From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fout-b3-smtp.messagingengine.com (fout-b3-smtp.messagingengine.com [202.12.124.146]) (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 1BC924248CE for ; Sun, 4 Oct 2026 12:13:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.146 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791116000; cv=none; b=nLXb5ho97uQTYeXTjCyN9ZEyfc+lrRswCO3GIw1mnvaGvLe2UhQg/F7n5K2VRfrmDWPhEg+GywCeKvEoYwXkAcoQvcV7WqwbNIV9SL3GmENfaTxPigVA89A1HgkEgeNr+B6zT31P6io0G3VFJ6drLgSFbBYzYe6cCmw1QIZW2XU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791116000; c=relaxed/simple; bh=ITA3OVcNcMjOC4ejeIYmsiFl6yGeCi0trPklszX/v3k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=SBybYL97u1Ppb40hQsTTSb9jihmwhGq4Dc6HCqc/nPxzpCMcsmHFoHN0V1OdaJJtPLHT0jfBkrUHhL2ihgt2tG/Bz5rGHBMl+u/CelXrk5yqOWpMJro7c0iPMY7iaqt4VoKW127SSwnu6Pj7W9x3jTiJj5MsXr+L3KKE8nf/DXo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=flapping.org; spf=pass smtp.mailfrom=flapping.org; dkim=pass (2048-bit key) header.d=flapping.org header.i=@flapping.org header.b=ddqMgXX8; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=FWhHOHp+; arc=none smtp.client-ip=202.12.124.146 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=flapping.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flapping.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=flapping.org header.i=@flapping.org header.b="ddqMgXX8"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="FWhHOHp+" Received: from phl-compute-02.internal (phl-compute-02.internal [10.202.2.42]) by mailfout.stl.internal (Postfix) with ESMTP id 5F5DF1D0014C for ; Sun, 4 Oct 2026 08:13:17 -0400 (EDT) Received: from phl-frontend-04 ([10.202.2.163]) by phl-compute-02.internal (MEProxy); Sun, 04 Oct 2026 08:13:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=flapping.org; h= cc:cc:content-transfer-encoding:content-type:date:date:from:from :in-reply-to:message-id:mime-version:reply-to:subject:subject:to :to; s=fm3; t=1791115994; x=1791202394; bh=1ZoTvrC2BNK9y0X6wptni XwBXAUofHrlvUBugHQcQFc=; b=ddqMgXX8Kibiw2pP4eOHqsJTHOWHBl2KABsRN XE9GqgnvNhK0c3LeLiiYsg9KRHDwCE5GBJPiuwDEPhiVL0vJ04FG34eyQ8CF7OBi nw8CZin96d7BMIQOCVEijrDjhjMOK770vA1WrrxQWQcidQ9fxmXGN6AQSIkUkLIq HFFf/rulJa9iFl7Tm4QvtJSn5vN89r/wACRIGNO2avTjTITMgddqutI+/2WnZIzj NDXfPIC7ot4/8OeR6ZNVND3RU/ohBnOq2LY8AS7PLR/InEw/Y3afiUDla1199RfP RP9e2Koxz229mTYiZgVd+jZH36DRCu9tGU0ADjofxZcnUYozg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:message-id:mime-version:reply-to:subject:subject:to :to:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t= 1791115994; x=1791202394; bh=1ZoTvrC2BNK9y0X6wptniXwBXAUofHrlvUB ugHQcQFc=; b=FWhHOHp+XiWtM+JjL7EWZhjGeC8E3yrkEv4IgMwzC0g2UMyDhMB pJ9e2bGOlQbTX3LkedDKLzhGfXCsGnkqrZK1Un5ie7Eg9T7qeodG21CKQxPVytq2 gnSrZgbUkYE2D1Em9jnvjj+Sh4ret2I7VGn9W+9o/GZgpKkTo1l5+EGyl1Otjldy RgQVTdopRuKwkeTE49pDnwX3F6OxoAAnCTJzeL4EBVVt+UK60jqcUIxXZp06BUZi eII7yk4BqSzNHoM1/4RABD2zJVOZUUQOldEnGV05Hff7bsVsdQG0043WCJzsashd VjfjxkGcWL1ze8/w7JYGVM2n3CcZs8lEjzw== X-DKIM2-Info: draft=ietf-dkim-dkim2-spec-06; repo=github.com/dkim2wg/interop; date=2026-09-30; sw=lmtpprox; action=sign d=flapping.org a=rsa-sha256; DKIM2-Signature: i=1; m=1; t=1791115994; d=flapping.org; mf=PHRvbW9AZmxhcHBpbmcub3JnPg==; rt=PHJ1c3QtZm9yLWxpbnV4QHZnZXIua2VybmVsLm9yZz4=; s=fm3:rsa-sha256:AA5+obKOlIybRfogICLBWB+oy7sX2RlkZ3qOqbNRrVOnVMJ Ewgpz+J/lroGWLvgKFENWJ+e4WM9/xev6qLjKYUkaXpm2ND/oOEpKz1H1mwkwk7R 3s/6MBGrJUGJhpx4lPM2WpjZM5YD2bkLfLtpAQfw6X5z6D2YxDKN08nabQAqVPvs 1tGcFSdkbrLEmq3Cu3R5B6UH7Rp4pd4x17rI3yPa1wtECZHILZLK7PEzr054aTgK 7wS4bzuyxTYYPtxn/Jh5j6k/j/3EYwSk+JixO/BFOR8czf4MfXWNDmH2yd2DqsP1 