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2016-08-27KEYS: 64-bit MIPS needs to use compat_sys_keyctl for 32-bit userspaceDavid Howells
commit 20f06ed9f61a185c6dabd662c310bed6189470df upstream. MIPS64 needs to use compat_sys_keyctl for 32-bit userspace rather than calling sys_keyctl. The latter will work in a lot of cases, thereby hiding the issue. Reported-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: David Howells <dhowells@redhat.com> cc: stable@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: keyrings@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13832/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: KVM: Fix modular KVM under QEMUJames Hogan
commit 797179bc4fe06c89e47a9f36f886f68640b423f8 upstream. Copy __kvm_mips_vcpu_run() into unmapped memory, so that we can never get a TLB refill exception in it when KVM is built as a module. This was observed to happen with the host MIPS kernel running under QEMU, due to a not entirely transparent optimisation in the QEMU TLB handling where TLB entries replaced with TLBWR are copied to a separate part of the TLB array. Code in those pages continue to be executable, but those mappings persist only until the next ASID switch, even if they are marked global. An ASID switch happens in __kvm_mips_vcpu_run() at exception level after switching to the guest exception base. Subsequent TLB mapped kernel instructions just prior to switching to the guest trigger a TLB refill exception, which enters the guest exception handlers without updating EPC. This appears as a guest triggered TLB refill on a host kernel mapped (host KSeg2) address, which is not handled correctly as user (guest) mode accesses to kernel (host) segments always generate address error exceptions. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [james.hogan@imgtec.com: backported for stable 3.14] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: Fix 64k page support for 32 bit kernels.Ralf Baechle
commit d7de413475f443957a0c1d256e405d19b3a2cb22 upstream. TASK_SIZE was defined as 0x7fff8000UL which for 64k pages is not a multiple of the page size. Somewhere further down the math fails such that executing an ELF binary fails. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Tested-by: Joshua Henderson <joshua.henderson@microchip.com> Cc: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: ath79: make bootconsole wait for both THRE and TEMTMatthias Schiffer
commit f5b556c94c8490d42fea79d7b4ae0ecbc291e69d upstream. This makes the ath79 bootconsole behave the same way as the generic 8250 bootconsole. Also waiting for TEMT (transmit buffer is empty) instead of just THRE (transmit buffer is not full) ensures that all characters have been transmitted before the real serial driver starts reconfiguring the serial controller (which would sometimes result in garbage being transmitted.) This change does not cause a visible performance loss. In addition, this seems to fix a hang observed in certain configurations on many AR7xxx/AR9xxx SoCs during autoconfig of the real serial driver. A more complete follow-up patch will disable 8250 autoconfig for ath79 altogether (the serial controller is detected as a 16550A, which is not fully compatible with the ath79 serial, and the autoconfig may lead to undefined behavior on ath79.) Cc: <stable@vger.kernel.org> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: Fix siginfo.h to use strict posix typesJames Hogan
commit 5daebc477da4dfeb31ae193d83084def58fd2697 upstream. Commit 85efde6f4e0d ("make exported headers use strict posix types") changed the asm-generic siginfo.h to use the __kernel_* types, and commit 3a471cbc081b ("remove __KERNEL_STRICT_NAMES") make the internal types accessible only to the kernel, but the MIPS implementation hasn't been updated to match. Switch to proper types now so that the exported asm/siginfo.h won't produce quite so many compiler errors when included alone by a user program. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Christopher Ferris <cferris@google.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 2.6.30- Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12477/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: math-emu: Fix jalr emulation when rd == $0Paul Burton
commit ab4a92e66741b35ca12f8497896bafbe579c28a1 upstream. When emulating a jalr instruction with rd == $0, the code in isBranchInstr was incorrectly writing to GPR $0 which should actually always remain zeroed. This would lead to any further instructions emulated which use $0 operating on a bogus value until the task is next context switched, at which point the value of $0 in the task context would be restored to the correct zero by a store in SAVE_SOME. Fix this by not writing to rd if it is $0. Fixes: 102cedc32a6e ("MIPS: microMIPS: Floating point support.") Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13160/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: KVM: Propagate kseg0/mapped tlb fault errorsJames Hogan
