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Pull MIPS bug fixes from Ralf Baechle:
"Two more fixes for 4.2.
One fixes a build issue with the LLVM assembler - LLVM assembler macro
names are case sensitive, GNU as macro names are insensitive; the
other corrects a license string (GPL v2, not GPLv2) such that the
module loader will recognice the license correctly"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
FIRMWARE: bcm47xx_nvram: Fix module license.
MIPS: Fix LLVM build issue.
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Pull ARM fixes from Russell King:
"Another couple of small ARM fixes.
A patch from Masahiro Yamada who noticed that "make -jN all zImage"
would end up generating bad images where N > 1, and a patch from
Nicolas to fix the Marvell CPU user access optimisation code when page
faults are disabled"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8418/1: add boot image dependencies to not generate invalid images
ARM: 8414/1: __copy_to_user_memcpy: fix mmap semaphore usage
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Various low level fixes: fix more fallout from the FPU rework and the
asm entry code rework, plus an MSI rework fix, and an idle-tracing fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu/math-emu: Fix crash in fork()
x86/fpu/math-emu: Fix math-emu boot crash
x86/idle: Restore trace_cpu_idle to mwait_idle() calls
x86/irq: Build correct vector mapping for multiple MSI interrupts
Revert "sched/x86_64: Don't save flags on context switch"
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"A series of small fixlets for a regression visible on OMAP devices
caused by the conversion of the OMAP interrupt chips to hierarchical
interrupt domains. Mostly one liners on the driver side plus a small
helper function in the core to avoid open coded mess in the drivers"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/crossbar: Restore set_wake functionality
irqchip/crossbar: Restore the mask on suspend behaviour
ARM: OMAP: wakeupgen: Restore the irq_set_type() mechanism
irqchip/crossbar: Restore the irq_set_type() mechanism
genirq: Introduce irq_chip_set_type_parent() helper
genirq: Don't return ENOSYS in irq_chip_retrigger_hierarchy
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During later stages of math-emu bootup the following crash triggers:
math_emulate: 0060:c100d0a8
Kernel panic - not syncing: Math emulation needed in kernel
CPU: 0 PID: 1511 Comm: login Not tainted 4.2.0-rc7+ #1012
[...]
Call Trace:
[<c181d50d>] dump_stack+0x41/0x52
[<c181c918>] panic+0x77/0x189
[<c1003530>] ? math_error+0x140/0x140
[<c164c2d7>] math_emulate+0xba7/0xbd0
[<c100d0a8>] ? fpu__copy+0x138/0x1c0
[<c1109c3c>] ? __alloc_pages_nodemask+0x12c/0x870
[<c136ac20>] ? proc_clear_tty+0x40/0x70
[<c136ac6e>] ? session_clear_tty+0x1e/0x30
[<c1003530>] ? math_error+0x140/0x140
[<c1003575>] do_device_not_available+0x45/0x70
[<c100d0a8>] ? fpu__copy+0x138/0x1c0
[<c18258e6>] error_code+0x5a/0x60
[<c1003530>] ? math_error+0x140/0x140
[<c100d0a8>] ? fpu__copy+0x138/0x1c0
[<c100c205>] arch_dup_task_struct+0x25/0x30
[<c1048cea>] copy_process.part.51+0xea/0x1480
[<c115a8e5>] ? dput+0x175/0x200
[<c136af70>] ? no_tty+0x30/0x30
[<c1157242>] ? do_vfs_ioctl+0x322/0x540
[<c104a21a>] _do_fork+0xca/0x340
[<c1057b06>] ? SyS_rt_sigaction+0x66/0x90
[<c104a557>] SyS_clone+0x27/0x30
[<c1824a80>] sysenter_do_call+0x12/0x12
The reason is the incorrect assumption in fpu_copy(), that FNSAVE
can be executed from math-emu kernels as well.
Don't try to copy the registers, the soft state will be copied
by fork anyway, so the child task inherits the parent task's
soft math state.
With this fix applied math-emu kernels boot up fine on modern
hardware and the 'no387 nofxsr' boot options.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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On a math-emu bootup the following crash occurs:
Initializing CPU#0
------------[ cut here ]------------
kernel BUG at arch/x86/kernel/traps.c:779!
invalid opcode: 0000 [#1] SMP
[...]
EIP is at do_device_not_available+0xe/0x70
[...]
Call Trace:
[<c18238e6>] error_code+0x5a/0x60
[<c1002bd0>] ? math_error+0x140/0x140
[<c100bbd9>] ? fpu__init_cpu+0x59/0xa0
[<c1012322>] cpu_init+0x202/0x330
[<c104509f>] ? __native_set_fixmap+0x1f/0x30
[<c1b56ab0>] trap_init+0x305/0x346
[<c1b548af>] start_kernel+0x1a5/0x35d
[<c1b542b4>] i386_start_kernel+0x82/0x86
The reason is that in the following commit:
b1276c48e91b ("x86/fpu: Initialize fpregs in fpu__init_cpu_generic()")
I failed to consider math-emu's limitation that it cannot execute the
FNINIT instruction in kernel mode.
