From nobody Thu Dec 18 21:43:55 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 A9EAB1FFC69; Thu, 13 Feb 2025 14:55:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739458542; cv=none; b=qr4LWZYmHhhGfIJkcBWYWVEJRzZBHCqOdaH+VEiw3pYB2kIu+0W50K9+ju7TaKC2HgT098uA7krvEsqvLKAHANy3JDsagcAto0BzoczhuTTKXRi45FDhiRJlg0nO+oZ9UMVBnhV6kl1kPEnGmT8aVBi+J8BS6hvNaHWTfS4t4v4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739458542; c=relaxed/simple; bh=VsJP2WA7ooxf6Q50q5cBWRfJTkxkoykLDjcBCjCSHrI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=EQPKj5ZMD7AviyJS6oOyTOVithpftapfP6LRCACmObFx4Pmkz16aqvp/xhnqNLUGkuaX58CniXu8poURoiQjeDXHTx4dn4X82aT5+mSQkq8mIpyLimWlS7S7or231z2cSzyUlaeyeO8+YrutwY6ZJlU2xxn+dGsmJHXBnILj4aA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=2Y5db328; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=siXfTNw2; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="2Y5db328"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="siXfTNw2" From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1739458534; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U0Uz4M0nysayxZy8O+uDEBR3eTZPLx7yuVwYwNJRJKg=; b=2Y5db328te54wyfew7h4HOb/N3hvFahLRa/HQxYQcn2qIWZk3Lnq6EZ8/wF9jNz+fCeWuo 0HKZCzi7w8BSY7jRDy5Kqmx6rq/0R4LRN14jTCwismiU/vsAVHzUDCw5a0xIsbacTmA4g8 BmY43HogkQ7hDQEY20pr3fO9VlXPyiAQANb3WIwDzpIh/cDg6rpDzfF9jh7PYpqqmZT0IW sa+tIsilWygLkASpnSfQI+n6LE2WP6m4iXC03lPsqAz2PkZJY5Fvc/hwtWt6f/vOm6faZq HvRd0WX2FGRArDD6TY29E9fkuiSywKsSf9tQUp7m44zhL+VHAjoSpUpfL8jC9g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1739458534; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U0Uz4M0nysayxZy8O+uDEBR3eTZPLx7yuVwYwNJRJKg=; b=siXfTNw2xSiOkdln54UCJxk/2Isv3RzFueCNsMvTaaXKOelkE8j18podtAhYikCkPREM6S tS4OoxlyvbrQlzCw== Date: Thu, 13 Feb 2025 15:55:18 +0100 Subject: [PATCH 2/2] kbuild: userprogs: use lld to link through clang Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250213-kbuild-userprog-fixes-v1-2-f255fb477d98@linutronix.de> References: <20250213-kbuild-userprog-fixes-v1-0-f255fb477d98@linutronix.de> In-Reply-To: <20250213-kbuild-userprog-fixes-v1-0-f255fb477d98@linutronix.de> To: Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Sam Ravnborg Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, =?utf-8?q?Thomas_Wei=C3=9Fschuh?= , stable@vger.kernel.org X-Developer-Signature: v=1; a=ed25519-sha256; t=1739458532; l=1464; i=thomas.weissschuh@linutronix.de; s=20240209; h=from:subject:message-id; bh=VsJP2WA7ooxf6Q50q5cBWRfJTkxkoykLDjcBCjCSHrI=; b=8OMIVLKzPjKBGa+nsuyZo48SgY/H7ox75L6z9V8p2CPGZuYfEbGXiibYamh8B6s+e9cikZVwq UOOjyGCL6v+DwjajMJZig3VnB/KagLzox2tccsCQfBkVnRBxL8VhKQQ X-Developer-Key: i=thomas.weissschuh@linutronix.de; a=ed25519; pk=pfvxvpFUDJV2h2nY0FidLUml22uGLSjByFbM6aqQQws= The userprog infrastructure links objects files through $(CC). Either explicitly by manually calling $(CC) on multiple object files or implicitly by directly compiling a source file to an executable. The documentation at Documentation/kbuild/llvm.rst indicates that ld.lld wo= uld be used for linking if LLVM=3D1 is specified. However clang instead will use either a globally installed cross linker from $PATH called ${target}-ld or fall back to the system linker, which probably does not support crosslinking. For the normal kernel build this is not an issue because the linker is alwa= ys executed directly, without the compiler being involved. Fix this by passing -fuse-lld and let clang find its matching lld. Fixes: 7f3a59db274c ("kbuild: add infrastructure to build userspace program= s") Cc: stable@vger.kernel.org Signed-off-by: Thomas Wei=C3=9Fschuh --- Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/Makefile b/Makefile index bb5737ce7f9e79f4023c9c1f578a49a951d1e239..b4c208ae4041c1f4e32c2a15832= 2422ce7353d06 100644 --- a/Makefile +++ b/Makefile @@ -510,6 +510,7 @@ OBJCOPY =3D $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX) OBJDUMP =3D $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX) READELF =3D $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX) STRIP =3D $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX) +KBUILD_USERLDFLAGS +=3D -fuse-ld=3Dlld else CC =3D $(CROSS_COMPILE)gcc LD =3D $(CROSS_COMPILE)ld --=20 2.48.1