commit 9b731bcfdec4c159ad2e4312e25d69221709b96a upstream. Propagate errors from kvm_mips_handle_kseg0_tlb_fault() and kvm_mips_handle_mapped_seg_tlb_fault(), usually triggering an internal error since they normally indicate the guest accessed bad physical memory or the commpage in an unexpected way. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: KVM: Fix gfn range check in kseg0 tlb faultsJames Hogan
commit 0741f52d1b980dbeb290afe67d88fc2928edd8ab upstream. Two consecutive gfns are loaded into host TLB, so ensure the range check isn't off by one if guest_pmap_npages is odd. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: KVM: Add missing gfn range checkJames Hogan
commit 8985d50382359e5bf118fdbefc859d0dbf6cebc7 upstream. kvm_mips_handle_mapped_seg_tlb_fault() calculates the guest frame number based on the guest TLB EntryLo values, however it is not range checked to ensure it lies within the guest_pmap. If the physical memory the guest refers to is out of range then dump the guest TLB and emit an internal error. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-08-21MIPS: KVM: Fix mapped fault broken commpage handlingJames Hogan
commit c604cffa93478f8888bec62b23d6073dad03d43a upstream. kvm_mips_handle_mapped_seg_tlb_fault() appears to map the guest page at virtual address 0 to PFN 0 if the guest has created its own mapping there. The intention is unclear, but it may have been an attempt to protect the zero page from being mapped to anything but the comm page in code paths you wouldn't expect from genuine commpage accesses (guest kernel mode cache instructions on that address, hitting trapping instructions when executing from that address with a coincidental TLB eviction during the KVM handling, and guest user mode accesses to that address). Fix this to check for mappings exactly at KVM_GUEST_COMMPAGE_ADDR (it may not be at address 0 since commit 42aa12e74e91 ("MIPS: KVM: Move commpage so 0x0 is unmapped")), and set the corresponding EntryLo to be interpreted as 0 (invalid). Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-03-03MIPS: KVM: Uninit VCPU in vcpu_create error pathJames Hogan
commit 585bb8f9a5e592f2ce7abbe5ed3112d5438d2754 upstream. If either of the memory allocations in kvm_arch_vcpu_create() fail, the vcpu which has been allocated and kvm_vcpu_init'd doesn't get uninit'd in the error handling path. Add a call to kvm_vcpu_uninit() to fix this. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03MIPS: KVM: Fix CACHE immediate offset sign extensionJames Hogan
commit c5c2a3b998f1ff5a586f9d37e154070b8d550d17 upstream. The immediate field of the CACHE instruction is signed, so ensure that it gets sign extended by casting it to an int16_t rather than just masking the low 16 bits. Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03MIPS: KVM: Fix ASID restoration logicJames Hogan
commit 002374f371bd02df864cce1fe85d90dc5b292837 upstream. ASID restoration on guest resume should determine the guest execution mode based on the guest Status register rather than bit 30 of the guest PC. Fix the two places in locore.S that do this, loading the guest status from the cop0 area. Note, this assembly is specific to the trap & emulate implementation of KVM, so it doesn't need to check the supervisor bit as that mode is not implemented in the guest. Fixes: b680f70fc111 ("KVM/MIPS32: Entry point for trampolining to...") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-22MIPS: dma-default: Fix 32-bit fall back to GFP_DMAJames Hogan
commit 53960059d56ecef67d4ddd546731623641a3d2d1 upstream. If there is a DMA zone (usually 24bit = 16MB I believe), but no DMA32 zone, as is the case for some 32-bit kernels, then massage_gfp_flags() will cause DMA memory allocated for devices with a 32..63-bit coherent_dma_mask to fall back to using __GFP_DMA, even though there may only be 32-bits of physical address available anyway. Correct that case to compare against a mask the size of phys_addr_t instead of always using a 64-bit mask. Signed-off-by: James Hogan <james.hogan@imgtec.com> Fixes: a2e715a86c6d ("MIPS: DMA: Fix computation of DMA flags from device's coherent_dma_mask.") Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9610/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16signal: fix information leak in copy_siginfo_from_user32Amanieu d'Antras
commit 3c00cb5e68dc719f2fc73a33b1b230aadfcb1309 upstream. This function can leak kernel stack data when the user siginfo_t has a positive si_code value. The top 16 bits of si_code descibe which fields in the siginfo_t union are active, but they are treated inconsistently between copy_siginfo_from_user32, copy_siginfo_to_user32 and copy_siginfo_to_user. copy_siginfo_from_user32 is called from rt_sigqueueinfo and rt_tgsigqueueinfo in which the user has full control overthe top 16 bits of si_code. This fixes the following information leaks: x86: 8 bytes leaked when sending a signal from a 32-bit process to itself. This leak grows to 16 bytes if the process uses x32. (si_code = __SI_CHLD) x86: 100 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = -1) sparc: 4 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = any) parsic and s390 have similar bugs, but they are not vulnerable because rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code to a different process. These bugs are also fixed for consistency. Signed-off-by: Amanieu d'Antras <amanieu@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16MIPS: Make set_pte() SMP safe.David Daney
