* 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
clocksource: apb: Share APB timer code with other platforms
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-64, vdso: Do not allocate memory for the vDSO
clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option
x86, vdso: Drop now wrong comment
Document the vDSO and add a reference parser
ia64: Replace clocksource.fsys_mmio with generic arch data
x86-64: Move vread_tsc and vread_hpet into the vDSO
clocksource: Replace vread with generic arch data
x86-64: Add --no-undefined to vDSO build
x86-64: Allow alternative patching in the vDSO
x86: Make alternative instruction pointers relative
x86-64: Improve vsyscall emulation CS and RIP handling
x86-64: Emulate legacy vsyscalls
x86-64: Fill unused parts of the vsyscall page with 0xcc
x86-64: Remove vsyscall number 3 (venosys)
x86-64: Map the HPET NX
x86-64: Remove kernel.vsyscall64 sysctl
x86-64: Give vvars their own page
x86-64: Document some of entry_64.S
x86-64: Fix alignment of jiffies variable
* 'x86-signal-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Kill handle_signal()->set_fs()
x86, do_signal: Simplify the TS_RESTORE_SIGMASK logic
x86, signals: Convert the X86_32 code to use set_current_blocked()
x86, signals: Convert the IA32_EMULATION code to use set_current_blocked()
* 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, mce: Use mce_sysdev_ prefix to group functions
x86, mce: Use mce_chrdev_ prefix to group functions
x86, mce: Cleanup mce_read()
x86, mce: Cleanup mce_create()/remove_device()
x86, mce: Check the result of ancient_init()
x86, mce: Introduce mce_gather_info()
x86, mce: Replace MCM_ with MCI_MISC_
x86, mce: Replace MCE_SELF_VECTOR by irq_work
x86, mce, severity: Clean up trivial coding style problems
x86, mce, severity: Cleanup severity table
x86, mce, severity: Make formatting a bit more readable
x86, mce, severity: Fix two severities table signatures
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, smpboot: Mark the names[] array in __inquire_remote_apic() as const
x86: Convert vmalloc()+memset() to vzalloc()
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, ioapic: Print IR_IO_APIC_route_entry when IR is enabled
x86, ioapic: Print IRTE when IR is enabled
x86, x2apic: Preserve high 32-bits of IA32_APIC_BASE MSR
x86, ioapic: Also print Dest field
x86, ioapic: Format clean up for IOAPIC output
x86: print APIC data a little later during boot
* 'timers-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
mips: Fix i8253 clockevent fallout
i8253: Cleanup outb/inb magic
arm: Footbridge: Use common i8253 clockevent
mips: Use common i8253 clockevent
x86: Use common i8253 clockevent
i8253: Create common clockevent implementation
i8253: Export i8253_lock unconditionally
pcpskr: MIPS: Make config dependencies finer grained
pcspkr: Cleanup Kconfig dependencies
i8253: Move remaining content and delete asm/i8253.h
i8253: Consolidate definitions of PIT_LATCH
x86: i8253: Consolidate definitions of global_clock_event
i8253: Alpha, PowerPC: Remove unused asm/8253pit.h
alpha: i8253: Cleanup remaining users of i8253pit.h
i8253: Remove I8253_LOCK config
i8253: Make pcsp sound driver use the shared i8253_lock
i8253: Make pcspkr input driver use the shared i8253_lock
i8253: Consolidate all kernel definitions of i8253_lock
i8253: Unify all kernel declarations of i8253_lock
i8253: Create linux/i8253.h and use it in all 8253 related files
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (123 commits)
perf: Remove the nmi parameter from the oprofile_perf backend
x86, perf: Make copy_from_user_nmi() a library function
perf: Remove perf_event_attr::type check
x86, perf: P4 PMU - Fix typos in comments and style cleanup
perf tools: Make test use the preset debugfs path
perf tools: Add automated tests for events parsing
perf tools: De-opt the parse_events function
perf script: Fix display of IP address for non-callchain path
perf tools: Fix endian conversion reading event attr from file header
perf tools: Add missing 'node' alias to the hw_cache[] array
perf probe: Support adding probes on offline kernel modules
perf probe: Add probed module in front of function
perf probe: Introduce debuginfo to encapsulate dwarf information
perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
perf probe: Remove redundant dwarf functions
perf probe: Move strtailcmp to string.c
perf probe: Rename DIE_FIND_CB_FOUND to DIE_FIND_CB_END
tracing/kprobe: Update symbol reference when loading module
tracing/kprobes: Support module init function probing
kprobes: Return -ENOENT if probe point doesn't exist
...
