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* ARM: smp: add support for per-task stack canariesArd Biesheuvel2018-12-121-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | On ARM, we currently only change the value of the stack canary when switching tasks if the kernel was built for UP. On SMP kernels, this is impossible since the stack canary value is obtained via a global symbol reference, which means a) all running tasks on all CPUs must use the same value b) we can only modify the value when no kernel stack frames are live on any CPU, which is effectively never. So instead, use a GCC plugin to add a RTL pass that replaces each reference to the address of the __stack_chk_guard symbol with an expression that produces the address of the 'stack_canary' field that is added to struct thread_info. This way, each task will use its own randomized value. Cc: Russell King <linux@armlinux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: Emese Revfy <re.emese@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Laura Abbott <labbott@redhat.com> Cc: kernel-hardening@lists.openwall.com Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* include/linux/compiler*.h: make compiler-*.h mutually exclusiveNick Desaulniers2018-08-231-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6") recently exposed a brittle part of the build for supporting non-gcc compilers. Both Clang and ICC define __GNUC__, __GNUC_MINOR__, and __GNUC_PATCHLEVEL__ for quick compatibility with code bases that haven't added compiler specific checks for __clang__ or __INTEL_COMPILER. This is brittle, as they happened to get compatibility by posing as a certain version of GCC. This broke when upgrading the minimal version of GCC required to build the kernel, to a version above what ICC and Clang claim to be. Rather than always including compiler-gcc.h then undefining or redefining macros in compiler-intel.h or compiler-clang.h, let's separate out the compiler specific macro definitions into mutually exclusive headers, do more proper compiler detection, and keep shared definitions in compiler_types.h. Fixes: cafa0010cd51 ("Raise the minimum required gcc version to 4.6") Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com> Suggested-by: Eli Friedman <efriedma@codeaurora.org> Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variablesLinus Torvalds2018-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ARM: 8757/1: NOMMU: Support PMSAv8 MPUVladimir Murzin2018-05-191-0/+2
| | | | | | | | | | | | | | | | | | ARMv8R/M architecture defines new memory protection scheme - PMSAv8 which is not compatible with PMSAv7. Key differences to PMSAv7 are: - Region geometry is defined by base and limit addresses - Addresses need to be either 32 or 64 byte aligned - No region priority due to overlapping regions are not allowed - It is unified, i.e. no distinction between data/instruction regions - Memory attributes are controlled via MAIR This patch implements support for PMSAv8 MPU defined by ARMv8R/M architecture. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* ARM: 8754/1: NOMMU: Move PMSAv7 MPU under it's own namespaceVladimir Murzin2018-05-191-3/+3
| | | | | | | | | | We are going to support different MPU which programming model is not compatible to PMSAv7, so move PMSAv7 MPU under it's own namespace. Tested-by: Szemz? András <sza@esh.hu> Tested-by: Alexandre TORGUE <alexandre.torgue@st.com> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* ARM: 8708/1: NOMMU: Rework MPU to be mostly done in CVladimir Murzin2017-10-231-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, there are several issues with how MPU is setup: 1. We won't boot if MPU is missing 2. We won't boot if use XIP 3. Further extension of MPU setup requires asm skills The 1st point can be relaxed, so we can continue with boot CPU even if MPU is missed and fail boot for secondaries only. To address the 2nd point we could create region covering CONFIG_XIP_PHYS_ADDR - _end and that might work for the first stage of MPU enable, but due to MPU's alignment requirement we could cover too much, IOW we need more flexibility in how we're partitioning memory regions... and it'd be hardly possible to archive because of the 3rd point. This patch is trying to address 1st and 3rd issues and paves the path for 2nd and further improvements. The most visible change introduced with this patch is that we start using mpu_rgn_info array (as it was supposed?), so change in MPU setup done by boot CPU is recorded there and feed to secondaries. It allows us to keep minimal region setup for boot CPU and do the rest in C. Since we start programming MPU regions in C evaluation of MPU constrains (number of regions supported and minimal region order) can be done once, which in turn open possibility to free-up "probe" region early. Tested-by: Szemző András <sza@esh.hu> Tested-by: Alexandre TORGUE <alexandre.torgue@st.