The long term fix might be to allow math-emu to execute (certain) kernel
mode FPU instructions, but for now apply the safe (albeit somewhat ugly)
fix: initialize the emulation state explicitly without trapping out to
the FPU emulator.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Commit b253149b843f ("sched/idle/x86: Restore mwait_idle() to fix boot
hangs, to improve power savings and to improve performance") restores
mwait_idle(), but the trace_cpu_idle related calls are missing. This
causes powertop on my old desktop powered by Intel Core2 E6550 to
report zero wakeups and zero events.
Add them back to restore the proper behaviour.
Fixes: b253149b843f ("sched/idle/x86: Restore mwait_idle() to ...")
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Cc: <len.brown@intel.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1440046479-4262-1-git-send-email-jszhang@marvell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen build fix from David Vrabel:
"Fix i386 build with an (uncommon) configuration"
* tag 'for-linus-4.2-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: make CONFIG_XEN depend on CONFIG_X86_LOCAL_APIC
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Since commit feb44f1f7a4ac299d1ab1c3606860e70b9b89d69 (x86/xen:
Provide a "Xen PV" APIC driver to support >255 VCPUs) Xen guests need
a full APIC driver and thus should depend on X86_LOCAL_APIC.
This fixes an i386 build failure with !SMP && !CONFIG_X86_UP_APIC by
disabling Xen support in this configuration.
Users needing Xen support in a non-SMP i386 kernel will need to enable
CONFIG_X86_UP_APIC.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: <stable@vger.kernel.org>
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The conversion of the wakeupgen irqchip to hierarchical irq domains
failed to provide a mechanism to properly set the trigger type of an
interrupt.
The wakeupgen irq chip itself has no mechanism and therefor no
irq_set_type() callback. The code before the conversion relayed the
trigger configuration directly to the underlying GIC.
Restore the correct behaviour by setting the wakeupgen irq_set_type
callback to irq_chip_set_type_parent(). This propagates the
set_trigger() call to the underlying GIC irqchip.
[ tglx: Massaged changelog ]
Fixes: 7136d457f365 ('ARM: omap: convert wakeupgen to stacked domains')
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: <linux@arm.linux.org.uk>
Cc: <nsekhar@ti.com>
Cc: <jason@lakedaemon.net>
Cc: <balbi@ti.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1439554830-19502-5-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Alex Deucher, Mark Rustad and Alexander Holler reported a regression
with the latest v4.2-rc4 kernel, which breaks some SATA controllers.
With multi-MSI capable SATA controllers, only the first port works,
all other ports time out when executing SATA commands.
This happens because the first argument to assign_irq_vector_policy()
is always the base linux irq number of the multi MSI interrupt block,
so all subsequent vector assignments operate on the base linux irq
number, so all MSI irqs are handled as the first irq number. Therefor
the other MSI irqs of a device are never set up correctly and never
fire.
Add the loop iterator to the base irq number so all vectors are
assigned correctly.
Fixes: b5dc8e6c21e7 "x86/irq: Use hierarchical irqdomain to manage CPU interrupt vectors"
Reported-and-tested-by: Alex Deucher <alexdeucher@gmail.com>
Reported-and-tested-by: Mark Rustad <mrustad@gmail.com>
Reported-and-tested-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1439911228-9880-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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U-Boot is often used to boot the kernel on ARM boards, but uImage
is not built by "make all", so we are often inclined to do
"make all uImage" to generate DTBs, modules and uImage in a single
command, but we should notice a pitfall behind it. In fact,
"make all uImage" could generate an invalid uImage if it is run with
the parallel option (-j).
You can reproduce this problem with the following procedure:
[1] First, build "all" and "uImage" separately.