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
iommu/core: Fix build with INTR_REMAP=y && CONFIG_DMAR=n
iommu/amd: Don't use MSI address range for DMA addresses
iommu/amd: Move missing parts to drivers/iommu
iommu: Move iommu Kconfig entries to submenu
x86/ia64: intel-iommu: move to drivers/iommu/
x86: amd_iommu: move to drivers/iommu/
msm: iommu: move to drivers/iommu/
drivers: iommu: move to a dedicated folder
x86/amd-iommu: Store device alias as dev_data pointer
x86/amd-iommu: Search for existind dev_data before allocting a new one
x86/amd-iommu: Allow dev_data->alias to be NULL
x86/amd-iommu: Use only dev_data in low-level domain attach/detach functions
x86/amd-iommu: Use only dev_data for dte and iotlb flushing routines
x86/amd-iommu: Store ATS state in dev_data
x86/amd-iommu: Store devid in dev_data
x86/amd-iommu: Introduce global dev_data_list
x86/amd-iommu: Remove redundant device_flush_dte() calls
iommu-api: Add missing header file
Fix up trivial conflicts (independent additions close to each other) in
drivers/Makefile and include/linux/pci.h
* 'of-pci' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
pci/of: Consolidate pci_bus_to_OF_node()
pci/of: Consolidate pci_device_to_OF_node()
x86/devicetree: Use generic PCI <-> OF matching
microblaze/pci: Move the remains of pci_32.c to pci-common.c
microblaze/pci: Remove powermac originated cruft
pci/of: Match PCI devices to OF nodes dynamically
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1287 commits)
icmp: Fix regression in nexthop resolution during replies.
net: Fix ppc64 BPF JIT dependencies.
acenic: include NET_SKB_PAD headroom to incoming skbs
ixgbe: convert to ndo_fix_features
ixgbe: only enable WoL for magic packet by default
ixgbe: remove ifdef check for non-existent define
ixgbe: Pass staterr instead of re-reading status and error bits from descriptor
ixgbe: Move interrupt related values out of ring and into q_vector
ixgbe: add structure for containing RX/TX rings to q_vector
ixgbe: inline the ixgbe_maybe_stop_tx function
ixgbe: Update ATR to use recorded TX queues instead of CPU for routing
igb: Fix for DH89xxCC near end loopback test
e1000: always call e1000_check_for_link() on e1000_ce4100 MACs.
netxen: add fw version compatibility check
be2net: request native mode each time the card is reset
ipv4: Constrain UFO fragment sizes to multiples of 8 bytes
virtio_net: Fix panic in virtnet_remove
ipv6: make fragment identifications less predictable
ipv6: unshare inetpeers
can: make function can_get_bittiming static
...
The Host used to create some page tables for the Guest to use at the
top of Guest memory; it would then tell the Guest where this was. In
particular, it created linear mappings for 0 and 0xC0000000 addresses
because lguest used to switch to its real page tables quite late in
boot.
However, since d50d8fe19 Linux initialized boot page tables in
head_32.S even before the "are we lguest?" boot jump. So, now we can
simplify things: the Host pagetable code assumes 1:1 linear mapping
until it first calls the LHCALL_NEW_PGTABLE hypercall, which we now do
before we reach C code.
This also means that the Host doesn't need to know anything about the
Guest's PAGE_OFFSET. (Non-Linux guests might not even have such a
thing).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Yet another variant of the Dell Latitude series which requires
reboot=pci.
