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* Merge tag 'arm64-upstream' of ↵Linus Torvalds2015-11-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - "genirq: Introduce generic irq migration for cpu hotunplugged" patch merged from tip/irq/for-arm to allow the arm64-specific part to be upstreamed via the arm64 tree - CPU feature detection reworked to cope with heterogeneous systems where CPUs may not have exactly the same features. The features reported by the kernel via internal data structures or ELF_HWCAP are delayed until all the CPUs are up (and before user space starts) - Support for 16KB pages, with the additional bonus of a 36-bit VA space, though the latter only depending on EXPERT - Implement native {relaxed, acquire, release} atomics for arm64 - New ASID allocation algorithm which avoids IPI on roll-over, together with TLB invalidation optimisations (using local vs global where feasible) - KASan support for arm64 - EFI_STUB clean-up and isolation for the kernel proper (required by KASan) - copy_{to,from,in}_user optimisations (sharing the memcpy template) - perf: moving arm64 to the arm32/64 shared PMU framework - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware - Support for the contiguous PTE hint on kernel mapping (16 consecutive entries may be able to use a single TLB entry) - Generic CONFIG_HZ now used on arm64 - defconfig updates * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits) arm64/efi: fix libstub build under CONFIG_MODVERSIONS ARM64: Enable multi-core scheduler support by default arm64/efi: move arm64 specific stub C code to libstub arm64: page-align sections for DEBUG_RODATA arm64: Fix build with CONFIG_ZONE_DMA=n arm64: Fix compat register mappings arm64: Increase the max granular size arm64: remove bogus TASK_SIZE_64 check arm64: make Timer Interrupt Frequency selectable arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED arm64: cachetype: fix definitions of ICACHEF_* flags arm64: cpufeature: declare enable_cpu_capabilities as static genirq: Make the cpuhotplug migration code less noisy arm64: Constify hwcap name string arrays arm64/kvm: Make use of the system wide safe values arm64/debug: Make use of the system wide safe value arm64: Move FP/ASIMD hwcap handling to common code arm64/HWCAP: Use system wide safe values arm64/capabilities: Make use of system wide safe value arm64: Delay cpu feature capability checks ...
| * arm64: Delay cpu feature capability checksSuzuki K. Poulose2015-10-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment we run through the arm64_features capability list for each CPU and set the capability if one of the CPU supports it. This could be problematic in a heterogeneous system with differing capabilities. Delay the CPU feature checks until all the enabled CPUs are up(i.e, smp_cpus_done(), so that we can make better decisions based on the overall system capability. Once we decide and advertise the capabilities the alternatives can be applied. From this state, we cannot roll back a feature to disabled based on the values from a new hotplugged CPU, due to the runtime patching and other reasons. So, for all new CPUs, we need to make sure that they have the established system capabilities. Failing which, we bring the CPU down, preventing it from turning online. Once the capabilities are decided, any new CPU booting up goes through verification to ensure that it has all the enabled capabilities and also invokes the respective enable() method on the CPU. The CPU errata checks are not delayed and is still executed per-CPU to detect the respective capabilities. If we ever come across a non-errata capability that needs to be checked on each-CPU, we could introduce them via a new capability table(or introduce a flag), which can be processed per CPU. The next patch will make the feature checks use the system wide safe value of a feature register. NOTE: The enable() methods associated with the capability is scheduled on all the CPUs (which is the only use case at the moment). If we need a different type of 'enable()' which only needs to be run once on any CPU, we should be able to handle that when needed. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> [catalin.marinas@arm.com: static variable and coding style fixes] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | arm64: readahead: fault retry breaks mmap file read random detectionMark Salyzyn2015-10-05
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | This is the arm64 portion of commit 45cac65b0fcd ("readahead: fault retry breaks mmap file read random detection"), which was absent from the initial port and has since gone unnoticed. The original commit says: > .fault now can retry. The retry can break state machine of .fault. In > filemap_fault, if page is miss, ra->mmap_miss is increased. In the second > try, since the page is in page cache now, ra->mmap_miss is decreased. And > these are done in one fault, so we can't detect random mmap file access. > > Add a new flag to indicate .fault is tried once. In the second try, skip > ra->mmap_miss decreasing. The filemap_fault state machine is ok with it. With this change, Mark reports that: > Random read improves by 250%, sequential read improves by 40%, and > random write by 400% to an eMMC device with dm crypto wrapped around it. Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Riley Andrews <riandrews@android.