[v3,bpf,3/3] bpf: Update bpf_design_QA.rst to clarify that BTF_ID does not ABIify a function

Commit Message

Paul E. McKenney Aug. 2, 2022, 5:39 p.m. UTC

This patch updates bpf_design_QA.rst to clarify that mentioning a function
to the BTF_ID macro does not make that function become part of the Linux
kernel's ABI.

Suggested-by: Alexei Starovoitov <[e-mail]>
Signed-off-by: Paul E. McKenney <[e-mail]>
---
 Documentation/bpf/bpf_design_QA.rst | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/Documentation/bpf/bpf_design_QA.rst b/Documentation/bpf/bpf_design_QA.rst
index a06ae8a828e3d..a210b8a4df005 100644
--- a/Documentation/bpf/bpf_design_QA.rst
+++ b/Documentation/bpf/bpf_design_QA.rst
@@ -291,3 +291,10 @@  The kernel function prototypes will change, and BPF programs attaching to
 them will need to change.  The BPF compile-once-run-everywhere (CO-RE)
 should be used in order to make it easier to adapt your BPF programs to
 different versions of the kernel.
+
+Q: Marking a function with BTF_ID makes that function an ABI?
+-------------------------------------------------------------
+A: NO.
+
+The BTF_ID macro does not cause a function to become part of the ABI
+any more than does the EXPORT_SYMBOL_GPL macro.