From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 1E2F72EE293 for ; Thu, 24 Jul 2025 18:53:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753383206; cv=none; b=S5xzQYdmr32CQ7fDYS1WsmJRocWOKf90Szovl33nkZxejrbmIqzuyc6c9zh1Ot8fOM4jXFNZjTkybZ/kcbR4fv0lVmcKzY2GpWMiHNkqAgLGDgGR9CqY5RGUf0/qEkpU8FnC7Sv4u00Hl/qCqOO/TqREDZtLcT2CzSIJpgW4PPo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753383206; c=relaxed/simple; bh=1cKp71OvP7YG8ixH5LKid29XhFAE7kjeQc19MfODs+A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UXbVyZ3TbtcOsti3gRfP9pWXd3Cu2N7fvw4TfzyelThIzeMqjULN2ZKNrpxgiPofXj92KwBH7W4VOJ+F+iIz10c2PaQMQ/97NYgp1nrNzRY0TtUK+398zBxChQbL0IUdqhhe2fuzZD2jReQ0p5KZcOVw5bdcCzEETvaY8yn9OTA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=QPYYiK/l; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QPYYiK/l" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1753383204; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bdevymO+VWaeP1oPd2AyCC29bi4KScNsc4kXrzWL+0c=; b=QPYYiK/lXC+eNdqGrKrzA9YNkMxmFXG4PcneNpJwzYWST3EzWZvVike0/dHKny+Lu+mtUU 46ofPBmwSAKzAjstCMjbDoDjh/9Uf7lhFkTBICJockVzCSf7D5LTng5nOiXXanvSaFXkgM yHyx5gdotGweg5hpT1eO69UlRDCSU8w= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-124-GI4I4ewdO7SH1RAh3szMUQ-1; Thu, 24 Jul 2025 14:53:19 -0400 X-MC-Unique: GI4I4ewdO7SH1RAh3szMUQ-1 X-Mimecast-MFC-AGG-ID: GI4I4ewdO7SH1RAh3szMUQ_1753383197 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 72C911955D95; Thu, 24 Jul 2025 18:53:17 +0000 (UTC) Received: from chopper.lyude.net (unknown [10.22.88.223]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7D4BB195608D; Thu, 24 Jul 2025 18:53:13 +0000 (UTC) From: Lyude Paul To: rust-for-linux@vger.kernel.org, Thomas Gleixner , Boqun Feng , linux-kernel@vger.kernel.org, Andreas Hindborg , FUJITA Tomonori Cc: Frederic Weisbecker , Anna-Maria Behnsen , John Stultz , Stephen Boyd , Miguel Ojeda , Alex Gaynor , Gary Guo , =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= , Benno Lossin , Alice Ryhl , Trevor Gross , Danilo Krummrich Subject: [PATCH v6 6/7] rust: time: Add Instant::from_nanos() Date: Thu, 24 Jul 2025 14:49:32 -0400 Message-ID: <20250724185236.556482-7-lyude@redhat.com> In-Reply-To: <20250724185236.556482-1-lyude@redhat.com> References: <20250724185236.556482-1-lyude@redhat.com> 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 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 For implementing Rust bindings which can return a point in time. Signed-off-by: Lyude Paul --- V4: * Turn from_nanos() into an unsafe function in order to ensure that we uphold the invariants of Instant V5: * Add debug_assert!() to from_nanos Signed-off-by: Lyude Paul --- rust/kernel/time.rs | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/rust/kernel/time.rs b/rust/kernel/time.rs index 64c8dcf548d63..75088d080b834 100644 --- a/rust/kernel/time.rs +++ b/rust/kernel/time.rs @@ -200,6 +200,29 @@ pub fn elapsed(&self) -> Delta { pub(crate) fn as_nanos(&self) -> i64 { self.inner } + + /// Create an [`Instant`] from a time duration specified in nanoseconds without checking if it + /// is positive. + /// + /// # Panics + /// + /// On debug builds, this function will panic if `nanos` violates our safety contract. + /// + /// # Safety + /// + /// The caller promises that `nanos` is in the range from 0 to `KTIME_MAX`. + #[expect(unused)] + #[inline] + pub(crate) unsafe fn from_nanos(nanos: i64) -> Self { + debug_assert!(nanos >= 0); + + // INVARIANT: Our safety contract ensures that `nanos` is in the range from 0 to + // `KTIME_MAX`. + Self { + inner: nanos as bindings::ktime_t, + _c: PhantomData, + } + } } impl core::ops::Sub for Instant { -- 2.50.0