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64/BUG: Use BRK instruction for generic BUG trapsDave P Martin2015-07-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the minimal default BUG() implementation from asm- generic is used for arm64. This patch uses the BRK software breakpoint instruction to generate a trap instead, similarly to most other arches, with the generic BUG code generating the dmesg boilerplate. This allows bug metadata to be moved to a separate table and reduces the amount of inline code at BUG and WARN sites. This also avoids clobbering any registers before they can be dumped. To mitigate the size of the bug table further, this patch makes use of the existing infrastructure for encoding addresses within the bug table as 32-bit offsets instead of absolute pointers. (Note that this limits the kernel size to 2GB.) Traps are registered at arch_initcall time for aarch64, but BUG has minimal real dependencies and it is desirable to be able to generate bug splats as early as possible. This patch redirects all debug exceptions caused by BRK directly to bug_handler() until the full debug exception support has been initialised. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: kernel: Add support for Privileged Access NeverJames Morse2015-07-27
| | | | | | | | | | | | | | | | | 'Privileged Access Never' is a new arm8.1 feature which prevents privileged code from accessing any virtual address where read or write access is also permitted at EL0. This patch enables the PAN feature on all CPUs, and modifies {get,put}_user helpers temporarily to permit access. This will catch kernel bugs where user memory is accessed directly. 'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use ALTERNATIVE in asm and tidy up pan_enable check] Signed-off-by: Will Deacon <will.deacon@arm.com>
* Merge tag 'arm64-fixes' of ↵Linus Torvalds2015-07-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes (and cleanups) from Catalin Marinas: "Various arm64 fixes: - suspicious RCU usage warning - BPF (out of bounds array read and endianness conversion) - perf (of_node usage after of_node_put, cpu_pmu->plat_device assignment) - huge pmd/pud check for value 0 - rate-limiting should only take unhandled signals into account Clean-up: - incorrect use of pgprot_t type - unused header include - __init annotation to arm_cpuidle_init - pr_debug instead of pr_error for disabled GICC entries in ACPI/MADT" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Fix show_unhandled_signal_ratelimited usage ARM64 / SMP: Switch pr_err() to pr_debug() for disabled GICC entry arm64: cpuidle: add __init section marker to arm_cpuidle_init arm64: Don't report clear pmds and puds as huge arm64: perf: fix unassigned cpu_pmu->plat_device when probing PMU PPIs arm64: perf: Don't use of_node after putting it arm64: fix incorrect use of pgprot_t variable arm64/hw_breakpoint.c: remove unnecessary header arm64: bpf: fix endianness conversion bugs arm64: bpf: fix out-of-bounds read in bpf2a64_offset() ARM64: smp: Fix suspicious RCU usage with ipi tracepoints
| * arm64: Fix show_unhandled_signal_ratelimited usageSuzuki K. Poulose2015-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 86dca36e6ba introduced ratelimited usage for 'unhandled_signal' messages. The commit checks the ratelimit irrespective of whether the signal is handled or not, which is wrong and leads to false reports like the below in dmesg : __do_user_fault: 127 callbacks suppressed Do the ratelimit check only if the signal is unhandled. Fixes: 86dca36e6ba0 ("arm64: use private ratelimit state along with show_unhandled_signals") Cc: Vladimir Murzin <Vladimir.Murzin@arm.com> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | Merge tag 'arm64-upstream' of ↵Linus Torvalds2015-06-24
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Mostly refactoring/clean-up: - CPU ops and PSCI (Power State Coordination Interface) refactoring following the merging of the arm64 ACPI support, together with handling of Trusted (secure) OS instances - Using fixmap for permanent FDT mapping, removing the initial dtb placement requirements (within 512MB from the start of the kernel image). This required moving the FDT self reservation out of the memreserve processing - Idmap (1:1 mapping used for MMU on/off) handling clean-up - Removing flush_cache_all() - not safe on ARM unless the MMU is off. Last stages of CPU power down/up are handled by firmware already - "Alternatives" (run-time code patching) refactoring and support for immediate branch patching, GICv3 CPU interface access - User faults handling clean-up And some fixes: - Fix for VDSO building with broken ELF toolchains - Fix another case of init_mm.pgd usage for user mappings (during ASID roll-over broadcasting) - Fix for FPSIMD reloading after CPU hotplug - Fix for missing syscall trace exit - Workaround for .inst asm bug - Compat fix for switching the user tls tpidr_el0 register" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits) arm64: use private ratelimit state along with show_unhandled_signals arm64: show unhandled SP/PC alignment faults arm64: vdso: work-around broken ELF toolchains in Makefile arm64: kernel: rename __cpu_suspend to keep it aligned with arm arm64: compat: print compat_sp instead of sp arm64: mm: Fix freeing of the wrong memmap entries with !SPARSEMEM_VMEMMAP arm64: entry: fix context tracking for el0_sp_pc arm64: defconfig: enable memtest arm64: mm: remove reference to tlb.S from comment block arm64: Do not attempt to use init_mm in reset_context() arm64: KVM: Switch vgic save/restore to alternative_insn arm64: alternative: Introduce feature for GICv3 CPU interface arm64: psci: fix !CONFIG_HOTPLUG_CPU build warning arm64: fix bug for reloading FPSIMD state after CPU hotplug. arm64: kernel thread don't need to save fpsimd context. arm64: fix missing syscall trace exit arm64: alternative: Work around .inst assembler bugs arm64: alternative: Merge alternative-asm.h into alternative.h arm64: alternative: Allow immediate branch as alternative instruction arm64: Rework alternate sequence for ARM erratum 845719 ...
