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=-22.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 9EA97C433DF for ; Thu, 11 Jun 2020 18:34:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B1EE206C3 for ; Thu, 11 Jun 2020 18:34:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="o9hdq+lD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727845AbgFKSec (ORCPT ); Thu, 11 Jun 2020 14:34:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726386AbgFKSea (ORCPT ); Thu, 11 Jun 2020 14:34:30 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 790CAC08C5C1 for ; Thu, 11 Jun 2020 11:34:29 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id e192so7501657ybf.17 for ; Thu, 11 Jun 2020 11:34:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=COXpdfYzdd6T2PLhteaDM1tUQElcqbQJ6tIcGD3EDRg=; b=o9hdq+lDTGdQ7pL6eS2ne+STn2zEfYAr6Sd9feD0gHCYpOzUsbmVOKpoiBtQP4hRhP 0vd+WlglqyfcLJ9dwxfzJSViO0X4kGcUGdetOJVW7F8FeiZ3juWzPuV4sYw8rkN4ZUFy ylPg5u3vQGVe4MIfSCCWw6tJHtuBZQwPWcIIZrmAC2kmzRmTpimzaiVMSBkDHqWhdaOb ltCNz/98+IdgtXrP5J6B/vhq33ooa+nN/IByEuPkV65mBCzcpLEHo9u945AUVWVPhjSJ vXHubQ1UlbdcVVpDy6aFT+gAJEiM3RnQ/3xkqa7FelQYD7aZpbTIWafK9jGSDpUUzR1q HAHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=COXpdfYzdd6T2PLhteaDM1tUQElcqbQJ6tIcGD3EDRg=; b=NbisULiaOD08I4CflxApm2xjp/ezUXpeNvd1H/7FcB+cjYCSOnPc+vJtnWo1lsnNzw DonXsrMkix7kDKIUMnUCA9bQ/nkIZX2hvKz/G/FmyoJtas+xOpG6gB77EKpPY6fgLcaQ 93nRCTpG9gTAgGmTqcKi8gq4IrGpaZxj3PB1s8nLJE+aRg1+tvW6fWAYroON3YAGbUms hho5qEn+mdNtWw6RozGb8AZXcV2SqB+1k2DHFCdS1bVNX2Azz0F/ggo5xMtvwDvaQ5N9 WpmiKvOfA23kCgkurLBCgEgT5isej9ucokg3fRWZNKDvc2O6OwfSjZqPs2KbZIbHGo5r 6ZKw== X-Gm-Message-State: AOAM533U6W6wII4ArxIYWpHUeTE7G1PS3zA2RtaqTxkS8fMrlShDLbhv xUessvGIDpgrb0A357U0LAPw/lGC4Q== X-Google-Smtp-Source: ABdhPJycnzJzYBE1uCXDWobHSfMgy7yeM2Oc8KQ/6LbE+KEXMBUsHdFKo8h/UNp7B8daeNUFZH40Nkv7kQ== X-Received: by 2002:a25:3103:: with SMTP id x3mr17950241ybx.36.1591900468187; Thu, 11 Jun 2020 11:34:28 -0700 (PDT) Date: Thu, 11 Jun 2020 18:32:35 +0000 Message-Id: <20200611183235.37508-1-nhuck@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.27.0.278.ge193c7cf3a9-goog Subject: [PATCH] riscv/atomic: Fix sign extension for RV64I From: Nathan Huckleberry To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Nathan Huckleberry Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: clang-built-linux@googlegroups.com Signed-off-by: Nathan Huckleberry --- 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 d969bab4a26b..262e5bbb2776 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: \ -- 2.27.0.278.ge193c7cf3a9-goog