[v16,4/5] linux-user: Introduce TARGET_HAVE_ARCH_STRUCT_FLOCK

From: Aleksandar Markovic <amarkovic@wavecomp.com>

Bring target_flock definitions to be more in sync with the way
flock is defined in kernel.

Basically, the rules from the kernel are:

1. Majority of architectures have a common flock definition.

2. Architectures with 32-bit MIPS ABIs have a sligtly different
flock definition; those architectures are the only arcitectures
that have HAVE_ARCH_STRUCT_FLOCK defined, and that preprocessor
constant is used in the common header as a flag for including or
not including common flock definition.

3. Sparc architectures also have a sligtly different flock
definition, but the difference is only the padding at the end of
the structure. The presence of that padding is determined by
preprocessor constants __ARCH_FLOCK6_PAD and __ARCH_FLOCK64_PAD.

QEMU linux-user already implements rules 1. and 3. in a very
similar way as they are implemented in kernel. However, rule 2.
is implemented in a dissimilar way (for example, the constant
TARGET_HAVE_ARCH_STRUCT_FLOCK is missing), and this patch brings
QEMU implementation much closer to the kernel implementation.
TARGET_HAVE_ARCH_STRUCT_FLOCK64 constant is also introduced to
mimic HAVE_ARCH_STRUCT_FLOCK64 from kernel, but it is not defined
anywhere, however, this is the case with HAVE_ARCH_STRUCT_FLOCK64
in kernel as well.

Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/generic/fcntl.h     |  8 +++++---
 linux-user/mips/target_fcntl.h | 17 +++++++++++++----
 2 files changed, 18 insertions(+), 7 deletions(-)

Le 28/06/2019 à 12:43, Aleksandar Markovic a écrit :
> From: Aleksandar Markovic <amarkovic@wavecomp.com>
> 
> Bring target_flock definitions to be more in sync with the way
> flock is defined in kernel.
> 
> Basically, the rules from the kernel are:
> 
> 1. Majority of architectures have a common flock definition.
> 
> 2. Architectures with 32-bit MIPS ABIs have a sligtly different
> flock definition; those architectures are the only arcitectures
> that have HAVE_ARCH_STRUCT_FLOCK defined, and that preprocessor
> constant is used in the common header as a flag for including or
> not including common flock definition.
> 
> 3. Sparc architectures also have a sligtly different flock
> definition, but the difference is only the padding at the end of
> the structure. The presence of that padding is determined by
> preprocessor constants __ARCH_FLOCK6_PAD and __ARCH_FLOCK64_PAD.
> 
> QEMU linux-user already implements rules 1. and 3. in a very
> similar way as they are implemented in kernel. However, rule 2.
> is implemented in a dissimilar way (for example, the constant
> TARGET_HAVE_ARCH_STRUCT_FLOCK is missing), and this patch brings
> QEMU implementation much closer to the kernel implementation.
> TARGET_HAVE_ARCH_STRUCT_FLOCK64 constant is also introduced to
> mimic HAVE_ARCH_STRUCT_FLOCK64 from kernel, but it is not defined
> anywhere, however, this is the case with HAVE_ARCH_STRUCT_FLOCK64
> in kernel as well.
> 
> Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> ---
>  linux-user/generic/fcntl.h     |  8 +++++---
>  linux-user/mips/target_fcntl.h | 17 +++++++++++++----
>  2 files changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/linux-user/generic/fcntl.h b/linux-user/generic/fcntl.h
> index 1b48dde..9f727d4 100644
> --- a/linux-user/generic/fcntl.h
> +++ b/linux-user/generic/fcntl.h
> @@ -120,6 +120,7 @@ struct target_f_owner_ex {
>  #define TARGET_F_SHLCK         8
>  #endif
>  
> +#ifndef TARGET_HAVE_ARCH_STRUCT_FLOCK
>  #ifndef TARGET_ARCH_FLOCK_PAD
>  #define TARGET_ARCH_FLOCK_PAD
>  #endif
> @@ -129,13 +130,12 @@ struct target_flock {
>      short l_whence;
>      abi_long l_start;
>      abi_long l_len;
> -#if defined(TARGET_MIPS) && (TARGET_ABI_BITS == 32)
> -    abi_long l_sysid;
> -#endif
>      int l_pid;
>      TARGET_ARCH_FLOCK_PAD
>  };
> +#endif
>  
> +#ifndef TARGET_HAVE_ARCH_STRUCT_FLOCK64
>  #ifndef TARGET_ARCH_FLOCK64_PAD
>  #define TARGET_ARCH_FLOCK64_PAD
>  #endif
> @@ -149,3 +149,5 @@ struct target_flock64 {
>      TARGET_ARCH_FLOCK64_PAD
>  };
>  #endif
> +
> +#endif
> diff --git a/linux-user/mips/target_fcntl.h b/linux-user/mips/target_fcntl.h
> index 795bba7..6fc7b8a 100644
> --- a/linux-user/mips/target_fcntl.h
> +++ b/linux-user/mips/target_fcntl.h
> @@ -28,11 +28,20 @@
>  #define TARGET_F_GETOWN        23       /*  for sockets. */
>  
>  #if (TARGET_ABI_BITS == 32)
> -#define TARGET_ARCH_FLOCK_PAD abi_long pad[4];
> -#else
> -#define TARGET_ARCH_FLOCK_PAD
> +
> +struct target_flock {
> +    short l_type;
> +    short l_whence;
> +    abi_long l_start;
> +    abi_long l_len;
> +    abi_long l_sysid;
> +    int l_pid;
> +    abi_long pad[4];
> +};
> +
> +#define TARGET_HAVE_ARCH_STRUCT_FLOCK
> +
>  #endif
> -#define TARGET_ARCH_FLOCK64_PAD
>  
>  #define TARGET_F_GETLK64       33      /*  using 'struct flock64' */
>  #define TARGET_F_SETLK64       34
> 

Applied to my linux-user branch.

Thanks,
Laurent