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* ARM: signal handling support for FDPIC_FUNCPTRS functionsNicolas Pitre2017-09-111-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | Signal handlers are not direct function pointers but pointers to function descriptor in that case. Therefore we must retrieve the actual function address and load the GOT value into r9 from the descriptor before branching to the actual handler. If a restorer is provided, we also have to load its address and GOT from its descriptor. That descriptor address and the code to load it is pushed onto the stack to be executed as soon as the signal handler returns. However, to be compatible with NX stacks, the FDPIC bounce code is also copied to the signal page along with the other code stubs. Therefore this code must get at the descriptor address whether it executes from the stack or the signal page. To do so we use the stack pointer which points at the signal stack frame where the descriptor address was stored. Because the rt signal frame is different from the simpler frame, two versions of the bounce code are needed, and two variants (ARM and Thumb) as well. The asm-offsets facility is used to determine the actual offset in the signal frame for each version, meaning that struct sigframe and rt_sigframe had to be moved to a separate file. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Mickael GUENE <mickael.guene@st.com> Tested-by: Vincent Abriou <vincent.abriou@st.com> Tested-by: Andras Szemzo <szemzo.andras@gmail.com>
* ARM: save and reset the address limit when entering an exceptionRussell King2016-07-071-0/+1
| | | | | | | | | | When we enter an exception, the current address limit should not apply to the exception context: if the exception context wishes to access kernel space via the user accessors (eg, perf code), it must explicitly request such access. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* ARM: introduce svc_pt_regs structureRussell King2016-06-221-0/+2
| | | | | | | | | Since the privileged mode pt_regs are an extended version of the saved userland pt_regs, introduce a new svc_pt_regs structure to describe this layout. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* ARM: rename S_FRAME_SIZE to PT_REGS_SIZERussell King2016-06-221-1/+1
| | | | | | | | | S_FRAME_SIZE is no longer the size of the kernel stack frame, so this name is misleading. It is the size of the kernel pt_regs structure. Name it so. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
* ARM: KVM: Remove unused hyp_pc fieldMarc Zyngier2016-02-291-1/+0
| | | | | | | | This field was never populated, and the panic code already does something similar. Delete the related code. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: KVM: Cleanup asm-offsets.cMarc Zyngier2016-02-291-30/+0
| | | | | | | | Since we don't have much assembler left, most of the KVM stuff in asm-offsets.c is now superfluous. Let's get rid of it. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: KVM: Move GP registers into the CPU context structureMarc Zyngier2016-02-291-9/+9
| | | | | | | | Continuing our rework of the CPU context, we now move the GP registers into the CPU context structure. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: KVM: Move CP15 array into the CPU context structureMarc Zyngier2016-02-291-1/+1
| | | | | | | | | | | Continuing our rework of the CPU context, we now move the CP15 array into the CPU context structure. As this causes quite a bit of churn, we introduce the vcpu_cp15() macro that abstract the location of the actual array. This will probably help next time we have to revisit that code. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: KVM: Move VFP registers to a CPU context structureMarc Zyngier2016-02-291-2/+3
| | | | | | | | | In order to turn the WS code into something that looks a bit more like the arm64 version, move the VFP registers into a CPU context container for both the host and the guest. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* Merge branch 'exec_domain_rip_v2' of ↵Linus Torvalds2015-04-151-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc Pull exec domain removal from Richard Weinberger: "This series removes execution domain support from Linux. The idea behind exec domains was to support different ABIs. The feature was never complete nor stable. Let's rip it out and make the kernel signal handling code less complicated" * 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits) arm64: Removed unused variable sparc: Fix execution domain removal Remove rest of exec domains. arch: Remove exec_domain from remaining archs arc: Remove signal translation and exec_domain xtensa: Remove signal translation and exec_domain xtensa: Autogenerate offsets in struct thread_info x86: Remove signal translation and exec_domain unicore32: Remove signal translation and exec_domain um: Remove signal translation and exec_domain tile: Remove signal translation and exec_domain sparc: Remove signal translation and exec_domain sh: Remove signal translation and exec_domain s390: Remove signal translation and exec_domain mn10300: Remove signal translation and exec_domain microblaze: Remove signal translation and exec_domain m68k: Remove signal translation and exec_domain m32r: Remove signal translation and exec_domain m32r: Autogenerate offsets in struct thread_info frv: Remove signal translation and exec_domain ...
