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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10393C6FD1F for ; Thu, 16 Mar 2023 09:58:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7E7CA900003; Thu, 16 Mar 2023 05:58:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7981F900002; Thu, 16 Mar 2023 05:58:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 65F65900003; Thu, 16 Mar 2023 05:58:42 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 57E95900002 for ; Thu, 16 Mar 2023 05:58:42 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 261BC408F9 for ; Thu, 16 Mar 2023 09:58:42 +0000 (UTC) X-FDA: 80574312084.22.6B38C18 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by imf04.hostedemail.com (Postfix) with ESMTP id 6B57940016 for ; Thu, 16 Mar 2023 09:58:38 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=quicinc.com header.s=qcppdkim1 header.b=D4hsQ4kD; dmarc=pass (policy=none) header.from=quicinc.com; spf=pass (imf04.hostedemail.com: domain of quic_pkondeti@quicinc.com designates 205.220.168.131 as permitted sender) smtp.mailfrom=quic_pkondeti@quicinc.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1678960718; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/i8sE88y4FYJE1h5LheXEbG3SbjlercD8ty7RP0GvyY=; b=XxWRir851nFujxip+qdj5+sT7mmwSu3fG9KpKYbSprAjbMr8b3/SXFZcI9Iys8wzv81gsu DGwBfnVP1FhS4h7PJksO5a8UfZ4Ei7O4GIeOfiuqHC7KMUqompeqIWEJ82yRBGoXGqlfK6 PE+QllZdNmhOPFbgJ1G5FVi03R7tXaQ= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=quicinc.com header.s=qcppdkim1 header.b=D4hsQ4kD; dmarc=pass (policy=none) header.from=quicinc.com; spf=pass (imf04.hostedemail.com: domain of quic_pkondeti@quicinc.com designates 205.220.168.131 as permitted sender) smtp.mailfrom=quic_pkondeti@quicinc.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1678960718; a=rsa-sha256; cv=none; b=pkAepcMQFCQRbwMOgNjzkCZvpdtFaLTEZ1WBe7d8R2Xo0bnRmZIA3diy6LoXvRwTroDJYZ y5krcKlLi1ogznIgCcMCx31uNGS6RlNj7jvts0YTfTLOe7ySfhegzvVQyVzLWwhStMk8GK Xm/pbaTiX6+leHcLeuh5TBWPXgiHLgs= Received: from pps.filterd (m0279864.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 32G5F3cl020554; Thu, 16 Mar 2023 09:58:22 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=qcppdkim1; bh=/i8sE88y4FYJE1h5LheXEbG3SbjlercD8ty7RP0GvyY=; b=D4hsQ4kDD6R0sVl5ffEEkRQa/I5d60FQyo63LCmx3CaITLgX/tzTQZr+SrPTrw2pPPZE 88vQile0ZjAlk9peY1wFPvihQcOWtf4PJm8MhMJrT04tRNRD3cAi94P4Qjjf2XNLW2p1 88XPdsMFY1TiyOoo+0twNRrlzNzndAqdG4v35oF6XtDJPGWSCTP67/zWhuSv3GgYGTcZ k99gztA7dCzVPZsyc+U2rI2Y2DOnAmy+jhWKQcYeQV9Hxw+0kc3sut9YNy3XJYdy7nVo 72WgovmOtu+XHxJOwmuuV4UdxPTqgr4PaSiPu4Ic6DGwz2uVPRPaMZ5K6AnPwzzS3YzX CA== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3pbpxnhedn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Mar 2023 09:58:22 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 32G9wLOw027999 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Mar 2023 09:58:21 GMT Received: from hu-pkondeti-hyd.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.41; Thu, 16 Mar 2023 02:58:16 -0700 Date: Thu, 16 Mar 2023 15:28:12 +0530 From: Pavan Kondeti To: Zhenhua Huang CC: , , , , , , , , , , , , , , , , Subject: Re: [PATCH v9] mm,kfence: decouple kfence from page granularity mapping judgement Message-ID: <20230316095812.GA1695912@hu-pkondeti-hyd.qualcomm.com> References: <1678956620-26103-1-git-send-email-quic_zhenhuah@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1678956620-26103-1-git-send-email-quic_zhenhuah@quicinc.com> X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 50vNI7lbbzLRFPvmqzRdmgBt9HurgfFk X-Proofpoint-ORIG-GUID: 50vNI7lbbzLRFPvmqzRdmgBt9HurgfFk X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-16_06,2023-03-15_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 lowpriorityscore=0 phishscore=0 mlxscore=0 clxscore=1015 suspectscore=0 adultscore=0 mlxlogscore=993 spamscore=0 bulkscore=0 malwarescore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303150002 definitions=main-2303160084 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 6B57940016 X-Stat-Signature: 4ajy9bdo6haakmxqppwa383n4pn5g3bc X-HE-Tag: 1678960718-18694 X-HE-Meta: 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 +0t1lfNX 7Udkn2Mku71sTgi9D5vjLNa0XjHFiEqH8CdVMdlnHYtsKhH5/8hrJ7018VENPn3U6VwzVBrT9/l336vFo37bKxs2FRl2KwDFv7nRFEUVqdklVLneneQUL9D8m2muV7vbLEiIwSZFwT2c8oX24o3J+5dGSndyLYR1wW2dxj/sKq7aC1NNRWyrzOyeZHuUUe3CtXUGYm8oKNTAd3ASv62RVR4xB/G4/qLOkb56qLa7AQM71eIDEXw8w5jL4bAkDBQtBV9hWWsM+KBRE1dyBszv1wyD1ZaI/+hozbCHc/Wk9rVzkJp5ILQokGCVbt6xqQrI2vVcyk/sTT4vlX/nQbBvczeFuH1CpBqaSivczJE3QVXyJ0mw= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 