From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by mx.groups.io with SMTP id smtpd.web08.9100.1645271933337984887 for ; Sat, 19 Feb 2022 03:58:53 -0800 Authentication-Results: mx.groups.io; dkim=fail reason="unable to parse pub key" header.i=@intel.com header.s=intel header.b=KqdaQgl8; spf=pass (domain: intel.com, ip: 192.55.52.151, mailfrom: min.m.xu@intel.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645271933; x=1676807933; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=groiRdo+TngrJpQC3hJTa5wIn1g+k+xns4QhlUTh47M=; b=KqdaQgl8ROSWAtNQXcCO3CkHZPwl+FfnOuzcHno2B+6r7KTLH6M3UVge mKzjlQMaZxBaG6EhHQpe39FuSYRYNLffUTKKqrTCYEdPVjx09DJb2ZkN9 pg3KpqdBvRGfJZl4hsrJTUm+lR4Lq4OBIEv7c5V91AuuACQb5gdQShg5h J3BaJAw9Dxg85UslbYDVsWDevhjmmdpZmQfIEsKsoue2XedrOGCRhwDjF tHCx3YaCCQ3NxEW9SlAe58pztrPUA1Y+jR175zXhy1r6h2Xl7XeCekKlE Z3QlqhFLKw6laZy9yitOnXA5/LD7OAesZQS7cmPg+TZkfPGa35hd/yVJ8 g==; X-IronPort-AV: E=McAfee;i="6200,9189,10262"; a="231915513" X-IronPort-AV: E=Sophos;i="5.88,381,1635231600"; d="scan'208";a="231915513" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Feb 2022 03:58:29 -0800 X-IronPort-AV: E=Sophos;i="5.88,381,1635231600"; d="scan'208";a="546691335" Received: from mxu9-mobl1.ccr.corp.intel.com ([10.249.175.253]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Feb 2022 03:58:26 -0800 From: "Min Xu" To: devel@edk2.groups.io Cc: Min Xu , Ard Biesheuvel , Jordan Justen , Brijesh Singh , Erdem Aktas , James Bottomley , Jiewen Yao , Tom Lendacky , Gerd Hoffmann Subject: [PATCH V6 27/42] OvmfPkg/Sec: Declare local variable as volatile in SecCoreStartupWithStack Date: Sat, 19 Feb 2022 19:56:40 +0800 Message-Id: X-Mailer: git-send-email 2.29.2.windows.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429 Declare the local variables in SecCoreStartupWithStack that actually move the data elements as volatile to prevent the optimizer from replacing this function with the intrinsic memcpy(). Cc: Ard Biesheuvel Cc: Jordan Justen Cc: Brijesh Singh Cc: Erdem Aktas Cc: James Bottomley Cc: Jiewen Yao Cc: Tom Lendacky Cc: Gerd Hoffmann Signed-off-by: Min Xu --- OvmfPkg/Sec/SecMain.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/OvmfPkg/Sec/SecMain.c b/OvmfPkg/Sec/SecMain.c index 2c5561661ef3..02520e25ab9a 100644 --- a/OvmfPkg/Sec/SecMain.c +++ b/OvmfPkg/Sec/SecMain.c @@ -757,12 +757,17 @@ SecCoreStartupWithStack ( // IdtTableInStack.PeiService = NULL; for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index++) { - UINT8 *Src; - UINT8 *Dst; - UINTN Byte; + // + // Declare the local variables that actually move the data elements as + // volatile to prevent the optimizer from replacing this function with + // the intrinsic memcpy() + // + CONST UINT8 *Src; + volatile UINT8 *Dst; + UINTN Byte; - Src = (UINT8 *)&mIdtEntryTemplate; - Dst = (UINT8 *)&IdtTableInStack.IdtTable[Index]; + Src = (CONST UINT8 *)&mIdtEntryTemplate; + Dst = (volatile UINT8 *)&IdtTableInStack.IdtTable[Index]; for (Byte = 0; Byte < sizeof (mIdtEntryTemplate); Byte++) { Dst[Byte] = Src[Byte]; } -- 2.29.2.windows.2