You will get a valid uImage
$ git clean -f -x -d
$ export CROSS_COMPILE=<your-tools-prefix>
$ make -s -j8 ARCH=arm multi_v7_defconfig
$ make -s -j8 ARCH=arm all
$ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 uImage
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
CHK include/generated/timeconst.h
CHK include/generated/bounds.h
CHK include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
CHK include/generated/compile.h
Kernel: arch/arm/boot/Image is ready
Kernel: arch/arm/boot/zImage is ready
UIMAGE arch/arm/boot/uImage
Image Name: Linux-4.2.0-rc5-00156-gdd2384a-d
Created: Sat Aug 8 23:21:35 2015
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 6138648 Bytes = 5994.77 kB = 5.85 MB
Load Address: 80208000
Entry Point: 80208000
Image arch/arm/boot/uImage is ready
$ ls -l arch/arm/boot/*Image
-rwxrwxr-x 1 masahiro masahiro 13766656 Aug 8 23:20 arch/arm/boot/Image
-rw-rw-r-- 1 masahiro masahiro 6138712 Aug 8 23:21 arch/arm/boot/uImage
-rwxrwxr-x 1 masahiro masahiro 6138648 Aug 8 23:20 arch/arm/boot/zImage
[2] Update some source file(s)
$ touch init/main.c
[3] Then, re-build "all" and "uImage" simultaneously.
You will get an invalid uImage at random.
$ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 all uImage
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
CHK include/generated/timeconst.h
CHK include/generated/bounds.h
CHK include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
CC init/main.o
CHK include/generated/compile.h
LD init/built-in.o
LINK vmlinux
LD vmlinux.o
MODPOST vmlinux.o
GEN .version
CHK include/generated/compile.h
UPD include/generated/compile.h
CC init/version.o
LD init/built-in.o
KSYM .tmp_kallsyms1.o
KSYM .tmp_kallsyms2.o
LD vmlinux
SORTEX vmlinux
SYSMAP System.map
OBJCOPY arch/arm/boot/Image
Building modules, stage 2.
Kernel: arch/arm/boot/Image is ready
GZIP arch/arm/boot/compressed/piggy.gzip
AS arch/arm/boot/compressed/piggy.gzip.o
Kernel: arch/arm/boot/Image is ready
LD arch/arm/boot/compressed/vmlinux
GZIP arch/arm/boot/compressed/piggy.gzip
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
UIMAGE arch/arm/boot/uImage
Image Name: Linux-4.2.0-rc5-00156-gdd2384a-d
Created: Sat Aug 8 23:23:14 2015
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 26472 Bytes = 25.85 kB = 0.03 MB
Load Address: 80208000
Entry Point: 80208000
Image arch/arm/boot/uImage is ready
MODPOST 192 modules
AS arch/arm/boot/compressed/piggy.gzip.o
LD arch/arm/boot/compressed/vmlinux
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
$ ls -l arch/arm/boot/*Image
-rwxrwxr-x 1 masahiro masahiro 13766656 Aug 8 23:23 arch/arm/boot/Image
-rw-rw-r-- 1 masahiro masahiro 26536 Aug 8 23:23 arch/arm/boot/uImage
-rwxrwxr-x 1 masahiro masahiro 6138648 Aug 8 23:23 arch/arm/boot/zImage
Please notice the uImage is extremely small when this issue is
encountered. Besides, "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, before and after the uImage log.
The root cause of this is the race condition between zImage and
uImage. Actually, uImage depends on zImage, but the dependency
between the two is only described in arch/arm/boot/Makefile.
Because arch/arm/boot/Makefile is not included from the top-level
Makefile, it cannot know the dependency between zImage and uImage.
Consequently, when we run make with the parallel option, Kbuild
updates vmlinux first, and then two different threads descends into
the arch/arm/boot/Makefile almost at the same time, one for updating
zImage and the other for uImage. While one thread is re-generating
zImage, the other also tries to update zImage before creating uImage
on top of that. zImage is overwritten by the slower thread and then
uImage is created based on the half-written zImage.
This is the reason why "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, and a broken uImage is created.
The same problem could happen on bootpImage.
This commit adds dependencies among Image, zImage, uImage, and
bootpImage to arch/arm/Makefile, which is included from the
top-level Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The mmap semaphore should not be taken when page faults are disabled.
Since pagefault_disable() no longer disables preemption, we now need
to use faulthandler_disabled() in place of in_atomic().
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Matthew Fortune <Matthew.Fortune@imgtec.com> reports:
The genex.S file appears to mix the case of a macro between its definition and
use. A cut down example of this is below. The macro __build_clear_none has
lower case 'build' but ends up being instantiated with upper case BUILD. Can
this be fixed on master. It has been picked up by the LLVM integrated assembler
which is currently case sensitive. We are likely to fix the assembler as well
but the code is currently inconsistent in the kernel.
.macro __build_clear_none
.endm
.macro __BUILD_HANDLER exception handler clear verbose ext
.align 5
.globl handle_\exception; .align 2; .type handle_\exception, @function; .ent
handle_\exception, 0; handle_\exception: .frame $29, 184, $29
.set noat
.globl handle_\exception\ext; .type handle_\exception\ext, @function;
handle_\exception\ext:
__BUILD_clear_\clear
.endm
.macro BUILD_HANDLER exception handler clear verbose
__BUILD_HANDLER \exception \handler \clear \verbose _int
.endm
BUILD_HANDLER ftlb ftlb none silent
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: Matthew Fortune <Matthew.Fortune@imgtec.com>
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This reverts commit:
2c7577a75837 ("sched/x86_64: Don't save flags on context switch")
It was a nice speedup. It's also not quite correct: SYSENTER
enables interrupts too early.
