Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64...

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / Kconfig

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7c1dbeb73e8d3505c1213461afd6c8e2f0559828..b8d96f1554af11aef71af0627278925f244067a9 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1,6 +1,5 @@
 config ARM64
        def_bool y
-       select ARCH_BINFMT_ELF_RANDOMIZE_PIE
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_HAS_ELF_RANDOMIZE
        select ARCH_HAS_GCOV_PROFILE_ALL
@@ -369,6 +368,27 @@ config ARM64_ERRATUM_832075
 
          If unsure, say Y.
 
+config ARM64_ERRATUM_845719
+       bool "Cortex-A53: 845719: a load might read incorrect data"
+       depends on COMPAT
+       default y
+       help
+         This option adds an alternative code sequence to work around ARM
+         erratum 845719 on Cortex-A53 parts up to r0p4.
+
+         When running a compat (AArch32) userspace on an affected Cortex-A53
+         part, a load at EL0 from a virtual address that matches the bottom 32
+         bits of the virtual address used by a recent load at (AArch64) EL1
+         might return incorrect data.
+
+         The workaround is to write the contextidr_el1 register on exception
+         return to a 32-bit task.
+         Please note that this does not necessarily enable the workaround,
+         as it depends on the alternative framework, which will only patch
+         the kernel if an affected CPU is detected.
+
+         If unsure, say Y.
+
 endmenu
 
 
@@ -456,8 +476,8 @@ config SCHED_SMT
          places. If unsure say N here.
 
 config NR_CPUS
-       int "Maximum number of CPUs (2-64)"
-       range 2 64
+       int "Maximum number of CPUs (2-4096)"
+       range 2 4096
        depends on SMP
        # These have to remain sorted largest to smallest
        default "64"
@@ -471,6 +491,10 @@ config HOTPLUG_CPU
 
 source kernel/Kconfig.preempt
 
+config UP_LATE_INIT
+       def_bool y
+       depends on !SMP
+
 config HZ
        int
        default 100
@@ -671,7 +695,7 @@ source "fs/Kconfig.binfmt"
 
 config COMPAT
        bool "Kernel support for 32-bit EL0"
-       depends on !ARM64_64K_PAGES
+       depends on !ARM64_64K_PAGES || EXPERT
        select COMPAT_BINFMT_ELF
        select HAVE_UID16
        select OLD_SIGSUSPEND3
@@ -682,6 +706,10 @@ config COMPAT
          the user helper functions, VFP support and the ptrace interface are
          handled appropriately by the kernel.
 
+         If you also enabled CONFIG_ARM64_64K_PAGES, please be aware that you
+         will only be able to execute AArch32 binaries that were compiled with
+         64k aligned segments.
+
          If you want to execute 32-bit userspace applications, say Y.
 
 config SYSVIPC_COMPAT