commit 46011e6ea39235e4aca656673c500eac81a07a17 upstream. On MIPS the GLOBAL bit of the PTE must have the same value in any aligned pair of PTEs. These pairs of PTEs are referred to as "buddies". In a SMP system is is possible for two CPUs to be calling set_pte() on adjacent PTEs at the same time. There is a race between setting the PTE and a different CPU setting the GLOBAL bit in its buddy PTE. This race can be observed when multiple CPUs are executing vmap()/vfree() at the same time. Make setting the buddy PTE's GLOBAL bit an atomic operation to close the race condition. The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not* handled. Signed-off-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10835/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-16MIPS: Fix sched_getaffinity with MT FPAFF enabledFelix Fietkau
commit 1d62d737555e1378eb62a8bba26644f7d97139d2 upstream. p->thread.user_cpus_allowed is zero-initialized and is only filled on the first sched_setaffinity call. To avoid adding overhead in the task initialization codepath, simply OR the returned mask in sched_getaffinity with p->cpus_allowed. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10740/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03MIPS: KVM: Do not sign extend on unsigned MMIO loadNicholas Mc Guire
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 <hofrat@osadl.org> Reviewed-by: James Hogan <james.hogan@imgtec.com> Tested-by: James Hogan <james.hogan@imgtec.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> 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 <ralf@linux-mips.org> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-10MIPS: Fix KVM guest fixmap addressJames Hogan
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 <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9887/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-22MIPS: Fix enabling of DEBUG_STACKOVERFLOWJames Hogan
commit 5f35b9cd553fd64415b563497d05a563c988dbd6 upstream. Commit 334c86c494b9 ("MIPS: IRQ: Add stackoverflow detection") added kernel stack overflow detection, however it only enabled it conditional upon the preprocessor definition DEBUG_STACKOVERFLOW, which is never actually defined. The Kconfig option is called DEBUG_STACKOVERFLOW, which manifests to the preprocessor as CONFIG_DEBUG_STACKOVERFLOW, so switch it to using that definition instead. Fixes: 334c86c494b9 ("MIPS: IRQ: Add stackoverflow detection") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Adam Jiang <jiang.adam@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/10531/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06nosave: consolidate __nosave_{begin,end} in <asm/sections.h>Geert Uytterhoeven
commit 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0 upstream. The different architectures used their own (and different) declarations: extern __visible const void __nosave_begin, __nosave_end; extern const void __nosave_begin, __nosave_end; extern long __nosave_begin, __nosave_end; Consolidate them using the first variant in <asm/sections.h>. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-06MIPS: Hibernate: flush TLB entries earlierHuacai Chen
commit a843d00d038b11267279e3b5388222320f9ddc1d upstream. We found that TLB mismatch not only happens after kernel resume, but also happens during snapshot restore. So move it to the beginning of swsusp_arch_suspend(). Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/9621/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-29vm: add VM_FAULT_SIGSEGV handling supportLinus Torvalds
commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream. The core VM already knows about VM_FAULT_SIGBUS, but cannot return a "you should SIGSEGV" error, because the SIGSEGV case was generally handled by the caller - usually the architecture fault handler. That results in lots of duplication - all the architecture fault handlers end up doing very similar "look up vma, check permissions, do retries etc" - but it generally works. However, there are cases where the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV. In particular, when accessing the stack guard page, libsigsegv expects a SIGSEGV. And it usually got one, because the stack growth is handled by that duplicated architecture fault handler. However, when the generic VM layer started propagating the error return from the stack expansion in commit fee7e49d4514 ("mm: propagate error from stack expansion even for guard page"), that now exposed the existing VM_FAULT_SIGBUS result to user space. And user space really expected SIGSEGV, not SIGBUS. To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those duplicate architecture fault handlers about it. They all already have the code to handle SIGSEGV, so it's about just tying that new return value to the existing code, but it's all a bit annoying. This is the mindless minimal patch to do this. A more extensive patch would be to try to gather up the mostly shared fault handling logic into one generic helper routine, and long-term we really should do that cleanup. Just from this patch, you can generally see that most architectures just copied (directly or indirectly) the old x86 way of doing things, but in the meantime that original x86 model has been improved to hold the VM semaphore for shorter times etc and to handle VM_FAULT_RETRY and other "newer" things, so it would be a good idea to bring all those improvements to the generic case and teach other architectures about them too. Reported-and-tested-by: Takashi Iwai <tiwai@suse.de> Tested-by: Jan Engelhardt <jengelh@inai.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots" Cc: linux-arch@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [shengyong: Backport to 3.10 - adjust context - ignore modification for arch nios2, because 3.10 does not support it - ignore modification for driver lustre, because 3.10 does not support it - ignore VM_FAULT_FALLBACK in VM_FAULT_ERROR, becase 3.10 does not support this flag - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.10 does not separate it to copro_fault.c - add SIGSEGV handling in mm/memory.c, because 3.10 does not separate it to gup.c ] Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-18KVM: MIPS: Fix trace event to save PC directlyJames Hogan
commit b3cffac04eca9af46e1e23560a8ee22b1bd36d43 upstream. Currently the guest exit trace event saves the VCPU pointer to the structure, and the guest PC is retrieved by dereferencing it when the event is printed rather than directly from the trace record. This isn't safe as the printing may occur long afterwards, after the PC has changed and potentially after the VCPU has been freed. Usually this results in the same (wrong) PC being printed for multiple trace events. It also isn't portable as userland has no way to access the VCPU data structure when interpreting the trace record itself. Lets save the actual PC in the structure so that the correct value is accessible later. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-06MIPS: Export FP functions used by lose_fpu(1) for KVMJames Hogan
commit 3ce465e04bfd8de9956d515d6e9587faac3375dc upstream. Export the _save_fp asm function used by the lose_fpu(1) macro to GPL modules so that KVM can make use of it when it is built as a module. This fixes the following build error when CONFIG_KVM=m due to commit f798217dfd03 ("KVM: MIPS: Don't leak FPU/DSP to guest"): ERROR: "_save_fp" [arch/mips/kvm/kvm.ko] undefined! Signed-off-by: James Hogan <james.hogan@imgtec.com> Fixes: f798217dfd03 (KVM: MIPS: Don't leak FPU/DSP to guest) Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9260/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [james.hogan@imgtec.com: Only export when CPU_R4K_FPU=y prior to v3.16, so as not to break the Octeon build which excludes FPU support. KVM depends on MIPS32r2 anyway.] Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-06KVM: MIPS: Don't leak FPU/DSP to guestJames Hogan
commit f798217dfd038af981a18bbe4bc57027a08bb182 upstream. The FPU and DSP are enabled via the CP0 Status CU1 and MX bits by kvm_mips_set_c0_status() on a guest exit, presumably in case there is active state that needs saving if pre-emption occurs. However neither of these bits are cleared again when returning to the guest. This effectively gives the guest access to the FPU/DSP hardware after the first guest exit even though it is not aware of its presence, allowing FP instructions in guest user code to intermittently actually execute instead of trapping into the guest OS for emulation. It will then read & manipulate the hardware FP registers which technically belong to the user process (e.g. QEMU), or are stale from another user process. It can also crash the guest OS by causing an FP exception, for which a guest exception handler won't have been registered. First lets save and disable the FPU (and MSA) state with lose_fpu(1) before entering the guest. This simplifies the problem, especially for when guest FPU/MSA support is added in the future, and prevents FR=1 FPU state being live when the FR bit gets cleared for the guest, which according to the architecture causes the contents of the FPU and vector registers to become UNPREDICTABLE. We can then safely remove the enabling of the FPU in kvm_mips_set_c0_status(), since there should never be any active FPU or MSA state to save at pre-emption, which should plug the FPU leak. DSP state is always live rather than being lazily restored, so for that it is simpler to just clear the MX bit again when re-entering the guest. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Sanjay Lal <sanjayl@kymasys.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # v3.10+: 044f0f03eca0: MIPS: KVM: Deliver guest interrupts Cc: <stable@vger.kernel.org> # v3.10+ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-06MIPS: KVM: Deliver guest interrupts after local_irq_disable()James Hogan
