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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 910F3C3A5A1 for ; Wed, 28 Aug 2019 05:34:28 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id D5BAD2173E for ; Wed, 28 Aug 2019 05:34:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5BAD2173E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-16809-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 9734 invoked by uid 550); 28 Aug 2019 05:34:20 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 9699 invoked from network); 28 Aug 2019 05:34:19 -0000 Subject: Re: [PATCH v6 04/12] powerpc/fsl_booke/32: introduce create_tlb_entry() helper To: Scott Wood CC: , , , , , , , , , , , , References: <20190809100800.5426-1-yanaijie@huawei.com> <20190809100800.5426-5-yanaijie@huawei.com> <20190827220752.GA17757@home.buserror.net> From: Jason Yan Message-ID: <1bfdc7c4-e615-0df2-1c0d-4358edcdb43b@huawei.com> Date: Wed, 28 Aug 2019 13:33:58 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <20190827220752.GA17757@home.buserror.net> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.96.203] X-CFilter-Loop: Reflected Hi Scott, Thanks for your reply. On 2019/8/28 6:07, Scott Wood wrote: > On Fri, Aug 09, 2019 at 06:07:52PM +0800, Jason Yan wrote: >> Add a new helper create_tlb_entry() to create a tlb entry by the virtual >> and physical address. This is a preparation to support boot kernel at a >> randomized address. >> >> Signed-off-by: Jason Yan >> Cc: Diana Craciun >> Cc: Michael Ellerman >> Cc: Christophe Leroy >> Cc: Benjamin Herrenschmidt >> Cc: Paul Mackerras >> Cc: Nicholas Piggin >> Cc: Kees Cook >> Reviewed-by: Christophe Leroy >> Reviewed-by: Diana Craciun >> Tested-by: Diana Craciun >> --- >> arch/powerpc/kernel/head_fsl_booke.S | 29 ++++++++++++++++++++++++++++ >> arch/powerpc/mm/mmu_decl.h | 1 + >> 2 files changed, 30 insertions(+) >> >> diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S >> index adf0505dbe02..04d124fee17d 100644 >> --- a/arch/powerpc/kernel/head_fsl_booke.S >> +++ b/arch/powerpc/kernel/head_fsl_booke.S >> @@ -1114,6 +1114,35 @@ __secondary_hold_acknowledge: >> .long -1 >> #endif >> >> +/* >> + * Create a 64M tlb by address and entry >> + * r3/r4 - physical address >> + * r5 - virtual address >> + * r6 - entry >> + */ >> +_GLOBAL(create_tlb_entry) > > This function is broadly named but contains various assumptions about the > entry being created. I'd just call it create_kaslr_tlb_entry. > OK. >> + lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ >> + rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */ >> + mtspr SPRN_MAS0,r7 /* Write MAS0 */ >> + >> + lis r6,(MAS1_VALID|MAS1_IPROT)@h >> + ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l >> + mtspr SPRN_MAS1,r6 /* Write MAS1 */ >> + >> + lis r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h >> + ori r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l >> + and r6,r6,r5 >> + ori r6,r6,MAS2_M@l >> + mtspr SPRN_MAS2,r6 /* Write MAS2(EPN) */ >> + >> + ori r8,r4,(MAS3_SW|MAS3_SR|MAS3_SX) >> + mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */ >> + >> + tlbwe /* Write TLB */ >> + isync >> + sync >> + blr > > Should set MAS7 under MMU_FTR_BIG_PHYS (or CONFIG_PHYS_64BIT if it's > too early for features) -- even if relocatable kernels over 4GiB aren't > supported (I don't remember if they work or not), MAS7 might be non-zero > on entry. And the function claims to take a 64-bit phys addr as input... > Good catch. And I should consider 32-bit phys addr as input too. I will fix this in next version. Thanks. > MAS2_M should be MAS2_M_IF_NEEDED to match other kmem tlb entries. > OK > -Scott > > . >