From nobody Thu Apr 9 07:16:34 2026 Received: from mail-pf1-f182.google.com (mail-pf1-f182.google.com [209.85.210.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7151D42668F for ; Tue, 10 Mar 2026 09:57:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773136661; cv=none; b=Y6xHVJl8sIUhav9e5F+CYOf/UuMfya7hwlnHIm1QrZtpVyMv35SfDdzR7Q9UZVmBDiuUxFynzpSJRKPT8GO4ii6V3xgPlLYN+ram1Wsn9xleVHeU9W+0eTk+fhPfqe3fnhtenuid0alzWYsEVyjhKlmIEfJmV88tJWG51NBmuxE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773136661; c=relaxed/simple; bh=dGBJzTjz5m+NMa32dIJtv8wj8C76M3988tpUHTl+siQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=FRjx4zFSxMATqbs2pQ7xgO7rX0+5ziEPzzWWN3/N5Nid+9ntKd4p0pkmJj+MrlD1Saq2nCbygkOjAOZN1th6rGo+Tdg63htiZ7zsEwnCZrkSgNOlbqSrTRoL1+mhEFUCp+L4Lr3PMy9ApQ0PlxWTu3lBsH7nbVvda7AeU2jeVWI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=C7CpuY6S; arc=none smtp.client-ip=209.85.210.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="C7CpuY6S" Received: by mail-pf1-f182.google.com with SMTP id d2e1a72fcca58-829ac8d56c5so3379706b3a.3 for ; Tue, 10 Mar 2026 02:57:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1773136660; x=1773741460; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=M+5TAXXK2Id9C75JxvtSg5OOL0DW00u/yNAzn1WJF60=; b=C7CpuY6S+OJjYIE6bs444s48Ad1UJ6ipy75LxMDl9ODW6JZSqGf6pq5vzx68eyFcOk RTJKt2+x+o2x5b8fFfTQarlCBGn0rsIT08Y3YUBJIa5uowSuwgaD+i8PbhTEsvAmw3VA xqwhk/OLmJB4g3lt6rpMOB2wXSWAvalTo+Y1GhX94OXm9YYAKPjCWAUk2iXJ9GiY6opN Q4L03G15B92Nki+FPNeR+vApxvecUNSTp8rI3cLVdqBqZagP9uiBFcgteRy4B2kip8ds rcTJ91I7GbnNCQPaIJ1b95LlJFqTIZR/jKfXNaYqJ8gP7a4ChHE/8iuIAZtihCTGEClH HQzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1773136660; x=1773741460; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=M+5TAXXK2Id9C75JxvtSg5OOL0DW00u/yNAzn1WJF60=; b=mwhnq/EaLBLwTbb0N8u9QBOgN4RAXCEfJ7rR/gWaLgQlIayHZJHj+egqlCOB2bS12F EHyybSZF7lTbc2tatiGagowF45jv5C6bcBfmNo4E7XgltiAtcUaes8pzPcY8c0Cw3K05 r7I+Vp4m6gN2mfCTw3VbBuV9woXIfDiYRcTlcOsmtp3TMUOS6ML4U9at96ogiiSQIw9n Ph6h3S1geYuDs0XhINcN+U+pAXoVVoG5RxPd+IMVZgSk5Unxv28nmLSDYv2fWTAzfxnp RFZ8kscjcKyGATJTYs+pCn9MsXNdOKD1VpI0O+jEiyMITZ++kGMIx+MZ//m26Otqmoe0 7gUA== X-Forwarded-Encrypted: i=1; AJvYcCUPJ0IqG6qyOaurtRUHNCbEyVDBdIU5znlM9jprGFrPYrXkQ7T6Xopchku5MS5O+ccUyuSoXeBtMimepcg=@vger.kernel.org X-Gm-Message-State: AOJu0YwWa3juDd35wk78jlSvVY+pNx246erMRONptz2+foaR8Wwphkk8 ljB3oVpyzRSoWs1hdw/ojkGHfCpdLYbtGb4fvkTpVyY5tNLd6BNeweGB03PoGUaV X-Gm-Gg: ATEYQzwh2DLjGDBbZmLrcGdO6n8YKV+mRg546CYsbmJBvvFxNlB5IJ2uYj2uscM6CiY 4e4CUGSZ3V+7yt1lgstn1ekW1vpteM0XFV8xBeiKADLC/UNrdhUSdALhgObN+RYe7EkNkH3YWcB TAtQkbIN6ZVaLPIkboFFN2hER8hXgae/SmRrzkVjP3P2Qxa3iXuexPjM0mql9jW4BQ1LUaz8hVM XYov7JVzHDPCpnAOJ81cwksJKfHTu6ldk8QbRh2ypgoom/ebeYtptrVmELjzv0iSx897Xy9X5Kh JZCBUCPsSU/11ndomUTnNdhD4SJEXu9mzOa0siZw42QZB/cTG8y29cjCmDcDyvrHt2M0xgqt03b Kw7DbmVHOXaeMEG2nZqsQDdDOOacCQ5AHtQW4+2VAUD8OWTYb3aC3VEGJhMVyB0gbWB/zIXQdG5 SG4AjS+QMTapgbeXzKfdx3TSjg777rtEAV24gC+Tt0Q6ljDll3rO2BMdizDkXikCjimwxOr/7sf ew/DnhtcZ8= X-Received: by 2002:a05:6a00:2351:b0:81e:c5a:8c25 with SMTP id d2e1a72fcca58-829a2ef7a72mr12136818b3a.44.1773136659657; Tue, 10 Mar 2026 02:57:39 -0700 (PDT) Received: from Albab.localdomain ([114.130.187.116]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-829a48a3b74sm17105000b3a.45.2026.03.10.02.57.