| * arm: Remove signal translation and exec_domainRichard Weinberger2015-04-121-1/+0
| | | | | | | | | | | | | | | | As execution domain support is gone we can remove signal translation from the signal code and remove exec_domain from thread_info. Signed-off-by: Richard Weinberger <richard@nod.at>
* | Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds2015-04-151-0/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ARM updates from Russell King: "Included in this update are both some long term fixes and some new features. Fixes: - An integer overflow in the calculation of ELF_ET_DYN_BASE. - Avoiding OOMs for high-order IOMMU allocations - SMP requires the data cache to be enabled for synchronisation primitives to work, so prevent the CPU_DCACHE_DISABLE option being visible on SMP builds. - A bug going back 10+ years in the noMMU ARM94* CPU support code, where it corrupts registers. Found by folk getting Linux running on their cameras. - Versatile Express needs an errata workaround enabled for CPU hot-unplug to work. Features: - Clean up module linker by handling out of range relocations separately from relocation cases we don't handle. - Fix a long term bug in the pci_mmap_page_range() code, which we hope won't impact userspace (we hope there's no users of the existing broken interface.) - Don't map DMA coherent allocations when we don't have a MMU. - Drop experimental status for SMP_ON_UP. - Warn when DT doesn't specify ePAPR mandatory cache properties. - Add documentation concerning how we find the start of physical memory for AUTO_ZRELADDR kernels, detailing why we have chosen the mask and the implications of changing it. - Updates from Ard Biesheuvel to address some issues with large kernels (such as allyesconfig) failing to link. - Allow hibernation to work on modern (ARMv7) CPUs - this appears to have never worked in the past on these CPUs. - Enable IRQ_SHOW_LEVEL, which changes the /proc/interrupts output format (hopefully without userspace breaking... let's hope that if it causes someone a problem, they tell us.) - Fix tegra-ahb DT offsets. - Rework ARM errata 643719 code (and ARMv7 flush_cache_louis()/ flush_dcache_all()) code to be more efficient, and enable this errata workaround by default for ARMv7+SMP CPUs. This complements the Versatile Express fix above. - Rework ARMv7 context code for errata 430973, so that only Cortex A8 CPUs are impacted by the branch target buffer flush when this errata is enabled. Also update the help text to indicate that all r1p* A8 CPUs are impacted. - Switch ARM to the generic show_mem() implementation, it conveys all the information which we were already reporting. - Prevent slow timer sources being used for udelay() - timers running at less than 1MHz are not useful for this, and can cause udelay() to return immediately, without any wait. Using such a slow timer is silly. - VDSO support for 32-bit ARM, mainly for gettimeofday() using the ARM architected timer. - Perf support for Scorpion performance monitoring units" vdso semantic conflict fixed up as per linux-next. * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (52 commits) ARM: update errata 430973 documentation to cover Cortex A8 r1p* ARM: ensure delay timer has sufficient accuracy for delays ARM: switch to use the generic show_mem() implementation ARM: proc-v7: avoid errata 430973 workaround for non-Cortex A8 CPUs ARM: enable ARM errata 643719 workaround by default ARM: cache-v7: optimise test for Cortex A9 r0pX devices ARM: cache-v7: optimise branches in v7_flush_cache_louis ARM: cache-v7: consolidate initialisation of cache level index ARM: cache-v7: shift CLIDR to extract appropriate field before masking ARM: cache-v7: use movw/movt instructions ARM: allow 16-bit instructions in ALT_UP() ARM: proc-arm94*.S: fix setup function ARM: vexpress: fix CPU hotplug with CT9x4 tile. ARM: 8276/1: Make CPU_DCACHE_DISABLE depend on !SMP ARM: 8335/1: Documentation: DT bindings: Tegra AHB: document the legacy base address ARM: 8334/1: amba: tegra-ahb: detect and correct bogus base address ARM: 8333/1: amba: tegra-ahb: fix register offsets in the macros ARM: 8339/1: Enable CONFIG_GENERIC_IRQ_SHOW_LEVEL ARM: 8338/1: kexec: Relax SMP validation to improve DT compatibility ARM: 8337/1: mm: Do not invoke OOM for higher order IOMMU DMA allocations ...
