Under perf, the fp unwinding scheme requires access to user space memory
and can provoke a pagefault via call to __copy_from_user_inatomic from
user_backtrace. This unwinding can take place in response to an interrupt
(__perf_event_overflow). This is undesirable as we may already have
mmap_sem held for write. One example being a process that calls mprotect
just as a the PMU counters overflow.
An example that can provoke this behaviour:
perf record -e event:tocapture --call-graph fp ./application_to_test
This patch addresses this issue by disabling pagefaults briefly in
user_backtrace (as is done in the other architectures: ARM64, x86, Sparc etc.).
Without the patch a deadlock occurs when __perf_event_overflow is called
while reading the data from the user space:
[ INFO: possible recursive locking detected ]
3.16.0-rc2-00038-g0ed7ff6 #46 Not tainted
---------------------------------------------
stress/1634 is trying to acquire lock:
(&mm->mmap_sem){++++++}, at: [<c001dc04>] do_page_fault+0xa8/0x428
but task is already holding lock:
(&mm->mmap_sem){++++++}, at: [<c00f4098>] SyS_mprotect+0xa8/0x1c8
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&mm->mmap_sem);
lock(&mm->mmap_sem);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by stress/1634:
#0: (&mm->mmap_sem){++++++}, at: [<c00f4098>] SyS_mprotect+0xa8/0x1c8
#1: (rcu_read_lock){......}, at: [<c00c29dc>] __perf_event_overflow+0x120/0x294
stack backtrace:
CPU: 1 PID: 1634 Comm: stress Not tainted 3.16.0-rc2-00038-g0ed7ff6 #46
[<c0017c8c>] (unwind_backtrace) from [<c0012eec>] (show_stack+0x20/0x24)
[<c0012eec>] (show_stack) from [<c04de914>] (dump_stack+0x7c/0x98)
[<c04de914>] (dump_stack) from [<c006a360>] (__lock_acquire+0x1484/0x1cf0)
[<c006a360>] (__lock_acquire) from [<c006b14c>] (lock_acquire+0xa4/0x11c)
[<c006b14c>] (lock_acquire) from [<c04e3880>] (down_read+0x40/0x7c)
[<c04e3880>] (down_read) from [<c001dc04>] (do_page_fault+0xa8/0x428)
[<c001dc04>] (do_page_fault) from [<c00084ec>] (do_DataAbort+0x44/0xa8)
[<c00084ec>] (do_DataAbort) from [<c0013a1c>] (__dabt_svc+0x3c/0x60)
Exception stack(0xed7c5ae0 to 0xed7c5b28)
5ae0: ed7c5b5c b6dadff4 ffffffec 00000000 b6dadff4 ebc08000 00000000 ebc08000
5b00: 0000007e 00000000 ed7c4000 ed7c5b94 00000014 ed7c5b2c c001a438 c0236c60
5b20: 00000013 ffffffff
[<c0013a1c>] (__dabt_svc) from [<c0236c60>] (__copy_from_user+0xa4/0x3a4)
Acked-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Jean Pihet <jean.pihet@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
An event may occur when an mm is already released.
As per commit 20afc60f89
'x86, perf: Check that current->mm is alive before getting user callchain'
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jean Pihet <jean.pihet@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The ldousb_reg regulator provides power to the USB1 and USB2
High Speed PHYs.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Add TPS65218 device tree nodes. i2c clock frequency setting
also added as part of tps65218 nodes addition. As i2c clock
enabling is required.
Signed-off-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Add TPS65218 device tree nodes. i2c clock frequency setting
also added as part of tps65218 nodes addition. As i2c clock
enabling is required.
Signed-off-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
There is a IRQ crossbar device in the soc, which
maps the irq requests from the peripherals to the
mpu interrupt controller's inputs. The Peripheral irq
requests are connected to only one crossbar
input and the output of the crossbar is connected to only one
controller's input line. The crossbar device is used to map
a peripheral input to a free mpu's interrupt controller line.
Here, adding a new crossbar device node and replacing all the peripheral
interrupt numbers with its fixed crossbar input lines.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
There is a IRQ crossbar device in the soc, which maps the
irq requests from the peripherals to the mpu interrupt
controller's inputs. The gic provides the support for such
IPs in the form of routable-irqs. So adding the property
here to gic node.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
The mach-omap2 directory contains full register defines for OMAP4
control module but only around 27 of those are used. There are is
a total of 1795 register defines in four files with only 27 in use.
That is pretty low usefulness ratio...
