The final version of the KEYCTL_DH_COMPUTE syscall that went in to kernel 4.7 added a reserved arg. In the future, this arg will be used to optionally specify a key derivation function. For now, it's needed so the system call doesn't return -1 (errno == EINVAL) every time. --- ell/key.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/ell/key.c b/ell/key.c index adeac04..e6ae92a 100644 --- a/ell/key.c +++ b/ell/key.c @@ -99,7 +99,8 @@ static long kernel_dh_compute(int32_t private, int32_t prime, int32_t base, .prime = prime, .base = base }; - return syscall(__NR_keyctl, KEYCTL_DH_COMPUTE, &params, payload, len); + return syscall(__NR_keyctl, KEYCTL_DH_COMPUTE, &params, payload, len, + NULL); } static bool setup_internal_keyring(void) -- 2.9.0