config KERNEL_ARM_PMU
bool
- default n
+ default y if TARGET_armsr_armv8
depends on (arm || aarch64)
config KERNEL_X86_VSYSCALL_EMULATION
bool "Enable vsyscall emulation"
- default n
depends on x86_64
help
This enables emulation of the legacy vsyscall page. Disabling
config KERNEL_PERF_EVENTS
bool "Compile the kernel with performance events and counters"
- default n
select KERNEL_ARM_PMU if (arm || aarch64)
config KERNEL_PROFILING
bool "Compile the kernel with profiling enabled"
- default n
select KERNEL_PERF_EVENTS
help
Enable the extended profiling support mechanisms used by profilers such
will have no effect.
if KERNEL_KASAN
- config KERNEL_KASAN_GENERIC
- def_bool y
+choice
+ prompt "KASAN mode"
+ depends on KERNEL_KASAN
+ default KERNEL_KASAN_GENERIC
+ help
+ KASAN has three modes:
+
+ 1. Generic KASAN (supported by many architectures, enabled with
+ CONFIG_KASAN_GENERIC, similar to userspace ASan),
+ 2. Software Tag-Based KASAN (arm64 only, based on software memory
+ tagging, enabled with CONFIG_KASAN_SW_TAGS, similar to userspace
+ HWASan), and
+ 3. Hardware Tag-Based KASAN (arm64 only, based on hardware memory
+ tagging, enabled with CONFIG_KASAN_HW_TAGS).
+
+config KERNEL_KASAN_GENERIC
+ bool "Generic KASAN"
+ select KERNEL_SLUB_DEBUG
+ help
+ Enables Generic KASAN.
+
+ Consumes about 1/8th of available memory at kernel start and adds an
+ overhead of ~50% for dynamic allocations.
+ The performance slowdown is ~x3.
+
+config KERNEL_KASAN_SW_TAGS
+ bool "Software Tag-Based KASAN"
+ depends on aarch64
+ select KERNEL_SLUB_DEBUG
+ help
+ Enables Software Tag-Based KASAN.
+
+ Supported only on arm64 CPUs and relies on Top Byte Ignore.
+
+ Consumes about 1/16th of available memory at kernel start and
+ add an overhead of ~20% for dynamic allocations.
+
+ May potentially introduce problems related to pointer casting and
+ comparison, as it embeds a tag into the top byte of each pointer.
+
+config KERNEL_KASAN_HW_TAGS
+ bool "Hardware Tag-Based KASAN"
+ depends on aarch64
+ select KERNEL_SLUB_DEBUG
+ select KERNEL_ARM64_MTE
+ help
+ Enables Hardware Tag-Based KASAN.
+
+ Supported only on arm64 CPUs starting from ARMv8.5 and relies on
+ Memory Tagging Extension and Top Byte Ignore.
+
+ Consumes about 1/32nd of available memory.
+
+ May potentially introduce problems related to pointer casting and
+ comparison, as it embeds a tag into the top byte of each pointer.
+
+endchoice
+
+ config KERNEL_ARM64_MTE
+ def_bool n
- config KERNEL_KASAN_SW_TAGS
- def_bool n
endif
choice
prompt "Instrumentation type"
depends on KERNEL_KASAN
+ depends on !KERNEL_KASAN_HW_TAGS
default KERNEL_KASAN_OUTLINE
config KERNEL_KASAN_OUTLINE
config KERNEL_TASKSTATS
bool "Compile the kernel with task resource/io statistics and accounting"
- default n
help
Enable the collection and publishing of task/io statistics and
accounting. Enable this option to enable i/o monitoring in system
config KERNEL_FTRACE
bool "Compile the kernel with tracing support"
depends on !TARGET_uml
- default n
config KERNEL_FTRACE_SYSCALLS
bool "Trace system calls"
depends on KERNEL_FTRACE
- default n
config KERNEL_ENABLE_DEFAULT_TRACERS
bool "Trace process context switches and events"
depends on KERNEL_FTRACE
- default n
config KERNEL_FUNCTION_TRACER
bool "Function tracer"
depends on KERNEL_FTRACE
- default n
config KERNEL_FUNCTION_GRAPH_TRACER
bool "Function graph tracer"
depends on KERNEL_FUNCTION_TRACER
- default n
config KERNEL_DYNAMIC_FTRACE
bool "Enable/disable function tracing dynamically"
depends on KERNEL_FUNCTION_TRACER
- default n
config KERNEL_FUNCTION_PROFILER
bool "Function profiler"
depends on KERNEL_FUNCTION_TRACER
- default n
config KERNEL_IRQSOFF_TRACER
bool "Interrupts-off Latency Tracer"
config KERNEL_DEBUG_KERNEL
bool
- default n
config KERNEL_DEBUG_INFO
bool "Compile the kernel with debug information"
help
This will compile your kernel and modules with debug information.