| * | ARM: 8330/1: add VDSO user-space codeNathan Lynch2015-03-271-0/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Place VDSO-related user-space code in arch/arm/kernel/vdso/. It is almost completely written in C with some assembly helpers to load the data page address, sample the counter, and fall back to system calls when necessary. The VDSO can service gettimeofday and clock_gettime when CONFIG_ARM_ARCH_TIMER is enabled and the architected timer is present (and correctly configured). It reads the CP15-based virtual counter to compute high-resolution timestamps. Of particular note is that a post-processing step ("vdsomunge") is necessary to produce a shared object which is architecturally allowed to be used by both soft- and hard-float EABI programs. The 2012 edition of the ARM ABI defines Tag_ABI_VFP_args = 3 "Code is compatible with both the base and VFP variants; the user did not permit non-variadic functions to pass FP parameters/results." Unfortunately current toolchains do not support this tag, which is ideally what we would use. The best available option is to ensure that both EF_ARM_ABI_FLOAT_SOFT and EF_ARM_ABI_FLOAT_HARD are unset in the ELF header's e_flags, indicating that the shared object is "old" and should be accepted for backward compatibility's sake. While binutils < 2.24 appear to produce a vdso.so with both flags clear, 2.24 always sets EF_ARM_ABI_FLOAT_SOFT, with no way to inhibit this behavior. So we have to fix things up with a custom post-processing step. In fact, the VDSO code in glibc does much less validation (including checking these flags) than the code for handling conventional file-backed shared libraries, so this is a bit moot unless glibc's VDSO code becomes more strict. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* / arm/arm64: KVM: Kill CONFIG_KVM_ARM_{VGIC,TIMER}Christoffer Dall2015-03-121-4/+0
|/ | | | | | | | | | | | We can definitely decide at run-time whether to use the GIC and timers or not, and the extra code and data structures that we allocate space for is really negligable with this config option, so I don't think it's worth the extra complexity of always having to define stub static inlines. The !CONFIG_KVM_ARM_VGIC/TIMER case is pretty much an untested code path anyway, so we're better off just getting rid of it. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: Blacklist GCC 4.8.0 to GCC 4.8.2 - PR58854Russell King2014-10-191-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | These stock GCC versions miscompile the kernel by incorrectly optimising the function epilogue code - by first increasing the stack pointer, and then loading entries from below the stack. This means that an opportune interrupt or exception will corrupt the current function's saved state, which may result in the parent function seeing different register values. As this bug has been known to result in corrupted filesystems, and these buggy compiler versions seem to be frequently used, we have little option but to blacklist these compiler versions. Distributions may have fixed PR58854, but as their compilers are totally indistinguishable from the buggy versions, it is unfortunate that this also results in those also being blacklisted. Given the filesystem corruption potential of the original, this is the lesser evil. People who want to build with their fixed compiler versions will need to adjust the kernel source. (Distros need to think about the implications of fixing such a compiler bug, and consider how to ensure that their fixed compiler versions can be detected if they wish to avoid this.) Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* KVM: arm/arm64: vgic: move GICv2 registers to their own structureMarc Zyngier2014-07-111-7/+7
| | | | | | | | | In order to make way for the GICv3 registers, move the v2-specific registers to their own structure. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: KVM: introduce per-vcpu HYP Configuration RegisterMarc Zyngier2014-03-031-0/+1
| | | | | | | | | | | | | | | So far, KVM/ARM used a fixed HCR configuration per guest, except for the VI/VF/VA bits to control the interrupt in absence of VGIC. With the upcoming need to dynamically reconfigure trapping, it becomes necessary to allow the HCR to be changed on a per-vcpu basis. The fix here is to mimic what KVM/arm64 already does: a per vcpu HCR field, initialized at setup time. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
* ARM: kernel: implement stack pointer save array through MPIDR hashingLorenzo Pieralisi2013-06-201-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current implementation of cpu_{suspend}/cpu_{resume} relies on the MPIDR to index the array of pointers where the context is saved and restored. The current approach works as long as the MPIDR can be considered a linear index, so that the pointers array can simply be dereferenced by using the MPIDR[7:0] value. On ARM multi-cluster systems, where the MPIDR may not be a linear index, to properly dereference the stack pointer array, a mapping function should be applied to it so that it can be used for arrays look-ups. This patch adds code in the cpu_{suspend}/cpu_{resume} implementation that relies on shifting and ORing hashing method to map a MPIDR value to a set of buckets precomputed at boot to have a collision free mapping from MPIDR to