From the E5420 bug report by Daniel J Blueman:
> The E6420 is affected also (same platform, different casing and
> features), which provides an external confirmation of the issue; I can
> submit a patch for that later or include it if you prefer:
> http://linux.koolsolutions.com/2009/08/04/howto-fix-linux-hangfreeze-during-reboots-and-restarts/
Reported-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org>
Rebooting on the Dell E5420 often hangs with the keyboard or ACPI
methods, but is reliable via the PCI method.
[ hpa: this was deferred because we believed for a long time that the
recent reshuffling of the boot priorities in commit
660e34cebf fixed this platform.
Unfortunately that turned out to be incorrect. ]
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Link: http://lkml.kernel.org/r/1305248699-2347-1-git-send-email-daniel.blueman@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org>
copy_from_user_nmi() is used in oprofile and perf. Moving it to other
library functions like copy_from_user(). As this is x86 code for 32
and 64 bits, create a new file usercopy.c for unified code.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110607172413.GJ20052@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch:
- fixes typos in comments and clarifies the text
- renames obscure p4_event_alias::original and ::alter members to
::original and ::alternative as appropriate
- drops parenthesis from the return of p4_get_alias_event()
No functional changes.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/20110721160625.GX7492@sun
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the printk_once() so that it actually prints (didn't print before
due to a stray comma.)
[ hpa: changed to an incremental patch and adjusted the description
accordingly. ]
Signed-off-by: Len Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1107151732480.18606@x980
Cc: <table@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
handle_signal()->set_fs() has a nice comment which explains what
set_fs() is, but it doesn't explain why it is needed and why it
depends on CONFIG_X86_64.
Afaics, the history of this confusion is:
1. I guess today nobody can explain why it was needed
in arch/i386/kernel/signal.c, perhaps it was always
wrong. This predates 2.4.0 kernel.
2. then it was copy-and-past'ed to the new x86_64 arch.
3. then it was removed from i386 (but not from x86_64)
by b93b6ca3 "i386: remove unnecessary code".
4. then it was reintroduced under CONFIG_X86_64 when x86
unified i386 and x86_64, because the patch above didn't
touch x86_64.
Remove it. ->addr_limit should be correct. Even if it was possible
that it is wrong, it is too late to fix it after setup_rt_frame().
Linus commented in:
http://lkml.kernel.org/r/alpine.LFD.0.999.0707170902570.19166@woody.linux-foundation.org
... about the equivalent bit from i386:
Heh. I think it's entirely historical.
Please realize that the whole reason that function is called "set_fs()" is
that it literally used to set the %fs segment register, not
"->addr_limit".
So I think the "set_fs(USER_DS)" is there _only_ to match the other
regs->xds = __USER_DS;
regs->xes = __USER_DS;
regs->xss = __USER_DS;
regs->xcs = __USER_CS;
things, and never mattered. And now it matters even less, and has been
copied to all other architectures where it is just totally insane.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20110710164424.GA20261@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
1. do_signal() looks at TS_RESTORE_SIGMASK and calculates the
mask which should be stored in the signal frame, then it
passes "oldset" to the callees, down to setup_rt_frame().
This is ugly, setup_rt_frame() can do this itself and nobody
else needs this sigset_t. Move this code into setup_rt_frame.
2. do_signal() also clears TS_RESTORE_SIGMASK if handle_signal()
succeeds.
We can move this to setup_rt_frame() as well, this avoids the
unnecessary checks and makes the logic more clear.
3. use set_current_blocked() instead of sigprocmask(SIG_SETMASK),
sigprocmask() should be avoided.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20110710182203.GA27979@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
sys_sigsuspend() and sys_sigreturn() change ->blocked directly.
This is not correct, see the changelog in e6fa16ab
"signal: sigprocmask() should do retarget_shared_pending()"
Change them to use set_current_blocked().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20110710192727.GA31759@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Instead of hw_nmi_watchdog_set_attr() weak function
and appropriate x86_pmu::hw_watchdog_set_attr() call
we introduce even alias mechanism which allow us
to drop this routines completely and isolate quirks
of Netburst architecture inside P4 PMU code only.
