From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=lersek@redhat.com; receiver=edk2-devel@lists.01.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id DDB6B20347175 for ; Fri, 20 Oct 2017 08:40:01 -0700 (PDT) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0E5096A13; Fri, 20 Oct 2017 15:43:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 0E5096A13 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=lersek@redhat.com Received: from lacos-laptop-7.usersys.redhat.com (ovpn-120-150.rdu2.redhat.com [10.10.120.150]) by smtp.corp.redhat.com (Postfix) with ESMTP id F28105C1A3; Fri, 20 Oct 2017 15:43:39 +0000 (UTC) To: Leif Lindholm , Ard Biesheuvel Cc: edk2-devel@lists.01.org References: <20171020112325.10814-1-ard.biesheuvel@linaro.org> <20171020130024.l73uww7cxsjnwbsv@bivouac.eciton.net> From: Laszlo Ersek Message-ID: <51d0ef33-022f-7153-9acd-9bc4a26cdd59@redhat.com> Date: Fri, 20 Oct 2017 17:43:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171020130024.l73uww7cxsjnwbsv@bivouac.eciton.net> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 20 Oct 2017 15:43:41 +0000 (UTC) Subject: Re: [PATCH] ArmPlatformPkg/PrePeiCore: seed temporary stack before entering PEI core X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Oct 2017 15:40:02 -0000 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 10/20/17 15:00, Leif Lindholm wrote: > On Fri, Oct 20, 2017 at 12:23:25PM +0100, Ard Biesheuvel wrote: >> DEBUG builds of PEI code will print a diagnostic message regarding >> the utilization of temporary RAM before switching to permanent RAM. >> For example, >> >> Total temporary memory: 16352 bytes. >> temporary memory stack ever used: 4820 bytes. >> temporary memory heap used for HobList: 4720 bytes. >> >> Tracking stack utilization like this requires the stack to be seeded >> with a known magic value, and this needs to occur before entering C >> code, given that it uses the stack. Currently, only Nt32Pkg appears >> to implement this feature, but it is useful nonetheless, so let's >> wire it up for PrePeiCore. >> >> Contributed-under: TianoCore Contribution Agreement 1.1 >> Signed-off-by: Ard Biesheuvel >> --- >> ArmPlatformPkg/PrePeiCore/AArch64/PrePeiCoreEntryPoint.S | 7 +++++++ >> ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.S | 10 ++++++++++ >> ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.asm | 10 ++++++++++ >> 3 files changed, 27 insertions(+) >> >> diff --git a/ArmPlatformPkg/PrePeiCore/AArch64/PrePeiCoreEntryPoint.S b/ArmPlatformPkg/PrePeiCore/AArch64/PrePeiCoreEntryPoint.S >> index aab5edab0c42..7a33e2754869 100644 >> --- a/ArmPlatformPkg/PrePeiCore/AArch64/PrePeiCoreEntryPoint.S >> +++ b/ArmPlatformPkg/PrePeiCore/AArch64/PrePeiCoreEntryPoint.S >> @@ -13,6 +13,8 @@ >> >> #include >> >> +#define INIT_CAR_VALUE 0x5AA55AA55AA55AA5 >> + >> ASM_FUNC(_ModuleEntryPoint) >> // Do early platform specific actions >> bl ASM_PFX(ArmPlatformPeiBootAction) >> @@ -84,4 +86,9 @@ _PrepareArguments: >> >> _SetupPrimaryCoreStack: >> mov sp, x1 >> + MOV64 (x8, FixedPcdGet64(PcdCPUCoresStackBase)) >> + MOV64 (x9, INIT_CAR_VALUE) >> +0:stp x9, x9, [x8], #16 >> + cmp x8, x1 >> + b.lt 0b >> b _PrepareArguments >> diff --git a/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.S b/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.S >> index 14344425ad4c..7342e49bea59 100644 >> --- a/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.S >> +++ b/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.S >> @@ -13,6 +13,8 @@ >> >> #include >> >> +#define INIT_CAR_VALUE 0x5AA55AA5 >> + > > Worth moving to a common header somewhere? > > Also defined/used in MdeModulePkg/Core/Pei/Dispatcher/Dispatcher.c. Furthermore, open-coded in: EmulatorPkg/Unix/Host/Host.c: *StackPointer = 0x5AA55AA5; Nt32Pkg/Sec/SecMain.c: *StackPointer = 0x5AA55AA5; Honestly I think it should be a Fixed-At-Build PCD, in MdeModulePkg.dec, similarly to gEfiMdePkgTokenSpaceGuid.PcdDebugClearMemoryValue in MdePkg.dec. I'm unhappy that we have to annoy Ard with a request to "upstream" this constant to MdeModulePkg in some form, but we'll need it yet again in OVMF... > > That file has an explicit comment saying "temporary memory is filled > with this initial value during SEC phase". Should this end have a > corresponding comment saying "checked for during PEI phase"? Thanks Laszlo > > / > Leif > >> ASM_FUNC(_ModuleEntryPoint) >> // Do early platform specific actions >> bl ASM_PFX(ArmPlatformPeiBootAction) >> @@ -65,6 +67,14 @@ _PrepareArguments: >> >> _SetupPrimaryCoreStack: >> mov sp, r1 >> + MOV32 (r8, FixedPcdGet64(PcdCPUCoresStackBase)) >> + MOV32 (r9, INIT_CAR_VALUE) >> + mov r10, r9 >> + mov r11, r9 >> + mov r12, r9 >> +0:stm r8!, {r9-r12} >> + cmp r8, r1 >> + blt 0b >> b _PrepareArguments >> >> _NeverReturn: >> diff --git a/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.asm b/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.asm >> index abea675828df..7455de8aa66e 100644 >> --- a/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.asm >> +++ b/ArmPlatformPkg/PrePeiCore/Arm/PrePeiCoreEntryPoint.asm >> @@ -13,6 +13,8 @@ >> >> #include >> >> +#define INIT_CAR_VALUE 0x5AA55AA5 >> + >> INCLUDE AsmMacroIoLib.inc >> >> IMPORT CEntryPoint >> @@ -79,6 +81,14 @@ _PrepareArguments >> >> _SetupPrimaryCoreStack >> mov sp, r1 >> + mov32 r8, FixedPcdGet64(PcdCPUCoresStackBase) >> + mov32 r9, INIT_CAR_VALUE >> + mov r10, r9 >> + mov r11, r9 >> + mov r12, r9 >> +0:stm r8!, {r9-r12} >> + cmp r8, r1 >> + blt 0b >> b _PrepareArguments >> >> _NeverReturn >> -- >> 2.11.0 >>