user/sven/linux.git/arch, branch v3.10.85

MIPS: KVM: Do not sign extend on unsigned MMIO load

2015-08-03T16:29:47Z

commit ed9244e6c534612d2b5ae47feab2f55a0d4b4ced upstream. Fix possible unintended sign extension in unsigned MMIO loads by casting to uint16_t in the case of mmio_needed != 2. Signed-off-by: Nicholas Mc Guire Reviewed-by: James Hogan Tested-by: James Hogan Cc: Gleb Natapov Cc: Paolo Bonzini Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9985/ Signed-off-by: Ralf Baechle Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

arm64: vdso: work-around broken ELF toolchains in Makefile

2015-08-03T16:29:41Z

commit 6f1a6ae87c0c60d7c462ef8fd071f291aa7a9abb upstream. When building the kernel with a bare-metal (ELF) toolchain, the -shared option may not be passed down to collect2, resulting in silent corruption of the vDSO image (in particular, the DYNAMIC section is omitted). The effect of this corruption is that the dynamic linker fails to find the vDSO symbols and libc is instead used for the syscalls that we intended to optimise (e.g. gettimeofday). Functionally, there is no issue as the sigreturn trampoline is still intact and located by the kernel. This patch fixes the problem by explicitly passing -shared to the linker when building the vDSO. Reported-by: Szabolcs Nagy Reported-by: James Greenlaigh Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: mm: Fix freeing of the wrong memmap entries with !SPARSEMEM_VMEMMAP

2015-08-03T16:29:41Z

commit b9bcc919931611498e856eae9bf66337330d04cc upstream. The memmap freeing code in free_unused_memmap() computes the end of each memblock by adding the memblock size onto the base. However, if SPARSEMEM is enabled then the value (start) used for the base may already have been rounded downwards to work out which memmap entries to free after the previous memblock. This may cause memmap entries that are in use to get freed. In general, you're not likely to hit this problem unless there are at least 2 memblocks and one of them is not aligned to a sparsemem section boundary. Note that carve-outs can increase the number of memblocks by splitting the regions listed in the device tree. This problem doesn't occur with SPARSEMEM_VMEMMAP, because the vmemmap code deals with freeing the unused regions of the memmap instead of requiring the arch code to do it. This patch gets the memblock base out of the memblock directly when computing the block end address to ensure the correct value is used. Signed-off-by: Dave Martin Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

arm64: Do not attempt to use init_mm in reset_context()

2015-08-03T16:29:41Z

commit 565630d503ef24e44c252bed55571b3a0d68455f upstream. After secondary CPU boot or hotplug, the active_mm of the idle thread is &init_mm. The init_mm.pgd (swapper_pg_dir) is only meant for TTBR1_EL1 and must not be set in TTBR0_EL1. Since when active_mm == &init_mm the TTBR0_EL1 is already set to the reserved value, there is no need to perform any context reset. Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

ARC: add compiler barrier to LLSC based cmpxchg

2015-08-03T16:29:41Z

commit d57f727264f1425a94689bafc7e99e502cb135b5 upstream. When auditing cmpxchg call sites, Chuck noted that gcc was optimizing away some of the desired LDs. | do { | new = old = *ipi_data_ptr; | new |= 1U << msg; | } while (cmpxchg(ipi_data_ptr, old, new) != old); was generating to below | 8015cef8: ld r2,[r4,0] <-- First LD | 8015cefc: bset r1,r2,r1 | | 8015cf00: llock r3,[r4] <-- atomic op | 8015cf04: brne r3,r2,8015cf10 | 8015cf08: scond r1,[r4] | 8015cf0c: bnz 8015cf00 | | 8015cf10: brne r3,r2,8015cf00 <-- Branch doesn't go to orig LD Although this was fixed by adding a ACCESS_ONCE in this call site, it seems safer (for now at least) to add compiler barrier to LLSC based cmpxchg Reported-by: Chuck Jordan Acked-by: Peter Zijlstra (Intel) Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman

KVM: x86: make vapics_in_nmi_mode atomic

2015-07-10T17:40:22Z

commit 42720138b06301cc8a7ee8a495a6d021c4b6a9bc upstream. Writes were a bit racy, but hard to turn into a bug at the same time. (Particularly because modern Linux doesn't use this feature anymore.) Signed-off-by: Radim Krčmář [Actually the next patch makes it much, much easier to trigger the race so I'm including this one for stable@ as well. - Paolo] Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

