From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1084986-1526513665-5-8804692866073709680 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.248, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1526513664; b=Cdm0Up0NEBAmezj23uAU+T4WELwLplNYriaVslXe/SN0R6vVZw l8qnkDfFUmNKF52HaLpii+p7h7cvsKrUoXZm3uj3PN8Z3f2Y1WMhsIrIE4EnOS/+ bBf3YAYuF5K2SpCjTYkpMpzGN63/kUIwNORr19F2OaFREdjy2HjxtkdDx9UpsMdS kUPl48nv0jS02I3GYgdBA3ioet/kisXIO71Yn5TN+t28Usq6C1y9BibcmgfILTrV l3FroDjQnhPlsC2f2eyecZFsidj1ewcg2CVdlzV0ticm45QNnFwyQlW5+4n88zeW KW4daarqe5y66vQLYuieiA8OrzeaIv8BU3oQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:sender:list-id; s=fm2; t=1526513664; bh= /+BijJleNJp5wlL61lLCuZbbhG+2sBdk3QzTkUb4U+Q=; b=WkCHurOJBQ+AHuCj iSCLgllqLwyGcLtQAKrA14VPGK1SfWCOHoClpyRdPbUSZrOzHPxE6HEnPK91r162 6l2rGYTvPwyuq6sxGq4RJOXgc88sepFykQvdzTYO9qsfG11P8OTC+GG1xli8yyw+ og1RdX3vL+FkO/NcD1pplaldGHTLtCxLFuZpzeRfMCyY+OJSlSG/BgeofBkFCXr4 /nZU5ffd33Na4+tLujrytlGF8++oUUHI82AeLdcNigp7DsA4qUeXrrKhy4GKaCfH CXuRZZBVEC1SQ3BEbJwsKqZ+1TKt+CbzpwXYqugdHL2jozvC0Y7GvZjrgn1NxYpP d4ZWyg== ARC-Authentication-Results: i=1; mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=hpe.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=hpe.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx1.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=hpe.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=hpe.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfDrdDMPexuLW+6bF7ahtlRyHzQ8kS86uLwXQTKSI+LWsGaKjb8OF3h/QB7oMwXW0/j6cd5ae5TDiGzi0gpfIUYCcR8CMKYWTb8ffYYZ5dcYZepcgUiIP zvWWb9omi4LDKTBd1KljR0lfhetuUw+c9VqGHQ9jX3TUS8p5B2A6ZpM3r2Jr6qX9dYIF1dRVZdnSelBazUkWKdADJAQdW2m3hivf8aWQd05SoIv8ta6Nh5FZ X-CM-Analysis: v=2.3 cv=WaUilXpX c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=VUJBJC2UJ8kA:10 a=tA7aZXjiAAAA:8 a=MvuuwTCpAAAA:8 a=Z4Rwk6OoAAAA:8 a=iox4zFpeAAAA:8 a=20KFwNOVAAAA:8 a=oGMlB6cnAAAA:8 a=VwQbUJbxAAAA:8 a=hCsESo4FuRblPrCuPTwA:9 a=kIIFJ0VLUOy1gFZzwZHL:22 a=dVHiktpip_riXrfdqayU:22 a=HkZW87K1Qel5hWWM3VKY:22 a=WzC6qhA0u3u7Ye7llzcV:22 a=NdAtdrkLVvyUPsUoGJp4:22 a=AjGcO6oz07-iQ99wixmX:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751254AbeEPXd1 (ORCPT ); Wed, 16 May 2018 19:33:27 -0400 Received: from g4t3425.houston.hpe.com ([15.241.140.78]:43805 "EHLO g4t3425.houston.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751980AbeEPXdZ (ORCPT ); Wed, 16 May 2018 19:33:25 -0400 From: Toshi Kani To: mhocko@suse.com, akpm@linux-foundation.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com Cc: cpandya@codeaurora.org, linux-mm@kvack.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Toshi Kani , Joerg Roedel , stable@vger.kernel.org Subject: [PATCH v3 1/3] x86/mm: disable ioremap free page handling on x86-PAE Date: Wed, 16 May 2018 17:32:05 -0600 Message-Id: <20180516233207.1580-2-toshi.kani@hpe.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180516233207.1580-1-toshi.kani@hpe.com> References: <20180516233207.1580-1-toshi.kani@hpe.com> Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: ioremap() supports pmd mappings on x86-PAE. However, kernel's pmd tables are not shared among processes on x86-PAE. Therefore, any update to sync'd pmd entries need re-syncing. Freeing a pte page also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one(). Disable free page handling on x86-PAE. pud_free_pmd_page() and pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present. This assures that ioremap() does not update sync'd pmd entries at the cost of falling back to pte mappings. Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Reported-by: Joerg Roedel Signed-off-by: Toshi Kani Cc: Andrew Morton Cc: Michal Hocko Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Joerg Roedel Cc: --- arch/x86/mm/pgtable.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index ffc8c13c50e4..3f7180bc5f52 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -715,6 +715,7 @@ int pmd_clear_huge(pmd_t *pmd) return 0; } +#ifdef CONFIG_X86_64 /** * pud_free_pmd_page - Clear pud entry and free pmd page. * @pud: Pointer to a PUD. @@ -762,4 +763,22 @@ int pmd_free_pte_page(pmd_t *pmd) return 1; } + +#else /* !CONFIG_X86_64 */ + +int pud_free_pmd_page(pud_t *pud) +{ + return pud_none(*pud); +} + +/* + * Disable free page handling on x86-PAE. This assures that ioremap() + * does not update sync'd pmd entries. See vmalloc_sync_one(). + */ +int pmd_free_pte_page(pmd_t *pmd) +{ + return pmd_none(*pmd); +} + +#endif /* CONFIG_X86_64 */ #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */