems to be the
default_send_IPI_mask_allbutself_phys() takes quite some time (I
measured it could be several ms) to complete sending NMIs to all
the other 23 CPUs, and for HZ=250/1000 system, the time is long
enough for a timer interrupt to happen, which will in turn
trigger to kick load balance to a stopped CPU and cause this
warning in native_smp_send_reschedule().
So disabling the local irq before stop_other_cpu() can fix this
problem (tested 25 times reboot ok), and it is fine as there
should be nobody caring the timer interrupt in such reboot
stage.
The latest 3.4 kernel slightly changes this behavior by sending
REBOOT_VECTOR first and only send NMI_VECTOR if the REBOOT_VCTOR
fails, and this patch is still needed to prevent the problem.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120530231541.4c13433a@feng-i7
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The allmodconfig hits:
WARNING: vmlinux.o(.text+0x6553d): Section mismatch in
reference from the function intel_scu_devices_create() to the
function .devinit.text: spi_register_board_info()
[...]
This patch marks intel_scu_devices_create() as devinit because
it only calls a devinit function, spi_register_board_info().
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Link: http://lkml.kernel.org/r/20120531212025.GA8519@breakpoint.cc
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When hot-adding a CPU, the system outputs following messages
since node_to_cpumask_map[2] was not allocated memory.
Booting Node 2 Processor 32 APIC 0xc0
node_to_cpumask_map[2] NULL
Pid: 0, comm: swapper/32 Tainted: G A 3.3.5-acd #21
Call Trace:
[<ffffffff81048845>] debug_cpumask_set_cpu+0x155/0x160
[<ffffffff8105e28a>] ? add_timer_on+0xaa/0x120
[<ffffffff8150665f>] numa_add_cpu+0x1e/0x22
[<ffffffff815020bb>] identify_cpu+0x1df/0x1e4
[<ffffffff815020d6>] identify_econdary_cpu+0x16/0x1d
[<ffffffff81504614>] smp_store_cpu_info+0x3c/0x3e
[<ffffffff81505263>] smp_callin+0x139/0x1be
[<ffffffff815052fb>] start_secondary+0x13/0xeb
The reason is that the bit of node 2 was not set at
numa_nodes_parsed. numa_nodes_parsed is set by only
acpi_numa_processor_affinity_init /
acpi_numa_x2apic_affinity_init. Thus even if hot-added memory
which is same PXM as hot-added CPU is written in ACPI SRAT
Table, if the hot-added CPU is not written in ACPI SRAT table,
numa_nodes_parsed is not set.
But according to ACPI Spec Rev 5.0, it says about ACPI SRAT
table as follows: This optional table provides information that
allows OSPM to associate processors and memory ranges, including
ranges of memory provided by hot-added memory devices, with
system localities / proximity domains and clock domains.
It means that ACPI SRAT table only provides information for CPUs
present at boot time and for memory including hot-added memory.
So hot-added memory is written in ACPI SRAT table, but hot-added
CPU is not written in it. Thus numa_nodes_parsed should be set
by not only acpi_numa_processor_affinity_init /
acpi_numa_x2apic_affinity_init but also
acpi_numa_memory_affinity_init for the case.
Additionally, if system has cpuless memory node,
acpi_numa_processor_affinity_init /
acpi_numa_x2apic_affinity_init cannot set numa_nodes_parseds
since these functions cannot find cpu description for the node.
In this case, numa_nodes_parsed needs to be set by
acpi_numa_memory_affinity_init.
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: liuj97@gmail.com
Cc: kosaki.motohiro@gmail.com
Link: http://lkml.kernel.org/r/4FCC2098.4030007@jp.fujitsu.com
[ merged it ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
commit 82f7af09 ("x86/mce: Cleanup timer mess) dropped the
initialization of the per cpu timer interval. Duh :(
Restore the previous behaviour.
Reported-by: Chen Gong <gong.chen@linux.intel.com>
Cc: bp@amd64.org
Cc: tony.luck@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix the x86 instruction decoder to decode bsr/bsf/jmpe with
operand-size prefix (66h). This fixes the test case failure
reported by Linus, attached below.
bsf/bsr/jmpe have a special encoding. Opcode map in
Intel Software Developers Manual vol2 says they have
TZCNT/LZCNT variants if it has F3h prefix. However, there
is no information if it has other 66h or F2h prefixes.
Current instruction decoder supposes that those are
bad instructions, but it actually accepts at least
operand-size prefixes.
H. Peter Anvin further explains:
" TZCNT/LZCNT are F3 + BSF/BSR exactly because the F2 and
F3 prefixes have historically been no-ops with most instructions.
This allows software to unconditionally use the prefixed versions
and get TZCNT/LZCNT on the processors that have them if they don't
care about the difference. "
This fixes errors reported by test_get_len:
Warning: arch/x86/tools/test_get_len found difference at <em_bsf>:ffffffff81036d87
Warning: ffffffff81036de5: 66 0f bc c2 bsf %dx,%ax
Warning: objdump says 4 bytes, but insn_get_length() says 3
Warning: arch/x86/tools/test_get_len found difference at <em_bsr>:ffffffff81036ea6
Warning: ffffffff81036f04: 66 0f bd c2 bsr %dx,%ax
Warning: objdump says 4 bytes, but insn_get_length() says 3
Warning: decoded and checked 13298882 instructions with 2 warnings
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <yrl.pp-manager.tt@hitachi.com>
Link: http://lkml.kernel.org/r/20120604150911.22338.43296.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In commit 82f7af09 (x86/mce: Cleanup timer mess), Thomas just forgot
the "/ 2" there while cleaning up.
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Pull scheduler fixes from Ingo Molnar.
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Remove NULL assignment of dattr_cur
sched: Remove the last NULL entry from sched_feat_names
sched: Make sched_feat_names const
sched/rt: Fix SCHED_RR across cgroups
sched: Move nr_cpus_allowed out of 'struct sched_rt_entity'
sched: Make sure to not re-read variables after validation
sched: Fix SD_OVERLAP
sched: Don't try allocating memory from offline nodes
sched/nohz: Fix rq->cpu_load calculations some more
sched/x86: Use cpu_llc_shared_mask(cpu) for coregroup_mask
Pull straggler x86 fixes from Peter Anvin:
"Three groups of patches:
- EFI boot stub documentation and the ability to print error messages;
- Removal for PTRACE_ARCH_PRCTL for x32 (obsolete interface which
should never have been ported, and the port is broken and
potentially dangerous.)
- ftrace stack corruption fixes. I'm not super-happy about the
technical implementation, but it is probably the least invasive in
the short term. In the future I would like a single method for
nesting the debug stack, however."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, x32, ptrace: Remove PTRACE_ARCH_PRCTL for x32
x86, efi: Add EFI boot stub documentation
x86, efi; Add EFI boot stub console support
x86, efi: Only close open files in error path
ftrace/x86: Do not change stacks in DEBUG when calling lockdep
x86: Allow nesting of the debug stack IDT setting
x86: Reset the debug_stack update counter
ftrace: Use breakpoint method to update ftrace caller
ftrace: Synchronize variable setting with breakpoints
When I added x32 ptrace to 3.4 kernel, I also include PTRACE_ARCH_PRCTL
support for x32 GDB For ARCH_GET_FS/GS, it takes a pointer to int64. But
at user level, ARCH_GET_FS/GS takes a pointer to int32. So I have to add
x32 ptrace to glibc to handle it with a temporary int64 passed to kernel and
copy it back to GDB as int32. Roland suggested that PTRACE_ARCH_PRCTL
is obsolete and x32 GDB should use fs_base and gs_base fields of
user_regs_struct instead.
