[net-next PATCH v3 2/6] net: xdp: add invalid buffer warning
From: John Fastabend <john.fastabend@gmail.com>
Date: 2016-11-29 20:10:25
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Martin KaFai Lau, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
This adds a warning for drivers to use when encountering an invalid buffer for XDP. For normal cases this should not happen but to catch this in virtual/qemu setups that I may not have expected from the emulation layer having a standard warning is useful. Signed-off-by: John Fastabend <redacted> --- include/linux/filter.h | 1 + net/core/filter.c | 6 ++++++ 2 files changed, 7 insertions(+)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 1f09c52..0c79004 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h@@ -595,6 +595,7 @@ int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, const struct bpf_insn *patch, u32 len); void bpf_warn_invalid_xdp_action(u32 act); +void bpf_warn_invalid_xdp_buffer(void); #ifdef CONFIG_BPF_JIT extern int bpf_jit_enable;
diff --git a/net/core/filter.c b/net/core/filter.c
index dece94f..5f3ed4e 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -2774,6 +2774,12 @@ void bpf_warn_invalid_xdp_action(u32 act) } EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action); +void bpf_warn_invalid_xdp_buffer(void) +{ + WARN_ONCE(1, "Illegal XDP buffer encountered, expect throughput degradation\n"); +} +EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_buffer); + static u32 sk_filter_convert_ctx_access(enum bpf_access_type type, int dst_reg, int src_reg, int ctx_off, struct bpf_insn *insn_buf,