From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (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 7F6CA387357 for ; Thu, 26 Mar 2026 10:10:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774519815; cv=none; b=cG7BxmJmVW4yLG5RvpaP5a+TVEgKZ6KDDAVbjsHVHWNElNfuY2NCO0rCkqPzlxnbD+6kq8ttzWNUhsSyPr9SQfNGR/zpbNguQs+Lnl3IwzOEuFTVipje1MPTTVuIzrZxxFwg03DK8IpbKLztYlPDOqDgZM81ZV/u6rtu6Sr5xXk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774519815; c=relaxed/simple; bh=uTL56eo9X2lUBgWDNCn1Tquwax2vc9PBJBXL6+0eRfU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=rosvulbShMuyz9rT94yuzI4e76IARy0lig3ZoDZvGKIjLLav3vcBxwJKK30bbOZTJ2s/2R9t5J15Ld9Yc4fAcnsiyIC9yAZhb1L2ZqjvB3wvKF7tYDLPxfDxtL1Ik9ZIQ6ySVxz5FTilMW79/GXfBbG/NtcebO4loA8QGWNG3Rs= 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=Gtxwl7/R; arc=none smtp.client-ip=209.85.128.73 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="Gtxwl7/R" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-486f89b7f69so10053735e9.0 for ; Thu, 26 Mar 2026 03:10:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1774519812; x=1775124612; 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=lBGicU27laianFvyzY656GHLSJPIgkYXNKTwZ0wPpek=; b=Gtxwl7/RO9OKVWl14OP7PbEfqvIiZCsYGYPHYoynzBc8T7xnL21pKakUBZYRwPGhVJ OGCKjQKOPK6RFHRdnp4kagvoPS4jC+WKZgixIaxiOohpnobHr0NbHQ3VnVBM8B7kRnBE RFQq0vXbpSYYIyHqGvwf0q23RkJ25iyoUkTy+SgNLBorzeur1m4xujZHHVq7yA6ycbVJ 8pXRd4Ic8LXab36dJ1Z+SF9WxLSh33aGbiQFpqDh3kNAJFJpvuBtHoJMI04RAgNaeAsS BISdBA/54hEa652ORLSDI6xVVh5/nftXvRH0IFM5w76Gm4V9ZZc0fTgXWlLCJrc7x4hh 8Shw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774519812; x=1775124612; 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=lBGicU27laianFvyzY656GHLSJPIgkYXNKTwZ0wPpek=; b=RizTfcimmxSErJQfdryOG2lFO93a6DbTI5r3pywHok7N3d0f3hcQyp+/HkZJFHm5is v0SUpHvKMDDDCFKSP1uKGgXk3ioDa3aAccsU7xDx+xp5YZ0idHU2mNS+202ssQKsKSRS BluZ/hDX0NrvLO2BNsvSJVD+NU1kQvBJGecY96B8QcaW5oMpWjJqLlfBthETW3TmfqHB h9dCHZzVPbMLVIK6OdDqy8jfrzkUqwdklIOafaSSt7vYn8AN5bCc1mnkp8Lf0UsZX/81 dZ0I2GTZzYvJZMXsjdqkVOg3OJA1n3ggg3Th4EVB4EP1ucQB6O3m/FHdQ/GEaRu3FtWQ hCNA== X-Forwarded-Encrypted: i=1; AJvYcCX95dU9+f/38ZlkHbaR7obAhr/3DsI4T5p9AOaE5TeBgArSSGMsGLG54BaGQbgKd3n+YjJXcardgxIDg5w=@vger.kernel.org X-Gm-Message-State: AOJu0Yy+30lbNokAFO3bz05rZtCctsX9BFtO+REJt7gnnSH/8jFT4lLV 8o/3brU08wWob7a9rm/rOHRKOvlS4NF4Y+4wYB2I5qYOXLqVN0BMzUlpjvuHLI84mTNo/b2QIS1 E91IhHcbi2hgvveXWYA== X-Received: from wmoo2.prod.google.com ([2002:a05:600d:102:b0:47d:5bef:a379]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:890b:b0:485:6ec7:2df with SMTP id 5b1f17b1804b1-48715fd50abmr80350625e9.8.1774519811752; Thu, 26 Mar 2026 03:10:11 -0700 (PDT) Date: Thu, 26 Mar 2026 10:10:10 +0000 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260322192159.88138-1-ojeda@kernel.org> <20260323000327.111235-1-ojeda@kernel.org> Message-ID: Subject: Re: Re: [PATCH v2 0/3] Inline helpers into Rust without full LTO From: Alice Ryhl To: "Russell King (Oracle)" Cc: Miguel Ojeda , a.hindborg@kernel.org, acourbot@nvidia.com, akpm@linux-foundation.org, anton.ivanov@cambridgegreys.com, bjorn3_gh@protonmail.com, boqun.feng@gmail.com, dakr@kernel.org, david@davidgow.net, gary@garyguo.net, johannes@sipsolutions.net, justinstitt@google.com, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-um@lists.infradead.org, llvm@lists.linux.dev, lossin@kernel.org, mark.rutland@arm.com, mmaurer@google.com, morbo@google.com, nathan@kernel.org, nick.desaulniers+lkml@gmail.com, nicolas.schier@linux.dev, nsc@kernel.org, peterz@infradead.org, richard@nod.at, rust-for-linux@vger.kernel.org, tmgross@umich.edu, urezki@gmail.com, will@kernel.org Content-Type: text/plain; charset="utf-8" On Mon, Mar 23, 2026 at 10:03:26AM +0000, Russell King (Oracle) wrote: > On Mon, Mar 23, 2026 at 01:03:27AM +0100, Miguel Ojeda wrote: > > On Sun, 22 Mar 2026 20:21:59 +0100 Miguel Ojeda wrote: > > > > > > On the other hand, regardless of whether we fix this (and another > > > issue in a separate email found thanks to the UML build), we could > > > instead add `depends on` listing explicitly the architectures where > > > this is going to be actually tested. That way maintainers can decide > > > whether they want to support it when they are ready. Thoughts? > > > > Another one for arm 32-bit: > > > > LD .tmp_vmlinux1 > > ld.lld: error: undefined symbol: __aeabi_read_tp > > >>> referenced by uaccess.rs:349 (rust/kernel/uaccess.rs:349) > > >>> samples/rust/rust_misc_device.o:(::ioctl) in archive vmlinux.a > > >>> referenced by uaccess.rs:543 (rust/kernel/uaccess.rs:543) > > >>> samples/rust/rust_misc_device.o:(::ioctl) in archive vmlinux.a > > >>> referenced by uaccess.rs:543 (rust/kernel/uaccess.rs:543) > > >>> drivers/android/binder/rust_binder_main.o:(rust_binder_main::rust_binder_ioctl) in archive vmlinux.a > > >>> referenced 36 more times > > Why is Rust generating code for userspace thread accessors for kernel > space, where userspace threads are meaningless. This is totally wrong. > The kernel must not reference __aeabi_read_tp(). > > Note: I know nothing about Rust, but I know enough to say the above is > pointing to a fundamental issue in Rust for 32-bit ARM. I noticed that the Makefile currently uses the arm-unknown-linux-gnueabi target. It should probably not be -linux target to avoid this? Probably it should just be armv7a-none-eabi, right? We gate HAVE_RUST on CPU_32v7, so we should not need to consider the other variants. Alice