[RFC] ptrace: add generic SET_SYSCALL request

[arnd@arndb.de (Arnd Bergmann)]

On Thursday 13 November 2014 15:49:20 Ulrich Weigand wrote:
> Arnd Bergmann <arnd@arndb.de> wrote on 13.11.2014 11:21:28:
> 
> > I have to admit that I don't really understand gdb internals, but from
> > a first look I get the impression that it will just do the right thing
> > if you reuse NT_S390_SYSTEM_CALL on ARM64 with the same semantics.
> 
> There's an interface between BFD and GDB proper involved here.  BFD will
> detect the presence of register set notes in the core dump, and will
> translate them into virtual sections; GDB will then simply look up such
> sections under well-known names.
> 
> In particular, the NT_S390_SYSTEM_CALL note will be translated by BFD
> into a virtual section named ".reg-s390-system-call"; GDB platform-
> specific code will look for sections of this particular name.
> 
> So if you were to create notes using the same note type, by default it
> would do nothing on ARM64.  You might add code to the ARM64 back-end
> to also look for a section ".reg-s390-system-call", but that would be
> somewhat confusing.  Using a new, platform-specific note type for ARM64
> would appear to fit better with existing precedent.

Ok, thanks a lot for your insight and for confirming what Takahiro AKASHI
said. Let's use a new NT_ARM64_SYSTEM_CALL type with a different
number then.

	Arnd