context pointers. The hashing algorithm must be simple, fast, and implementable with few instructions since in the cpu_resume path the mapping is carried out with the MMU off and the I-cache off, hence code and data are fetched from DRAM with no-caching available. Simplicity is counterbalanced with a little increase of memory (allocated dynamically) for stack pointers buckets, that should be anyway fairly limited on most systems. Memory for context pointers is allocated in a early_initcall with size precomputed and stashed previously in kernel data structures. Memory for context pointers is allocated through kmalloc; this guarantees contiguous physical addresses for the allocated memory which is fundamental to the correct functioning of the resume mechanism that relies on the context pointer array to be a chunk of contiguous physical memory. Virtual to physical address conversion for the context pointer array base is carried out at boot to avoid fiddling with virt_to_phys conversions in the cpu_resume path which is quite fragile and should be optimized to execute as few instructions as possible. Virtual and physical context pointer base array addresses are stashed in a struct that is accessible from assembly using values generated through the asm-offsets.c mechanism. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Amit Kucheria <amit.kucheria@linaro.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@linaro.org> Tested-by: Stephen Warren <swarren@wwwdotorg.org>
* Merge tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2013-05-051-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm updates from Gleb Natapov: "Highlights of the updates are: general: - new emulated device API - legacy device assignment is now optional - irqfd interface is more generic and can be shared between arches x86: - VMCS shadow support and other nested VMX improvements - APIC virtualization and Posted Interrupt hardware support - Optimize mmio spte zapping ppc: - BookE: in-kernel MPIC emulation with irqfd support - Book3S: in-kernel XICS emulation (incomplete) - Book3S: HV: migration fixes - BookE: more debug support preparation - BookE: e6500 support ARM: - reworking of Hyp idmaps s390: - ioeventfd for virtio-ccw And many other bug fixes, cleanups and improvements" * tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits) kvm: Add compat_ioctl for device control API KVM: x86: Account for failing enable_irq_window for NMI window request KVM: PPC: Book3S: Add API for in-kernel XICS emulation kvm/ppc/mpic: fix missing unlock in set_base_addr() kvm/ppc: Hold srcu lock when calling kvm_io_bus_read/write kvm/ppc/mpic: remove users kvm/ppc/mpic: fix mmio region lists when multiple guests used kvm/ppc/mpic: remove default routes from documentation kvm: KVM_CAP_IOMMU only available with device assignment ARM: KVM: iterate over all CPUs for CPU compatibility check KVM: ARM: Fix spelling in error message ARM: KVM: define KVM_ARM_MAX_VCPUS unconditionally KVM: ARM: Fix API documentation for ONE_REG encoding ARM: KVM: promote vfp_host pointer to generic host cpu context ARM: KVM: add architecture specific hook for capabilities ARM: KVM: perform HYP initilization for hotplugged CPUs ARM: KVM: switch to a dual-step HYP init code ARM: KVM: rework HYP page table freeing ARM: KVM: enforce maximum size for identity mapped code ARM: KVM: move to a KVM provided HYP idmap ...
| * ARM: KVM: promote vfp_host pointer to generic host cpu contextMarc Zyngier2013-04-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use the vfp_host pointer to store the host VFP context, should the guest start using VFP itself. Actually, we can use this pointer in a more generic way to store CPU speficic data, and arm64 is using it to dump the whole host state before switching to the guest. Simply rename the vfp_host field to host_cpu_context, and the corresponding type to kvm_cpu_context_t. No change in functionnality. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
| * Merge branch 'kvm-arm-cleanup' from git://github.com/columbia/linux-kvm-arm.gitGleb Natapov2013-04-251-4/+4
| |\
* | \ Merge branch 'mcpm' of git://git.linaro.org/people/nico/linux into devel-stableRussell King2013-04-251-1/+5
|\ \ \ | |_|/ |/| |
| * | ARM: mcpm_head.S: vlock-based first man electionDave Martin2013-04-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of requiring the first man to be elected in advance (which can be suboptimal in some situations), this patch uses a per- cluster mutex to co-ordinate selection of the first man. This should also make it more feasible to reuse this code path for asynchronous cluster resume (as in CPUidle scenarios). We must ensure that the vlock data doesn't share a cacheline with anything else, or dirty cache eviction could corrupt it. Signed-off-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Will Deacon <will.deacon@arm.com>