+config KERNEL_DEBUG_INFO_BTF
+
+ bool "Enable additional BTF type information"
+ depends on !HOST_OS_MACOS
+ depends on KERNEL_DEBUG_INFO && !KERNEL_DEBUG_INFO_REDUCED
+ select DWARVES
+ help
+ Generate BPF Type Format (BTF) information from DWARF debug info.
+ Turning this on expects presence of pahole tool, which will convert
+ DWARF type info into equivalent deduplicated BTF type info.
+
+ Required to run BPF CO-RE applications.
+
+config KERNEL_MODULE_ALLOW_BTF_MISMATCH
+ bool "Allow loading modules with non-matching BTF type info"
+ depends on KERNEL_DEBUG_INFO_BTF
+ help
+ For modules whose split BTF does not match vmlinux, load without
+ BTF rather than refusing to load. The default behavior with
+ module BTF enabled is to reject modules with such mismatches;
+ this option will still load module BTF where possible but ignore
+ it when a mismatch is found.
+
+config KERNEL_DEBUG_INFO_REDUCED
+ bool "Reduce debugging information"
+ default y
+ depends on KERNEL_DEBUG_INFO
+ help
+ If you say Y here gcc is instructed to generate less debugging
+ information for structure types. This means that tools that
+ need full debugging information (like kgdb or systemtap) won't
+ be happy. But if you merely need debugging information to
+ resolve line numbers there is no loss. Advantage is that
+ build directory object sizes shrink dramatically over a full
+ DEBUG_INFO build and compile times are reduced too.
+ Only works with newer gcc versions.
+
+config KERNEL_FRAME_WARN
+ int
+ range 0 8192
+ default 1280 if KERNEL_KASAN && !ARCH_64BIT
+ default 1024 if !ARCH_64BIT
+ default 2048 if ARCH_64BIT
+ help
+ Tell the compiler to warn at build time for stack frames larger than this.
+ Setting this too low will cause a lot of warnings.
+ Setting it to 0 disables the warning.
+
+# KERNEL_DEBUG_LL symbols must have the default value set as otherwise
+# KConfig wont evaluate them unless KERNEL_EARLY_PRINTK is selected
+# which means that buildroot wont override the DEBUG_LL symbols in target
+# kernel configurations and lead to devices that dont have working console
config KERNEL_DEBUG_LL_UART_NONE
bool
default n
help
ARM low level debugging.
+config KERNEL_DEBUG_VIRTUAL
+ bool "Compile the kernel with VM translations debugging"
+ select KERNEL_DEBUG_KERNEL
+ help
+ Enable checks sanity checks to catch invalid uses of
+ virt_to_phys()/phys_to_virt() against the non-linear address space.
+
config KERNEL_DYNAMIC_DEBUG
bool "Compile the kernel with dynamic printk"
select KERNEL_DEBUG_FS
- default n
help
Compiles debug level messages into the kernel, which would not
otherwise be available at runtime. These messages can then be
config KERNEL_EARLY_PRINTK
bool "Compile the kernel with early printk"
default y if TARGET_bcm53xx
- default n
depends on arm
select KERNEL_DEBUG_KERNEL
select KERNEL_DEBUG_LL if arm
config KERNEL_KPROBES
bool "Compile the kernel with kprobes support"
- default n
select KERNEL_FTRACE
select KERNEL_PERF_EVENTS
help
bool
default y if KERNEL_KPROBES
+config KERNEL_BPF_EVENTS
+ bool "Compile the kernel with BPF event support"
+ select KERNEL_KPROBES
+ help
+ Allows to attach BPF programs to kprobe, uprobe and tracepoint events.
+ This is required to use BPF maps of type BPF_MAP_TYPE_PERF_EVENT_ARRAY
+ for sending data from BPF programs to user-space for post-processing
+ or logging.
+
config KERNEL_BPF_KPROBE_OVERRIDE
bool
depends on KERNEL_KPROBES
config KERNEL_IO_URING
bool "Compile the kernel with io_uring support"
- default y if !SMALL_FLASH
+ depends on !SMALL_FLASH
+ default y if (x86_64 || aarch64)
config KERNEL_FHANDLE
bool "Compile the kernel with support for fhandle syscalls"
config KERNEL_BLK_DEV_BSG
bool "Compile the kernel with SCSI generic v4 support for any block device"
- default n
config KERNEL_TRANSPARENT_HUGEPAGE
bool
bool "Compile the kernel with HugeTLB support"
select KERNEL_TRANSPARENT_HUGEPAGE
select KERNEL_HUGETLBFS
- default n
config KERNEL_MAGIC_SYSRQ
bool "Compile the kernel with SysRq support"
config KERNEL_PROVE_LOCKING
bool "Enable kernel lock checking"
select KERNEL_DEBUG_KERNEL
- default n
config KERNEL_SOFTLOCKUP_DETECTOR
bool "Compile the kernel with detect Soft Lockups"
chance to run. The current stack trace is displayed upon
detection and the system will stay locked up.
+config KERNEL_HARDLOCKUP_DETECTOR
+ bool "Compile the kernel with detect Hard Lockups"
+ depends on KERNEL_DEBUG_KERNEL
+ help
+ Say Y here to enable the kernel to act as a watchdog to detect
+ hard lockups.
+
+ Hardlockups are bugs that cause the CPU to loop in kernel mode
+ for more than 10 seconds, without letting other interrupts have a
+ chance to run. The current stack trace is displayed upon detection
+ and the system will stay locked up.
+
config KERNEL_DETECT_HUNG_TASK
bool "Compile the kernel with detect Hung Tasks"
depends on KERNEL_DEBUG_KERNEL
default y
config KERNEL_SLUB_DEBUG
- bool
+ bool "Enable SLUB debugging support"
+ help
+ This enables various debugging features:
+ - Accepts "slub_debug" kernel parameter
+ - Provides caches debugging options (e.g. tracing, validating)
+ - Adds /sys/kernel/slab/ attrs for reading amounts of *objects*
+ - Enables /proc/slabinfo support
+ - Prints info when running out of memory
+
+ Enabling this can result in a significant increase of code size.
config KERNEL_SLUB_DEBUG_ON
- bool
+ depends on KERNEL_SLUB_DEBUG
+ bool "Boot kernel with basic caches debugging enabled"
+ help
+ This enables by default sanity_checks, red_zone, poison and store_user
+ debugging options for all caches.
config KERNEL_SLABINFO
select KERNEL_SLUB_DEBUG
config USE_SPARSE
bool "Enable sparse check during kernel build"
- default n
config KERNEL_DEVTMPFS
bool "Compile the kernel with device tmpfs enabled"
- default n
help
devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
devices nodes for all registered devices to simplify boot, but leaves more
config KERNEL_DEVTMPFS_MOUNT
bool "Automatically mount devtmpfs after root filesystem is mounted"
- default n
endif
config KERNEL_PERSISTENT_KEYRINGS
bool "Enable kernel persistent keyrings"
depends on KERNEL_KEYS
- default n
config KERNEL_KEYS_REQUEST_CACHE
bool "Enable temporary caching of the last request_key() result"
depends on KERNEL_KEYS
- default n
config KERNEL_BIG_KEYS
bool "Enable large payload keys on kernel keyrings"
depends on KERNEL_KEYS
- default n
#
# CGROUP support symbols
config KERNEL_CGROUP_DEBUG
bool "Example debug cgroup subsystem"
- default n
help
This option enables a simple cgroup subsystem that
exports useful debugging information about the cgroups
config KERNEL_CGROUP_FREEZER
bool "legacy Freezer cgroup subsystem"
- default n
select KERNEL_FREEZER
help
Provides a way to freeze and unfreeze all tasks in a
config KERNEL_CGROUP_DEVICE
bool "legacy Device controller for cgroups"
- default n
help
Provides a cgroup implementing whitelists for devices which
a process in the cgroup can mknod or open.