commit 044f0f03eca0110e1835b2ea038a484b93950328 upstream. When about to run the guest, deliver guest interrupts after disabling host interrupts. This should prevent an hrtimer interrupt from being handled after delivering guest interrupts, and therefore not delivering the guest timer interrupt until after the next guest exit. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-11MIPS: Fix kernel lockup or crash after CPU offline/onlineHemmo Nieminen
commit c7754e75100ed5e3068ac5085747f2bfc386c8d6 upstream. As printk() invocation can cause e.g. a TLB miss, printk() cannot be called before the exception handlers have been properly initialized. This can happen e.g. when netconsole has been loaded as a kernel module and the TLB table has been cleared when a CPU was offline. Call cpu_report() in start_secondary() only after the exception handlers have been initialized to fix this. Without the patch the kernel will randomly either lockup or crash after a CPU is onlined and the console driver is a module. Signed-off-by: Hemmo Nieminen <hemmo.nieminen@iki.fi> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/8953/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-11MIPS: IRQ: Fix disable_irq on CPU IRQsFelix Fietkau
commit a3e6c1eff54878506b2dddcc202df9cc8180facb upstream. If the irq_chip does not define .irq_disable, any call to disable_irq will defer disabling the IRQ until it fires while marked as disabled. This assumes that the handler function checks for this condition, which handle_percpu_irq does not. In this case, calling disable_irq leads to an IRQ storm, if the interrupt fires while disabled. This optimization is only useful when disabling the IRQ is slow, which is not true for the MIPS CPU IRQ. Disable this optimization by implementing .irq_disable and .irq_enable Signed-off-by: Felix Fietkau <nbd@openwrt.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8949/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-06MIPS: Loongson: Make platform serial setup always built-in.Aaro Koskinen
commit 26927f76499849e095714452b8a4e09350f6a3b9 upstream. If SERIAL_8250 is compiled as a module, the platform specific setup for Loongson will be a module too, and it will not work very well. At least on Loongson 3 it will trigger a build failure, since loongson_sysconf is not exported to modules. Fix by making the platform specific serial code always built-in. Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Reported-by: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Huacai Chen <chenhc@lemote.com> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/8533/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-12-06MIPS: oprofile: Fix backtrace on 64-bit kernelAaro Koskinen
commit bbaf113a481b6ce32444c125807ad3618643ce57 upstream. Fix incorrect cast that always results in wrong address for the new frame on 64-bit kernels. Signed-off-by: Aaro Koskinen <aaro.koskinen@nsn.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8110/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-21arch: mm: pass userspace fault flag to generic fault handlerJohannes Weiner
commit 759496ba6407c6994d6a5ce3a5e74937d7816208 upstream. Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-21arch: mm: do not invoke OOM killer on kernel fault OOMJohannes Weiner
commit 871341023c771ad233620b7a1fb3d9c7031c4e5c upstream. Kernel faults are expected to handle OOM conditions gracefully (gup, uaccess etc.), so they should never invoke the OOM killer. Reserve this for faults triggered in user context when it is the only option. Most architectures already do this, fix up the remaining few. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-21MIPS: Fix forgotten preempt_enable() when CPU has inclusive pcachesYoichi Yuasa
