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| author | Daniel Borkmann <daniel@iogearbox.net> | 2016-09-09 02:45:29 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-09-09 19:36:04 -0700 |
| commit | f035a51536af9802f55d8c79bd87f184ebffb093 (patch) | |
| tree | b10ca650031a03f3752a1ea9f7178282e8eb0a75 /include/linux/filter.h | |
| parent | 6088b5823b4cb132a838878747384cbfb5ce6646 (diff) | |
| download | blackbird-obmc-linux-f035a51536af9802f55d8c79bd87f184ebffb093.tar.gz blackbird-obmc-linux-f035a51536af9802f55d8c79bd87f184ebffb093.zip | |
bpf: add BPF_SIZEOF and BPF_FIELD_SIZEOF macros
Add BPF_SIZEOF() and BPF_FIELD_SIZEOF() macros to improve the code a bit
which otherwise often result in overly long bytes_to_bpf_size(sizeof())
and bytes_to_bpf_size(FIELD_SIZEOF()) lines. So place them into a macro
helper instead. Moreover, we currently have a BUILD_BUG_ON(BPF_FIELD_SIZEOF())
check in convert_bpf_extensions(), but we should rather make that generic
as well and add a BUILD_BUG_ON() test in all BPF_SIZEOF()/BPF_FIELD_SIZEOF()
users to detect any rewriter size issues at compile time. Note, there are
currently none, but we want to assert that it stays this way.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/filter.h')
| -rw-r--r-- | include/linux/filter.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index a16439b99fd9..7fabad8dc3fc 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -314,6 +314,20 @@ struct bpf_prog_aux; bpf_size; \ }) +#define BPF_SIZEOF(type) \ + ({ \ + const int __size = bytes_to_bpf_size(sizeof(type)); \ + BUILD_BUG_ON(__size < 0); \ + __size; \ + }) + +#define BPF_FIELD_SIZEOF(type, field) \ + ({ \ + const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \ + BUILD_BUG_ON(__size < 0); \ + __size; \ + }) + #ifdef CONFIG_COMPAT /* A struct sock_filter is architecture independent. */ struct compat_sock_fprog { |