Accordingly, remove PTRACE_ARCH_PRCTL completely from the x32 code to
avoid possible memory overrun when pointer to int32 is passed to
kernel.
Link: http://lkml.kernel.org/r/CAMe9rOpDzHfS7NH7m1vmD9QRw8SSj4Sc%2BaNOgcWm_WJME2eRsQ@mail.gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org> v3.4
Pull third pile of signal handling patches from Al Viro:
"This time it's mostly helpers and conversions to them; there's a lot
of stuff remaining in the tree, but that'll either go in -rc2
(isolated bug fixes, ideally via arch maintainers' trees) or will sit
there until the next cycle."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
x86: get rid of calling do_notify_resume() when returning to kernel mode
blackfin: check __get_user() return value
whack-a-mole with TIF_FREEZE
FRV: Optimise the system call exit path in entry.S [ver #2]
FRV: Shrink TIF_WORK_MASK [ver #2]
FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions
new helper: signal_delivered()
powerpc: get rid of restore_sigmask()
most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
set_restore_sigmask() is never called without SIGPENDING (and never should be)
TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is set
don't call try_to_freeze() from do_signal()
pull clearing RESTORE_SIGMASK into block_sigmask()
sh64: failure to build sigframe != signal without handler
openrisc: tracehook_signal_handler() is supposed to be called on success
new helper: sigmask_to_save()
new helper: restore_saved_sigmask()
new helpers: {clear,test,test_and_clear}_restore_sigmask()
HAVE_RESTORE_SIGMASK is defined on all architectures now
Pull vfs changes from Al Viro.
"A lot of misc stuff. The obvious groups:
* Miklos' atomic_open series; kills the damn abuse of
->d_revalidate() by NFS, which was the major stumbling block for
all work in that area.
* ripping security_file_mmap() and dealing with deadlocks in the
area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in
general.
* ->encode_fh() switched to saner API; insane fake dentry in
mm/cleancache.c gone.
* assorted annotations in fs (endianness, __user)
* parts of Artem's ->s_dirty work (jff2 and reiserfs parts)
* ->update_time() work from Josef.
* other bits and pieces all over the place.
Normally it would've been in two or three pull requests, but
signal.git stuff had eaten a lot of time during this cycle ;-/"
Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the
'truncate_range' inode method was removed by the VM changes, the VFS
update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due
to sparse fix added twice, with other changes nearby).
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits)
nfs: don't open in ->d_revalidate
vfs: retry last component if opening stale dentry
vfs: nameidata_to_filp(): don't throw away file on error
vfs: nameidata_to_filp(): inline __dentry_open()
vfs: do_dentry_open(): don't put filp
vfs: split __dentry_open()
vfs: do_last() common post lookup
vfs: do_last(): add audit_inode before open
vfs: do_last(): only return EISDIR for O_CREAT
vfs: do_last(): check LOOKUP_DIRECTORY
vfs: do_last(): make ENOENT exit RCU safe
vfs: make follow_link check RCU safe
vfs: do_last(): use inode variable
vfs: do_last(): inline walk_component()
vfs: do_last(): make exit RCU safe
vfs: split do_lookup()
Btrfs: move over to use ->update_time
fs: introduce inode operation ->update_time
reiserfs: get rid of resierfs_sync_super
reiserfs: mark the superblock as dirty a bit later
...
If we end up calling do_notify_resume() with !user_mode(refs), it
does nothing (do_signal() explicitly bails out and we can't get there
with TIF_NOTIFY_RESUME in such situations). Then we jump to
resume_userspace_sig, which rechecks the same thing and bails out
to resume_kernel, thus breaking the loop.
It's easier and cheaper to check *before* calling do_notify_resume()
and bail out to resume_kernel immediately. And kill the check in
do_signal()...
Note that on amd64 we can't get there with !user_mode() at all - asm
glue takes care of that.
