ptrace: Add compat PTRACE_{G,S}ETSIGMASK handlers

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8JVJ3
CVE: NA

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



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compat_ptrace_request() lacks handlers for PTRACE_{G,S}ETSIGMASK,
instead using those in ptrace_request(). The compat variant should
read a compat_sigset_t from userspace instead of ptrace_request()s
sigset_t.

While compat_sigset_t is the same size as sigset_t, it is defined as
2xu32, instead of a single u64. On a big-endian CPU this means that
compat_sigset_t is passed to user-space using middle-endianness,
where the least-significant u32 is written most significant byte
first.

If ptrace_request()s code is used userspace will read the most
significant u32 where it expected the least significant.

Instead of duplicating ptrace_request()s code as a special case in
the arch code, handle it here.

Fixes: 29000cae ("ptrace: add ability to get/set signal-blocked mask")
CC: Andrey Vagin <avagin@openvz.org>
Signed-off-by: James Morse <james.morse@arm.com>

Yury:
Replace sigset_{to,from}_compat() with new {get,put}_compat_sigset()
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>
Patchwork Links: http://patchwork.huawei.com/project/hulk5.10/list/?series=12937


Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>