commit 5596b0b245fb9d2cefb5023b11061050351c1398 upstream. [ 1.904000] BUG: scheduling while atomic: swapper/1/0x00000002 [ 1.908000] Modules linked in: [ 1.916000] CPU: 0 PID: 1 Comm: swapper Not tainted 3.12.0-rc2-lemote-los.git-5318619-dirty #1 [ 1.920000] Stack : 0000000031aac000 ffffffff810d0000 0000000000000052 ffffffff802730a4 0000000000000000 0000000000000001 ffffffff810cdf90 ffffffff810d0000 ffffffff8068b968 ffffffff806f5537 ffffffff810cdf90 980000009f0782e8 0000000000000001 ffffffff80720000 ffffffff806b0000 980000009f078000 980000009f290000 ffffffff805f312c 980000009f05b5d8 ffffffff80233518 980000009f05b5e8 ffffffff80274b7c 980000009f078000 ffffffff8068b968 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 980000009f05b520 0000000000000000 ffffffff805f2f6c 0000000000000000 ffffffff80700000 ffffffff80700000 ffffffff806fc758 ffffffff80700000 ffffffff8020be98 ffffffff806fceb0 ffffffff805f2f6c ... [ 2.028000] Call Trace: [ 2.032000] [<ffffffff8020be98>] show_stack+0x80/0x98 [ 2.036000] [<ffffffff805f2f6c>] __schedule_bug+0x44/0x6c [ 2.040000] [<ffffffff805fac58>] __schedule+0x518/0x5b0 [ 2.044000] [<ffffffff805f8a58>] schedule_timeout+0x128/0x1f0 [ 2.048000] [<ffffffff80240314>] msleep+0x3c/0x60 [ 2.052000] [<ffffffff80495400>] do_probe+0x238/0x3a8 [ 2.056000] [<ffffffff804958b0>] ide_probe_port+0x340/0x7e8 [ 2.060000] [<ffffffff80496028>] ide_host_register+0x2d0/0x7a8 [ 2.064000] [<ffffffff8049c65c>] ide_pci_init_two+0x4e4/0x790 [ 2.068000] [<ffffffff8049f9b8>] amd74xx_probe+0x148/0x2c8 [ 2.072000] [<ffffffff803f571c>] pci_device_probe+0xc4/0x130 [ 2.076000] [<ffffffff80478f60>] driver_probe_device+0x98/0x270 [ 2.080000] [<ffffffff80479298>] __driver_attach+0xe0/0xe8 [ 2.084000] [<ffffffff80476ab0>] bus_for_each_dev+0x78/0xe0 [ 2.088000] [<ffffffff80478468>] bus_add_driver+0x230/0x310 [ 2.092000] [<ffffffff80479b44>] driver_register+0x84/0x158 [ 2.096000] [<ffffffff80200504>] do_one_initcall+0x104/0x160 Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org> Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi> Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: linux-mips@linux-mips.org Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org> Patchwork: https://patchwork.linux-mips.org/patch/5941/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Alexandre Oliva <lxoliva@fsfla.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-14MIPS: tlbex: Properly fix HUGE TLB Refill exception handlerDavid Daney
commit 9e0f162a36914937a937358fcb45e0609ef2bfc4 upstream. In commit 8393c524a25609 (MIPS: tlbex: Fix a missing statement for HUGETLB), the TLB Refill handler was fixed so that non-OCTEON targets would work properly with huge pages. The change was incorrect in that it broke the OCTEON case. The problem is shown here: xxx0: df7a0000 ld k0,0(k1) . . . xxxc0: df610000 ld at,0(k1) xxxc4: 335a0ff0 andi k0,k0,0xff0 xxxc8: e825ffcd bbit1 at,0x5,0x0 xxxcc: 003ad82d daddu k1,at,k0 . . . In the non-octeon case there is a destructive test for the huge PTE bit, and then at 0, $k0 is reloaded (that is what the 8393c524a25609 patch added). In the octeon case, we modify k1 in the branch delay slot, but we never need k0 again, so the new load is not needed, but since k1 is modified, if we do the load, we load from a garbage location and then get a nested TLB Refill, which is seen in userspace as either SIGBUS or SIGSEGV (depending on the garbage). The real fix is to only do this reloading if it is needed, and never where it is harmful. Signed-off-by: David Daney <david.daney@cavium.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8151/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05MIPS: mcount: Adjust stack pointer for static trace in MIPS32Markos Chandras
commit 8a574cfa2652545eb95595d38ac2a0bb501af0ae upstream. Every mcount() call in the MIPS 32-bit kernel is done as follows: [...] move at, ra jal _mcount addiu sp, sp, -8 [...] but upon returning from the mcount() function, the stack pointer is not adjusted properly. This is explained in details in 58b69401c797 (MIPS: Function tracer: Fix broken function tracing). Commit ad8c396936e3 ("MIPS: Unbreak function tracer for 64-bit kernel.) fixed the stack manipulation for 64-bit but it didn't fix it completely for MIPS32. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7792/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05MIPS: ZBOOT: add missing <linux/string.h> includeAurelien Jarno
commit 29593fd5a8149462ed6fad0d522234facdaee6c8 upstream. Commit dc4d7b37 (MIPS: ZBOOT: gather string functions into string.c) moved the string related functions into a separate file, which might cause the following build error, depending on the configuration: | CC arch/mips/boot/compressed/decompress.o | In file included from linux/arch/mips/boot/compressed/../../../../lib/decompress_unxz.c:234:0, | from linux/arch/mips/boot/compressed/decompress.c:67: | linux/arch/mips/boot/compressed/../../../../lib/xz/xz_dec_stream.c: In function 'fill_temp': | linux/arch/mips/boot/compressed/../../../../lib/xz/xz_dec_stream.c:162:2: error: implicit declaration of function 'memcpy' [-Werror=implicit-function-declaration] | cc1: some warnings being treated as errors | linux/scripts/Makefile.build:308: recipe for target 'arch/mips/boot/compressed/decompress.o' failed | make[6]: *** [arch/mips/boot/compressed/decompress.o] Error 1 | linux/arch/mips/Makefile:308: recipe for target 'vmlinuz' failed It does not fail with the standard configuration, as when CONFIG_DYNAMIC_DEBUG is not enabled <linux/string.h> gets included in include/linux/dynamic_debug.h. There might be other ways for it to get indirectly included. We can't add the include directly in xz_dec_stream.c as some architectures might want to use a different version for the boot/ directory (see for example arch/x86/boot/string.h). Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7420/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: Fix accessing to per-cpu data when flushing the cacheRalf Baechle
