arm64: ilp32: introduce syscall table for ILP32

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

Reference: https://github.com/norov/linux/commits/ilp32-5.2



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Depending on the personality of the task, syscalls has to be dispatched
to either aarch64, aarch32 or aarch64/ilp32 syscall handlers. We add
the support of ILP32 mode in this series, therefore introduce
corresponding syscall table.

Some system calls are wired to aarch32 syscall handlers, as listed in
arch/arm64/kernel/sys_ilp32.c.

For aarch64/ilp32, top halves of syscall arguments are meaningless
anthough not zeroed by hardware. Do that in the delouse_pt_regs()
routine to avoid passing garbage by userspace.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Yury Norov <ynorov@marvell.com>

 Conflicts:
	arch/arm64/kernel/syscall.c

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>