We can re-add this optimization once the SYSENTER code is beaten
into shape, which should happen in 4.3 or 4.4.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org # v3.19
Link: http://lkml.kernel.org/r/85f56651f59f76624e80785a8fd3bdfdd089a818.1439838962.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"A smallish batch of fixes, a little more than expected this late, but
all fixes are contained to their platforms and seem reasonably low
risk:
- a somewhat large SMP fix for ux500 that still seemed warranted to
include here
- OMAP DT fixes for pbias regulator specification that broke due to
some DT reshuffling
- PCIe IRQ routing bugfix for i.MX
- networking fixes for keystone
- runtime PM for OMAP GPMC
- a couple of error path bug fixes for exynos"
* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file
ARM: dts: keystone: fix the clock node for mdio
memory: omap-gpmc: Don't try to save uninitialized GPMC context
ARM: imx6: correct i.MX6 PCIe interrupt routing
ARM: ux500: add an SMP enablement type and move cpu nodes
ARM: dts: dra7: Fix broken pbias device creation
ARM: dts: OMAP5: Fix broken pbias device creation
ARM: dts: OMAP4: Fix broken pbias device creation
ARM: dts: omap243x: Fix broken pbias device creation
ARM: EXYNOS: fix double of_node_put() on error path
ARM: EXYNOS: Fix potentian kfree() of ro memory
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Pull MIPS bugfix from Ralf Baechle:
"Only a single MIPS fix - the math when invoking syscall_trace_enter
was wrong"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Fix seccomp syscall argument for MIPS64
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Merge x86 fixes from Ingo Molnar:
"Two followup fixes related to the previous LDT fix"
Also applied a further FPU emulation fix from Andy Lutomirski to the
branch before actually merging it.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
x86/ldt: Further fix FPU emulation
x86/ldt: Correct FPU emulation access to LDT
x86/ldt: Correct LDT access in single stepping logic
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The previous fix confused a selector with a segment prefix. Fix it.
Compile-tested only.
Cc: stable@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 4809146b86c3 ("x86/ldt: Correct FPU emulation access to LDT")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone into fixes
ARM: Couple of Keysyone MDIO DTS fixes for 4.2-rc6+
These are necessary to get the NIC card working on all Keystone
EVMs. Couple of boards are broken without these two fixes.
* tag 'keystone-dts-late-fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone:
ARM: dts: keystone: Fix the mdio bindings by moving it to soc specific file
ARM: dts: keystone: fix the clock node for mdio
Signed-off-by: Olof Johansson <olof@lixom.net>
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Commit 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)")
fixed indirect system calls on O32 but it also introduced a bug for MIPS64
where it erroneously modified the v0 (syscall) register with the assumption
that the sycall offset hasn't been taken into consideration. This breaks
seccomp on MIPS64 n64 and n32 ABIs. We fix this by replacing the addition
with a move instruction.
Fixes: 4c21b8fd8f14 ("MIPS: seccomp: Handle indirect system calls (o32)")
Cc: <stable@vger.kernel.org> # 3.15+
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10951/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Pull KVM fixes from Paolo Bonzini:
"Just two very small & simple patches"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: Use adjustment in guest cycles when handling MSR_IA32_TSC_ADJUST
KVM: x86: zero IDT limit on entry to SMM
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"Misc fixes: PMU driver corner cases, tooling fixes, and an 'AUX'
(Intel PT) race related core fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/cqm: Do not access cpu_data() from CPU_UP_PREPARE handler
perf/x86/intel: Fix memory leak on hot-plug allocation fail
perf: Fix PERF_EVENT_IOC_PERIOD migration race
perf: Fix double-free of the AUX buffer
perf: Fix fasync handling on inherited events
perf tools: Fix test build error when bindir contains double slash
perf stat: Fix transaction lenght metrics
perf: Fix running time accounting
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Pull ARM fixes from Russell King:
"Another few small ARM fixes, mostly addressing some VDSO issues"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8410/1: VDSO: fix coarse clock monotonicity regression
ARM: 8409/1: Mark ret_fast_syscall as a function
ARM: 8408/1: Fix the secondary_startup function in Big Endian case
ARM: 8405/1: VDSO: fix regression with toolchains lacking ld.bfd executable
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Commit 3f5159a9221f ("x86/asm/entry/32: Update -ENOSYS handling to match
the 64-bit logic") broke the ENOSYS handling for the 32-bit compat case.
