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.
+ 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.
+
+ The kernel physical and virtual address can be randomized
+ from 16MB up to 1GB on 64-bit and 512MB on 32-bit. (Note that
+ using RANDOMIZE_BASE reduces the memory space available to
+ kernel modules from 1.5GB to 1GB.)
+
+ 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.
+
+ Since the kernel is built using 2GB addressing, and
+ PHYSICAL_ALIGN must be at a minimum of 2MB, only 10 bits of
+ entropy is theoretically possible. Currently, with the
+ default value for PHYSICAL_ALIGN and due to page table
+ layouts, 64-bit uses 9 bits of entropy and 32-bit uses 8 bits.
+
+ 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).
- 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.
-
- 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
projects / cascardo / linux.git / blobdiff