Re: [Qemu-devel] [PATCH 1/3] linux-user: Fix handling of arm_fadvise64_64 syscall

[Laurent Vivier]

Le 31/05/2016 à 16:45, Peter Maydell a écrit :
> 32-bit ARM has an odd variant of the fadvise syscall which has
> rearranged arguments, which we try to implement. Unfortunately we got
> the rearrangement wrong.
> 
> This is a six-argument syscall whose arguments are:
>  * fd
>  * advise parameter
>  * offset high half
>  * offset low half
>  * len high half
>  * len low half
> 
> Stop trying to share code with the standard fadvise syscalls,
> and just implement the syscall with the correct argument order.
> 
> Signed-off-by: Peter Maydell <address@hidden>
> ---
>  linux-user/syscall.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 7d5f123..4894919 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -9329,18 +9329,18 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>  #endif
>  #ifdef TARGET_NR_arm_fadvise64_64
>      case TARGET_NR_arm_fadvise64_64:
> -     {
> -             /*
> -              * arm_fadvise64_64 looks like fadvise64_64 but
> -              * with different argument order
> -              */
> -             abi_long temp;
> -             temp = arg3;
> -             arg3 = arg4;
> -             arg4 = temp;
> -     }
> +        /* arm_fadvise64_64 looks like fadvise64_64 but
> +         * with different argument order: fd, advice, offset, len
> +         * rather than the usual fd, offset, len, advice.
> +         * Note that offset and len are both 64-bit so appear as
> +         * pairs of 32-bit registers.
> +         */
> +        ret = posix_fadvise(arg1, target_offset64(arg3, arg4),
> +                            target_offset64(arg5, arg6), arg2);
> +        ret = -host_to_target_errno(ret);
> +        break;
>  #endif
> -#if defined(TARGET_NR_fadvise64_64) || defined(TARGET_NR_arm_fadvise64_64) 
> || defined(TARGET_NR_fadvise64)
> +#if defined(TARGET_NR_fadvise64_64) || defined(TARGET_NR_fadvise64)
>  #ifdef TARGET_NR_fadvise64_64
>      case TARGET_NR_fadvise64_64:
>  #endif
> 

Reviewed-by: Laurent Vivier <address@hidden>