16, 2023 at 04:50:20PM +0800, Zhenhua Huang wrote: > Kfence only needs its pool to be mapped as page granularity, if it is > inited early. Previous judgement was a bit over protected. From [1], Mark > suggested to "just map the KFENCE region a page granularity". So I > decouple it from judgement and do page granularity mapping for kfence > pool only. Need to be noticed that late init of kfence pool still requires > page granularity mapping. > > Page granularity mapping in theory cost more(2M per 1GB) memory on arm64 > platform. Like what I've tested on QEMU(emulated 1GB RAM) with > gki_defconfig, also turning off rodata protection: > Before: > [root@liebao ]# cat /proc/meminfo > MemTotal: 999484 kB > After: > [root@liebao ]# cat /proc/meminfo > MemTotal: 1001480 kB > > To implement this, also relocate the kfence pool allocation before the > linear mapping setting up, arm64_kfence_alloc_pool is to allocate phys > addr, __kfence_pool is to be set after linear mapping set up. > > LINK: [1] https://lore.kernel.org/linux-arm-kernel/Y+IsdrvDNILA59UN@FVFF77S0Q05N/ > Suggested-by: Mark Rutland > Signed-off-by: Zhenhua Huang > --- > arch/arm64/include/asm/kfence.h | 16 +++++++++++ > arch/arm64/mm/mmu.c | 59 +++++++++++++++++++++++++++++++++++++++++ > arch/arm64/mm/pageattr.c | 9 +++++-- > include/linux/kfence.h | 1 + > mm/kfence/core.c | 4 +++ > 5 files changed, 87 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/kfence.h b/arch/arm64/include/asm/kfence.h > index aa855c6..8143c91 100644 > --- a/arch/arm64/include/asm/kfence.h > +++ b/arch/arm64/include/asm/kfence.h > @@ -10,6 +10,22 @@ > > #include > > +extern phys_addr_t early_kfence_pool; > + > +#ifdef CONFIG_KFENCE > + > +extern char *__kfence_pool; > +static inline void kfence_set_pool(phys_addr_t addr) > +{ > + __kfence_pool = phys_to_virt(addr); > +} > + > +#else > + > +static inline void kfence_set_pool(phys_addr_t addr) { } > + > +#endif > + > static inline bool arch_kfence_init_pool(void) { return true; } > > static inline bool kfence_protect_page(unsigned long addr, bool protect) > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 6f9d889..61944c70 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -24,6 +24,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -38,6 +39,7 @@ > #include > #include > #include > +#include > > #define NO_BLOCK_MAPPINGS BIT(0) > #define NO_CONT_MAPPINGS BIT(1) > @@ -525,6 +527,48 @@ static int __init enable_crash_mem_map(char *arg) > } > early_param("crashkernel", enable_crash_mem_map); > > +#ifdef CONFIG_KFENCE > + > +static bool kfence_early_init __initdata = !!CONFIG_KFENCE_SAMPLE_INTERVAL; > +/* > + * early_param can be parsed before linear mapping > + * set up > + */ > +static int __init parse_kfence_early_init(char *p) > +{ > + int val; > + > + if (get_option(&p, &val)) > + kfence_early_init = !!val; > + return 0; > +} > +early_param("kfence.sample_interval", parse_kfence_early_init); > + > +static phys_addr_t arm64_kfence_alloc_pool(void) > +{ > + phys_addr_t kfence_pool; > + > + if (!kfence_early_init) > + return 0; > + > + kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); > + if (!kfence_pool) > + pr_err("failed to allocate kfence pool\n"); > + > + return kfence_pool; > +} > + > +#else > + > +static phys_addr_t arm64_kfence_alloc_pool(void) > +{ > + return 0; > +} > + > +#endif > + > +phys_addr_t early_kfence_pool; > + > static void __init map_mem(pgd_t *pgdp) > { > static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN); > @@ -543,6 +587,10 @@ static void __init map_mem(pgd_t *pgdp) > */ > BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end)); > > + early_kfence_pool = arm64_kfence_alloc_pool(); > + if (early_kfence_pool) > + memblock_mark_nomap(early_kfence_pool, KFENCE_POOL_SIZE); > + > if (can_set_direct_map()) > flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; > > @@ -608,6 +656,17 @@ static void __init map_mem(pgd_t *pgdp) > } > } > #endif > + > + /* Kfence pool needs page-level mapping */ > + if (early_kfence_pool) { > + __map_memblock(pgdp, early_kfence_pool, > + early_kfence_pool + KFENCE_POOL_SIZE, > + pgprot_tagged(PAGE_KERNEL), > + NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS); > + memblock_clear_nomap(early_kfence_pool, KFENCE_POOL_SIZE); > + /* kfence_pool really mapped now */ > + kfence_set_pool(early_kfence_pool); > + } Why not wrap this under CONFIG_KFENCE ? early_kfence_pool can also go in there? Thanks, Pavan