Feedback-ID: i56a14606:Fastmail
User-Agent: Cyrus-JMAP/3.9.0-alpha0-183-gbf7d00f500-fm-20230220.001-gbf7d00f5
Mime-Version: 1.0
Message-Id: <ae739199-9e9e-4afe-bb32-be1e6ec28e76@app.fastmail.com>
In-Reply-To: <20230222200838.8149-6-casey@schaufler-ca.com>
References: <20230222200838.8149-1-casey@schaufler-ca.com>
 <20230222200838.8149-6-casey@schaufler-ca.com>
Date:   Fri, 03 Mar 2023 19:32:18 +0100
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     "Casey Schaufler" <casey@schaufler-ca.com>,
        "Paul Moore" <paul@paul-moore.com>,
        linux-security-module@vger.kernel.org
Cc:     jmorris@namei.org, "Kees Cook" <keescook@chromium.org>,
        john.johansen@canonical.com,
        "Tetsuo Handa" <penguin-kernel@i-love.sakura.ne.jp>,
        stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org,
        linux-api@vger.kernel.org,
        =?UTF-8?Q?Micka=C3=ABl_Sala=C3=BCn?= <mic@digikod.net>
Subject: Re: [PATCH v6 05/11] LSM: Create lsm_module_list system call
Content-Type: text/plain
Precedence: bulk

On Wed, Feb 22, 2023, at 21:08, Casey Schaufler wrote:
> @@ -1062,6 +1062,7 @@ asmlinkage long 
> sys_set_mempolicy_home_node(unsigned long start, unsigned long l
>  asmlinkage long sys_lsm_get_self_attr(struct lsm_ctx *ctx, size_t 
> *size,
>  				      __u64 flags);
>  asmlinkage long sys_lsm_set_self_attr(struct lsm_ctx *ctx, __u64 
> flags);
> +asmlinkage long sys_lsm_module_list(u64 *ids, size_t *size, int flags);
...
> + */
> +SYSCALL_DEFINE3(lsm_module_list,
> +		u64 __user *, ids,
> +		size_t __user *, size,
> +		u64, flags)
> +{

I see that the prototype does not match the definition here,
which really should raise a compiler error, but I suspect that
broke at some point.

Since none of the flags bits are actually used here, can we
please make this a 32-bit field as in the prototype rather
than the 64-bit one in the argument list?

Passing 64-bit arguments through 32-bit registers would make
the calling conventions incompatible with compat mode tasks
on 64-bit kernels.

       Arnd