5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yuan Chen chenyuan@kylinos.cn
[ Upstream commit 4236f114a3ffbbfd217436c08852e94cae372f57 ]
During the xdp_adjust_tail test, probabilistic failure occurs and SKB package is discarded by the kernel. After checking the issues by tracking SKB package, it is identified that they were caused by checksum errors. Refer to checksum of the arch/arm64/include/asm/checksum.h for fixing.
v2: Based on Alexei Starovoitov's suggestions, it is necessary to keep the code implementation consistent.
Fixes: c6ffd1ff7856 (bpf: add bpf_xdp_adjust_tail sample prog) Signed-off-by: Yuan Chen chenyuan@kylinos.cn Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20240930024115.52841-1-chenyuan_fl@163.com Signed-off-by: Sasha Levin sashal@kernel.org --- samples/bpf/xdp_adjust_tail_kern.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c index cd9ff2a40a398..d9c409190c2c2 100644 --- a/samples/bpf/xdp_adjust_tail_kern.c +++ b/samples/bpf/xdp_adjust_tail_kern.c @@ -54,6 +54,7 @@ static __always_inline void swap_mac(void *data, struct ethhdr *orig_eth)
static __always_inline __u16 csum_fold_helper(__u32 csum) { + csum = (csum & 0xffff) + (csum >> 16); return ~((csum & 0xffff) + (csum >> 16)); }