bpf: Support pointer param types via SCALAR_VALUE for trampolines

Browse source

Add BPF verifier support for single- and multi-level pointer
parameters and return values in BPF trampolines by treating these
parameters as SCALAR_VALUE.

This extends the existing support for int and void pointers that are
already treated as SCALAR_VALUE.

This provides consistent logic for single and multi-level pointers:
if a type is treated as SCALAR for a single-level pointer, the same
applies to multi-level pointers. The exception is pointer-to-struct,
which is currently PTR_TO_BTF_ID for single-level but treated as
scalar for multi-level pointers since the verifier lacks context
to infer the size of target memory regions.

Safety is ensured by existing BTF verification, which rejects invalid
pointer types at the BTF verification stage.

Signed-off-by: Slava Imameev <slava.imameev@crowdstrike.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260314082127.7939-2-slava.imameev@crowdstrike.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

...

This commit is contained in:

Slava Imameev 2026-03-14 19:21:26 +11:00 • committed by Alexei Starovoitov

parent 7b4f1a29c7

commit 4145203841

1 changed files with 7 additions and 10 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

17

kernel/bpf/btf.c

View file