From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0AE0C433DF for ; Tue, 23 Jun 2020 17:40:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 839C7206D4 for ; Tue, 23 Jun 2020 17:40:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592934057; bh=jCXcHNF4ffgYfk2J1Ar2eqA5w3GtOFqVWiURn6wkmOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hLX9guvvQn8+fVZmKalN41d9TvEow/DgUYr2/JrDFJlf/D+aLhw58/GNIKn/gys4+ rtYoJQSmwo6ZmgFILp3vsRDG4uHJ3ydA5jGRW2J90NvzC9NEvEAzkke1qZykCKlpyh dHxERhc5M5r4rkLOT4QhvLQBxpR0oPl3lBza0O8g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387731AbgFWRkz (ORCPT ); Tue, 23 Jun 2020 13:40:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:32876 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387468AbgFWRgF (ORCPT ); Tue, 23 Jun 2020 13:36:05 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1EF9C20780; Tue, 23 Jun 2020 17:36:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592933764; bh=jCXcHNF4ffgYfk2J1Ar2eqA5w3GtOFqVWiURn6wkmOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J+xGIT6dUgOaHTUkHzBUw2CwvSxYE+AiCWAtTJwPFdhymvvp8b96yVm1m+esBfSHK 2ERbvNXrWcU/BNGHR2O1p84DzYZAKilzu+E3n2Ctn8OwjHaRLUiPF9Q+tHlcXhw3j2 hVlAk3IV/TvHcl32MKFLPBunessIfqvAbjsulxQc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Huckleberry , Palmer Dabbelt , Sasha Levin , linux-riscv@lists.infradead.org, clang-built-linux@googlegroups.com Subject: [PATCH AUTOSEL 5.4 04/24] riscv/atomic: Fix sign extension for RV64I Date: Tue, 23 Jun 2020 13:35:39 -0400 Message-Id: <20200623173559.1355728-4-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200623173559.1355728-1-sashal@kernel.org> References: <20200623173559.1355728-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nathan Huckleberry [ Upstream commit 6c58f25e6938c073198af8b1e1832f83f8f0df33 ] The argument passed to cmpxchg is not guaranteed to be sign extended, but lr.w sign extends on RV64I. This makes cmpxchg fail on clang built kernels when __old is negative. To fix this, we just cast __old to long which sign extends on RV64I. With this fix, clang built RISC-V kernels now boot. Link: https://github.com/ClangBuiltLinux/linux/issues/867 Signed-off-by: Nathan Huckleberry Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/include/asm/cmpxchg.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h index d969bab4a26b5..262e5bbb27760 100644 --- a/arch/riscv/include/asm/cmpxchg.h +++ b/arch/riscv/include/asm/cmpxchg.h @@ -179,7 +179,7 @@ " bnez %1, 0b\n" \ "1:\n" \ : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" (__old), "rJ" (__new) \ + : "rJ" ((long)__old), "rJ" (__new) \ : "memory"); \ break; \ case 8: \ @@ -224,7 +224,7 @@ RISCV_ACQUIRE_BARRIER \ "1:\n" \ : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" (__old), "rJ" (__new) \ + : "rJ" ((long)__old), "rJ" (__new) \ : "memory"); \ break; \ case 8: \ @@ -270,7 +270,7 @@ " bnez %1, 0b\n" \ "1:\n" \ : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" (__old), "rJ" (__new) \ + : "rJ" ((long)__old), "rJ" (__new) \ : "memory"); \ break; \ case 8: \ @@ -316,7 +316,7 @@ " fence rw, rw\n" \ "1:\n" \ : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \ - : "rJ" (__old), "rJ" (__new) \ + : "rJ" ((long)__old), "rJ" (__new) \ : "memory"); \ break; \ case 8: \ -- 2.25.1