The main idea remains the same though -- to allow
nmi-watchdog and perf top run simultaneously.
Note the aliasing mechanism applies to generic
PERF_COUNT_HW_CPU_CYCLES event only because arbitrary
event (say passed as RAW initially) might have some
additional bits set inside ESCR register changing
the behaviour of event and we can't guarantee anymore
that alias event will give the same result.
P.S. Thanks a huge to Don and Steven for for testing
and early review.
Acked-by: Don Zickus <dzickus@redhat.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Stephane Eranian <eranian@google.com>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20110708201712.GS23657@sun
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since 2.6.36 (23016bf0d2), Linux prints the existence of "epb" in /proc/cpuinfo,
Since 2.6.38 (d5532ee7b4), the x86_energy_perf_policy(8) utility has
been available in-tree to update MSR_IA32_ENERGY_PERF_BIAS.
However, the typical BIOS fails to initialize the MSR, presumably
because this is handled by high-volume shrink-wrap operating systems...
Linux distros, on the other hand, do not yet invoke x86_energy_perf_policy(8).
As a result, WSM-EP, SNB, and later hardware from Intel will run in its
default hardware power-on state (performance), which assumes that users
care for performance at all costs and not for energy efficiency.
While that is fine for performance benchmarks, the hardware's intended default
operating point is "normal" mode...
Initialize the MSR to the "normal" by default during kernel boot.
x86_energy_perf_policy(8) is available to change the default after boot,
should the user have a different preference.
Signed-off-by: Len Brown <len.brown@intel.com>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1107140051020.18606@x980
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@kernel.org>
The vread field was bloating struct clocksource everywhere except
x86_64, and I want to change the way this works on x86_64, so let's
split it out into per-arch data.
Cc: x86@kernel.org
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: linux-ia64@vger.kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/3ae5ec76a168eaaae63f08a2a1060b91aa0b7759.1310563276.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Three fixes here:
- Send SIGSEGV if called from compat code or with a funny CS.
- Don't BUG on impossible addresses.
- Add a missing local_irq_disable.
This patch also removes an unused variable.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/6fb2b13ab39b743d1e4f466eef13425854912f7f.1310563276.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
When "apic=debug" is used as a boot parameter, Linux prints the IOAPIC routing
entries in "dmesg". Below is output from IOAPIC whose apic_id is 8:
# dmesg | grep "routing entry"
IOAPIC[8]: Set routing entry (8-1 -> 0x31 -> IRQ 1 Mode:0 Active:0 Dest:0)
IOAPIC[8]: Set routing entry (8-2 -> 0x30 -> IRQ 0 Mode:0 Active:0 Dest:0)
IOAPIC[8]: Set routing entry (8-3 -> 0x33 -> IRQ 3 Mode:0 Active:0 Dest:0)
...
Similarly, when IR (interrupt remapping) is enabled, and the IRTE
(interrupt remapping table entry) is set up we should display it.
After the fix:
# dmesg | grep IRTE
IOAPIC[8]: Set IRTE entry (P:1 FPD:0 Dst_Mode:0 Redir_hint:1 Trig_Mode:0 Dlvry_Mode:0 Avail:0 Vector:31 Dest:00000000 SID:00F1 SQ:0 SVT:1)
IOAPIC[8]: Set IRTE entry (P:1 FPD:0 Dst_Mode:0 Redir_hint:1 Trig_Mode:0 Dlvry_Mode:0 Avail:0 Vector:30 Dest:00000000 SID:00F1 SQ:0 SVT:1)
IOAPIC[8]: Set IRTE entry (P:1 FPD:0 Dst_Mode:0 Redir_hint:1 Trig_Mode:0 Dlvry_Mode:0 Avail:0 Vector:33 Dest:00000000 SID:00F1 SQ:0 SVT:1)
...
The IRTE is defined in Sec 9.5 of the Intel VT-d Specification.