MIPS: Fix KVM guest fixmap address

2015-07-10T17:40:22Z

commit 8e748c8d09a9314eedb5c6367d9acfaacddcdc88 upstream. KVM guest kernels for trap & emulate run in user mode, with a modified set of kernel memory segments. However the fixmap address is still in the normal KSeg3 region at 0xfffe0000 regardless, causing problems when cache alias handling makes use of them when handling copy on write. Therefore define FIXADDR_TOP as 0x7ffe0000 in the guest kernel mapped region when CONFIG_KVM_GUEST is defined. Signed-off-by: James Hogan Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9887/ Signed-off-by: Ralf Baechle Signed-off-by: Greg Kroah-Hartman

x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A

2015-07-10T17:40:22Z

commit 1dace0116d0b05c967d94644fc4dfe96be2ecd3d upstream. The Foxconn K8M890-8237A has two PCI host bridges, and we can't assign resources correctly without the information from _CRS that tells us which address ranges are claimed by which bridge. In the bugs mentioned below, we incorrectly assign a sound card address (this example is from 1033299): bus: 00 index 2 [mem 0x80000000-0xfcffffffff] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-7f]) pci_root PNP0A08:00: host bridge window [mem 0x80000000-0xbfefffff] (ignored) pci_root PNP0A08:00: host bridge window [mem 0xc0000000-0xdfffffff] (ignored) pci_root PNP0A08:00: host bridge window [mem 0xf0000000-0xfebfffff] (ignored) ACPI: PCI Root Bridge [PCI1] (domain 0000 [bus 80-ff]) pci_root PNP0A08:01: host bridge window [mem 0xbff00000-0xbfffffff] (ignored) pci 0000:80:01.0: [1106:3288] type 0 class 0x000403 pci 0000:80:01.0: reg 10: [mem 0xbfffc000-0xbfffffff 64bit] pci 0000:80:01.0: address space collision: [mem 0xbfffc000-0xbfffffff 64bit] conflicts with PCI Bus #00 [mem 0x80000000-0xfcffffffff] pci 0000:80:01.0: BAR 0: assigned [mem 0xfd00000000-0xfd00003fff 64bit] BUG: unable to handle kernel paging request at ffffc90000378000 IP: [] azx_create+0x37c/0x822 [snd_hda_intel] We assigned 0xfd_0000_0000, but that is not in any of the host bridge windows, and the sound card doesn't work. Turn on pci=use_crs automatically for this system. Link: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/931368 Link: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1033299 Signed-off-by: Bjorn Helgaas Signed-off-by: Greg Kroah-Hartman

powerpc/perf: Fix book3s kernel to userspace backtraces

2015-07-10T17:40:22Z

commit 72e349f1124a114435e599479c9b8d14bfd1ebcd upstream. When we take a PMU exception or a software event we call perf_read_regs(). This overloads regs->result with a boolean that describes if we should use the sampled instruction address register (SIAR) or the regs. If the exception is in kernel, we start with the kernel regs and backtrace through the kernel stack. At this point we switch to the userspace regs and backtrace the user stack with perf_callchain_user(). Unfortunately these regs have not got the perf_read_regs() treatment, so regs->result could be anything. If it is non zero, perf_instruction_pointer() decides to use the SIAR, and we get issues like this: 0.11% qemu-system-ppc [kernel.kallsyms] [k] _raw_spin_lock_irqsave | ---_raw_spin_lock_irqsave | |--52.35%-- 0 | | | |--46.39%-- __hrtimer_start_range_ns | | kvmppc_run_core | | kvmppc_vcpu_run_hv | | kvmppc_vcpu_run | | kvm_arch_vcpu_ioctl_run | | kvm_vcpu_ioctl | | do_vfs_ioctl | | sys_ioctl | | system_call | | | | | |--67.08%-- _raw_spin_lock_irqsave <--- hi mum | | | | | | | --100.00%-- 0x7e714 | | | 0x7e714 Notice the bogus _raw_spin_irqsave when we transition from kernel (system_call) to userspace (0x7e714). We inserted what was in the SIAR. Add a check in regs_use_siar() to check that the regs in question are from a PMU exception. With this fix the backtrace makes sense: 0.47% qemu-system-ppc [kernel.vmlinux] [k] _raw_spin_lock_irqsave | ---_raw_spin_lock_irqsave | |--53.83%-- 0 | | | |--44.73%-- hrtimer_try_to_cancel | | kvmppc_start_thread | | kvmppc_run_core | | kvmppc_vcpu_run_hv | | kvmppc_vcpu_run | | kvm_arch_vcpu_ioctl_run | | kvm_vcpu_ioctl | | do_vfs_ioctl | | sys_ioctl | | system_call | | __ioctl | | 0x7e714 | | 0x7e714 Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

arm: KVM: force execution of HCPTR access on VM exit

2015-07-10T17:40:21Z

commit 85e84ba31039595995dae80b277378213602891b upstream. On VM entry, we disable access to the VFP registers in order to perform a lazy save/restore of these registers. On VM exit, we restore access, test if we did enable them before, and save/restore the guest/host registers if necessary. In this sequence, the FPEXC register is always accessed, irrespective of the trapping configuration. If the guest didn't touch the VFP registers, then the HCPTR access has now enabled such access, but we're missing a barrier to ensure architectural execution of the new HCPTR configuration. If the HCPTR access has been delayed/reordered, the subsequent access to FPEXC will cause a trap, which we aren't prepared to handle at all. The same condition exists when trapping to enable VFP for the guest. The fix is to introduce a barrier after enabling VFP access. In the vmexit case, it can be relaxed to only takes place if the guest hasn't accessed its view of the VFP registers, making the access to FPEXC safe. The set_hcptr macro is modified to deal with both vmenter/vmexit and vmtrap operations, and now takes an optional label that is branched to when the guest hasn't touched the VFP registers. Reported-by: Vikram Sethi Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman