Re: [PATCH V11 14/22] LoongArch: Add signal handling support

["Eric W. Biederman" <ebiederm@xmission.com>]

Huacai Chen <chenhuacai@loongson.cn> writes:

> Add ucontext/sigcontext definition and signal handling support for
> LoongArch.
>
> Cc: Eric Biederman <ebiederm@xmission.com>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> ---
>  arch/loongarch/include/uapi/asm/sigcontext.h |  44 ++
>  arch/loongarch/include/uapi/asm/signal.h     |  13 +
>  arch/loongarch/include/uapi/asm/ucontext.h   |  35 ++
>  arch/loongarch/kernel/signal.c               | 566 +++++++++++++++++++
>  4 files changed, 658 insertions(+)
>  create mode 100644 arch/loongarch/include/uapi/asm/sigcontext.h
>  create mode 100644 arch/loongarch/include/uapi/asm/signal.h
>  create mode 100644 arch/loongarch/include/uapi/asm/ucontext.h
>  create mode 100644 arch/loongarch/kernel/signal.c
>
> diff --git a/arch/loongarch/include/uapi/asm/sigcontext.h b/arch/loongarch/include/uapi/asm/sigcontext.h
> new file mode 100644
> index 000000000000..be3d3c6ac83e
> --- /dev/null
> +++ b/arch/loongarch/include/uapi/asm/sigcontext.h
> @@ -0,0 +1,44 @@
> +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
> +/*
> + * Author: Hanlu Li <lihanlu@loongson.cn>
> + *         Huacai Chen <chenhuacai@loongson.cn>
> + *
> + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
> + */
> +#ifndef _UAPI_ASM_SIGCONTEXT_H
> +#define _UAPI_ASM_SIGCONTEXT_H
> +
> +#include <linux/types.h>
> +#include <linux/posix_types.h>
> +
> +/* FP context was used */
> +#define SC_USED_FP		(1 << 0)
> +/* Address error was due to memory load */
> +#define SC_ADDRERR_RD		(1 << 30)
> +/* Address error was due to memory store */
> +#define SC_ADDRERR_WR		(1 << 31)
> +
> +struct sigcontext {
> +	__u64	sc_pc;
> +	__u64	sc_regs[32];
> +	__u32	sc_flags;
> +	__u64	sc_extcontext[0] __attribute__((__aligned__(16)));
> +};
> +
> +#define CONTEXT_INFO_ALIGN	16
> +struct _ctxinfo {
> +	__u32	magic;
> +	__u32	size;
> +	__u64	padding;	/* padding to 16 bytes */
> +};

This is probably something I a missing but what is struct _ctxinfo and
why is it in a uapi header?

I don't see anything else in the uapi implementation using it.

Symbols that start with an underscore "_" are reserved and should not
be used in general, and especially not in uapi header files.

Eric