commit ff522058bd717506b2fa066fa564657f2b86477e upstream. This fixes the following issue BUG: using smp_processor_id() in preemptible [00000000] code: kjournald/1761 caller is blast_dcache32+0x30/0x254 Call Trace: [<8047f02c>] dump_stack+0x8/0x34 [<802e7e40>] debug_smp_processor_id+0xe0/0xf0 [<80114d94>] blast_dcache32+0x30/0x254 [<80118484>] r4k_dma_cache_wback_inv+0x200/0x288 [<80110ff0>] mips_dma_map_sg+0x108/0x180 [<80355098>] ide_dma_prepare+0xf0/0x1b8 [<8034eaa4>] do_rw_taskfile+0x1e8/0x33c [<8035951c>] ide_do_rw_disk+0x298/0x3e4 [<8034a3c4>] do_ide_request+0x2e0/0x704 [<802bb0dc>] __blk_run_queue+0x44/0x64 [<802be000>] queue_unplugged.isra.36+0x1c/0x54 [<802beb94>] blk_flush_plug_list+0x18c/0x24c [<802bec6c>] blk_finish_plug+0x18/0x48 [<8026554c>] journal_commit_transaction+0x3b8/0x151c [<80269648>] kjournald+0xec/0x238 [<8014ac00>] kthread+0xb8/0xc0 [<8010268c>] ret_from_kernel_thread+0x14/0x1c Caches in most systems are identical - but not always, so we can't avoid the use of smp_call_function() by just looking at the boot CPU's data, have to fiddle with preemption instead. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5835 Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: OCTEON: make get_system_type() thread-safeAaro Koskinen
commit 608308682addfdc7b8e2aee88f0e028331d88e4d upstream. get_system_type() is not thread-safe on OCTEON. It uses static data, also more dangerous issue is that it's calling cvmx_fuse_read_byte() every time without any synchronization. Currently it's possible to get processes stuck looping forever in kernel simply by launching multiple readers of /proc/cpuinfo: (while true; do cat /proc/cpuinfo > /dev/null; done) & (while true; do cat /proc/cpuinfo > /dev/null; done) & ... Fix by initializing the system type string only once during the early boot. Signed-off-by: Aaro Koskinen <aaro.koskinen@nsn.com> Reviewed-by: Markos Chandras <markos.chandras@imgtec.com> Patchwork: http://patchwork.linux-mips.org/patch/7437/ Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: asm: thread_info: Add _TIF_SECCOMP flagMarkos Chandras
commit 137f7df8cead00688524c82360930845396b8a21 upstream. Add _TIF_SECCOMP flag to _TIF_WORK_SYSCALL_ENTRY to indicate that the system call needs to be checked against a seccomp filter. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Reviewed-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6405/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.2: various other flags are not included in _TIF_WORK_SYSCALL_ENTRY] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: Cleanup flags in syscall flags handlers.Ralf Baechle
commit e7f3b48af7be9f8007a224663a5b91340626fed5 upstream. This will simplify further modifications. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: asm/reg.h: Make 32- and 64-bit definitions available at the same timeAlex Smith
commit bcec7c8da6b092b1ff3327fd83c2193adb12f684 upstream. Get rid of the WANT_COMPAT_REG_H test and instead define both the 32- and 64-bit register offset definitions at the same time with MIPS{32,64}_ prefixes, then define the existing EF_* names to the correct definitions for the kernel's bitness. This patch is a prerequisite of the following bug fix patch. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7451/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: Remove BUG_ON(!is_fpu_owner()) in do_ade()Huacai Chen
commit 2e5767a27337812f6850b3fa362419e2f085e5c3 upstream. In do_ade(), is_fpu_owner() isn't preempt-safe. For example, when an unaligned ldc1 is executed, do_cpu() is called and then FPU will be enabled (and TIF_USEDFPU will be set for the current process). Then, do_ade() is called because the access is unaligned. If the current process is preempted at this time, TIF_USEDFPU will be cleard. So when the process is scheduled again, BUG_ON(!is_fpu_owner()) is triggered. This small program can trigger this BUG in a preemptible kernel: int main (int argc, char *argv[]) { double u64[2]; while (1) { asm volatile ( ".set push \n\t" ".set noreorder \n\t" "ldc1 $f3, 4(%0) \n\t" ".set pop \n\t" ::"r"(u64): ); } return 0; } V2: Remove the BUG_ON() unconditionally due to Paul's suggestion. Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Jie Chen <chenj@lemote.com> Signed-off-by: Rui Wang <wangr@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: tlbex: Fix a missing statement for HUGETLBHuacai Chen
