Hi, Eric,
On Thu, May 19, 2022 at 12:40 AM Eric W. Biederman
<ebiederm@xxxxxxxxxxxx> wrote:
>
> Huacai Chen <chenhuacai@xxxxxxxxxxx> writes:
>
> > Add ucontext/sigcontext definition and signal handling support for
> > LoongArch.
> >
> > Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
> > Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxx>
> > + * Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > + *
> > + * 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.
This is used by get_ctx_through_ctxinfo() in signal.c and I think
similar function is also needed by userspace.
Its name is once before called context_info but conflict with another
software, then I want to use ctx_info but conflict with another kernel
struct. :(
>
> Symbols that start with an underscore "_" are reserved and should not
> be used in general, and especially not in uapi header files.
Then, maybe we can use sctx_info here?
Huacai
>
> Eric
