# Kernel Configuration for BPF Features - bpf-developer-tutorial

# Kernel Configuration for BPF Features

## BPF Related Kernel Configurations

Functionalities | Kernel Configuration | Description
--- | --- | ---
Basic | CONFIG_BPF_SYSCALL | Enable the bpf() system call
| CONFIG_BPF_JIT | BPF programs are normally handled by a BPF interpreter. This option allows the kernel to generate native code when a program is loaded into the kernel. This will significantly speed-up processing of BPF programs
| CONFIG_HAVE_BPF_JIT | Enable BPF Just In Time compiler
| CONFIG_HAVE_EBPF_JIT | Extended BPF JIT (eBPF)
| CONFIG_HAVE_CBPF_JIT | Classic BPF JIT (cBPF)
| CONFIG_MODULES | Enable to build loadable kernel modules
| CONFIG_BPF | BPF VM interpreter
| CONFIG_BPF_EVENTS | Allow the user to attach BPF programs to kprobe, uprobe, and tracepoint events
| CONFIG_PERF_EVENTS | Kernel performance events and counters
| CONFIG_HAVE_PERF_EVENTS | Enable perf events
| CONFIG_PROFILING | Enable the extended profiling support mechanisms used by profilers
BTF | CONFIG_DEBUG_INFO_BTF | Generate deduplicated BTF type information from DWARF debug info
| CONFIG_PAHOLE_HAS_SPLIT_BTF | Generate BTF for each selected kernel module
| CONFIG_DEBUG_INFO_BTF_MODULES | Generate compact split BTF type information for kernel modules
Security | CONFIG_BPF_JIT_ALWAYS_ON | Enable BPF JIT and removes BPF interpreter to avoid speculative execution
| CONFIG_BPF_UNPRIV_DEFAULT_OFF | Disable unprivileged BPF by default by setting
Cgroup | CONFIG_CGROUP_BPF | Support for BPF programs attached to cgroups
Network | CONFIG_BPFILTER | BPF based packet filtering framework (BPFILTER)
| CONFIG_BPFILTER_UMH | This builds bpfilter kernel module with embedded user mode helper
| CONFIG_NET_CLS_BPF | BPF-based classifier - to classify packets based on programmable BPF (JIT'ed) filters as an alternative to ematches
| CONFIG_NET_ACT_BPF | Execute BPF code on packets. The BPF code will decide if the packet should be dropped or not
| CONFIG_BPF_STREAM_PARSER | Enable this to allow a TCP stream parser to be used with BPF_MAP_TYPE_SOCKMAP
| CONFIG_LWTUNNEL_BPF | Allow to run BPF programs as a nexthop action following a route lookup for incoming and outgoing packets
| CONFIG_NETFILTER_XT_MATCH_BPF | BPF matching applies a linux socket filter to each packet and accepts those for which the filter returns non-zero
| CONFIG_IPV6_SEG6_BPF | To support BPF seg6local hook. bpf: Add IPv6 Segment Routing helpersy. Reference
kprobes | CONFIG_KPROBE_EVENTS | This allows the user to add tracing events (similar to tracepoints) on the fly via the ftrace interface
| CONFIG_KPROBES | Enable kprobes-based dynamic events
| CONFIG_HAVE_KPROBES | Check if krpobes enabled
| CONFIG_HAVE_REGS_AND_STACK_ACCESS_API | This symbol should be selected by an architecture if it supports the API needed to access registers and stack entries from pt_regs. For example the kprobes-based event tracer needs this API.
| CONFIG_KPROBES_ON_FTRACE | Have kprobes on function tracer if arch supports full passing of pt_regs to function tracing
kprobe multi | CONFIG_FPROBE | Enable fprobe to attach the probe on multiple functions at once
kprobe override | CONFIG_BPF_KPROBE_OVERRIDE | Enable BPF programs to override a kprobed function
uprobes | CONFIG_UPROBE_EVENTS | Enable uprobes-based dynamic events
| CONFIG_ARCH_SUPPORTS_UPROBES | Arch specific uprobes support
| CONFIG_UPROBES | Uprobes is the user-space counterpart to kprobes: they enable instrumentation applications (such as 'perf probe') to establish unintrusive probes in user-space binaries and libraries, by executing handler functions when the probes are hit by user-space applications.
| CONFIG_MMU | MMU-based virtualised addressing space support by paged memory management
Tracepoints | CONFIG_TRACEPOINTS | Enable inserting tracepoints in the kernel and connect to proble functions
| CONFIG_HAVE_SYSCALL_TRACEPOINTS | Enable syscall enter/exit tracing
Raw Tracepoints | Same as Tracepoints |
LSM | CONFIG_BPF_LSM | Enable instrumentation of the security hooks with BPF programs for implementing dynamic MAC and Audit Policies
LIRC | CONFIG_BPF_LIRC_MODE2 | Allow attaching BPF programs to a lirc device