commit 8393c524a25609a30129e4a8975cf3b91f6c16a5 upstream. In commit 2c8c53e28f1 (MIPS: Optimize TLB handlers for Octeon CPUs) build_r4000_tlb_refill_handler() is modified. But it doesn't compatible with the original code in HUGETLB case. Because there is a copy & paste error and one line of code is missing. It is very easy to produce a bug with LTP's hugemmap05 test. Signed-off-by: Huacai Chen <chenhc@lemote.com> Signed-off-by: Binbin Zhou <zhoubb@lemote.com> Cc: John Crispin <john@phrozen.org> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/7496/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: Prevent user from setting FCSR cause bitsPaul Burton
commit b1442d39fac2fcfbe6a4814979020e993ca59c9e upstream. If one or more matching FCSR cause & enable bits are set in saved thread context then when that context is restored the kernel will take an FP exception. This is of course undesirable and considered an oops, leading to the kernel writing a backtrace to the console and potentially rebooting depending upon the configuration. Thus the kernel avoids this situation by clearing the cause bits of the FCSR register when handling FP exceptions and after emulating FP instructions. However the kernel does not prevent userland from setting arbitrary FCSR cause & enable bits via ptrace, using either the PTRACE_POKEUSR or PTRACE_SETFPREGS requests. This means userland can trivially cause the kernel to oops on any system with an FPU. Prevent this from happening by clearing the cause bits when writing to the saved FCSR context via ptrace. This problem appears to exist at least back to the beginning of the git era in the PTRACE_POKEUSR case. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Paul Burton <paul.burton@imgtec.com> Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7438/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-17MIPS: GIC: Prevent array overrunJeffrey Deans
commit ffc8415afab20bd97754efae6aad1f67b531132b upstream. A GIC interrupt which is declared as having a GIC_MAP_TO_NMI_MSK mapping causes the cpu parameter to gic_setup_intr() to be increased to 32, causing memory corruption when pcpu_masks[] is written to again later in the function. Signed-off-by: Jeffrey Deans <jeffrey.deans@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7375/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06MIPS: KVM: Fix memory leak on VCPUDeng-Cheng Zhu
commit 8c9eb041cf76038eb3b62ee259607eec9b89f48d upstream. kvm_arch_vcpu_free() is called in 2 code paths: 1) kvm_vm_ioctl() kvm_vm_ioctl_create_vcpu() kvm_arch_vcpu_destroy() kvm_arch_vcpu_free() 2) kvm_put_kvm() kvm_destroy_vm() kvm_arch_destroy_vm() kvm_mips_free_vcpus() kvm_arch_vcpu_free() Neither of the paths handles VCPU free. We need to do it in kvm_arch_vcpu_free() corresponding to the memory allocation in kvm_arch_vcpu_create(). Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06MIPS: KVM: Remove redundant NULL checks before kfree()James Hogan
commit c6c0a6637f9da54f9472144d44f71cf847f92e20 upstream. The kfree() function already NULL checks the parameter so remove the redundant NULL checks before kfree() calls in arch/mips/kvm/. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-06MIPS: MSC: Prevent out-of-bounds writes to MIPS SC ioremap'd regionMarkos Chandras
commit ab6c15bc6620ebe220970cc040b29bcb2757f373 upstream. Previously, the lower limit for the MIPS SC initialization loop was set incorrectly allowing one extra loop leading to writes beyond the MSC ioremap'd space. More precisely, the value of the 'imp' in the last loop increased beyond the msc_irqmap_t boundaries and as a result of which, the 'n' variable was loaded with an incorrect value. This value was used later on to calculate the offset in the MSC01_IC_SUP which led to random crashes like the following one: CPU 0 Unable to handle kernel paging request at virtual address e75c0200, epc == 8058dba4, ra == 8058db90 [...] Call Trace: [<8058dba4>] init_msc_irqs+0x104/0x154 [<8058b5bc>] arch_init_irq+0xd8/0x154 [<805897b0>] start_kernel+0x220/0x36c Kernel panic - not syncing: Attempted to kill the idle task! This patch fixes the problem Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7118/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-26MIPS: KVM: Allocate at least 16KB for exception handlersJames Hogan
commit 7006e2dfda9adfa40251093604db76d7e44263b3 upstream. Each MIPS KVM guest has its own copy of the KVM exception vector. This contains the TLB refill exception handler at offset 0x000, the general exception handler at offset 0x180, and interrupt exception handlers at offset 0x200 in case Cause_IV=1. A common handler is copied to offset 0x2000 and offset 0x3000 is used for temporarily storing k1 during entry from guest. However the amount of memory allocated for this purpose is calculated as 0x200 rounded up to the next page boundary, which is insufficient if 4KB pages are in use. This can lead to the common handler at offset 0x2000 being overwritten and infinitely recursive exceptions on the next exit from the guest. Increase the minimum size from 0x200 to 0x4000 to cover the full use of the page. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>