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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 /net | |
| parent | bpf: minor cleanups in helpers (diff) | |
| download | linux-dev-f035a51536af9802f55d8c79bd87f184ebffb093.tar.xz linux-dev-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 'net')
| -rw-r--r-- | net/core/filter.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 628ed8c7d38d..120c813ef030 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -233,9 +233,8 @@ static bool convert_bpf_extensions(struct sock_filter *fp, case SKF_AD_OFF + SKF_AD_HATYPE: BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, type) != 2); - BUILD_BUG_ON(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)) < 0); - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)), + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev), BPF_REG_TMP, BPF_REG_CTX, offsetof(struct sk_buff, dev)); /* if (tmp != 0) goto pc + 1 */ @@ -2685,7 +2684,7 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg, case offsetof(struct __sk_buff, ifindex): BUILD_BUG_ON(FIELD_SIZEOF(struct net_device, ifindex) != 4); - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, dev)), + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, dev), dst_reg, src_reg, offsetof(struct sk_buff, dev)); *insn++ = BPF_JMP_IMM(BPF_JEQ, dst_reg, 0, 1); @@ -2750,7 +2749,7 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg, break; case offsetof(struct __sk_buff, data): - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct sk_buff, data)), + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, data), dst_reg, src_reg, offsetof(struct sk_buff, data)); break; @@ -2759,8 +2758,8 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg, ctx_off -= offsetof(struct __sk_buff, data_end); ctx_off += offsetof(struct sk_buff, cb); ctx_off += offsetof(struct bpf_skb_data_end, data_end); - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(sizeof(void *)), - dst_reg, src_reg, ctx_off); + *insn++ = BPF_LDX_MEM(BPF_SIZEOF(void *), dst_reg, src_reg, + ctx_off); break; case offsetof(struct __sk_buff, tc_index): @@ -2795,12 +2794,12 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg, switch (ctx_off) { case offsetof(struct xdp_md, data): - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data)), + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data), dst_reg, src_reg, offsetof(struct xdp_buff, data)); break; case offsetof(struct xdp_md, data_end): - *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data_end)), + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct xdp_buff, data_end), dst_reg, src_reg, offsetof(struct xdp_buff, data_end)); break; |