| * arm64: use private ratelimit state along with show_unhandled_signalsVladimir Murzin2015-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | printk_ratelimit() shares the ratelimiting state with other callers what may lead to scenarios where at the time we want to print out debug information we already limited, so nothing appears in the dmesg - this makes exception-trace quite poor helper in debugging. Additionally, we have imbalance with some messages limited with global ratelimit state and other messages limited with their private state defined via pr_*_ratelimited(). To address this inconsistency show_unhandled_signals_ratelimited() macro is introduced and caller sites are converted to use it. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| * arm64: show unhandled SP/PC alignment faultsVladimir Murzin2015-06-19
| | | | | | | | | | | | | | | | Report unhandled SP/PC alignment faults if the show_unhandled_signals variable is set (via /proc/sys/debug/exception-trace). Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in ↵David Hildenbrand2015-05-19
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the handler Introduce faulthandler_disabled() and use it to check for irq context and disabled pagefaults (via pagefault_disable()) in the pagefault handlers. Please note that we keep the in_atomic() checks in place - to detect whether in irq context (in which case preemption is always properly disabled). In contrast, preempt_disable() should never be used to disable pagefaults. With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt counter, and therefore the result of in_atomic() differs. We validate that condition by using might_fault() checks when calling might_sleep(). Therefore, add a comment to faulthandler_disabled(), describing why this is needed. faulthandler_disabled() and pagefault_disable() are defined in linux/uaccess.h, so let's properly add that include to all relevant files. This patch is based on a patch from Thomas Gleixner. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* arm64: move to ESR_ELx macrosMark Rutland2015-01-15
| | | | | | | | | | | | | | Now that we have common ESR_ELx_* macros, move the core arm64 code over to them. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Will Deacon <will.deacon@arm.com>
* arm64: mm: report unhandled level-0 translation faults correctlyWill Deacon2014-11-21
| | | | | | | | | | | | | | | | | Translation faults that occur due to the input address being outside of the address range mapped by the relevant base register are reported as level 0 faults in ESR.DFSC. If the faulting access cannot be resolved by the kernel (e.g. because it is not mapped by a vma), then we report "input address range fault" on the console. This was fine until we added support for 48-bit VAs, which actually place PGDs at level 0 and can trigger faults for invalid addresses that are within the range of the page tables. This patch changes the string to report "level 0 translation fault", which is far less confusing. Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: mm: Implement 4 levels of translation tablesJungseok Lee2014-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements 4 levels of translation tables since 3 levels of page tables with 4KB pages cannot support 40-bit physical address space described in [1] due to the following issue. It is a restriction that kernel logical memory map with 4KB + 3 levels (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from 544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create mapping for this region in map_mem function since __phys_to_virt for this region reaches to address overflow. If SoC design follows the document, [1], over 32GB RAM would be placed from 544GB. Even 64GB system is supposed to use the region from 544GB to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels of page tables to avoid hacking __virt_to_phys and __phys_to_virt. However, it is recommended 4 levels of page table should be only enabled if memory map is too sparse or there is about 512GB RAM. References ---------- [1]: Principles of ARM Memory Maps, White Paper, Issue C Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE] [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels] [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
* Revert "arm64: Introduce execute-only page access permissions"Catalin Marinas2014-05-16
| | | | | | | | | | | This reverts commit bc07c2c6e9ed125d362af0214b6313dca180cb08. While the aim is increased security for --x memory maps, it does not protect against kernel level reads. Until SECCOMP is implemented for arm64, revert this patch to avoid giving a false idea of execute-only mappings. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Introduce execute-only page access permissionsCatalin Marinas2014-05-09
