Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <50995ce1-9a5e-df43-120f-dd72354160ba@gmail.com>
Date:   Wed, 29 Mar 2023 11:51:18 -0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.9.0
Subject: Re: [PATCH v2 3/6] rust: error: Add Error::from_errno()
Content-Language: en-US
To:     Asahi Lina <lina@asahilina.net>, Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?UTF-8?Q?Bj=c3=b6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        Sven Van Asbroeck <thesven73@gmail.com>
Cc:     Fox Chen <foxhlchen@gmail.com>,
        Andreas Hindborg <a.hindborg@samsung.com>,
        rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
        asahi@lists.linux.dev
References: <20230224-rust-error-v2-0-3900319812da@asahilina.net>
 <20230224-rust-error-v2-3-3900319812da@asahilina.net>
From:   Martin Rodriguez Reboredo <yakoyoku@gmail.com>
In-Reply-To: <20230224-rust-error-v2-3-3900319812da@asahilina.net>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 3/29/23 09:04, Asahi Lina wrote:
> [...]
>  
>  impl Error {
> +    /// Creates an [`Error`] from a kernel error code.
> +    ///
> +    /// It is a bug to pass an out-of-range `errno`. `EINVAL` would
> +    /// be returned in such a case.
> +    pub(crate) fn from_errno(errno: core::ffi::c_int) -> Error {
> +        if errno < -(bindings::MAX_ERRNO as i32) || errno >= 0 {
> +            // TODO: Make it a `WARN_ONCE` once available.
> +            crate::pr_warn!(
> +                "attempted to create `Error` with out of range `errno`: {}",
> +                errno
> +            );
> +            return code::EINVAL;
> +        }
> +
> +        // INVARIANT: The check above ensures the type invariant
> +        // will hold.
> +        Error(errno)
> +    }
> +
>      /// Returns the kernel error code.
>      pub fn to_errno(self) -> core::ffi::c_int {
>          self.0
> 

Reviewed-by: Martin Rodriguez Reboredo