The proper error return value was never loaded into %rax, except if
things just happened to go through the audit paths, which ended up
reloading the return value.
This moves the loading or %rax into the normal system call path, just to
make sure the error case triggers it. It's kind of sad, since it adds a
useless instruction to reload the register to the fast path, but it's
not like that single load from the stack is going to be noticeable.
Reported-by: David Drysdale <drysdale@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen bug fixes from David Vrabel:
- revert a fix from 4.2-rc5 that was causing lots of WARNING spam.
- fix a memory leak affecting backends in HVM guests.
- fix PV domU hang with certain configurations.
* tag 'for-linus-4.2-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/xenbus: Don't leak memory when unmapping the ring on HVM backend
Revert "xen/events/fifo: Handle linked events when closing a port"
x86/xen: build "Xen PV" APIC driver for domU as well
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This reverts commits 9a036b93a344 ("x86/signal/64: Remove 'fs' and 'gs'
from sigcontext") and c6f2062935c8 ("x86/signal/64: Fix SS handling for
signals delivered to 64-bit programs").
They were cleanups, but they break dosemu by changing the signal return
behavior (and removing 'fs' and 'gs' from the sigcontext struct - while
not actually changing any behavior - causes build problems).
Reported-and-tested-by: Stas Sergeev <stsp@list.ru>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently mdio bindings are defined in keystone.dtsi and this results
in incorrect unit address for the node on K2E and K2L SoCs. Fix this
by moving them to SoC specific DTS file.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
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Currently the MDIO clock is pointing to clkpa instead of clkcpgmac.
MDIO is part of the ethss and the clock should be clkcpgmac.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux into fixes
The i.MX fixes for 4.2, 3rd round:
- Fix i.MX6 PCIe interrupt routing which gets missed from stacked IRQ
domain conversion. The PCIe wakeup support is currently broken
because of this.
* tag 'imx-fixes-4.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
ARM: imx6: correct i.MX6 PCIe interrupt routing
Signed-off-by: Olof Johansson <olof@lixom.net>
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Two fixes for bugs in Exynos power domain error exit path:
1. kfree() of read-only memory (name of power domain returned
by kstrdup_const()),
2. Doubled of_node_put() leading to invalid ref count for OF node.
* tag 'samsung-mach-fixes-4.2' of https://github.com/krzk/linux:
ARM: EXYNOS: fix double of_node_put() on error path
ARM: EXYNOS: Fix potentian kfree() of ro memory
Signed-off-by: Olof Johansson <olof@lixom.net>
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Tony reports that booting his 144-cpu machine with maxcpus=10 triggers
the following WARN_ON():
[ 21.045727] WARNING: CPU: 8 PID: 647 at arch/x86/kernel/cpu/perf_event_intel_cqm.c:1267 intel_cqm_cpu_prepare+0x75/0x90()
[ 21.045744] CPU: 8 PID: 647 Comm: systemd-udevd Not tainted 4.2.0-rc4 #1
[ 21.045745] Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0066.R00.1506021730 06/02/2015
[ 21.045747] 0000000000000000 0000000082771b09 ffff880856333ba8 ffffffff81669b67
[ 21.045748] 0000000000000000 0000000000000000 ffff880856333be8 ffffffff8107b02a
[ 21.045750] ffff88085b789800 ffff88085f68a020 ffffffff819e2470 000000000000000a
[ 21.045750] Call Trace:
[ 21.045757] [<ffffffff81669b67>] dump_stack+0x45/0x57
[ 21.045759] [<ffffffff8107b02a>] warn_slowpath_common+0x8a/0xc0
[ 21.045761] [<ffffffff8107b15a>] warn_slowpath_null+0x1a/0x20
[ 21.045762] [<ffffffff81036725>] intel_cqm_cpu_prepare+0x75/0x90
[ 21.045764] [<ffffffff81036872>] intel_cqm_cpu_notifier+0x42/0x160
[ 21.045767] [<ffffffff8109a33d>] notifier_call_chain+0x4d/0x80
[ 21.045769] [<ffffffff8109a44e>] __raw_notifier_call_chain+0xe/0x10
[ 21.045770] [<ffffffff8107b538>] _cpu_up+0xe8/0x190
[ 21.045771] [<ffffffff8107b65a>] cpu_up+0x7a/0xa0
[ 21.045774] [<ffffffff8165e920>] cpu_subsys_online+0x40/0x90
[ 21.045777] [<ffffffff81433b37>] device_online+0x67/0x90
[ 21.045778] [<ffffffff81433bea>] online_store+0x8a/0xa0
[ 21.045782] [<ffffffff81430e78>] dev_attr_store+0x18/0x30
[ 21.045785] [<ffffffff8126b6ba>] sysfs_kf_write+0x3a/0x50
[ 21.045786] [<ffffffff8126ad40>] kernfs_fop_write+0x120/0x170
[ 21.045789] [<ffffffff811f0b77>] __vfs_write+0x37/0x100
[ 21.045791] [<ffffffff811f38b8>] ? __sb_start_write+0x58/0x110
[ 21.045795] [<ffffffff81296d2d>] ? security_file_permission+0x3d/0xc0
[ 21.045796] [<ffffffff811f1279>] vfs_write+0xa9/0x190
[ 21.045797] [<ffffffff811f2075>] SyS_write+0x55/0xc0
[ 21.045800] [<ffffffff81067300>] ? do_page_fault+0x30/0x80
[ 21.045804] [<ffffffff816709ae>] entry_SYSCALL_64_fastpath+0x12/0x71
[ 21.045805] ---[ end trace fe228b836d8af405 ]---
The root cause is that CPU_UP_PREPARE is completely the wrong notifier
action from which to access cpu_data(), because smp_store_cpu_info()
won't have been executed by the target CPU at that point, which in turn
means that ->x86_cache_max_rmid and ->x86_cache_occ_scale haven't been
filled out.