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Link: http://lkml.kernel.org/r/20110712211704.2939.71291.sendpatchset@nchumbalkar.americas.cpqcorp.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The code in setup_ioapic_irq() determines the Destination Field,
so why not also include it in the debug printk output that gets
displayed when the boot parameter "apic=debug" is used.
Before the change, "dmesg" will show:
IOAPIC[0]: Set routing entry (8-1 -> 0x31 -> IRQ 1 Mode:0 Active:0)
IOAPIC[0]: Set routing entry (8-2 -> 0x30 -> IRQ 0 Mode:0 Active:0)
IOAPIC[0]: Set routing entry (8-3 -> 0x33 -> IRQ 3 Mode:0 Active:0) ...
After the change, you will see:
IOAPIC[0]: Set routing entry (8-1 -> 0x31 -> IRQ 1 Mode:0 Active:0 Dest:0)
IOAPIC[0]: Set routing entry (8-2 -> 0x30 -> IRQ 0 Mode:0 Active:0 Dest:0)
IOAPIC[0]: Set routing entry (8-3 -> 0x33 -> IRQ 3 Mode:0 Active:0 Dest:0) ...
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Link: http://lkml.kernel.org/r/20110708184603.2734.91071.sendpatchset@nchumbalkar.americas.cpqcorp.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When IOAPIC data is displayed in "dmesg" with the help of the
boot parameter "apic=debug" certain values are not formatted
correctly wrt their size.
In the "dmesg" snippet below, note that the output for "max
redirection entries", and "IO APIC version" which are each
defined to be just 8-bits long are displayed as 2 bytes in
length. Similarly, "Dst" under the "IRQ redirection table"
should only be 8-bits long.
IO APIC #0......
...
...
.... register #01: 00170020
....... : max redirection entries: 0017
....... : PRQ implemented: 0
....... : IO APIC version: 0020
...
...
.... IRQ redirection table:
NR Dst Mask Trig IRR Pol Stat Dmod Deli Vect:
00 000 1 0 0 0 0 0 0 00
01 000 0 0 0 0 0 0 0 31
02 000 0 0 0 0 0 0 0 30
03 000 1 0 0 0 0 0 0 33
...
...
Do some formatting clean up, so you will see output like below:
IO APIC #0......
...
...
.... register #01: 00170020
....... : max redirection entries: 17
....... : PRQ implemented: 0
....... : IO APIC version: 20
...
...
.... IRQ redirection table:
NR Dst Mask Trig IRR Pol Stat Dmod Deli Vect:
00 00 1 0 0 0 0 0 0 00
01 00 0 0 0 0 0 0 0 31
02 00 0 0 0 0 0 0 0 30
03 00 1 0 0 0 0 0 0 33
...
...
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Link: http://lkml.kernel.org/r/20110708184557.2734.61830.sendpatchset@nchumbalkar.americas.cpqcorp.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some BIOSes will reset the Intel MISC_ENABLE MSR (specifically the
XD_DISABLE bit) when resuming from S3, which can interact poorly with
ebba638ae7. In 32bit PAE mode, this can
lead to a fault when EFER is restored by the kernel wakeup routines,
due to it setting the NX bit for a CPU that (thanks to the BIOS reset)
now incorrectly thinks it lacks the NX feature. (64bit is not affected
because it uses a common CPU bring-up that specifically handles the
XD_DISABLE bit.)
The need for MISC_ENABLE being restored so early is specific to the S3
resume path. Normally, MISC_ENABLE is saved in save_processor_state(),
but this happens after the resume header is created, so just reproduce
the logic here. (acpi_suspend_lowlevel() creates the header, calls
do_suspend_lowlevel, which calls save_processor_state(), so the saved
processor context isn't available during resume header creation.)
[ hpa: Consider for stable if OK in mainline ]
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Link: http://lkml.kernel.org/r/20110707011034.GA8523@outflux.net
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@kernel.org> 2.6.38+
Since git commit
660e34cebf x86: reorder reboot method
preferences,
my Acer Aspire One hangs on reboot. It appears that its ACPI method
for rebooting is broken. The attached patch adds a quirk so that the
machine will reboot via the BIOS.
