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2020-12-15mm: forbid splitting special mappingsDmitry Safonov1-9/+0
Don't allow splitting of vm_special_mapping's. It affects vdso/vvar areas. Uprobes have only one page in xol_area so they aren't affected. Those restrictions were enforced by checks in .mremap() callbacks. Restrict resizing with generic .split() callback. Link: https://lkml.kernel.org/r/20201013013416.390574-7-dima@arista.com Signed-off-by: Dmitry Safonov <dima@arista.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Geffon <bgeffon@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-21ARM: 8987/1: VDSO: Fix incorrect clock_gettime64Jaedon Shin1-0/+1
__vdso_*() should be removed and fallback used if CNTCVT is not available by cntvct_functional(). __vdso_clock_gettime64 when added previous commit is using the incorrect CNTCVT value in that state. __vdso_clock_gettime64 is also added to remove it's symbol. Cc: stable@vger.kernel.org Fixes: 74d06efb9c2f ("ARM: 8932/1: Add clock_gettime64 entry point") Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com> Tested-by: Robin Murphy <robin.mruphy@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2020-06-09mmap locking API: convert mmap_sem commentsMichel Lespinasse1-1/+1
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-21ARM: 8957/1: VDSO: Match ARMv8 timer in cntvct_functional()Florian Fainelli1-0/+2
It is possible for a system with an ARMv8 timer to run a 32-bit kernel. When this happens we will unconditionally have the vDSO code remove the __vdso_gettimeofday and __vdso_clock_gettime symbols because cntvct_functional() returns false since it does not match that compatibility string. Fixes: ecf99a439105 ("ARM: 8331/1: VDSO initialization, mapping, and synchronization") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15ARM: 8930/1: Add support for generic vDSOVincenzo Frascino1-83/+4
The arm vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library. Introduce the following changes: - Modification vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday - Implementation of elf note Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-08-23ARM: 8896/1: VDSO: Don't leak kernel addressesGeert Uytterhoeven1-1/+0
Since commit ad67b74d2469d9b8 ("printk: hash addresses printed with %p"), an obfuscated kernel pointer is printed at every boot if debugging is enabled: vdso: 1 text pages at base (____ptrval____) Remove the print completely, as it's useless without the address. Based on commit 0f1bf7e39822476b ("arm64/vdso: don't leak kernel addresses"). Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner1-12/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-24ARM: 8748/1: mm: Define vdso_start, vdso_end as arrayJinbum Park1-5/+7
Define vdso_start, vdso_end as array to avoid compile-time analysis error for the case of built with CONFIG_FORTIFY_SOURCE. and, since vdso_start, vdso_end are used in vdso.c only, move extern-declaration from vdso.h to vdso.c. If kernel is built with CONFIG_FORTIFY_SOURCE, compile-time error happens at this code. - if (memcmp(&vdso_start, "177ELF", 4)) The size of "&vdso_start" is recognized as 1 byte, but n is 4, So that compile-time error is reported. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jinbum Park <jinb.park7@gmail.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-06-21ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSODmitry Safonov1-0/+18
CRIU restores application mappings on the same place where they were before Checkpoint. That means, that we need to move vDSO and sigpage during restore on exactly the same place where they were before C/R. Make mremap() code update mm->context.{sigpage,vdso} pointers during VMA move. Sigpage is used for landing after handling a signal - if the pointer is not updated during moving, the application might crash on any signal after mremap(). vDSO pointer on ARM32 is used only for setting auxv at this moment, update it during mremap() in case of future usage. Without those updates, current work of CRIU on ARM32 is not reliable. Historically, we error Checkpointing if we find vDSO page on ARM32 and suggest user to disable CONFIG_VDSO. But that's not correct - it goes from x86 where signal processing is ended in vDSO blob. For arm32 it's sigpage, which is not disabled with `CONFIG_VDSO=n'. Looks like C/R was working by luck - because userspace on ARM32 at this moment always sets SA_RESTORER. Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: linux-arm-kernel@lists.infradead.org Cc: Will Deacon <will.deacon@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Christopher Covington <cov@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2016-10-06Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds1-5/+6
Pull ARM updates from Russell King: - Correct ARMs dma-mapping to use the correct printk format strings. - Avoid defining OBJCOPYFLAGS globally which upsets lkdtm rodata testing. - Cleanups to ARMs asm/memory.h include. - L2 cache cleanups. - Allow flat nommu binaries to be executed on ARM MMU systems. - Kernel hardening - add more read-only after init annotations, including making some kernel vdso variables const. - Ensure AMBA primecell clocks are appropriately defaulted. - ARM breakpoint cleanup. - Various StrongARM 11x0 and companion chip (SA1111) updates to bring this legacy platform to use more modern APIs for (eg) GPIOs and interrupts, which will allow us in the future to reduce some of the board-level driver clutter and elimate function callbacks into board code via platform data. There still appears to be interest in these platforms! - Remove the now redundant secure_flush_area() API. - Module