From: Ilya Maximets i.maximets@ovn.org
[ Upstream commit 25bfef430e960e695403b5d9c8dcc11b9f5d62be ]
'struct xdp_umem_reg' has 4 bytes of padding at the end that makes valgrind complain about passing uninitialized stack memory to the syscall:
Syscall param socketcall.setsockopt() points to uninitialised byte(s) at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so) by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172) Uninitialised value was created by a stack allocation at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140)
Padding bytes appeared after introducing of a new 'flags' field. memset() is required to clear them.
Fixes: 10d30e301732 ("libbpf: add flags to umem config") Signed-off-by: Ilya Maximets i.maximets@ovn.org Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: Andrii Nakryiko andriin@fb.com Link: https://lore.kernel.org/bpf/20191009164929.17242-1-i.maximets@ovn.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/xsk.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index a902838f9fccd..9d53480862030 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -163,6 +163,7 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area, umem->umem_area = umem_area; xsk_set_umem_config(&umem->config, usr_config);
+ memset(&mr, 0, sizeof(mr)); mr.addr = (uintptr_t)umem_area; mr.len = size; mr.chunk_size = umem->config.frame_size;