From nobody Sat Apr 11 07:07:33 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21E8EC678D4 for ; Thu, 2 Mar 2023 05:52:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230151AbjCBFwu (ORCPT ); Thu, 2 Mar 2023 00:52:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229988AbjCBFwR (ORCPT ); Thu, 2 Mar 2023 00:52:17 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9E77515C8; Wed, 1 Mar 2023 21:51:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1677736279; x=1709272279; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dQrYcTRM4xVVKpWEBRpp2gh8m1WDXg1zEAfOSTgEfys=; b=SMfaJpmTdnGP2YeSs8uNdFfQWmfprf/klOvS4uq3tMfUm2zpeNzYIHoX 308BCxIwwjfNvsIiJSprxdw8E6fHly0BRAv/Ut7jQEa+hUeOmfDY3+ATe ChpO85h/c9fv1A2yoQfwuErePmy/+r+rmCggauA7yHgxDbnhkcC9xB9NG +pbG+km+hdCr3G3i30YKgVew0FVrDJeEThwl82zzrf8U3NrK9gm/zsw+z qYPA4paMdAOaS1NBSJAd3uOUu0CXylvn0wOSp8boaRDRiDfSBWQ/Wsszo JAI7Qnh0+yRaGlq5yUKw9OM48dW7dOD6HwKpe3i0zt77hmqF4wP+IdyuF A==; X-IronPort-AV: E=McAfee;i="6500,9779,10636"; a="420887256" X-IronPort-AV: E=Sophos;i="5.98,226,1673942400"; d="scan'208";a="420887256" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Mar 2023 21:50:52 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10636"; a="920530954" X-IronPort-AV: E=Sophos;i="5.98,226,1673942400"; d="scan'208";a="920530954" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga006.fm.intel.com with ESMTP; 01 Mar 2023 21:50:50 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [PATCH v4 24/34] x86/fred: let ret_from_fork() jmp to fred_exit_user when FRED is enabled Date: Wed, 1 Mar 2023 21:25:01 -0800 Message-Id: <20230302052511.1918-25-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230302052511.1918-1-xin3.li@intel.com> References: <20230302052511.1918-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Let ret_from_fork() jmp to fred_exit_user when FRED is enabled, otherwise the existing IDT code is chosen. Signed-off-by: H. Peter Anvin (Intel) Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/entry/entry_64.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 7ecd2aeeeffc..7ffd20578b8c 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -299,7 +299,12 @@ SYM_CODE_START_NOALIGN(ret_from_fork) UNWIND_HINT_REGS movq %rsp, %rdi call syscall_exit_to_user_mode /* returns with IRQs disabled */ +#ifdef CONFIG_X86_FRED + ALTERNATIVE "jmp swapgs_restore_regs_and_return_to_usermode", \ + "jmp fred_exit_user", X86_FEATURE_FRED +#else jmp swapgs_restore_regs_and_return_to_usermode +#endif =20 1: /* kernel thread */ --=20 2.34.1