Acked-and-reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Does block_sigmask() + tracehook_signal_handler(); called when
sigframe has been successfully built. All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).
I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper. Open-coded instances switched...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Since we can't expect every user to read the EFI boot stub code it
seems prudent to have a couple of paragraphs explaining what it is and
how it works.
The "initrd=" option in particular is tricky because it only
understands absolute EFI-style paths (backslashes as directory
separators), and until now this hasn't been documented anywhere. This
has tripped up a couple of users.
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1331907517-3985-4-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
We need a way of printing useful messages to the user, for example
when we fail to open an initrd file, instead of just hanging the
machine without giving the user any indication of what went wrong. So
sprinkle some error messages throughout the EFI boot stub code to make
it easier for users to diagnose/report problems.
Reported-by: Keshav P R <the.ridikulus.rat@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1331907517-3985-3-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The loop at the 'close_handles' label in handle_ramdisks() should be
using 'i', which represents the number of initrd files that were
successfully opened, not 'nr_initrds' which is the number of initrd=
arguments passed on the command line.
Currently, if we execute the loop to close all file handles and we
failed to open any initrds we'll try to call the close function on a
garbage pointer, causing the machine to hang.
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1331907517-3985-2-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
When both DYNAMIC_FTRACE and LOCKDEP are set, the TRACE_IRQS_ON/OFF
will call into the lockdep code. The lockdep code can call lots of
functions that may be traced by ftrace. When ftrace is updating its
code and hits a breakpoint, the breakpoint handler will call into
lockdep. If lockdep happens to call a function that also has a breakpoint
attached, it will jump back into the breakpoint handler resetting
the stack to the debug stack and corrupt the contents currently on
that stack.
The 'do_sym' call that calls do_int3() is protected by modifying the
IST table to point to a different location if another breakpoint is
hit. But the TRACE_IRQS_OFF/ON are outside that protection, and if
a breakpoint is hit from those, the stack will get corrupted, and
the kernel will crash:
[ 1013.243754] BUG: unable to handle kernel NULL pointer dereference at 0000000000000002
[ 1013.272665] IP: [<ffff880145cc0000>] 0xffff880145cbffff
[ 1013.285186] PGD 1401b2067 PUD 14324c067 PMD 0
[ 1013.298832] Oops: 0010 [#1] PREEMPT SMP
[ 1013.310600] CPU 2
[ 1013.317904] Modules linked in: ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables crc32c_intel ghash_clmulni_intel microcode usb_debug serio_raw pcspkr iTCO_wdt i2c_i801 iTCO_vendor_support e1000e nfsd nfs_acl auth_rpcgss lockd sunrpc i915 video i2c_algo_bit drm_kms_helper drm i2c_core [last unloaded: scsi_wait_scan]
[ 1013.401848]
[ 1013.407399] Pid: 112, comm: kworker/2:1 Not tainted 3.4.0+ #30
[ 1013.437943] RIP: 8eb8:[<ffff88014630a000>] [<ffff88014630a000>] 0xffff880146309fff
[ 1013.459871] RSP: ffffffff8165e919:ffff88014780f408 EFLAGS: 00010046
[ 1013.477909] RAX: 0000000000000001 RBX: ffffffff81104020 RCX: 0000000000000000
[ 1013.499458] RDX: ffff880148008ea8 RSI: ffffffff8131ef40 RDI: ffffffff82203b20
[ 1013.521612] RBP: ffffffff81005751 R08: 0000000000000000 R09: 0000000000000000
[ 1013.543121] R10: ffffffff82cdc318 R11: 0000000000000000 R12: ffff880145cc0000
[ 1013.564614] R13: ffff880148008eb8 R14: 0000000000000002 R15: ffff88014780cb40
[ 1013.586108] FS: 0000000000000000(0000) GS:ffff880148000000(0000) knlGS:0000000000000000
[ 1013.609458] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1013.627420] CR2: 0000000000000002 CR3: 0000000141f10000 CR4: 00000000001407e0
