From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id 4581BAC1C68 for ; Tue, 23 Jan 2024 23:29:21 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=js8disWRolQ19+lGokBSuNtNKPiNXremxl62yS6gSWo=; c=relaxed/simple; d=groups.io; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject:To:Cc:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Type; s=20140610; t=1706052560; v=1; b=CwgkghpA77+o1o25Eqku0J+4h5+T2TF7xoJum91acod9OlC4Liev/j7XKHyq6h1tmA764sdZ rPROy/opAE9R7vv22FibSRpWuIZUXO4qQeoZF6EhCv0EShUG7zlBWI1xG5Q8Y8LL232JqhQ6Cx8 ouGQeLuWUjayzqD3hfxcBO5Q= X-Received: by 127.0.0.2 with SMTP id gbexYY7687511xMUey649rp2; Tue, 23 Jan 2024 15:29:20 -0800 X-Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by mx.groups.io with SMTP id smtpd.web10.9832.1706052559359076777 for ; Tue, 23 Jan 2024 15:29:19 -0800 X-Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id CB46A61F84 for ; Tue, 23 Jan 2024 23:29:18 +0000 (UTC) X-Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E6D4C43399 for ; Tue, 23 Jan 2024 23:29:18 +0000 (UTC) X-Received: by mail-lf1-f54.google.com with SMTP id 2adb3069b0e04-5100e817640so555669e87.2 for ; Tue, 23 Jan 2024 15:29:18 -0800 (PST) X-Gm-Message-State: NTsm3zHsv8249V1m3F2oEYC5x7686176AA= X-Google-Smtp-Source: AGHT+IEjmvZIOq5ru4Yz9oZ7GpGabHTvQRltzvIZCrvMZuE3n0ECZSK5ppluLmz+IaXr4IoAq25Oikemt/D6k/lSIgo= X-Received: by 2002:a19:e04f:0:b0:510:f3c:f1 with SMTP id g15-20020a19e04f000000b005100f3c00f1mr132280lfj.116.1706052556336; Tue, 23 Jan 2024 15:29:16 -0800 (PST) MIME-Version: 1.0 References: <20240122023141.1620010-1-nhi@os.amperecomputing.com> In-Reply-To: <20240122023141.1620010-1-nhi@os.amperecomputing.com> From: "Ard Biesheuvel" Date: Wed, 24 Jan 2024 00:29:05 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [edk2-devel] [PATCH RESEND 1/1] StandaloneMmPkg/Core: Remove optimization for depex evaluation To: devel@edk2.groups.io, nhi@os.amperecomputing.com Cc: ardb+tianocore@kernel.org, ray.ni@intel.com, sami.mujawar@arm.com, lersek@redhat.com, "levi . yun" Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,ardb@kernel.org List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: Content-Type: text/plain; charset="UTF-8" X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b=CwgkghpA; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=kernel.org (policy=none); spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io On Mon, 22 Jan 2024 at 03:34, Nhi Pham via groups.io wrote: > > From: Laszlo Ersek > > The current dependency evaluator violates the memory access permission > when patching depex grammar directly in the read-only depex memory area. > > Laszlo pointed out the optimization issue in the thread (1) "Memory > Attribute for depex section" and provided suggested patch to remove the > perf optimization. > > In my testing, removing the optimization does not make significant perf > reduction. That makes sense that StandaloneMM dispatcher only searches > in MM protocol database and does not depend on UEFI/DXE protocol > database. Also, we don't have many protocols in StandaloneMM like > UEFI/DXE. > > From Laszlo, > > "The patch removes the EFI_DEP_REPLACE_TRUE handling altogether, plus it > CONST-ifies the Iterator pointer (which points into the DEPEX section), > so that the compiler catch any possible accesses at *build time* that > would write to the write-protected DEPEX memory area." > > (1) https://edk2.groups.io/g/devel/message/113531 > > Signed-off-by: Nhi Pham > Tested-by: levi.yun > Reviewed-by: levi.yun Merged as #5289 Thanks, > --- > StandaloneMmPkg/Core/Dependency.c | 37 ++++---------------- > 1 file changed, 7 insertions(+), 30 deletions(-) > > diff --git a/StandaloneMmPkg/Core/Dependency.c b/StandaloneMmPkg/Core/Dependency.c > index 440fe3e45238..2bcb07d34666 100644 > --- a/StandaloneMmPkg/Core/Dependency.c > +++ b/StandaloneMmPkg/Core/Dependency.c > @@ -13,16 +13,6 @@ > > #include "StandaloneMmCore.h" > > -/// > -/// EFI_DEP_REPLACE_TRUE - Used to dynamically patch the dependency expression > -/// to save time. A EFI_DEP_PUSH is evaluated one an > -/// replaced with EFI_DEP_REPLACE_TRUE. If PI spec's Vol 2 > -/// Driver Execution Environment Core Interface use 0xff > -/// as new DEPEX opcode. EFI_DEP_REPLACE_TRUE should be > -/// defined to a new value that is not conflicting with PI spec. > -/// > -#define EFI_DEP_REPLACE_TRUE 0xff > - > /// > /// Define the initial size of the dependency expression evaluation stack > /// > @@ -170,12 +160,12 @@ MmIsSchedulable ( > IN EFI_MM_DRIVER_ENTRY *DriverEntry > ) > { > - EFI_STATUS Status; > - UINT8 *Iterator; > - BOOLEAN Operator; > - BOOLEAN Operator2; > - EFI_GUID DriverGuid; > - VOID *Interface; > + EFI_STATUS Status; > + CONST UINT8 *Iterator; > + BOOLEAN Operator; > + BOOLEAN Operator2; > + EFI_GUID DriverGuid; > + VOID *Interface; > > Operator = FALSE; > Operator2 = FALSE; > @@ -253,8 +243,7 @@ MmIsSchedulable ( > Status = PushBool (FALSE); > } else { > DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = TRUE\n", &DriverGuid)); > - *Iterator = EFI_DEP_REPLACE_TRUE; > - Status = PushBool (TRUE); > + Status = PushBool (TRUE); > } > > if (EFI_ERROR (Status)) { > @@ -356,18 +345,6 @@ MmIsSchedulable ( > DEBUG ((DEBUG_DISPATCH, " RESULT = %a\n", Operator ? "TRUE" : "FALSE")); > return Operator; > > - case EFI_DEP_REPLACE_TRUE: > - CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID)); > - DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = TRUE\n", &DriverGuid)); > - Status = PushBool (TRUE); > - if (EFI_ERROR (Status)) { > - DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unexpected error)\n")); > - return FALSE; > - } > - > - Iterator += sizeof (EFI_GUID); > - break; > - > default: > DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Unknown opcode)\n")); > goto Done; > -- > 2.25.1 > > > > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#114243): https://edk2.groups.io/g/devel/message/114243 Mute This Topic: https://groups.io/mt/103879487/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=-=-=-=-=-=-=-=-=-=-=-