Comment 9 for bug 1849785

Well this change made the ID 392 "known" to all architectures (in a try to sync numbers across everywhere) but it fails on those it isn't implemented (32bit, ppc, s390x + sparc which we don't have).

The path registering these calls goes
seccomp_rule_add
 -> seccomp_rule_add_array
     -> db_col_valid
     -> _syscall_valid
     -> db_col_rule_add <- still -204/392
         -> _db_rule_new
         -> db_col_transaction_start <- dups old rule (-201) ITERATES
            -> arch_filter_rule_add
                -> arch_syscall_translate
                    -> arch_syscall_resolve_num <- returns "semop" for -201
                    -> arch_syscall_resolve_name <- returns -201 for "semop"
            Returns RC=0 (db_col_transaction_start)
            The above defined the transaction start
         -> arch_filter_rule_add <- this adds the new rule -204/392
             -> arch_syscall_translate
                 -> arch_syscall_resolve_num
                      Good case returns "semtimedop" for
                      Bad case returns 0x0 for 392
                  From here it now returns -EFAULT (=> -14) and things break

So we enter:
Good: Breakpoint 14, s390x_syscall_resolve_num (num=-204) at arch-s390x-syscalls.c:533
Bad: Breakpoint 13, s390x_syscall_resolve_num (num=392) at arch-s390x-syscalls.c:533

This searches the table s390x_syscall_table and fails to find 392, from there things break.
The worst is, that "semtimedop" is there, but with __PNR_semtimedop as number.
As it used to have no number yet when last time generated.
If it would use __NR_semtimedop instead of __PNR_semtimedop it might even work as-is.
I'm not sure if src/arch-s390x-syscalls.c is allowed to use include/seccomp.h (where these compat defines are).
I need to suggest that upstream (or check if a change exists)

Summary of the above:
- kernel change defined numbers for all calls (implemented or not)
- due to that no more the fallback "#define __PNR_semtimedop -204" but provided 392 is used
- arch_syscall_translate tries to translate 392 in the context of the native architecure to the provided architecture and fails
- src/arch-s390x-syscalls.c contains syscall tables derived from 4.15-rc7 which need to be updated
- Definitions in this table should use __NR_ instead of __PNR_ to get the kernel value once it is defined (will be ==__PNR when not defined)
- Even if not using __NR it needs a redefine for newer kernels