I guess alot more was used when we had omap4 board files and
mach-omap2 contained more drivers but this has now changed.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
[tony@atomide.com: updated to apply]
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch is based on feedback from Viresh Kumar.
Since cpufreq-cpu0 driver has already check opp table, there is no
need to same check in mach-shmobile.
Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
The R-Car Gen 2 PCIe driver provides PCIe host support for
Renesas R-Car Gen2 platforms. To increase hardware support enable
the driver in the shmobile_defconfig multiplatform configuration.
Cc: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
As early printk is not supported when devices are initialised
using DT, so remove it from the command line.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
As early printk is not supported when devices are initialised
using DT, so remove it from the command line.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Currently, the coherency fabric support registers two bus notifiers;
one for platform, one for pci bus types, with the same notifier block.
However, this is illegal and can cause serious issues: the notifier
block is also a link in the notifier list and cannot be inserted twice.
This commit fixes this by using different notifier blocks (with the same
notifier callback) to set the platform and pci bus types notifiers.
Fixes: b0063aad5d ("ARM: mvebu: use hardware I/O coherency also for PCI devices")
Reported-by: Paolo Pisati <p.pisati@gmail.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Link: https://lkml.kernel.org/r/1404826657-6977-1-git-send-email-ezequiel.garcia@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
In the inline asm part of the function armada_370_xp_pmsu_idle_enter()
the input operand was used. The intent here was to let the compiler
choose this register so it could do the optimization it
needed.
However an input operand is not supposed to be modified by the inline
asm code. This can lead to improper generated instructions.
In some case generated instruction the compiler made the choice to
reuse the same register to store the return value. But in the assembly
part this register was modified, so it can lead to return an wrong
value.
The fix is to use a clobber. Thanks to this the compiler will know
that the value of this register will be modified.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1404483736-16938-1-git-send-email-gregory.clement@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
The mvebu_v5_defconfig is currently used for Kirkwood platforms, and
in the future hopefully used for Orion5x platforms. Those platforms
use fairly old bootloaders that don't have Device Tree support, so it
makes sense to enable appended DTB support by default, as well as the
backward compatibility with ATAGS passed by the bootloader for those
platforms. It helps having a defconfig that works fine out of the box
for most Kirkwood platforms.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1404375830-22169-1-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Enable internal AHB-PCI bridges for the USB EHCI/OHCI controllers attached to
them.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
[horms+renesas@verge.net.au: minor witespace changes]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Enable internal AHB-PCI bridges for the USB EHCI/OHCI controllers attached to
them.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
[horms+renesas@verge.net.au: minor witespace changes]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This removes the FIXME message above ocpi_enable being declared
for proper locking in this function. As of the current kernel
verisons there is no need for locking as only one driver uses
this function currently and therefore there is no need for real
locking requirements.
Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Add ABB device nodes for OMAP5 family of devices. Data is based on
final production OMAP543x Technical Reference Manual revision Z (April 2013).
Final production Data Manual for OMAP5432 SWPS050F(APRIL 2014).
[nm@ti.com: co-developer and updates to latest documentation]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Andrii.Tseglytskyi <andrii.tseglytskyi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This code is not working currently and it can be removed. There is a
conflict in sharing resources with the actual HDMI driver and with
the ASoC HDMI audio DAI driver.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Merge "Berlin DT changes for v3.17" from Sebastian Hesselbarth:
- L2CC latency properties for BG2Q
- DW i2c nodes for BG2Q and corresponding dev board
- SMP related nodes for BG2 and BG2Q
* tag 'berlin-dt-3.17-1' of git://git.infradead.org/users/hesselba/linux-berlin:
ARM: dts: berlin: add SMP related nodes and properties for BG2Q
ARM: dts: berlin: add SMP related nodes and properties for BG2
Documentation: bindings: add the marvell,berlin-smp CPU enable method
Documentation: bindings: add the Berlin CPU control doc
ARM: dts: berlin: enable i2c0 and i2c2
ARM: dts: berlin: add I2C nodes for BG2Q
ARM: dts: berlin2q: set L2CC tag and data latency to 2 cycles
Signed-off-by: Olof Johansson <olof@lixom.net>
Merge "Berlin SoC changes for v3.17" from Sebastian Hesselbarth:
- SMP support for BG2 and BG2Q
* tag 'berlin-soc-3.17-1' of git://git.infradead.org/users/hesselba/linux-berlin:
ARM: berlin: add SMP support
Signed-off-by: Olof Johansson <olof@lixom.net>
