After a series of amendments the seccomp.patch made ntpd work properly
but only on 32-bit systems.
This commit replaces that patch with the one submitted upstream by
cleverca22 and that fixes the issue also on 64-bit systems.
Close#38627, #45885
Fixes issue #21136.
The problem is that the seccomp system call filter configured by ntpd did not
include some system calls that were apparently needed. For example the
program hanged in getpid just after the filter was installed:
prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) = 0
seccomp(SECCOMP_SET_MODE_STRICT, 1, NULL) = -1 EINVAL (Invalid argument)
seccomp(SECCOMP_SET_MODE_FILTER, 0, {len=41, filter=0x5620d7f0bd90}) = 0
getpid() = ?
I do not know exactly why this is a problem on NixOS only, perhaps we have getpid
caching disabled.
The fcntl and setsockopt system calls also had to be added.