Instead let's invoke our handler from CPU_STARTING and rename it
appropriately.
Reported-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Link: http://lkml.kernel.org/r/1438863163-14083-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We fail to free the shared_regs allocation if the constraint_list
allocation fails.
Cure this and be more consistent in NULL-ing the pointers after free.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
Few trivial omap MMC regression fixes for card voltages where
the syscon areas for PBIAS regulator were missing "simple-bus"
that prevents probing of the children in the mapped region.
This probably was not noticed earlier as the bootloader has
already configured the regulator for the card in the slot.
* tag 'omap-for-v4.2/fixes-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
ARM: dts: dra7: Fix broken pbias device creation
ARM: dts: OMAP5: Fix broken pbias device creation
ARM: dts: OMAP4: Fix broken pbias device creation
ARM: dts: omap243x: Fix broken pbias device creation
Signed-off-by: Olof Johansson <olof@lixom.net>
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Since 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the
real timekeeper last") it has become possible on ARM to:
- Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp
via syscall.
- Subsequently obtain a timestamp for the same clock ID via VDSO which
predates the first timestamp (by one jiffy).
This is because ARM's update_vsyscall is deriving the coarse time
using the __current_kernel_time interface, when it should really be
using the timekeeper object provided to it by the timekeeping core.
It happened to work before only because __current_kernel_time would
access the same timekeeper object which had been passed to
update_vsyscall. This is no longer the case.
Cc: stable@vger.kernel.org
Fixes: 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last")
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Since 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the
real timekeeper last") it has become possible on arm64 to:
- Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp
via syscall.
- Subsequently obtain a timestamp for the same clock ID via VDSO which
predates the first timestamp (by one jiffy).
This is because arm64's update_vsyscall is deriving the coarse time
using the __current_kernel_time interface, when it should really be
using the timekeeper object provided to it by the timekeeping core.
It happened to work before only because __current_kernel_time would
access the same timekeeper object which had been passed to
update_vsyscall. This is no longer the case.
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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It turns out that a PV domU also requires the "Xen PV" APIC
driver. Otherwise, the flat driver is used and we get stuck in busy
loops that never exit, such as in this stack trace:
(gdb) target remote localhost:9999
Remote debugging using localhost:9999
__xapic_wait_icr_idle () at ./arch/x86/include/asm/ipi.h:56
56 while (native_apic_mem_read(APIC_ICR) & APIC_ICR_BUSY)
(gdb) bt
#0 __xapic_wait_icr_idle () at ./arch/x86/include/asm/ipi.h:56
#1 __default_send_IPI_shortcut (shortcut=<optimized out>,
dest=<optimized out>, vector=<optimized out>) at
./arch/x86/include/asm/ipi.h:75
#2 apic_send_IPI_self (vector=246) at arch/x86/kernel/apic/probe_64.c:54
#3 0xffffffff81011336 in arch_irq_work_raise () at
arch/x86/kernel/irq_work.c:47
#4 0xffffffff8114990c in irq_work_queue (work=0xffff88000fc0e400) at
kernel/irq_work.c:100
#5 0xffffffff8110c29d in wake_up_klogd () at kernel/printk/printk.c:2633
#6 0xffffffff8110ca60 in vprintk_emit (facility=0, level=<optimized
out>, dict=0x0 <irq_stack_union>, dictlen=<optimized out>,
fmt=<optimized out>, args=<optimized out>)
at kernel/printk/printk.c:1778
#7 0xffffffff816010c8 in printk (fmt=<optimized out>) at
kernel/printk/printk.c:1868
#8 0xffffffffc00013ea in ?? ()
#9 0x0000000000000000 in ?? ()
Mailing-list-thread: https://lkml.org/lkml/2015/8/4/755
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
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Pull MIPS fixes from Ralf Baechle:
"Another round of MIPS fixes for 4.2. No area does particularly stand
out but we have a two unpleasant ones:
- Kernel ptes are marked with a global bit which allows the kernel to
share kernel TLB entries between all processes. For this to work
both entries of an adjacent even/odd pte pair need to have the
global bit set. There has been a subtle race in setting the other
entry's global bit since ~ 2000 but it take particularly
pathological workloads that essentially do mostly vmalloc/vfree to
trigger this.
