arm64: ilp32: introduce ilp32-specific sigframe and ucontext

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

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



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ILP32 uses AARCH32 compat structures and syscall handlers for signals. But
ILP32 rt_sigframe and ucontext structures differ from both LP64 and AARCH32.
>From software point of view ILP32 is typical 32-bit compat ABI, and from
hardware point of view, it's just like LP64.

struct rt_sigframe defined in this patch in
arch/arm64/kernel/signal_ilp32.c redefines one in
arch/arm64/kernel/signal.c. And functions located in
arch/arm64/include/signal_common.h pick up new structure to generate the
code suitable for ILP32.

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