On Fri, Oct 27, 2023 at 11:46 AM Daniel Xu dxu@dxuuu.xyz wrote:
Switching to vmlinux.h definitions seems to make the verifier very unhappy with bitfield accesses. The error is:
; md.u.md2.dir = direction; 33: (69) r1 = *(u16 *)(r2 +11) misaligned stack access off (0x0; 0x0)+-64+11 size 2It looks like disabling CO-RE relocations seem to make the error go away.
for accessing bitfields libbpf provides BPF_CORE_READ_BITFIELD_PROBED() and BPF_CORE_READ_BITFIELD() macros
Signed-off-by: Daniel Xu dxu@dxuuu.xyz
tools/testing/selftests/bpf/progs/test_tunnel_kern.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c index 3065a716544d..ec7e04e012ae 100644 --- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c +++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c @@ -6,6 +6,7 @@
- modify it under the terms of version 2 of the GNU General Public
- License as published by the Free Software Foundation.
*/ +#define BPF_NO_PRESERVE_ACCESS_INDEX #include "vmlinux.h" #include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
2.42.0