This pull request fixes the 64-bit case but leaves the case of 32
bit CPUs with 64 bit ptes unsolved for now. The unfixed cases
affect hardware that is not available in the field yet.
- Instruction emulation requires loading instructions from user space
but the current fast but simplistic approach will fail on pages
that are PROT_EXEC but !PROT_READ. For this reason we temporarily
do not permit this permission and will map pages with PROT_EXEC |
PROT_READ.
The remainder of this pull request is more or less across the field
and the short log explains them well"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Make set_pte() SMP safe.
MIPS: Replace add and sub instructions in relocate_kernel.S with addiu
MIPS: Flush RPS on kernel entry with EVA
Revert "MIPS: BCM63xx: Provide a plat_post_dma_flush hook"
MIPS: BMIPS: Delete unused Kconfig symbol
MIPS: Export get_c0_perfcount_int()
MIPS: show_stack: Fix stack trace with EVA
MIPS: do_mcheck: Fix kernel code dump with EVA
MIPS: SMP: Don't increment irq_count multiple times for call function IPIs
MIPS: Partially disable RIXI support.
MIPS: Handle page faults of executable but unreadable pages correctly.
MIPS: Malta: Don't reinitialise RTC
MIPS: unaligned: Fix build error on big endian R6 kernels
MIPS: Fix sched_getaffinity with MT FPAFF enabled
MIPS: Fix build with CONFIG_OF=y for non OF-enabled targets
CPUFREQ: Loongson2: Fix broken build due to incorrect include.
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Commit 37868fe113ff ("x86/ldt: Make modify_ldt synchronous")
introduced a new struct ldt_struct anchored at mm->context.ldt.
Adapt the x86 fpu emulation code to use that new structure.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: <stable@vger.kernel.org> # On top of: 37868fe113ff: x86/ldt: Make modify_ldt synchronous
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: billm@melbpc.org.au
Link: http://lkml.kernel.org/r/1438883674-1240-1-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Commit 37868fe113ff ("x86/ldt: Make modify_ldt synchronous")
introduced a new struct ldt_struct anchored at mm->context.ldt.
convert_ip_to_linear() was changed to reflect this, but indexing
into the ldt has to be changed as the pointer is no longer void *.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: <stable@vger.kernel.org> # On top of: 37868fe113ff: x86/ldt: Make modify_ldt synchronous
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1438848278-12906-1-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC fixes from Vineet Gupta:
"Here's a late pull request for accumulated ARC fixes which came out of
extended testing of the new ARCv2 port with LTP etc. llock/scond
livelock workaround has been reviewed by PeterZ. The changes look a
lot but I've crafted them into finer grained patches for better
tracking later.
I have some more fixes (ARC Futex backend) ready to go but those will
have to wait for tglx to return from vacation.
Summary:
- Enable a reduced config of HS38 (w/o div-rem, ll64...)
- Add software workaround for LLOCK/SCOND livelock
- Fallout of a recent pt_regs update"
* tag 'arc-v4.2-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff
ARC: Make pt_regs regs unsigned
ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle
ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff
ARC: LLOCK/SCOND based rwlock
ARC: LLOCK/SCOND based spin_lock
ARC: refactor atomic inline asm operands with symbolic names
Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock"
ARCv2: [axs103_smp] Reduce clk for Quad FPGA configs
ARCv2: Fix the peripheral address space detection
ARCv2: allow selection of page size for MMUv4
ARCv2: lib: memset: Don't assume 64-bit load/stores
ARCv2: lib: memcpy: Missing PREFETCHW
ARCv2: add knob for DIV_REV in Kconfig
ARC/time: Migrate to new 'set-state' interface
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some USB and PHY fixes for 4.2-rc6 that resolve some reported
issues.