z7X04FQeVMPLGZHmbmBwfoWKyvAdll7O+DoDiOg==; X-DKIM2-Info: draft=ietf-dkim-dkim2-spec-06; repo=github.com/dkim2wg/interop; date=2026-09-30; sw=lmtpprox; action=mi-m=1; hc=9; hn=cc,content-transfer-encoding,date,feedback-id,from, message-id,mime-version,subject,to; Message-Instance: m=1; h=sha256:sgwF9fJp3L4AUwDVUpiyd9Q4Zh0GR9FWPtAHGMc+C4k=:ITA3OVcNcMjOC4ejeIYmsiFl6yGeCi0trPklszX/v3k=; X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTGEuSIb/FcWHjK3MYkrM93FyPS1RQ9Xtbd0J1NdUnSn+NhtL8G6aG4ljq0tgZmAOS NeiQk3VzgMLZ4cCu183M3FT7s0INEpjrCeS9qj1ViM3ovl8mdamj3YZuk+ruj4RYrmv6Tz Zlzt0s+vvgidwlidQxPfRCNmghtmV4onxaikaG3wnbtS6BExD+mxrSlcxs3p6i4pvb26Ba OnR7JKC4qghoHS+TauPbBqfkiFu0wEhPcT25R4wSei0e68xkS7mB0bdX9GZk1DJmbgKHr1 M1qMW5m6mmjLVt9d1hwfcYkL6rtJhP+TiHlht4l2Tv/NTU6CM8dITD3U/Ea4H0ZbG/pqX9 RD1Sn60J8E0BqIIoL9T6deRT8fNBY35qufAdNLTGdsS3DiHXnKRdNQQ/oV4UI/kfsaYx1D WPwlBA7c2hSCx/rvR9zaxxFEcgJ49FtNoPVgFLzukFmOxb9uhnROnfdul1b+Y3oL2AGEg4 lCqbx1b/RIdmX8O6sA8+BBv5tFb1hiGnLcHsBD9u/wlxRG3jjpwzFn1IwAltZgfekvgoWV VLoXZPoelQKLsfeGr4ENKN4Rt8dghROnOMS5rmSYaq5FH/6JbUt34wWxp+b/WffrIw0cun 4ZoNZOC3jEn7EoeLjJP0e/YHVhyJ0wacZ7+XnqoOut0/YyK3zIePLIyWP67w X-ME-Proxy: Feedback-ID: i51fe4b43:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sun, 4 Oct 2026 08:13:08 -0400 (EDT) From: FUJITA Tomonori To: anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, ojeda@kernel.org, richard@nod.at Cc: a.hindborg@kernel.org, acourbot@nvidia.com, aliceryhl@google.com, bjorn3_gh@protonmail.com, boqun@kernel.org, dakr@kernel.org, daniel.almeida@collabora.com, david@davidgow.net, gary@garyguo.net, linux-um@lists.infradead.org, lossin@kernel.org, tamird@kernel.org, tmgross@umich.edu, work@onurozkan.dev, rust-for-linux@vger.kernel.org, FUJITA Tomonori Subject: [PATCH v1] rust: arch/um: Fix loading Rust modules Date: Sun, 4 Oct 2026 21:12:30 +0900 Message-ID: <20261004121230.373216-1-tomo@flapping.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: FUJITA Tomonori Rust modules fail to load on x86_64 UML: # insmod rnull_mod.ko subarch: rnull_mod: Unknown rela relocation: 9 insmod: can't insert 'rnull_mod.ko': invalid module format arch/um/Makefile adds -Crelocation-model=pie to KBUILD_RUSTFLAGS. This comes after -Crelocation-model=static in the top-level Makefile, so all Rust code on UML, both built-in code and modules, is built as PIE. In PIE mode, rustc accesses statics in other crates through the GOT and emits R_X86_64_GOTPCREL (9) relocations. UML uses the x86 module loader, and it does not handle them. Remove the flag. Rust code, both built-in code and modules, then uses the static relocation model, the same as C code. Modules still fail to load with a larger mem=, such as mem=512M, because Rust code uses the small code model while C code uses -mcmodel=large. This is a separate problem. Tested with clang 20 and rustc 1.90: vmlinux builds and boots, and rnull_mod.ko loads with mem=32M. Reported-by: Zigit Zo Link: https://lore.kernel.org/rust-for-linux/62F5EEA0B866E9E0+20240903130606.292935-1-zig@iorw.io/ Assisted-by: LLM Signed-off-by: FUJITA Tomonori --- arch/um/Makefile | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/um/Makefile b/arch/um/Makefile index 937639edc295..c4a99073f014 100644 --- a/arch/um/Makefile +++ b/arch/um/Makefile @@ -62,8 +62,6 @@ KBUILD_CFLAGS += $(CFLAGS) $(CFLAGS-y) -D__arch_um__ \ -Din6addr_any=kernel_in6addr_any -Dstrrchr=kernel_strrchr \ -D__close_range=kernel__close_range -KBUILD_RUSTFLAGS += -Crelocation-model=pie - KBUILD_AFLAGS += $(ARCH_INCLUDE) USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -I%,,$(KBUILD_CFLAGS))) \ base-commit: 2dee3d3adcadcc57d62ba6608cd02f50b0c10264 -- 2.43.0