On 03/14, Ben Dooks wrote: > When building W=1, the following warningds get generated by lib/test_bpf.c > due to the BPF_LD_IMM64_RAW() truncating a 64bit to 32bit value without > a specific mask to do so. > > lib/test_bpf.c:6441:25: warning: cast truncates bits from constant value (ffffffff0000 becomes ffff0000) > lib/test_bpf.c:6442:25: warning: cast truncates bits from constant value (ffffffff0000 becomes ffff0000) > lib/test_bpf.c:6473:25: warning: cast truncates bits from constant value (123456789abcdef becomes 89abcdef) > lib/test_bpf.c:6489:25: warning: cast truncates bits from constant value (123456789abcdef becomes 89abcdef) > lib/test_bpf.c:6490:25: warning: cast truncates bits from constant value (123456780a0c0e0 becomes 80a0c0e0) > lib/test_bpf.c:6599:25: warning: cast truncates bits from constant value (123456789abcdef becomes 89abcdef) > lib/test_bpf.c:6637:25: warning: cast truncates bits from constant value (ffffffff0000 becomes ffff0000) > > (more warnings truncated) > > Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> I wonder how many other places (in the kernel) we have where we silently cast u64 to u32.. Surprised that's the only warning you get :-) Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