[ 1013.649051] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1013.670724] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 1013.692376] Process kworker/2:1 (pid: 112, threadinfo ffff88013fe0e000, task ffff88014020a6a0)
[ 1013.717028] Stack:
[ 1013.724131] ffff88014780f570 ffff880145cc0000 0000400000004000 0000000000000000
[ 1013.745918] cccccccccccccccc ffff88014780cca8 ffffffff811072bb ffffffff81651627
[ 1013.767870] ffffffff8118f8a7 ffffffff811072bb ffffffff81f2b6c5 ffffffff81f11bdb
[ 1013.790021] Call Trace:
[ 1013.800701] Code: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a <e7> d7 64 81 ff ff ff ff 01 00 00 00 00 00 00 00 65 d9 64 81 ff
[ 1013.861443] RIP [<ffff88014630a000>] 0xffff880146309fff
[ 1013.884466] RSP <ffff88014780f408>
[ 1013.901507] CR2: 0000000000000002
The solution was to reuse the NMI functions that change the IDT table to make the debug
stack keep its current stack (in kernel mode) when hitting a breakpoint:
call debug_stack_set_zero
TRACE_IRQS_ON
call debug_stack_reset
If the TRACE_IRQS_ON happens to hit a breakpoint then it will keep the current stack
and not crash the box.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When the NMI handler runs, it checks if it preempted a debug handler
and if that handler is using the debug stack. If it is, it changes the
IDT table not to update the stack, otherwise it will reset the debug
stack and corrupt the debug handler it preempted.
Now that ftrace uses breakpoints to change functions from nops to
callers, many more places may hit a breakpoint. Unfortunately this
includes some of the calls that lockdep performs. Which causes issues
with the debug stack. It too needs to change the debug stack before
tracing (if called from the debug handler).
Allow the debug_stack_set_zero() and debug_stack_reset() to be nested
so that the debug handlers can take advantage of them too.
[ Used this_cpu_*() over __get_cpu_var() as suggested by H. Peter Anvin ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When an NMI goes off and it sees that it preempted the debug stack,
to keep the debug stack safe, it changes the IDT to point to one that
does not modify the stack on breakpoint (to allow breakpoints in NMIs).
But the variable that gets set to know to undo it on exit never gets
cleared on exit. Thus every NMI will reset it on exit the first time
it is done even if it does not need to be reset.
[ Added H. Peter Anvin's suggestion to use this_cpu_read/write ]
Cc: <stable@vger.kernel.org> # v3.3
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
On boot up and module load, it is fine to modify the code directly,
without the use of breakpoints. This is because boot up modification
is done before SMP is initialized, thus the modification is serial,
and module load is done before the module executes.
But after that we must use a SMP safe method to modify running code.
Otherwise, if we are running the function tracer and update its
function (by starting off the stack tracer, or perf tracing)
the change of the function called by the ftrace trampoline is done
directly. If this is being executed on another CPU, that CPU may
take a GPF and crash the kernel.
The breakpoint method is used to change the nops at all the functions, but
the change of the ftrace callback handler itself was still using a
direct modification. If tracing was enabled and the function callback
was changed then another CPU could fault if it was currently calling
the original callback. This modification must use the breakpoint method
too.
Note, the direct method is still used for boot up and module load.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When the function tracer starts modifying the code via breakpoints
it sets a variable (modifying_ftrace_code) to inform the breakpoint
handler to call the ftrace int3 code.
But there's no synchronization between setting this code and the
handler, thus it is possible for the handler to be called on another
CPU before it sees the variable. This will cause a kernel crash as
the int3 handler will not know what to do with it.
I originally added smp_mb()'s to force the visibility of the variable
but H. Peter Anvin suggested that I just make it atomic.
[ Added comments as suggested by Peter Zijlstra ]
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
