Re: [PATCH] linux-user: fix layout of struct target_msq_id_ds

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi Andreas,

On 9/10/25 14:56, Andreas Schwab wrote:
> The msg_lspid and msg_lrpid members are of type pid_t, which is a 32-bit
> integer.
> 
> Signed-off-by: Andreas Schwab <schwab@suse.de>
> ---
>   linux-user/syscall.c | 12 ++++++------
>   1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 0956a7b310..3dcdb3ef42 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -4185,8 +4185,8 @@ struct target_msqid_ds
>       abi_ulong __msg_cbytes;
>       abi_ulong msg_qnum;
>       abi_ulong msg_qbytes;
> -    abi_ulong msg_lspid;
> -    abi_ulong msg_lrpid;
> +    unsigned int msg_lspid;
> +    unsigned int msg_lrpid;

Why not use the explicit 'uint32_t' type?

>       abi_ulong __unused4;
>       abi_ulong __unused5;
>   };
> @@ -4206,8 +4206,8 @@ static inline abi_long target_to_host_msqid_ds(struct msqid_ds *host_md,
>       host_md->__msg_cbytes = tswapal(target_md->__msg_cbytes);
>       host_md->msg_qnum = tswapal(target_md->msg_qnum);
>       host_md->msg_qbytes = tswapal(target_md->msg_qbytes);
> -    host_md->msg_lspid = tswapal(target_md->msg_lspid);
> -    host_md->msg_lrpid = tswapal(target_md->msg_lrpid);
> +    host_md->msg_lspid = tswap32(target_md->msg_lspid);
> +    host_md->msg_lrpid = tswap32(target_md->msg_lrpid);
>       unlock_user_struct(target_md, target_addr, 0);
>       return 0;
>   }
> @@ -4227,8 +4227,8 @@ static inline abi_long host_to_target_msqid_ds(abi_ulong target_addr,
>       target_md->__msg_cbytes = tswapal(host_md->__msg_cbytes);
>       target_md->msg_qnum = tswapal(host_md->msg_qnum);
>       target_md->msg_qbytes = tswapal(host_md->msg_qbytes);
> -    target_md->msg_lspid = tswapal(host_md->msg_lspid);
> -    target_md->msg_lrpid = tswapal(host_md->msg_lrpid);
> +    target_md->msg_lspid = tswap32(host_md->msg_lspid);
> +    target_md->msg_lrpid = tswap32(host_md->msg_lrpid);
>       unlock_user_struct(target_md, target_addr, 1);
>       return 0;
>   }