Commit Graph

7 Commits

Author SHA1 Message Date
Linus Torvalds 82fa407da0 Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
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
  ...
2016-10-06 07:59:37 -07:00
Scott Wood 1d8f51d41f arm/arm64: arch_timer: Use archdata to indicate vdso suitability
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>
2016-09-23 17:19:25 +01:00
Jisheng Zhang 92bb8d5d55 ARM: 8597/1: VDSO: put RO and RO after init objects into proper sections
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>
2016-08-15 18:54:43 +01:00
Prasanna Karthik 38fc2f6c98 ARM: 8476/1: VDSO: use PTR_ERR_OR_ZERO for vma check
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>
2015-12-17 10:29:01 +00:00
Nathan Lynch 09edea4f8f ARM: 8410/1: VDSO: fix coarse clock monotonicity regression
Since 906c55579a ("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: 906c55579a ("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>
2015-08-11 13:42:44 +01:00
Linus Torvalds bb0fd7ab09 Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
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
  ...
2015-04-14 21:03:26 -07:00
Nathan Lynch ecf99a4391 ARM: 8331/1: VDSO initialization, mapping, and synchronization
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>
2015-03-27 22:20:45 +00:00