X-Git-Url: https://git.karo-electronics.de/?p=karo-tx-linux.git;a=blobdiff_plain;f=arch%2Fx86%2FKconfig;h=591b19ec8af8216954888958c315195e3fe14ce4;hp=e0836de76f3c90dcb57ec0e7bbfb293cb7d0ca99;hb=955b2fee301c6fc3565e0b3f071236287b06d379;hpb=ef5bfcc8f2afb0fa3ee1a38a80bf1b16a9a0d01e

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e0836de76f3c..591b19ec8af8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -124,6 +124,7 @@ config X86
 	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
@@ -753,20 +754,25 @@ config DMI
 	  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"
@@ -1591,7 +1597,7 @@ config EFI_STUB
           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
@@ -1720,16 +1726,56 @@ config RELOCATABLE
 
 	  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---