From nobody Fri Dec 19 19:19:11 2025 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (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 816232046B4 for ; Wed, 8 Jan 2025 23:35:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736379312; cv=none; b=nIJIA9C5zaRdklvZ6b4sTl6fBnZJbkov0tFFWq67R7TE1yWU/6uMeA6xEptdNyJfQX23KZNhwu3t07DXNfyL9Pd2K/u4ZfmcW444xorH71XuV17m8nAJJh52Eod7+8/GPGkxnPuHD4mH+Yj59T2kkYOF7UmZvWCfIkESWs4Mrqc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736379312; c=relaxed/simple; bh=CKHJ/lFWSVkPjxOxjDZC4znki4qzFYKMBX705l8ha58=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=ewOjAbpLtL5v0PQgoadRLQOpbq0Uqw0kXMPY+UsFV61kLS7UG+JdsYlS5H+sxdNiNEaVPrM6wzmFx/ZWzI7xBuwFO5lP+yVm8Q615G1E90HJ389BHm+scWie0KcqS3pueNg7Osw7ixQo3uoPnIb1moerTdOX7Ez6uci2W7qs+O8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=uXr2PJi9; arc=none smtp.client-ip=209.85.214.201 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--mmaurer.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uXr2PJi9" Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-2178115051dso4107705ad.1 for ; Wed, 08 Jan 2025 15:35:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1736379311; x=1736984111; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=Gqhj0ixB52my3tDkcBBqhKKSd2GIEkc506F7tWVukqI=; b=uXr2PJi94Vx+kbBKDouasb35+zLkUbssWFRs8A88uhkOMUnAdwQMzet5PC1ZEIPspY KQSMahpMiYOdnd+Mj5ayz7dTiBdy7UdpHG0WXDov5isVSth7BbH3yTKWzeV6bfv63+Se 9YjNedV8M+AAmWftifdfpeUT+rEgcNvLATyd4mY/CHBbPMroXEUy/VAest+XrlvnYwmk EgGIHcDjsQep7fJ5HfVsYP0qcPbh3aPbOjpnTKa+nvaW1iR+aR2+P5d0jo36nK5mRnPs VElbir1z4uJKqv5/HuIwLVT2CCOZ/n2lSnUXvJ8kOk/cAORopYFhFgiiyNw19hw1Q+Dr 9/eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736379311; x=1736984111; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Gqhj0ixB52my3tDkcBBqhKKSd2GIEkc506F7tWVukqI=; b=WMbU3XgVYnRgYxbqiaOKhQU04hnFFqsNdmEYwk0lsc4y7I72cOGvkBxMF6uerQmhRj S13sgYHx/A3Z8OET1iGTLB3gxt5rCDHKBwbVKxkwqNiZANOD7Jjh5wjIGQVr4+lsWuXN 1ih7c9qRWvmz9t7yUmtgHs39yLiuXy3DRbPr/uBmTl2/BZUw52MW8gf+nq+e1eNfPeEV ootccDAnD4dl32sOiraYZa/gY/gQ8lCoyJjowZJvpx+f+MDV7yEKq1o7YVbd2nEbi5OI B00xxlnDNMhUbZYIV8I68zpA0fkxcnAt1Vh0YVDkZH450CnWruAGvybv/hnWV6+JhiV4 M6ZQ== X-Gm-Message-State: AOJu0Yx2OyfnvTLSxtMlH8ORSx/WquYmhq8QxMYWkZvenrOfozi/Mz/D xB/hxOY554ejbaAkvuK4h+T7QzKqEnZ3vWKjWprXS5ld0N4goJqIrcvdGMXcTIulPhF3IBdwRMH HC6nU8g== X-Google-Smtp-Source: AGHT+IFwFvB4At01kqg469ZGNHEiX4L1SakP2bBAUMb4Btldo6RIZqC/Foer4mABJAQfNFh68NUwLdonnCW+ X-Received: from pgkk1.prod.google.com ([2002:a63:2401:0:b0:801:9268:c344]) (user=mmaurer job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:4303:b0:1e1:f281:8d07 with SMTP id adf61e73a8af0-1e88cfa6ac2mr7148028637.10.1736379310886; Wed, 08 Jan 2025 15:35:10 -0800 (PST) Date: Wed, 08 Jan 2025 23:35:08 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAKsLf2cC/x3MQQqAIBBA0avIrBtQKYiuEi3UxhooDbUIorsnL d/i/wcyJaYMg3gg0cWZY6hQjQC3mrAQ8lwNWupOKtljOnNBWzxuJSIHF/fDFJSz7nqvvG3JQm2 PRJ7v/ztO7/sBAuh2smcAAAA= X-Change-Id: 20250108-rust-btf-lto-incompat-0d258f1fb4eb X-Mailer: b4 0.15-dev Message-ID: <20250108-rust-btf-lto-incompat-v1-1-60243ff6d820@google.com> Subject: [PATCH] rust: Disallow BTF generation with Rust + LTO From: Matthew Maurer To: Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , "=?utf-8?q?Bj=C3=B6rn_Roy_Baron?=" , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross Cc: linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, Matthias Maennich , Matthew Maurer Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The kernel cannot currently self-parse BTF containing Rust debug information. pahole uses the language of the CU to determine whether to filter out debug information when generating the BTF. When LTO is enabled, Rust code can cross CU boundaries, resulting in Rust debug information in CUs labeled as C. This results in a system which cannot parse its own BTF. Signed-off-by: Matthew Maurer --- init/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/init/Kconfig b/init/Kconfig index c1f9eb3d5f2e892e977ba1425599502dc830f552..eb1076be6242cf349c12ef0f447= 696cb3a9976fa 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1962,7 +1962,7 @@ config RUST depends on !MODVERSIONS depends on !GCC_PLUGIN_RANDSTRUCT depends on !RANDSTRUCT - depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE + depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO) depends on !CFI_CLANG || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC select CFI_ICALL_NORMALIZE_INTEGERS if CFI_CLANG depends on !CALL_PADDING || RUSTC_VERSION >=3D 108100 --- base-commit: 4b90165c7d1173e0f65538d25aa718ec7ecdd5d6 change-id: 20250108-rust-btf-lto-incompat-0d258f1fb4eb Best regards, --=20 Matthew Maurer