| * | ARM: mcpm: introduce helpers for platform coherency exit/setupDave Martin2013-04-241-0/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This provides helper methods to coordinate between CPUs coming down and CPUs going up, as well as documentation on the used algorithms, so that cluster teardown and setup operations are not done for a cluster simultaneously. For use in the power_down() implementation: * __mcpm_cpu_going_down(unsigned int cluster, unsigned int cpu) * __mcpm_outbound_enter_critical(unsigned int cluster) * __mcpm_outbound_leave_critical(unsigned int cluster) * __mcpm_cpu_down(unsigned int cluster, unsigned int cpu) The power_up_setup() helper should do platform-specific setup in preparation for turning the CPU on, such as invalidating local caches or entering coherency. It must be assembler for now, since it must run before the MMU can be switched on. It is passed the affinity level for which initialization should be performed. Because the mcpm_sync_struct content is looked-up and modified with the cache enabled or disabled depending on the code path, it is crucial to always ensure proper cache maintenance to update main memory right away. The sync_cache_*() helpers are used to that end. Also, in order to prevent a cached writer from interfering with an adjacent non-cached writer, we ensure each state variable is located to a separate cache line. Thanks to Nicolas Pitre and Achin Gupta for the help with this patch. Signed-off-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com>
| * ARM: 7659/1: mm: make mm->context.id an atomic64_t variableWill Deacon2013-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mm->context.id is updated under asid_lock when a new ASID is allocated to an mm_struct. However, it is also read without the lock when a task is being scheduled and checking whether or not the current ASID generation is up-to-date. If two threads of the same process are being scheduled in parallel and the bottom bits of the generation in their mm->context.id match the current generation (that is, the mm_struct has not been used for ~2^24 rollovers) then the non-atomic, lockless access to mm->context.id may yield the incorrect ASID. This patch fixes this issue by making mm->context.id and atomic64_t, ensuring that the generation is always read consistently. For code that only requires access to the ASID bits (e.g. TLB flushing by mm), then the value is accessed directly, which GCC converts to an ldrb. Cc: <stable@vger.kernel.org> # 3.8 Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | ARM: KVM: abstract fault register accessesMarc Zyngier2013-03-071-4/+4
|/ | | | | | | Instead of directly accessing the fault registers, use proper accessors so the core code can be shared. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: KVM: arch_timers: Add timer world switchMarc Zyngier2013-02-111-0/+6
| | | | | | | | | | Do the necessary save/restore dance for the timers in the world switch code. In the process, allow the guest to read the physical counter, which is useful for its own clock_event_device. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* ARM: KVM: VGIC control interface world switchMarc Zyngier2013-02-111-0/+12
| | | | | | | | Enable the VGIC control interface to be save-restored on world switch. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
* KVM: ARM: World-switch implementationChristoffer Dall2013-01-231-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provides complete world-switch implementation to switch to other guests running in non-secure modes. Includes Hyp exception handlers that capture necessary exception information and stores the information on the VCPU and KVM structures. The following Hyp-ABI is also documented in the code: Hyp-ABI: Calling HYP-mode functions from host (in SVC mode): Switching to Hyp mode is done through a simple HVC #0 instruction. The exception vector code will check that the HVC comes from VMID==0 and if so will push the necessary state (SPSR, lr_usr) on the Hyp stack. - r0 contains a pointer to a HYP function - r1, r2, and r3 contain arguments to the above function. - The HYP function will be called with its arguments in r0, r1 and r2. On HYP function return, we return directly to SVC. A call to a function executing in Hyp mode is performed like the following: <svc code> ldr r0, =BSYM(my_hyp_fn) ldr r1, =my_param hvc #0 ; Call my_hyp_fn(my_param) from HYP mode <svc code> Otherwise, the world-switch is pretty straight-forward. All state that can be modified by the guest is first backed up on the Hyp stack and the VCPU values is loaded onto the hardware. State, which is not loaded, but theoretically modifiable by the guest is protected through the virtualiation features to generate a trap and cause software emulation. Upon guest returns, all state is restored from hardware onto the VCPU struct and the original state is restored from the Hyp-stack onto the hardware. SMP support using the VMPIDR calculated on the basis of the host MPIDR and overriding the low bits with KVM vcpu_id contributed by Marc Zyngier. Reuse of VMIDs has been implemented by Antonios Motakis and adapated from a separate patch into the appropriate patches introducing the functionality. Note that the VMIDs are stored per VM as required by the ARM architecture reference manual. To support VFP/NEON we trap those instructions using the HPCTR. When we trap, we switch the FPU. After a guest exit, the VFP state is returned to the host. When disabling access to floating point instructions, we also mask FPEXC_EN in order to avoid the guest receiving Undefined instruction exceptions before we have a chance to switch back the floating point state. We are reusing vfp_hard_struct, so we depend on VFPv3 being enabled in the host kernel, if not, we still trap cp10 and cp11 in order to inject an undefined instruction exception whenever the guest tries to use VFP/NEON. VFP/NEON developed by Antionios Motakis and Rusty Russell. Aborts that are permission faults, and not stage-1 page table walk, do not report the faulting address in the HPFAR. We have to resolve the IPA, and store it just like the HPFAR register on the VCPU struct. If the IPA cannot be resolved, it means another CPU is playing with the page tables, and we simply restart the guest. This quirk was fixed by Marc Zyngier. Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
