select COMPAT_OLD_SIGACTION if IA32_EMULATION
select RTC_LIB
select HAVE_DEBUG_STACKOVERFLOW
+ select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
config INSTRUCTION_DECODER
def_bool y
default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
-config ARCH_CPU_PROBE_RELEASE
- def_bool y
- depends on HOTPLUG_CPU
-
config ARCH_SUPPORTS_UPROBES
def_bool y
BIOS code.
config GART_IOMMU
- bool "GART IOMMU support" if EXPERT
- default y
+ bool "Old AMD GART IOMMU support"
select SWIOTLB
depends on X86_64 && PCI && AMD_NB
---help---
- Support for full DMA access of devices with 32bit memory access only
- on systems with more than 3GB. This is usually needed for USB,
- sound, many IDE/SATA chipsets and some other devices.
- Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
- based hardware IOMMU and a software bounce buffer based IOMMU used
- on Intel systems and as fallback.
- The code is only active when needed (enough memory and limited
- device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
- too.
+ Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
+ GART based hardware IOMMUs.
+
+ The GART supports full DMA access for devices with 32-bit access
+ limitations, on systems with more than 3 GB. This is usually needed
+ for USB, sound, many IDE/SATA chipsets and some other devices.
+
+ Newer systems typically have a modern AMD IOMMU, supported via
+ the CONFIG_AMD_IOMMU=y config option.
+
+ In normal configurations this driver is only active when needed:
+ there's more than 3 GB of memory and the system contains a
+ 32-bit limited device.
+
+ If unsure, say Y.
config CALGARY_IOMMU
bool "IBM Calgary IOMMU support"
This kernel feature allows a bzImage to be loaded directly
by EFI firmware without the use of a bootloader.
- See Documentation/x86/efi-stub.txt for more information.
+ See Documentation/efi-stub.txt for more information.
config SECCOMP
def_bool y
Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
it has been loaded at and the compile time physical address
- (CONFIG_PHYSICAL_START) is ignored.
+ (CONFIG_PHYSICAL_START) is used as the minimum location.
-# Relocation on x86-32 needs some additional build support
+config RANDOMIZE_BASE
+ bool "Randomize the address of the kernel image"
+ depends on RELOCATABLE
+ depends on !HIBERNATION
+ default n
+ ---help---
+ Randomizes the physical and virtual address at which the
+ kernel image is decompressed, as a security feature that
+ deters exploit attempts relying on knowledge of the location
+ of kernel internals.
+
+ Entropy is generated using the RDRAND instruction if it
+ is supported. If not, then RDTSC is used, if supported. If
+ neither RDRAND nor RDTSC are supported, then no randomness
+ is introduced.
+
+ The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
+ and aligned according to PHYSICAL_ALIGN.
+
+config RANDOMIZE_BASE_MAX_OFFSET
+ hex "Maximum ASLR offset allowed"
+ depends on RANDOMIZE_BASE
+ range 0x0 0x20000000 if X86_32
+ default "0x20000000" if X86_32
+ range 0x0 0x40000000 if X86_64
+ default "0x40000000" if X86_64
+ ---help---
+ Determines the maximal offset in bytes that will be applied to the
+ kernel when Address Space Layout Randomization (ASLR) is active.
+ Must be less than or equal to the actual physical memory on the
+ system. This must be a multiple of CONFIG_PHYSICAL_ALIGN.
+
+ On 32-bit this is limited to 512MiB.
+
+ On 64-bit this is limited by how the kernel fixmap page table is
+ positioned, so this cannot be larger that 1GiB currently. Normally
+ there is a 512MiB to 1.5GiB split between kernel and modules. When
+ this is raised above the 512MiB default, the modules area will
+ shrink to compensate, up to the current maximum 1GiB to 1GiB split.
+
+# Relocation on x86 needs some additional build support
config X86_NEED_RELOCS
def_bool y
- depends on X86_32 && RELOCATABLE
+ depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
config PHYSICAL_ALIGN
hex "Alignment value to which kernel should be aligned"
- default "0x1000000"
+ default "0x200000"
range 0x2000 0x1000000 if X86_32
range 0x200000 0x1000000 if X86_64
---help---