config KERNEL_CGROUP_HUGETLB
bool "HugeTLB controller"
- default n
select KERNEL_HUGETLB_PAGE
config KERNEL_CGROUP_PIDS
config KERNEL_PROC_PID_CPUSET
bool "Include legacy /proc/<pid>/cpuset file"
- default n
depends on KERNEL_CPUSETS
config KERNEL_CGROUP_CPUACCT
bool "Memory Resource Controller for Control Groups"
default y
select KERNEL_FREEZER
- depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
+ depends on KERNEL_RESOURCE_COUNTERS
help
Provides a memory resource controller that manages both anonymous
memory and page cache. (See Documentation/cgroups/memory.txt)
config KERNEL_MEMCG_SWAP_ENABLED
bool "Memory Resource Controller Swap Extension enabled by default"
- default n
depends on KERNEL_MEMCG_SWAP
help
Memory Resource Controller Swap Extension comes with its price in
config KERNEL_CGROUP_PERF
bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
select KERNEL_PERF_EVENTS
- default n
help
This option extends the per-cpu mode to restrict monitoring to
threads which belong to the cgroup specified and run on the
config KERNEL_DEBUG_BLK_CGROUP
bool "Enable Block IO controller debugging"
- default n
depends on KERNEL_BLK_CGROUP
help
Enable some debugging help. Currently it exports additional stat
config KERNEL_NET_CLS_CGROUP
bool "legacy Control Group Classifier"
- default n
config KERNEL_CGROUP_NET_CLASSID
bool "legacy Network classid cgroup"
- default n
config KERNEL_CGROUP_NET_PRIO
bool "legacy Network priority cgroup"
- default n
endif
This module provides glue between core networking code and device
drivers to support L3 master devices like VRF.
+config KERNEL_XDP_SOCKETS
+ bool "XDP sockets support"
+ help
+ XDP sockets allows a channel between XDP programs and
+ userspace applications.
+
+config KERNEL_PAGE_POOL
+ def_bool n
+
+config KERNEL_PAGE_POOL_STATS
+ bool "Page pool stats support"
+ depends on KERNEL_PAGE_POOL
+
#
# NFS related symbols
#
menu "Filesystem ACL and attr support options"
config USE_FS_ACL_ATTR
bool "Use filesystem ACL and attr support by default"
- default n
help
Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
for kernel and packages, except tmpfs, flash filesystems,
config KERNEL_F2FS_FS_POSIX_ACL
bool "Enable POSIX ACL for F2FS Filesystems"
select KERNEL_FS_POSIX_ACL
- default n
config KERNEL_JFFS2_FS_POSIX_ACL
bool "Enable POSIX ACL for JFFS2 Filesystems"
select KERNEL_FS_POSIX_ACL
- default n
config KERNEL_TMPFS_POSIX_ACL
bool "Enable POSIX ACL for TMPFS Filesystems"
select KERNEL_FS_POSIX_ACL
- default n
config KERNEL_CIFS_ACL
bool "Enable CIFS ACLs"
config KERNEL_NFS_V3_ACL_SUPPORT
bool "Enable ACLs for NFSv3"
- default n
config KERNEL_NFSD_V2_ACL_SUPPORT
bool "Enable ACLs for NFSDv2"
- default n
config KERNEL_NFSD_V3_ACL_SUPPORT
bool "Enable ACLs for NFSDv3"
- default n
config KERNEL_REISER_FS_POSIX_ACL
bool "Enable POSIX ACLs for ReiserFS"
config KERNEL_JFFS2_FS_SECURITY
bool "JFFS2 Security Labels"
+
+config KERNEL_WERROR
+ bool "Compile the kernel with warnings as errors"
+ default BUILDBOT
+ default y if GCC_USE_VERSION_12
+ help
+ A kernel build should not cause any compiler warnings, and this
+ enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
+ to enforce that rule by default. Certain warnings from other tools
+ such as the linker may be upgraded to errors with this option as
+ well.
+
+ However, if you have a new (or very old) compiler or linker with odd
+ and unusual warnings, or you have some architecture with problems,
+ you may need to disable this config option in order to
+ successfully build the kernel.