* ARM: Don't unconditionally bloat thread_infoRussell King2012-08-291-0/+2
| | | | | | | | | | There is no point reserving space at the bottom of the kernel stack for per-thread crunch state, and per-thread VFP state if these are not being supported by the kernel being built. Remove these members from the thread union when these features are disabled. Reported-by: Tim Bird <tim.bird@am.sony.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: 7114/1: cache-l2x0: add resume entry for l2 in secure modeBarry Song2011-10-171-0/+12
| | | | | | | | | | | we save the l2x0 registers at the first initialization, and platform codes can get them to restore l2x0 status after wakeup. Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Barry Song <Baohua.Song@csr.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: vfp: fix a hole in VFP thread migrationRussell King2011-07-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a hole in the VFP thread migration. Lets define two threads. Thread 1, we'll call 'interesting_thread' which is a thread which is running on CPU0, using VFP (so vfp_current_hw_state[0] = &interesting_thread->vfpstate) and gets migrated off to CPU1, where it continues execution of VFP instructions. Thread 2, we'll call 'new_cpu0_thread' which is the thread which takes over on CPU0. This has also been using VFP, and last used VFP on CPU0, but doesn't use it again. The following code will be executed twice: cpu = thread->cpu; /* * On SMP, if VFP is enabled, save the old state in * case the thread migrates to a different CPU. The * restoring is done lazily. */ if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu]) { vfp_save_state(vfp_current_hw_state[cpu], fpexc); vfp_current_hw_state[cpu]->hard.cpu = cpu; } /* * Thread migration, just force the reloading of the * state on the new CPU in case the VFP registers * contain stale data. */ if (thread->vfpstate.hard.cpu != cpu) vfp_current_hw_state[cpu] = NULL; The first execution will be on CPU0 to switch away from 'interesting_thread'. interesting_thread->cpu will be 0. So, vfp_current_hw_state[0] points at interesting_thread->vfpstate. The hardware state will be saved, along with the CPU number (0) that it was executing on. 'thread' will be 'new_cpu0_thread' with new_cpu0_thread->cpu = 0. Also, because it was executing on CPU0, new_cpu0_thread->vfpstate.hard.cpu = 0, and so the thread migration check is not triggered. This means that vfp_current_hw_state[0] remains pointing at interesting_thread. The second execution will be on CPU1 to switch _to_ 'interesting_thread'. So, 'thread' will be 'interesting_thread' and interesting_thread->cpu now will be 1. The previous thread executing on CPU1 is not relevant to this so we shall ignore that. We get to the thread migration check. Here, we discover that interesting_thread->vfpstate.hard.cpu = 0, yet interesting_thread->cpu is now 1, indicating thread migration. We set vfp_current_hw_state[1] to NULL. So, at this point vfp_current_hw_state[] contains the following: [0] = &interesting_thread->vfpstate [1] = NULL Our interesting thread now executes a VFP instruction, takes a fault which loads the state into the VFP hardware. Now, through the assembly we now have: [0] = &interesting_thread->vfpstate [1] = &interesting_thread->vfpstate CPU1 stops due to ptrace (and so saves its VFP state) using the thread switch code above), and CPU0 calls vfp_sync_hwstate(). if (vfp_current_hw_state[cpu] == &thread->vfpstate) { vfp_save_state(&thread->vfpstate, fpexc | FPEXC_EN); BANG, we corrupt interesting_thread's VFP state by overwriting the more up-to-date state saved by CPU1 with the old VFP state from CPU0. Fix this by ensuring that we have sane semantics for the various state describing variables: 1. vfp_current_hw_state[] points to the current owner of the context information stored in each CPUs hardware, or NULL if that state information is invalid. 2. thread->vfpstate.hard.cpu always contains the most recent CPU number which the state was loaded into or NR_CPUS if no CPU owns the state. So, for a particular CPU to be a valid owner of the VFP state for a particular thread t, two things must be true: vfp_current_hw_state[cpu] == &t->vfpstate && t->vfpstate.hard.cpu == cpu. and that is valid from the moment a CPU loads the saved VFP context into the hardware. This gives clear and consistent semantics to interpreting these variables. This patch also fixes thread copying, ensuring that t->vfpstate.hard.cpu is invalidated, otherwise CPU0 may believe it was the last owner. The hole can happen thus: - thread1 runs on CPU2 using VFP, migrates to CPU3, exits and thread_info freed. - New thread allocated from a previously running thread on CPU2, reusing memory for thread1 and copying vfp.hard.cpu. At this point, the following are true: new_thread1->vfpstate.hard.cpu == 2 &new_thread1->vfpstate == vfp_current_hw_state[2] Lastly, this also addresses thread flushing in a similar way to thread copying. Hole is: - thread runs on CPU0, using VFP, migrates to CPU1 but does not use VFP. - thread calls execve(), so thread flush happens, leaving vfp_current_hw_state[0] intact. This vfpstate is memset to 0 causing thread->vfpstate.hard.cpu = 0. - thread migrates back to CPU0 before using VFP. At this point, the following are true: thread->vfpstate.hard.cpu == 0 &thread->vfpstate == vfp_current_hw_state[0] Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: pm: add generic CPU suspend/resume supportRussell King2011-02-221-0/+9
