Date:   Thu, 16 Feb 2023 14:57:38 +0100
From:   Oleg Nesterov <oleg@redhat.com>
To:     Gregory Price <gourry.memverge@gmail.com>
Cc:     linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        avagin@gmail.com, peterz@infradead.org, luto@kernel.org,
        krisman@collabora.com, tglx@linutronix.de, corbet@lwn.net,
        shuah@kernel.org, Gregory Price <gregory.price@memverge.com>
Subject: Re: [PATCH 2/2] ptrace,syscall_user_dispatch: checkpoint/restore
 support for SUD
Message-ID: <20230216135737.GC5200@redhat.com>
References: <20230214085215.106708-1-gregory.price@memverge.com>
 <20230214085215.106708-3-gregory.price@memverge.com>
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On 02/14, Gregory Price wrote:
>
> +struct compat_ptrace_sud_config {
> +        compat_ulong_t mode;
> +        compat_uptr_t selector;
> +        compat_ulong_t offset;
> +        compat_ulong_t len;
> +};

...

> +int syscall_user_dispatch_get_config(struct task_struct *task, unsigned long size,
> +		                     void __user *data)
> +{
> +	struct syscall_user_dispatch *sd = &task->syscall_dispatch;
> +#ifdef CONFIG_COMPAT
> +	if (unlikely(in_compat_syscall())) {
> +		struct compat_ptrace_sud_config cfg32;
> +
> +		if (size != sizeof(struct compat_ptrace_sud_config))
> +			return -EINVAL;
> +

Horror ;) why?

See my reply to v9, just make

	struct ptrace_sud_config {
		__u8  mode;
		__u64 selector;
		__u64 offset;
		__u64 len;
	};

Oleg.