From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD99620C023; Wed, 22 Oct 2025 14:32:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761143543; cv=none; b=eD5+IT2wypnf2nijXb4LTd5RYpKqTjD6YGKWISWpCpqksZ3tw3p/HMnwVTd3Xjr12H47GY4Jy19V/co86KvXHdSA2l773bu2PogaZexekzCnt/JBU3M2RDwbqvb2Xj/tN4nLzz/MS243iQ5qZWeMUw3u8GF3Jb/cyteSGo0my3s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761143543; c=relaxed/simple; bh=jHmBvtWqsYI0nOoIuE4dBO1onQPA3oDKKwTK/VZOrWo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZnY2eRjKMuX8+pf51j76SPt9QQaEhSY9z3TVNXwjsOxlQUVxJk3bkB7PRdH2TKTOrnONLuj0FcQ8fjAqG30e7YtHLAh9xrOTul/YIKRXZMK84dfL2BDoj2gNBjF4J+8dxc7xEeXfuGwbm4mmwL4gZ4t8f8KWMKVEeSH2Jsek0rw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pXxi+3QJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pXxi+3QJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 114E4C116D0; Wed, 22 Oct 2025 14:32:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761143541; bh=jHmBvtWqsYI0nOoIuE4dBO1onQPA3oDKKwTK/VZOrWo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pXxi+3QJ72t5ogUcvjNeDlp63lMgHF8xiXJ8DEPV+32dqrXksSNKM0OsRvF2VPuOp /HgRGZvx8YdVvH66Eq4lDxcLECpzRbRZAEONyCNI2OC7l5kYNo+KaxB0BLtP9TE38J qb0ciawsRx/QS0OrLGvivYAlFR5aXCT6ASyw1x90YKgJaFYRRQM2EbqlJ7o8hmNoIC dQZOjtemeKCu1xDcWkWFfbbafb50Ofqt4dGCL43lfTDawY11/BBV67w51ie0MHKFW3 x8DTbi1mz8k/md6BdzXotI5kW2MpTqORgMueVOlAJdvS73V4mcBJa1+Lo9o06ITman 5K4YKAyFOJHgg== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu, mmaurer@google.com Cc: rust-for-linux@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 03/10] rust: uaccess: add UserSliceReader::read_slice_file() Date: Wed, 22 Oct 2025 16:30:37 +0200 Message-ID: <20251022143158.64475-4-dakr@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251022143158.64475-1-dakr@kernel.org> References: <20251022143158.64475-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add UserSliceReader::read_slice_file(), which is the same as UserSliceReader::read_slice_partial() but updates the given file::Offset by the number of bytes read. This is equivalent to C's `simple_write_to_buffer()` and useful when dealing with file offsets from file operations. Signed-off-by: Danilo Krummrich --- rust/kernel/uaccess.rs | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/rust/kernel/uaccess.rs b/rust/kernel/uaccess.rs index c1cd3a76cff8..c2d3dfee8934 100644 --- a/rust/kernel/uaccess.rs +++ b/rust/kernel/uaccess.rs @@ -9,6 +9,7 @@ bindings, error::Result, ffi::{c_char, c_void}, + fs::file, prelude::*, transmute::{AsBytes, FromBytes}, }; @@ -303,6 +304,30 @@ pub fn read_slice_partial(&mut self, out: &mut [u8], offset: usize) -> Result Result { + if offset.is_negative() { + return Err(EINVAL); + } + + let Ok(offset_index) = (*offset).try_into() else { + return Ok(0); + }; + + let read = self.read_slice_partial(out, offset_index)?; + + *offset = offset.saturating_add_usize(read); + + Ok(read) + } + /// Reads a value of the specified type. /// /// Fails with [`EFAULT`] if the read happens on a bad address, or if the read goes out of -- 2.51.0