select HAVE_ARCH_SOFT_DIRTY if X86_64
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
- select HAVE_BPF_JIT if X86_64
+ select HAVE_EBPF_JIT if X86_64
select HAVE_CC_STACKPROTECTOR
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select HAVE_EXIT_THREAD
select HAVE_FENTRY if X86_64
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_GRAPH_FP_TEST
select HAVE_MEMBLOCK
select HAVE_MEMBLOCK_NODE_MAP
select HAVE_MIXED_BREAKPOINTS_REGS
+ select HAVE_NMI
select HAVE_OPROFILE
select HAVE_OPTPROBES
select HAVE_PCSPKR_PLATFORM
def_bool y
depends on KPROBES || PERF_EVENTS || UPROBES
-config PERF_EVENTS_INTEL_UNCORE
- def_bool y
- depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
-
config OUTPUT_FORMAT
string
default "elf32-i386" if X86_32
def_bool y
depends on X86_MCE_INTEL
+source "arch/x86/events/Kconfig"
+
config X86_LEGACY_VM86
bool "Legacy VM86 support"
default n
def_bool y
depends on MICROCODE
-config PERF_EVENTS_AMD_POWER
- depends on PERF_EVENTS && CPU_SUP_AMD
- tristate "AMD Processor Power Reporting Mechanism"
- ---help---
- Provide power reporting mechanism support for AMD processors.
- Currently, it leverages X86_FEATURE_ACC_POWER
- (CPUID Fn8000_0007_EDX[12]) interface to calculate the
- average power consumption on Family 15h processors.
-
config X86_MSR
tristate "/dev/cpu/*/msr - Model-specific register support"
---help---
(CONFIG_PHYSICAL_START) is used as the minimum location.
config RANDOMIZE_BASE
- bool "Randomize the address of the kernel image"
+ bool "Randomize the address of the kernel image (KASLR)"
depends on RELOCATABLE
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 RDTSC is supported, it is used as well. If
- neither RDRAND nor RDTSC are supported, then randomness is
- read from the i8254 timer.
-
- The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
- and aligned according to PHYSICAL_ALIGN. Since the kernel is
- built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
- minimum of 2MiB, only 10 bits of entropy is theoretically
- possible. At best, due to page table layouts, 64-bit can use
- 9 bits of entropy and 32-bit uses 8 bits.
-
- If unsure, say N.
-
-config RANDOMIZE_BASE_MAX_OFFSET
- hex "Maximum kASLR offset allowed" if EXPERT
- 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---
- The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
- memory is used to determine the maximal offset in bytes that will
- be applied to the kernel when kernel Address Space Layout
- Randomization (kASLR) is active. This must be a multiple of
- PHYSICAL_ALIGN.
-
- On 32-bit this is limited to 512MiB by page table layouts. The
- default is 512MiB.
+ In support of Kernel Address Space Layout Randomization (KASLR),
+ this randomizes the physical address at which the kernel image
+ is decompressed and the virtual address where the kernel
+ image is mapped, as a security feature that deters exploit
+ attempts relying on knowledge of the location of kernel
+ code internals.
+
+ On 64-bit, the kernel physical and virtual addresses are
+ randomized separately. The physical address will be anywhere
+ between 16MB and the top of physical memory (up to 64TB). The
+ virtual address will be randomized from 16MB up to 1GB (9 bits
+ of entropy). Note that this also reduces the memory space
+ available to kernel modules from 1.5GB to 1GB.
+
+ On 32-bit, the kernel physical and virtual addresses are
+ randomized together. They will be randomized from 16MB up to
+ 512MB (8 bits of entropy).
+
+ Entropy is generated using the RDRAND instruction if it is
+ supported. If RDTSC is supported, its value is mixed into
+ the entropy pool as well. If neither RDRAND nor RDTSC are
+ supported, then entropy is read from the i8254 timer. The
+ usable entropy is limited by the kernel being built using
+ 2GB addressing, and that PHYSICAL_ALIGN must be at a
+ minimum of 2MB. As a result, only 10 bits of entropy are
+ theoretically possible, but the implementations are further
+ limited due to memory layouts.
+
+ If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
+ time. To enable it, boot with "kaslr" on the kernel command
+ line (which will also disable hibernation).
- On 64-bit this is limited by how the kernel fixmap page table is
- positioned, so this cannot be larger than 1GiB currently. Without
- RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
- and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
- modules area will shrink to compensate, up to the current maximum
- 1GiB to 1GiB split. The default is 1GiB.
-
- If unsure, leave at the default value.
+ If unsure, say N.
# Relocation on x86 needs some additional build support
config X86_NEED_RELOCS
Don't change this unless you know what you are doing.
+config RANDOMIZE_MEMORY
+ bool "Randomize the kernel memory sections"
+ depends on X86_64
+ depends on RANDOMIZE_BASE
+ default RANDOMIZE_BASE
+ ---help---
+ Randomizes the base virtual address of kernel memory sections
+ (physical memory mapping, vmalloc & vmemmap). This security feature
+ makes exploits relying on predictable memory locations less reliable.
+
+ The order of allocations remains unchanged. Entropy is generated in
+ the same way as RANDOMIZE_BASE. Current implementation in the optimal
+ configuration have in average 30,000 different possible virtual
+ addresses for each memory section.
+
+ If unsure, say N.
+
config HOTPLUG_CPU
bool "Support for hot-pluggable CPUs"
depends on SMP
source "drivers/pci/Kconfig"
+config ISA_BUS
+ bool "ISA-style bus support on modern systems" if EXPERT
+ select ISA_BUS_API
+ help
+ Enables ISA-style drivers on modern systems. This is necessary to
+ support PC/104 devices on X86_64 platforms.
+
+ If unsure, say N.
+
# x86_64 have no ISA slots, but can have ISA-style DMA.
config ISA_DMA_API
bool "ISA-style DMA support" if (X86_64 && EXPERT)
git.samba.org / sfrench / cifs-2.6.git / blobdiff