[ hpa: verified that the ACPI control on this machine is just plain broken. ]
Signed-off-by: Peter Chubb <peter.chubb@nicta.com.au>
Link: http://lkml.kernel.org/r/w439iki5vl.wl%25peter@chubb.wattle.id.au
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
rbp is used in SAVE_ARGS_IRQ to save the old stack pointer
in order to restore it later in ret_from_intr.
It is convenient because we save its value in the irq regs
and it's easily restored using the leave instruction.
However this is a kind of abuse of the frame pointer which
role is to help unwinding the kernel by chaining frames
together, each node following the return address to the
previous frame.
But although we are breaking the frame by changing the stack
pointer, there is no preceding return address before the new
frame. Hence using the frame pointer to link the two stacks
breaks the stack unwinders that find a random value instead of
a return address here.
There is no workaround that can work in every case. We are using
the fixup_bp_irq_link() function to dereference that abused frame
pointer in the case of non nesting interrupt (which means stack
changed).
But that doesn't fix the case of interrupts that don't change the
stack (but we still have the unconditional frame link), which is
the case of hardirq interrupting softirq. We have no way to detect
this transition so the frame irq link is considered as a real frame
pointer and the return address is dereferenced but it is still a
spurious one.
There are two possible results of this: either the spurious return
address, a random stack value, luckily belongs to the kernel text
and then the unwinding can continue and we just have a weird entry
in the stack trace. Or it doesn't belong to the kernel text and
unwinding stops there.
This is the reason why stacktraces (including perf callchains) on
irqs that interrupted softirqs don't work very well.
To solve this, we don't save the old stack pointer on rbp anymore
but we save it to a scratch register that we push on the new
stack and that we pop back later on irq return.
This preserves the whole frame chain without spurious return addresses
in the middle and drops the need for the horrid fixup_bp_irq_link()
workaround.
And finally irqs that interrupt softirq are sanely unwinded.
Before:
99.81% perf [kernel.kallsyms] [k] perf_pending_event
|
--- perf_pending_event
irq_work_run
smp_irq_work_interrupt
irq_work_interrupt
|
|--41.60%-- __read
| |
| |--99.90%-- create_worker
| | bench_sched_messaging
| | cmd_bench
| | run_builtin
| | main
| | __libc_start_main
| --0.10%-- [...]
After:
1.64% swapper [kernel.kallsyms] [k] perf_pending_event
|
--- perf_pending_event
irq_work_run
smp_irq_work_interrupt
irq_work_interrupt
|
|--95.00%-- arch_irq_work_raise
| irq_work_queue
| __perf_event_overflow
| perf_swevent_overflow
| perf_swevent_event
| perf_tp_event
| perf_trace_softirq
| __do_softirq
| call_softirq
| do_softirq
| irq_exit
| |
| |--73.68%-- smp_apic_timer_interrupt
| | apic_timer_interrupt
| | |
| | |--96.43%-- amd_e400_idle
| | | cpu_idle
| | | start_secondary
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
The unwinder backlink in interrupt entry is very useless.
It's actually not part of the stack frame chain and thus is
never used.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
Just for clarity in the code. Have a first block that handles
the frame pointer and a separate one that handles pt_regs
pointer and its use.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
The save_regs function that saves the regs on low level
irq entry is complicated because of the fact it changes
its stack in the middle and also because it manipulates
data allocated in the caller frame and accesses there
are directly calculated from callee rsp value with the
return address in the middle of the way.
This complicates the static stack offsets calculation and
require more dynamic ones. It also needs a save/restore
of the function's return address.
To simplify and optimize this, turn save_regs() into a
macro.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
When regs are passed to dump_stack(), we fetch the frame
pointer from the regs but the stack pointer is taken from
the current frame.
