From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 2B9CF255231 for ; Fri, 2 May 2025 13:19:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746191986; cv=none; b=H7YNP2qZvj4pMQc+K/MvAtRiZ12ZIcr5t2p+42bTO/u9l56taFDoalABUrkrQmjUTAlLl3YQEbjBVkUhhOb0RZpUwZ5v22USWM1cKsAJJWzU1G1DF/Sn+/ZehLHha+ZKaNRSIvz43GvZbDWeJnx7w0if3CA+Z6MDmFurSGLugkw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746191986; c=relaxed/simple; bh=zedv0Ud5AXr6VBmDd8zA+6r8ej92u1QpNNcD/1j6Igg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=HGtAywx5Xm8HiP5UC5K+K3jfRwuNvCjVD1AYbTfyHVEU76nHapnI3mbJMQR42xWRSMSGHoDXHghOnX3UG1Dyd+Q5zbQpr5WwNzuUfqvFNM/fDWO+qI+EnT/46bLGbwznDw9pXspKt23ss9+Qhhz9w3ulV1KU4zaZOBxZBw+6QTY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ebGt8LWT; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ebGt8LWT" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-43cf172ffe1so12389375e9.3 for ; Fri, 02 May 2025 06:19:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1746191983; x=1746796783; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=+L34cKVl/QWezEuUTAS3yiE8vFcujdL77woAc6rzSjw=; b=ebGt8LWTAfx/NeAJKg7GwbapU6S1Q/fdMmdqmeSxAKGfpjrSAxCXL1Z61zWEDyN5uJ LBdWmUqB5RS2VFObhzSUZJQqImB8bUJrB6UjHzHp6Js2hya8Xp+hamoXWI0UG1On32tE FjBKok6uzsX8sVYCmgpPU8SxRN5QsWdHCvAcHAK0xIe2oO/xuFWWBUSuzqe+Ne+yCVSL Se913SSNZm9IJTA87tDkNQdkkSDgmu7jbI1HCtjAHGeNXm3BFvyPMHcRrfo1tsxcUwGe 3NdUfA8Tn0favvWBPOPdRwxcSkYZU9BC8CdDHRC3xumKXzo56QxAecuxiKDDI/8BBA+b rxHA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746191983; x=1746796783; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+L34cKVl/QWezEuUTAS3yiE8vFcujdL77woAc6rzSjw=; b=LpxMNx28DVje3dFiuh93hQKKUxbc1PKOb3jJfwbceNXpkskHPeQzmCdupbiZQ23p6w jxOsn3vHbWzVN6MJBttJELOG9LYOw4fXYB7XFsW/bfowTG97DtuCecBbd/c22hYHshUJ xuEzrQ4Eqe5sE9kJrvq3tXJtdVRjwAYGD4xqbkfZk2Nace9kvkpgeEW7Mcp9U1pi0yFu DQ4HUfV5KmbzPV98ZOE1YwR5D4C7aPBPIP+QeR1akaq6kIWvyZj/1cFeabuFNPUO+OIo Sh8I32AmMycxHze90DNBMUq7Ytjc1wU2GADinKXhObay/xR3m/dHJbsXfSYSCV5yrKuY AWcw== X-Forwarded-Encrypted: i=1; AJvYcCXNpTC/J8lo1WmN0dxvRcU7Yfa6/jwqVRgQAcBhCej0Jf+8hK/1voIGY+a7v0eKKc6uSuLWJ/e63efNOc909A==@vger.kernel.org X-Gm-Message-State: AOJu0YwRrI945tz/UwRL2i9hRhdOlsIrGJhh0JZGxw+YLBaQhUE1eJ1R uwgSopxpwMHDiCPPba66EiT4tyzV/Wa+6xS54w5DbVYSu10llzUr2rmSqk2xogfj7UuSiIO4mAp 1Pm21YmloIGtvwQ== X-Google-Smtp-Source: AGHT+IEuKQNKvecGdhwHBbYCN97yW+PFD8r7ZBIumcauLOIO27gV4LIw4vjXZi46OZNwh2XT0C1pG7y6e/XwrNU= X-Received: from wmpz12.prod.google.com ([2002:a05:600c:a0c:b0:43c:fd99:1b7e]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1e88:b0:43c:fd72:f039 with SMTP id 5b1f17b1804b1-441bbeb3813mr22539795e9.11.1746191983770; Fri, 02 May 2025 06:19:43 -0700 (PDT) Date: Fri, 02 May 2025 13:19:30 +0000 In-Reply-To: <20250502-vec-methods-v5-0-06d20ad9366f@google.com> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250502-vec-methods-v5-0-06d20ad9366f@google.com> X-Developer-Key: i=aliceryhl@google.com; a=openpgp; fpr=49F6C1FAA74960F43A5B86A1EE7A392FDE96209F X-Developer-Signature: v=1; a=openpgp-sha256; l=1873; i=aliceryhl@google.com; h=from:subject:message-id; bh=zedv0Ud5AXr6VBmDd8zA+6r8ej92u1QpNNcD/1j6Igg=; b=owEBbQKS/ZANAwAKAQRYvu5YxjlGAcsmYgBoFMZo1RXcw8Sq8mWMOC1GnKtfjkg4D0uDr8nSO nY7OzkiZUWJAjMEAAEKAB0WIQSDkqKUTWQHCvFIvbIEWL7uWMY5RgUCaBTGaAAKCRAEWL7uWMY5 RogXD/9KcwpDA3U5qoXW3BvFp4l3F1NrKDrLmMpvC3d69DwgcJx8IkHKhEeF7sv0xVwtrcvKmoS kzhPcQaO99mHFQeCEguPQgcabMjbGx5jyihq689LgYe3EzQNbjdRrxnWYb/dN81hREAj7C66s2j lVQXSt4e2a4jnlFe1IzAKFymyLNLF9ZqLim7ETRQruETTBbpgGQ3pwU77p+C2XdZ6lPNXttyfsx My1PyJQ/HgsWTyhjvxNOmmbeFMkozhG+/aZhs0yHkrlwWfPN+SUoiYBVtcEcfD9A90TxN9SSyVs KQL/0IX9zHDTwPlLWCmJp+N06YRg/kM4JGT5WSsuOWOD099f0jE/xSUICCmnTaExjb6A4aP+12e BFqG2FeZvgnTakHme8crge+PG9O/U/hPnQbOjAFVsNfY17+esW6XBCzbtlyP0aMGfL0AZikLY+Z YPB7S8+Xuxq0Tlr69XSJkEOxMo4HT4UkXML8tLAmo1Ee8la4ChtDQPPmxXAinyfymu3YCBWRTzX oKimKE2FcKkUQzhwEu0euCDgfaU3HiU/j3RN7XaBiJ/AUeKTKMik6mPRQ0n+oaUC79QVtmAcJQ6 jzElr6EyTgYQcABI7Q/aMqZbVkyiiRhIqrPFzKIgM/zibPsbfP4QwfF+ktWrLw7T3ajcNYz3D/Q dW+EZ9lfvvChORw== X-Mailer: b4 0.14.2 Message-ID: <20250502-vec-methods-v5-2-06d20ad9366f@google.com> Subject: [PATCH v5 2/7] rust: alloc: add Vec::pop From: Alice Ryhl To: Danilo Krummrich Cc: Matthew Maurer , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Alice Ryhl Content-Type: text/plain; charset="utf-8" This introduces a basic method that our custom Vec is missing. I expect that it will be used in many places, but at the time of writing, Rust Binder has six calls to Vec::pop. Signed-off-by: Alice Ryhl --- rust/kernel/alloc/kvec.rs | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs index 412a2fe3ce79a0681175bf358e8e0f628e77e875..ebca0cfd31c67f3ce13c4825d7039e34bb54f4d4 100644 --- a/rust/kernel/alloc/kvec.rs +++ b/rust/kernel/alloc/kvec.rs @@ -320,6 +320,37 @@ pub fn push(&mut self, v: T, flags: Flags) -> Result<(), AllocError> { Ok(()) } + /// Removes the last element from a vector and returns it, or `None` if it is empty. + /// + /// # Examples + /// + /// ``` + /// let mut v = KVec::new(); + /// v.push(1, GFP_KERNEL)?; + /// v.push(2, GFP_KERNEL)?; + /// assert_eq!(&v, &[1, 2]); + /// + /// assert_eq!(v.pop(), Some(2)); + /// assert_eq!(v.pop(), Some(1)); + /// assert_eq!(v.pop(), None); + /// # Ok::<(), Error>(()) + /// ``` + pub fn pop(&mut self) -> Option { + if self.is_empty() { + return None; + } + + let removed: *mut T = { + // SAFETY: We just checked that the length is at least one. + let slice = unsafe { self.dec_len(1) }; + // SAFETY: The argument to `dec_len` was 1 so this returns a slice of length 1. + unsafe { slice.get_unchecked_mut(0) } + }; + + // SAFETY: The guarantees of `dec_len` allow us to take ownership of this value. + Some(unsafe { removed.read() }) + } + /// Creates a new [`Vec`] instance with at least the given capacity. /// /// # Examples -- 2.49.0.967.g6a0df3ecc3-goog