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Diffstat (limited to 'Documentation/bpf/bpf_devel_QA.txt')
| -rw-r--r-- | Documentation/bpf/bpf_devel_QA.txt | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/bpf/bpf_devel_QA.txt b/Documentation/bpf/bpf_devel_QA.txt index 1a0b704e1a38..da57601153a0 100644 --- a/Documentation/bpf/bpf_devel_QA.txt +++ b/Documentation/bpf/bpf_devel_QA.txt @@ -557,6 +557,14 @@ A: Although LLVM IR generation and optimization try to stay architecture pulls in some header files containing file scope host assembly codes. - You can add "-fno-jump-tables" to work around the switch table issue. - Otherwise, you can use bpf target. + Otherwise, you can use bpf target. Additionally, you _must_ use bpf target + when: + + - Your program uses data structures with pointer or long / unsigned long + types that interface with BPF helpers or context data structures. Access + into these structures is verified by the BPF verifier and may result + in verification failures if the native architecture is not aligned with + the BPF architecture, e.g. 64-bit. An example of this is + BPF_PROG_TYPE_SK_MSG require '-target bpf' Happy BPF hacking! |