Thus the frame and stack pointers may not come from the same
context. For example this can result in the unwinder to
think the context is in irq, due to the current value of
the stack, but the frame pointer coming from the regs points
to a frame from another place. It then tries to fix up
the irq link but ends up dereferencing a random frame
pointer that doesn't belong to the irq stack:
[ 9131.706906] ------------[ cut here ]------------
[ 9131.707003] WARNING: at arch/x86/kernel/dumpstack_64.c:129 dump_trace+0x2aa/0x330()
[ 9131.707003] Hardware name: AMD690VM-FMH
[ 9131.707003] Perf: bad frame pointer = 0000000000000005 in callchain
[ 9131.707003] Modules linked in:
[ 9131.707003] Pid: 1050, comm: perf Not tainted 3.0.0-rc3+ #181
[ 9131.707003] Call Trace:
[ 9131.707003] <IRQ> [<ffffffff8104bd4a>] warn_slowpath_common+0x7a/0xb0
[ 9131.707003] [<ffffffff8104be21>] warn_slowpath_fmt+0x41/0x50
[ 9131.707003] [<ffffffff8178b873>] ? bad_to_user+0x6d/0x10be
[ 9131.707003] [<ffffffff8100c2da>] dump_trace+0x2aa/0x330
[ 9131.707003] [<ffffffff810107d3>] ? native_sched_clock+0x13/0x50
[ 9131.707003] [<ffffffff8101b164>] perf_callchain_kernel+0x54/0x70
[ 9131.707003] [<ffffffff810d391f>] perf_prepare_sample+0x19f/0x2a0
[ 9131.707003] [<ffffffff810d546c>] __perf_event_overflow+0x16c/0x290
[ 9131.707003] [<ffffffff810d5430>] ? __perf_event_overflow+0x130/0x290
[ 9131.707003] [<ffffffff810107d3>] ? native_sched_clock+0x13/0x50
[ 9131.707003] [<ffffffff8100fbb9>] ? sched_clock+0x9/0x10
[ 9131.707003] [<ffffffff810752e5>] ? T.375+0x15/0x90
[ 9131.707003] [<ffffffff81084da4>] ? trace_hardirqs_on_caller+0x64/0x180
[ 9131.707003] [<ffffffff810817bd>] ? trace_hardirqs_off+0xd/0x10
[ 9131.707003] [<ffffffff810d5764>] perf_event_overflow+0x14/0x20
[ 9131.707003] [<ffffffff810d588c>] perf_swevent_hrtimer+0x11c/0x130
[ 9131.707003] [<ffffffff817821a1>] ? error_exit+0x51/0xb0
[ 9131.707003] [<ffffffff81072e93>] __run_hrtimer+0x83/0x1e0
[ 9131.707003] [<ffffffff810d5770>] ? perf_event_overflow+0x20/0x20
[ 9131.707003] [<ffffffff81073256>] hrtimer_interrupt+0x106/0x250
[ 9131.707003] [<ffffffff812a3bfd>] ? trace_hardirqs_off_thunk+0x3a/0x3c
[ 9131.707003] [<ffffffff81024833>] smp_apic_timer_interrupt+0x53/0x90
[ 9131.707003] [<ffffffff81789053>] apic_timer_interrupt+0x13/0x20
[ 9131.707003] <EOI> [<ffffffff817821a1>] ? error_exit+0x51/0xb0
[ 9131.707003] [<ffffffff8178219c>] ? error_exit+0x4c/0xb0
[ 9131.707003] ---[ end trace b2560d4876709347 ]---
Fix this by simply taking the stack pointer from regs->sp
when regs are provided.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
This code uses PCI_CLASS_REVISION instead of PCI_REVISION_ID, so
it wasn't converted by commit 44c10138fd ("PCI: Change all
drivers to use pci_device->revision") before being moved to
arch/x86/...
Do it now at last -- and save one level of indentation...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/201107012242.08347.sshtylyov@ru.mvista.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The v1 PMU does not have any fixed counters. Using the v2 constraints,
which do have fixed counters, causes an additional choice to be present
in the weight calculation, but not when actually scheduling the event,
leading to an event being not scheduled at all.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1309362157-6596-3-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
