Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto' constructs, as outlined here: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 Implement a workaround suggested by Jakub Jelinek. Reported-and-tested-by: Fengguang Wu <fengguang.wu@intel.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Suggested-by: Jakub Jelinek <jakub@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
We've been keeping that field in thread_struct for a while, it contains the "limit" of the current stack pointer and is meant to be used for detecting stack overflows. It has a few problems however: - First, it was never actually *used* on 64-bit. Set and updated but not actually exploited - When switching stack to/from irq and softirq stacks, it's update is racy unless we hard disable interrupts, which is costly. This is fine on 32-bit as we don't soft-disable there but not on 64-bit. Thus rather than fixing 2 in order to implement 1 in some hypothetical future, let's remove the code completely from 64-bit. In order to avoid a clutter of ifdef's, we remove the updates from C code completely during interrupt stack switching, and instead maintain it from the asm helper that is used to do the stack switching in the first place. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Nowadays, irq_exit() calls __do_softirq() pretty much directly instead of calling do_softirq() which switches to the decicated softirq stack. This has lead to observed stack overflows on powerpc since we call irq_enter() and irq_exit() outside of the scope that switches to the irq stack. This fixes it by moving the stack switching up a level, making irq_enter() and irq_exit() run off the irq stack. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull IOMMU Updates from Joerg Roedel:
"This round the updates contain:
- A new driver for the Freescale PAMU IOMMU from Varun Sethi.
This driver has cooked for a while and required changes to the
IOMMU-API and infrastructure that were already merged before.
- Updates for the ARM-SMMU driver from Will Deacon
- Various fixes, the most important one is probably a fix from Alex
Williamson for a memory leak in the VT-d page-table freeing code
In summary not all that much. The biggest part in the diffstat is the
new PAMU driver"
* tag 'iommu-updates-v3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
intel-iommu: Fix leaks in pagetable freeing
iommu/amd: Fix resource leak in iommu_init_device()
iommu/amd: Clean up unnecessary MSI/MSI-X capability find
iommu/arm-smmu: Simplify VMID and ASID allocation
iommu/arm-smmu: Don't use VMIDs for stage-1 translations
iommu/arm-smmu: Tighten up global fault reporting
iommu/arm-smmu: Remove broken big-endian check
iommu/fsl: Remove unnecessary 'fsl-pamu' prefixes
iommu/fsl: Fix whitespace problems noticed by git-am
iommu/fsl: Freescale PAMU driver and iommu implementation.
iommu/fsl: Add additional iommu attributes required by the PAMU driver.
powerpc: Add iommu domain pointer to device archdata
iommu/exynos: Remove dead code (set_prefbuf)
Pull ARM SoC platform changes from Olof Johansson:
"This branch contains mostly additions and changes to platform
enablement and SoC-level drivers. Since there's sometimes a
dependency on device-tree changes, there's also a fair amount of
those in this branch.
Pieces worth mentioning are:
- Mbus driver for Marvell platforms, allowing kernel configuration
and resource allocation of on-chip peripherals.
- Enablement of the mbus infrastructure from Marvell PCI-e drivers.
- Preparation of MSI support for Marvell platforms.
- Addition of new PCI-e host controller driver for Tegra platforms
- Some churn caused by sharing of macro names between i.MX 6Q and 6DL
platforms in the device tree sources and header files.
- Various suspend/PM updates for Tegra, including LP1 support.
- Versatile Express support for MCPM, part of big little support.
- Allwinner platform support for A20 and A31 SoCs (dual and quad
Cortex-A7)
- OMAP2+ support for DRA7, a new Cortex-A15-based SoC.
The code that touches other architectures are patches moving MSI
arch-specific functions over to weak symbols and removal of
ARCH_SUPPORTS_MSI, acked by PCI maintainers"
* tag 'soc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (266 commits)
tegra-cpuidle: provide stub when !CONFIG_CPU_IDLE
PCI: tegra: replace devm_request_and_ioremap by devm_ioremap_resource
ARM: tegra: Drop ARCH_SUPPORTS_MSI and sort list
ARM: dts: vf610-twr: enable i2c0 device
ARM: dts: i.MX51: Add one more I2C2 pinmux entry
ARM: dts: i.MX51: Move pins configuration under "iomuxc" label
ARM: dtsi: imx6qdl-sabresd: Add USB OTG vbus pin to pinctrl_hog
ARM: dtsi: imx6qdl-sabresd: Add USB host 1 VBUS regulator
ARM: dts: imx27-phytec-phycore-som: Enable AUDMUX
ARM: dts: i.MX27: Disable AUDMUX in the template
ARM: dts: wandboard: Add support for SDIO bcm4329
ARM: i.MX5 clocks: Remove optional clock setup (CKIH1) from i.MX51 template
ARM: dts: imx53-qsb: Make USBH1 functional
ARM i.MX6Q: dts: Enable I2C1 with EEPROM and PMIC on Phytec phyFLEX-i.MX6 Ouad module
ARM i.MX6Q: dts: Enable SPI NOR flash on Phytec phyFLEX-i.MX6 Ouad module
ARM: dts: imx6qdl-sabresd: Add touchscreen support
ARM: imx: add ocram clock for imx53
ARM: dts: imx: ocram size is different between imx6q and imx6dl
ARM: dts: imx27-phytec-phycore-som: Fix regulator settings
ARM: dts: i.MX27: Remove clock name from CPU node
...