| | | | | | | | | | | | | | | | The ARMv8 architecture allows execute-only user permissions by clearing the PTE_UXN and PTE_USER bits. The kernel, however, can still access such page, so execute-only page permission does not protect against read(2)/write(2) etc. accesses. Systems requiring such protection must implement/enable features like SECCOMP. This patch changes the arm64 __P100 and __S100 protection_map[] macros to the new __PAGE_EXECONLY attributes. A side effect is that pte_valid_user() no longer triggers for __PAGE_EXECONLY since PTE_USER isn't set. To work around this, the check is done on the PTE_NG bit via the pte_valid_ng() macro. VM_READ is also checked now for page faults. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Provide read/write fault information in compat signal handlersCatalin Marinas2014-05-09
| | | | | | | | | | For AArch32, bit 11 (WnR) of the FSR/ESR register is set when the fault was caused by a write access and applications like Qemu rely on such information being provided in sigcontext. This patch introduces the ESR_EL1 tracking for the arm64 kernel faults and sets bit 11 accordingly in compat sigcontext. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Make do_bad_area() function staticCatalin Marinas2013-09-20
| | | | | | This function is only called from arch/arm64/mm/fault.c. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arch: mm: pass userspace fault flag to generic fault handlerJohannes Weiner2013-09-12
| | | | | | | | | | | | | | | | | | | | 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: Linus Torvalds <torvalds@linux-foundation.org>
* arch: mm: do not invoke OOM killer on kernel fault OOMJohannes Weiner2013-09-12
| | | | | | | | | | | | | | | | | 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>
* arm64: mm: don't treat user cache maintenance faults as writesWill Deacon2013-07-19
| | | | | | | | | | | | | | On arm64, cache maintenance faults appear as data aborts with the CM bit set in the ESR. The WnR bit, usually used to distinguish between faulting loads and stores, always reads as 1 and (slightly confusingly) the instructions are treated as reads by the architecture. This patch fixes our fault handling code to treat cache maintenance faults in the same way as loads. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* ARM64: mm: HugeTLB support.Steve Capper2013-06-14
| | | | | | | | | | | | | | | | Add huge page support to ARM64, different huge page sizes are supported depending on the size of normal pages: PAGE_SIZE is 4KB: 2MB - (pmds) these can be allocated at any time. 1024MB - (puds) usually allocated on bootup with the command line with something like: hugepagesz=1G hugepages=6 PAGE_SIZE is 64KB: 512MB - (pmds) usually allocated on bootup via command line. Signed-off-by: Steve Capper <steve.capper@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Do not report user faults for handled signalsCatalin Marinas2013-05-24
| | | | | | | | | Currently user faults (page, undefined instruction) are always reported even though the user may have a signal handler for them. This patch adds unhandled_signal() check together with printk_ratelimit() for these cases. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Ignore the 'write' ESR flag on cache maintenance faultsCatalin Marinas2013-05-08
| | | | | | | | | | | | | ESR.WnR bit is always set on data cache maintenance faults even though the page is not required to have write permission. If a translation fault (page not yet mapped) happens for read-only user address range, Linux incorrectly assumes a permission fault. This patch adds the check of the ESR.CM bit during the page fault handling to ignore the 'write' flag. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Tim Northover <Tim.Northover@arm.com> Cc: stable@vger.kernel.org
* arm64: mm: Correct show_pte behaviourSteve Capper2013-04-25
| | | | | | | | | | | | | | | show_pte makes use of the *_none_or_clear_bad style functions. If a pgd, pud or pmd is identified as being bad, it will then be cleared. As show_pte appears to be called from either the user or kernel fault handlers this side effect can lead to unpredictable behaviour; especially as TLB entries are not invalidated. This patch removes the page table sanitisation from show_pte. If a bad pgd, pud or pmd is encountered it is left unmodified. Signed-off-by: Steve Capper <steve.capper@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Make the user fault reporting more specificCatalin Marinas2012-11-14
| | | | | | | | For user space faults the kernel reports "unhandled page fault" and it gives the ESR value. With this patch the error message looked up in the fault info array to give a better description. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: MMU fault handling and page table managementCatalin Marinas2012-09-17
This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>