net: xdp: add invalid buffer warning
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 <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 6a16583..af8a180 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -602,6 +602,7 @@ bool bpf_helper_changes_pkt_data(void *func);
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 b146170..7190bd6 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2972,6 +2972,12 @@ 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,