>Architecture maintainers, can you comment on how easy/hard it is to do the
>same thing on your architectures? I _assume_ it's trivial (akin to the
>three-liner register state change in i386/kernel/signal.c).
For s390/s390x this is actually quite tricky. The system call number is
coded in the instruction, e.g. 0x0aa2 is svc 162 or sys_nanosleep. There
is no register involved that contains the system call number I could
simply change. I either have to change the instruction (no way) or I
have to avoid going back to userspace in this case. This would require
assembler magic in entry.S. Not nice.
blue skies,
Martin
Linux/390 Design & Development, IBM Deutschland Entwicklung GmbH
Schönaicherstr. 220, D-71032 Böblingen, Telefon: 49 - (0)7031 - 16-2247
E-Mail: schwidefsky@de.ibm.com
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