Pull powerpc updates from Ben Herrenschmidt:
"Here's the powerpc batch for this merge window. Some of the
highlights are:
- A bunch of endian fixes ! We don't have full LE support yet in that
release but this contains a lot of fixes all over arch/powerpc to
use the proper accessors, call the firmware with the right endian
mode, etc...
- A few updates to our "powernv" platform (non-virtualized, the one
to run KVM on), among other, support for bridging the P8 LPC bus
for UARTs, support and some EEH fixes.
- Some mpc51xx clock API cleanups in preparation for a clock API
overhaul
- A pile of cleanups of our old math emulation code, including better
support for using it to emulate optional FP instructions on
embedded chips that otherwise have a HW FPU.
- Some infrastructure in selftest, for powerpc now, but could be
generalized, initially used by some tests for our perf instruction
counting code.
- A pile of fixes for hotplug on pseries (that was seriously
bitrotting)
- The usual slew of freescale embedded updates, new boards, 64-bit
hiberation support, e6500 core PMU support, etc..."
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits)
powerpc: Correct FSCR bit definitions
powerpc/xmon: Fix printing of set of CPUs in xmon
powerpc/pseries: Move lparcfg.c to platforms/pseries
powerpc/powernv: Return secondary CPUs to firmware on kexec
powerpc/btext: Fix CONFIG_PPC_EARLY_DEBUG_BOOTX on ppc32
powerpc: Cleanup handling of the DSCR bit in the FSCR register
powerpc/pseries: Child nodes are not detached by dlpar_detach_node
powerpc/pseries: Add mising of_node_put in delete_dt_node
powerpc/pseries: Make dlpar_configure_connector parent node aware
powerpc/pseries: Do all node initialization in dlpar_parse_cc_node
powerpc/pseries: Fix parsing of initial node path in update_dt_node
powerpc/pseries: Pack update_props_workarea to map correctly to rtas buffer header
powerpc/pseries: Fix over writing of rtas return code in update_dt_node
powerpc/pseries: Fix creation of loop in device node property list
powerpc: Skip emulating & leave interrupts off for kernel program checks
powerpc: Add more exception trampolines for hypervisor exceptions
powerpc: Fix location and rename exception trampolines
powerpc: Add more trap names to xmon
powerpc/pseries: Add a warning in the case of cross-cpu VPA registration
powerpc: Update the 00-Index in Documentation/powerpc
...
Commit 74e400cee6 ("powerpc: Rework setting up H/FSCR bit definitions")
ended up with incorrect bit numbers for FSCR_PM_LG and FSCR_BHRB_LG.
This fixes them.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
From Anatolij: << There are cleanups for some mpc5121 specific drivers and DTS files in preparation to switch mpc5121 clock support to a clock driver based on common clock framework. Additionally Sebastian fixed the mpc52xx PIC driver so that it builds when using older gcc versions. >>
Pull KVM updates from Gleb Natapov: "The highlights of the release are nested EPT and pv-ticketlocks support (hypervisor part, guest part, which is most of the code, goes through tip tree). Apart of that there are many fixes for all arches" Fix up semantic conflicts as discussed in the pull request thread.. * 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (88 commits) ARM: KVM: Add newlines to panic strings ARM: KVM: Work around older compiler bug ARM: KVM: Simplify tracepoint text ARM: KVM: Fix kvm_set_pte assignment ARM: KVM: vgic: Bump VGIC_NR_IRQS to 256 ARM: KVM: Bugfix: vgic_bytemap_get_reg per cpu regs ARM: KVM: vgic: fix GICD_ICFGRn access ARM: KVM: vgic: simplify vgic_get_target_reg KVM: MMU: remove unused parameter KVM: PPC: Book3S PR: Rework kvmppc_mmu_book3s_64_xlate() KVM: PPC: Book3S PR: Make instruction fetch fallback work for system calls KVM: PPC: Book3S PR: Don't corrupt guest state when kernel uses VMX KVM: x86: update masterclock when kvmclock_offset is calculated (v2) KVM: PPC: Book3S: Fix compile error in XICS emulation KVM: PPC: Book3S PR: return appropriate error when allocation fails arch: powerpc: kvm: add signed type cast for comparation KVM: x86: add comments where MMIO does not return to the emulator KVM: vmx: count exits to userspace during invalid guest emulation KVM: rename __kvm_io_bus_sort_cmp to kvm_io_bus_cmp kvm: optimize away THP checks in kvm_is_mmio_pfn() ...