All of these have been in the linux-next tree for a while, full
details on the patches are in the shortlog below"
* tag 'usb-4.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
ARM: dts: dra7: Add syscon-pllreset syscon to SATA PHY
drivers/usb: Delete XHCI command timer if necessary
xhci: fix off by one error in TRB DMA address boundary check
usb: udc: core: add device_del() call to error pathway
phy: ti-pipe3: i783 workaround for SATA lockup after dpll unlock/relock
phy-sun4i-usb: Add missing EXPORT_SYMBOL_GPL for sun4i_usb_phy_set_squelch_detect
USB: sierra: add 1199:68AB device ID
usb: gadget: f_printer: actually limit the number of instances
usb: gadget: f_hid: actually limit the number of instances
usb: gadget: f_uac2: fix calculation of uac2->p_interval
usb: gadget: bdc: fix a driver crash on disconnect
usb: chipidea: ehci_init_driver is intended to call one time
USB: qcserial: Add support for Dell Wireless 5809e 4G Modem
USB: qcserial/option: make AT URCs work for Sierra Wireless MC7305/MC7355
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ret_fast_syscall runs when user space makes a syscall. However it
needs to be marked as such so the ELF information is correct. Before
it was:
101: 8000f300 0 NOTYPE LOCAL DEFAULT 2 ret_fast_syscall
But with this change it correctly shows as:
101: 8000f300 96 FUNC LOCAL DEFAULT 2 ret_fast_syscall
I see this function when using perf to unwind call stacks from kernel
space to user space. Without this change I would need to add some
special case logic when using the vmlinux ELF information.
Signed-off-by: Drew Richardson <drew.richardson@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Since the commit "b2c3e38a5471 ARM: redo TTBR setup code for LPAE",
the setup code had been reworked. As a result the secondary CPUs
failed to come online in Big Endian.
As explained by Russell, the new code expected the value in r4/r5 to
be the least significant 32bits in r4 and the most significant 32bits
in r5. However, in the secondary code, we load this using ldrd, which
on BE reverses that.
This patch swap r4/r5 after the ldrd. It is done using the xor
instructions in order to not use a temporary register.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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When kvm_set_msr_common() handles a guest's write to
MSR_IA32_TSC_ADJUST, it will calcuate an adjustment based on the data
written by guest and then use it to adjust TSC offset by calling a
call-back adjust_tsc_offset(). The 3rd parameter of adjust_tsc_offset()
indicates whether the adjustment is in host TSC cycles or in guest TSC
cycles. If SVM TSC scaling is enabled, adjust_tsc_offset()
[i.e. svm_adjust_tsc_offset()] will first scale the adjustment;
otherwise, it will just use the unscaled one. As the MSR write here
comes from the guest, the adjustment is in guest TSC cycles. However,
the current kvm_set_msr_common() uses it as a value in host TSC
cycles (by using true as the 3rd parameter of adjust_tsc_offset()),
which can result in an incorrect adjustment of TSC offset if SVM TSC
scaling is enabled. This patch fixes this problem.
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Cc: stable@vger.linux.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The recent BlackHat 2015 presentation "The Memory Sinkhole"
mentions that the IDT limit is zeroed on entry to SMM.
This is not documented, and must have changed some time after 2010
(see http://www.ssi.gouv.fr/uploads/IMG/pdf/IT_Defense_2010_final.pdf).
KVM was not doing it, but the fix is easy.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The increment of delay counter was 2 instructions:
Arithmatic Shfit Left (ASL) + set to 1 on overflow
This can be done in 1 using ROtate Left (ROL)
Suggested-by: Nigel Topham <ntopham@synopsys.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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Pull sparc fix from David Miller:
"FPU register corruption bug fix"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sparc64: Fix userspace FPU register corruptions.
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If we have a series of events from userpsace, with %fprs=FPRS_FEF,
like follows:
ETRAP
ETRAP
VIS_ENTRY(fprs=0x4)
VIS_EXIT
RTRAP (kernel FPU restore with fpu_saved=0x4)
RTRAP
We will not restore the user registers that were clobbered by the FPU
using kernel code in the inner-most trap.
Traps allocate FPU save slots in the thread struct, and FPU using
sequences save the "dirty" FPU registers only.
This works at the initial trap level because all of the registers
get recorded into the top-level FPU save area, and we'll return
to userspace with the FPU disabled so that any FPU use by the user
will take an FPU disabled trap wherein we'll load the registers
back up properly.
But this is not how trap returns from kernel to kernel operate.
The simplest fix for this bug is to always save all FPU register state
for anything other than the top-most FPU save area.
Getting rid of the optimized inner-slot FPU saving code ends up
making VISEntryHalf degenerate into plain VISEntry.
Longer term we need to do something smarter to reinstate the partial
save optimizations. Perhaps the fundament error is having trap entry
and exit allocate FPU save slots and restore register state. Instead,
the VISEntry et al. calls should be doing that work.
This bug is about two decades old.
Reported-by: James Y Knight <jyknight@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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