Re: [Qemu-devel] [PATCH 6/6] linux-user: Provide safe_syscall for ppc64

[Peter Maydell]

On 13 June 2016 at 22:45, Richard Henderson <address@hidden> wrote:
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  linux-user/host/ppc64/hostdep.h          | 34 +++++++++++++
>  linux-user/host/ppc64/safe-syscall.inc.S | 87 
> ++++++++++++++++++++++++++++++++
>  2 files changed, 121 insertions(+)
>  create mode 100644 linux-user/host/ppc64/hostdep.h
>  create mode 100644 linux-user/host/ppc64/safe-syscall.inc.S
>
> diff --git a/linux-user/host/ppc64/hostdep.h b/linux-user/host/ppc64/hostdep.h
> new file mode 100644
> index 0000000..81e3d55
> --- /dev/null
> +++ b/linux-user/host/ppc64/hostdep.h
> @@ -0,0 +1,34 @@
> +/*
> + * hostdep.h : things which are dependent on the host architecture
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef QEMU_HOSTDEP_H
> +#define QEMU_HOSTDEP_H
> +
> +/* We have a safe-syscall.inc.S */
> +#define HAVE_SAFE_SYSCALL
> +
> +#ifndef __ASSEMBLER__
> +
> +/* These are defined by the safe-syscall.inc.S file */
> +extern char safe_syscall_start[];
> +extern char safe_syscall_end[];
> +
> +/* Adjust the signal context to rewind out of safe-syscall if we're in it */
> +static inline void rewind_if_in_safe_syscall(void *puc)
> +{
> +    struct ucontext *uc = puc;
> +    unsigned long *pcreg = &uc->uc_mcontext.gp_regs[PT_NIP];
> +
> +    if (*pcreg > (uintptr_t)safe_syscall_start
> +        && *pcreg < (uintptr_t)safe_syscall_end) {
> +        *pcreg = (uintptr_t)safe_syscall_start;
> +    }
> +}
> +
> +#endif /* __ASSEMBLER__ */
> +
> +#endif
> diff --git a/linux-user/host/ppc64/safe-syscall.inc.S 
> b/linux-user/host/ppc64/safe-syscall.inc.S
> new file mode 100644
> index 0000000..89e979c
> --- /dev/null
> +++ b/linux-user/host/ppc64/safe-syscall.inc.S
> @@ -0,0 +1,87 @@
> +/*
> + * safe-syscall.inc.S : host-specific assembly fragment
> + * to handle signals occurring at the same time as system calls.
> + * This is intended to be included by linux-user/safe-syscall.S
> + *
> + * Copyright (C) 2015 Timothy Edward Baldwin <address@hidden>

I would say this ppc code was copyright you (or RedHat depending
which hat you're wearing), not Timothy.

thanks
-- PMM