| | | | | | | | | | | This adds core support for saving and restoring CPU coprocessor registers for suspend/resume support. This contains support for suspend with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Tested-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: move cache/processor/fault glue to separate include filesRussell King2011-02-121-0/+2
| | | | | | | | This allows the cache/processor/fault glue to be more easily used from assembler code. Tested on Assabet and Tegra 2. Tested-by: Colin Cross <ccross@android.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* arm: remove machine_desc.io_pg_offst and .phys_ioNicolas Pitre2010-10-201-2/+0
| | | | | | | | | | | | | | | Since we're now using addruart to establish the debug mapping, we can remove the io_pg_offst and phys_io members of struct machine_desc. The various declarations were removed using the following script: grep -rl MACHINE_START arch/arm | xargs \ sed -i '/MACHINE_START/,/MACHINE_END/ { /\.\(phys_io\|io_pg_offst\)/d }' [ Initial patch was from Jeremy Kerr, example script from Russell King ] Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org> Acked-by: Eric Miao <eric.miao at canonical.com>
* ARM: stack protector: change the canary value per taskNicolas Pitre2010-06-151-0/+3
| | | | | | | | | | | | | | | | | | | | A new random value for the canary is stored in the task struct whenever a new task is forked. This is meant to allow for different canary values per task. On ARM, GCC expects the canary value to be found in a global variable called __stack_chk_guard. So this variable has to be updated with the value stored in the task struct whenever a task switch occurs. Because the variable GCC expects is global, this cannot work on SMP unfortunately. So, on SMP, the same initial canary value is kept throughout, making this feature a bit less effective although it is still useful. One way to overcome this GCC limitation would be to locate the __stack_chk_guard variable into a memory page of its own for each CPU, and then use TLB locking to have each CPU see its own page at the same virtual address for each of them. Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* ARM: dma-mapping: provide per-cpu type map/unmap functionsRussell King2010-02-151-0/+5
| | | | | Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
* arm: use kbuild.h instead of macros in asm-offsets.cChristoph Lameter2008-04-291-7/+1
| | | | | | | Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add a prefetch abort handlerPaul Brook2008-04-181-0/+7
| | | | | | | | | This patch adds a prefetch abort handler similar to the data abort one and renames the latter for consistency. Initial implementation by Paul Brook with some renaming by Catalin Marinas. Signed-off-by: Paul Brook <paul@codesourcery.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* ARMv7: Add support for the ThumbEE state saving/restoringCatalin Marinas2008-04-181-0/+3
| | | | | | | This patch adds the detection and handling of the ThumbEE extension on ARMv7 CPUs. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* [ARM] ARMv6: add CPU_HAS_ASID configurationRussell King2007-05-171-1/+1
| | | | | | | | | | | | Presently, we check for the minimum ARM architecture that we're building for to determine whether we need ASID support. This is wrong - if we're going to support a range of CPUs which include ARMv6 or higher, we need the ASID. Convert the checks to use a new configuration symbol, and arrange for ARMv6 and higher CPU entries to select it. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] Include asm/elf.h instead of asm/procinfo.hRussell King2006-11-301-0/+1
| | | | | | | These files want to provide/access ELF hwcap information, so should be including asm/elf.h rather than asm/procinfo.h Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] Set bit 4 on section mappings correctly depending on CPURussell King2006-06-291-1/+2
| | | | | | | | | | | | | | On some CPUs, bit 4 of section mappings means "update the cache when written to". On others, this bit is required to be one, and others it's required to be zero. Finally, on ARMv6 and above, setting it turns on "no execute" and prevents speculative prefetches. With all these combinations, no one value fits all CPUs, so we have to pick a value depending on the CPU type, and the area we're mapping. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] 3370/2: ep93xx: add crunch supportLennert Buytenhek2006-06-281-0/+3
| | | | | | | | | Patch from Lennert Buytenhek Add the necessary kernel bits for crunch task switching. Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>