PLT relocation optimisations. Ard says: This series of 4 patches optimizes the ARM PLT generation code that is invoked at module load time, to get rid of the O(n^2) algorithm that results in pathological load times of 10 seconds or more for large modules on certain STB platforms. - ARMv7M cache maintanence support. - L2 cache PMU support * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (35 commits) ARM: sa1111: provide to_sa1111_device() macro ARM: sa1111: add sa1111_get_irq() ARM: sa1111: clean up duplication in IRQ chip implementation ARM: sa1111: implement a gpio_chip for SA1111 GPIOs ARM: sa1111: move irq cleanup to separate function ARM: sa1111: use devm_clk_get() ARM: sa1111: use devm_kzalloc() ARM: sa1111: ensure we only touch RAB bus type devices when removing ARM: 8611/1: l2x0: add PMU support ARM: 8610/1: V7M: Add dsb before jumping in handler mode ARM: 8609/1: V7M: Add support for the Cortex-M7 processor ARM: 8608/1: V7M: Indirect proc_info construction for V7M CPUs ARM: 8607/1: V7M: Wire up caches for V7M processors with cache support. ARM: 8606/1: V7M: introduce cache operations ARM: 8605/1: V7M: fix notrace variant of save_and_disable_irqs ARM: 8604/1: V7M: Add support for reading the CTR with read_cpuid_cachetype() ARM: 8603/1: V7M: Add addresses for mem-mapped V7M cache operations ARM: 8602/1: factor out CSSELR/CCSIDR operations that use cp15 directly ARM: kernel: avoid brute force search on PLT generation ARM: kernel: sort relocation sections before allocating PLTs ...
2016-09-23arm/arm64: arch_timer: Use archdata to indicate vdso suitabilityScott Wood1-1/+1
Instead of comparing the name to a magic string, use archdata to explicitly communicate whether the arch timer is suitable for direct vdso access. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Scott Wood <oss@buserror.net> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-15ARM: 8597/1: VDSO: put RO and RO after init objects into proper sectionsJisheng Zhang1-5/+6
vdso_data_mapping is never modified, so mark it as const. vdso_total_pages, vdso_data_page, vdso_text_mapping and cntvct_ok are initialized by vdso_init(), thereafter are read only. The fact that they are read only after init makes them candidates for __ro_after_init declarations. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Nathan Lynch <nathan_lynch@mentor.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-17ARM: 8476/1: VDSO: use PTR_ERR_OR_ZERO for vma checkPrasanna Karthik1-1/+1
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR Signed-off-by: Prasanna Karthik <mkarthi3@visteon.com> Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-11ARM: 8410/1: VDSO: fix coarse clock monotonicity regressionNathan Lynch1-4/+3
Since 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last") it has become possible on ARM to: - Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp via syscall. - Subsequently obtain a timestamp for the same clock ID via VDSO which predates the first timestamp (by one jiffy). This is because ARM's update_vsyscall is deriving the coarse time using the __current_kernel_time interface, when it should really be using the timekeeper object provided to it by the timekeeping core. It happened to work before only because __current_kernel_time would access the same timekeeper object which had been passed to update_vsyscall. This is no longer the case. Cc: stable@vger.kernel.org Fixes: 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last") Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-14Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds1-0/+337
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 ...
2015-03-27ARM: 8331/1: VDSO initialization, mapping, and synchronizationNathan Lynch1-0/+337
Initialize the VDSO page list at boot, install the VDSO mapping at exec time, and update the data page during timer ticks. This code is not built if CONFIG_VDSO is not enabled. Account for the VDSO length when randomizing the offset from the stack. The [vdso] and [vvar] pages are placed immediately following the sigpage with separate _install_special_mapping calls. We want to "penalize" systems lacking the arch timer as little as possible. Previous versions of this code installed the VDSO unconditionally and unmodified, making it a measurably slower way for glibc to invoke the real syscalls on such systems. E.g. calling gettimeofday via glibc goes from ~560ns to ~630ns on i.MX6Q. If we can indicate to glibc that the time-related APIs in the VDSO are not accelerated, glibc can continue to invoke the syscalls directly instead of dispatching through the VDSO only to fall back to the slow path. Thus, if the architected timer is unusable for whatever reason, patch the VDSO at boot time so that symbol lookups for gettimeofday and clock_gettime return NULL. (This is similar to what powerpc does and borrows code from there.) This allows glibc to perform the syscall directly instead of passing control to the VDSO, which minimizes the penalty. In my measurements the time taken for a gettimeofday call via glibc goes from ~560ns to ~580ns (again on i.MX6Q), and this is solely due to adding a test and branch to glibc's gettimeofday syscall wrapper. An alternative to patching the VDSO at boot would be to not install the VDSO at all when the arch timer isn't usable. Another alternative is to include a separate "dummy" vdso.so without gettimeofday and clock_gettime, which would be selected at boot time. Either of these would get cumbersome if the VDSO were to gain support for an API such as getcpu which is unrelated to arch timer support. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>