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Mar 2026 02:57:39 -0700 (PDT) From: Albab Hasan To: rust-for-linux@vger.kernel.org Cc: ojeda@kernel.org, acourbot@nvidia.com, linux-kernel@vger.kernel.org, Albab Hasan Subject: [PATCH] rust: transmute: use split_at_checked() and split_at_mut_checked() Date: Tue, 10 Mar 2026 15:57:10 +0600 Message-ID: <20260310095710.1166-1-albabhasan276@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Replace manual bounds checking followed by split_at() and split_at_mut() calls with the checked variants split_at_checked() and split_at_mut_checked(), which return None instead of panicking on out-of-bounds indices. These methods were stabilized in Rust 1.80.0, which is the current minimum supported Rust version for the kernel. This simplifies from_bytes_prefix(), from_bytes_mut_prefix(), and from_bytes_copy_prefix() by removing the explicit bounds checks and panic-avoidance comments that are no longer needed. Signed-off-by: Albab Hasan --- rust/kernel/transmute.rs | 33 ++++++--------------------------- 1 file changed, 6 insertions(+), 27 deletions(-) diff --git a/rust/kernel/transmute.rs b/rust/kernel/transmute.rs index 5711580c9f9b..643b19406a24 100644 --- a/rust/kernel/transmute.rs +++ b/rust/kernel/transmute.rs @@ -67,16 +67,9 @@ fn from_bytes_prefix(bytes: &[u8]) -> Option<(&Self, &[u= 8])> where Self: Sized, { - if bytes.len() < size_of::() { - None - } else { - // PANIC: We checked that `bytes.len() >=3D size_of::`, = thus `split_at` cannot - // panic. - // TODO: replace with `split_at_checked` once the MSRV is >=3D= 1.80. - let (prefix, remainder) =3D bytes.split_at(size_of::()); + let (prefix, remainder) =3D bytes.split_at_checked(size_of::= ())?; =20 - Self::from_bytes(prefix).map(|s| (s, remainder)) - } + Self::from_bytes(prefix).map(|s| (s, remainder)) } =20 /// Converts a mutable slice of bytes to a reference to `Self`. @@ -110,16 +103,9 @@ fn from_bytes_mut_prefix(bytes: &mut [u8]) -> Option<(= &mut Self, &mut [u8])> where Self: AsBytes + Sized, { - if bytes.len() < size_of::() { - None - } else { - // PANIC: We checked that `bytes.len() >=3D size_of::`, = thus `split_at_mut` cannot - // panic. - // TODO: replace with `split_at_mut_checked` once the MSRV is = >=3D 1.80. - let (prefix, remainder) =3D bytes.split_at_mut(size_of::= ()); + let (prefix, remainder) =3D bytes.split_at_mut_checked(size_of::())?; =20 - Self::from_bytes_mut(prefix).map(|s| (s, remainder)) - } + Self::from_bytes_mut(prefix).map(|s| (s, remainder)) } =20 /// Creates an owned instance of `Self` by copying `bytes`. @@ -149,16 +135,9 @@ fn from_bytes_copy_prefix(bytes: &[u8]) -> Option<(Sel= f, &[u8])> where Self: Sized, { - if bytes.len() < size_of::() { - None - } else { - // PANIC: We checked that `bytes.len() >=3D size_of::`, = thus `split_at` cannot - // panic. - // TODO: replace with `split_at_checked` once the MSRV is >=3D= 1.80. - let (prefix, remainder) =3D bytes.split_at(size_of::()); + let (prefix, remainder) =3D bytes.split_at_checked(size_of::= ())?; =20 - Self::from_bytes_copy(prefix).map(|s| (s, remainder)) - } + Self::from_bytes_copy(prefix).map(|s| (s, remainder)) } } =20 --=20 2.43.0