From b9b738eeafe54d960ccb240fc1b0c5031a0d76f5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 2 Aug 2022 10:39:11 -0700 Subject: [PATCH] bpf: Update bpf_design_QA.rst to clarify that kprobes is not ABI This patch updates bpf_design_QA.rst to clarify that the ability to attach a BPF program to a given point in the kernel code via kprobes does not make that attachment point be part of the Linux kernel's ABI. Signed-off-by: Paul E. McKenney Link: https://lore.kernel.org/r/20220802173913.4170192-1-paulmck@kernel.org Signed-off-by: Alexei Starovoitov --- Documentation/bpf/bpf_design_QA.rst | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/bpf/bpf_design_QA.rst b/Documentation/bpf/bpf_design_QA.rst index 437de2a7a5de..2ed9128cfbec 100644 --- a/Documentation/bpf/bpf_design_QA.rst +++ b/Documentation/bpf/bpf_design_QA.rst @@ -214,6 +214,12 @@ A: NO. Tracepoints are tied to internal implementation details hence they are subject to change and can break with newer kernels. BPF programs need to change accordingly when this happens. +Q: Are places where kprobes can attach part of the stable ABI? +-------------------------------------------------------------- +A: NO. The places to which kprobes can attach are internal implementation +details, which means that they are subject to change and can break with +newer kernels. BPF programs need to change accordingly when this happens. + Q: How much stack space a BPF program uses? ------------------------------------------- A: Currently all program types are limited to 512 bytes of stack -- 2.20.1