From patchwork Fri May 8 14:40:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joerg Roedel X-Patchwork-Id: 11536755 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 220B4139F for ; Fri, 8 May 2020 14:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09CBD21655 for ; Fri, 8 May 2020 14:41:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728275AbgEHOlE (ORCPT ); Fri, 8 May 2020 10:41:04 -0400 Received: from 8bytes.org ([81.169.241.247]:41754 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728148AbgEHOk4 (ORCPT ); Fri, 8 May 2020 10:40:56 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id 99367450; Fri, 8 May 2020 16:40:50 +0200 (CEST) From: Joerg Roedel To: x86@kernel.org Cc: hpa@zytor.com, Dave Hansen , Andy Lutomirski , Peter Zijlstra , rjw@rjwysocki.net, Arnd Bergmann , Andrew Morton , Steven Rostedt , Vlastimil Babka , Michal Hocko , Joerg Roedel , joro@8bytes.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 2/7] mm/vmalloc: Track which page-table levels were modified Date: Fri, 8 May 2020 16:40:38 +0200 Message-Id: <20200508144043.13893-3-joro@8bytes.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200508144043.13893-1-joro@8bytes.org> References: <20200508144043.13893-1-joro@8bytes.org> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org From: Joerg Roedel Track at which levels in the page-table entries were modified by vmap/vunmap. After the page-table has been modified, use that information do decide whether the new arch_sync_kernel_mappings() needs to be called. Signed-off-by: Joerg Roedel --- include/linux/vmalloc.h | 11 ++++++ mm/vmalloc.c | 88 ++++++++++++++++++++++++++++++----------- 2 files changed, 75 insertions(+), 24 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index a95d3cc74d79..eb364000cb03 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -144,6 +144,17 @@ extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, void vmalloc_sync_mappings(void); void vmalloc_sync_unmappings(void); +/* + * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values + * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings() + * needs to be called. + */ +#ifndef ARCH_PAGE_TABLE_SYNC_MASK +#define ARCH_PAGE_TABLE_SYNC_MASK 0 +#endif + +void arch_sync_kernel_mappings(unsigned long start, unsigned long end); + /* * Lowlevel-APIs (not for driver use!) */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 9a8227afa073..184f5a556cf7 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -69,7 +69,8 @@ static void free_work(struct work_struct *w) /*** Page table manipulation functions ***/ -static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) +static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) { pte_t *pte; @@ -78,73 +79,104 @@ static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); WARN_ON(!pte_none(ptent) && !pte_present(ptent)); } while (pte++, addr += PAGE_SIZE, addr != end); + *mask |= PGTBL_PTE_MODIFIED; } -static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end) +static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) { pmd_t *pmd; unsigned long next; + int cleared; pmd = pmd_offset(pud, addr); do { next = pmd_addr_end(addr, end); - if (pmd_clear_huge(pmd)) + + cleared = pmd_clear_huge(pmd); + if (cleared || pmd_bad(*pmd)) + *mask |= PGTBL_PMD_MODIFIED; + + if (cleared) continue; if (pmd_none_or_clear_bad(pmd)) continue; - vunmap_pte_range(pmd, addr, next); + vunmap_pte_range(pmd, addr, next, mask); } while (pmd++, addr = next, addr != end); } -static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end) +static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) { pud_t *pud; unsigned long next; + int cleared; pud = pud_offset(p4d, addr); do { next = pud_addr_end(addr, end); - if (pud_clear_huge(pud)) + + cleared = pud_clear_huge(pud); + if (cleared || pud_bad(*pud)) + *mask |= PGTBL_PUD_MODIFIED; + + if (cleared) continue; if (pud_none_or_clear_bad(pud)) continue; - vunmap_pmd_range(pud, addr, next); + vunmap_pmd_range(pud, addr, next, mask); } while (pud++, addr = next, addr != end); } -static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end) +static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) { p4d_t *p4d; unsigned long next; + int cleared; p4d = p4d_offset(pgd, addr); do { next = p4d_addr_end(addr, end); - if (p4d_clear_huge(p4d)) + + cleared = p4d_clear_huge(p4d); + if (cleared || p4d_bad(*p4d)) + *mask |= PGTBL_P4D_MODIFIED; + + if (cleared) continue; if (p4d_none_or_clear_bad(p4d)) continue; - vunmap_pud_range(p4d, addr, next); + vunmap_pud_range(p4d, addr, next, mask); } while (p4d++, addr = next, addr != end); } -static void vunmap_page_range(unsigned long addr, unsigned long end) +static void vunmap_page_range(unsigned long start, unsigned long end) { pgd_t *pgd; + unsigned long addr = start; unsigned long next; + pgtbl_mod_mask mask = 0; BUG_ON(addr >= end); + start = addr; pgd = pgd_offset_k(addr); do { next = pgd_addr_end(addr, end); + if (pgd_bad(*pgd)) + mask |= PGTBL_PGD_MODIFIED; if (pgd_none_or_clear_bad(pgd)) continue; - vunmap_p4d_range(pgd, addr, next); + vunmap_p4d_range(pgd, addr, next, &mask); } while (pgd++, addr = next, addr != end); + + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) + arch_sync_kernel_mappings(start, end); } static int vmap_pte_range(pmd_t *pmd, unsigned long addr, - unsigned long end, pgprot_t prot, struct page **pages, int *nr) + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) { pte_t *pte; @@ -153,7 +185,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, * callers keep track of where we're up to. */ - pte = pte_alloc_kernel(pmd, addr); + pte = pte_alloc_kernel_track(pmd, addr, mask); if (!pte) return -ENOMEM; do { @@ -166,55 +198,59 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); (*nr)++; } while (pte++, addr += PAGE_SIZE, addr != end); + *mask |= PGTBL_PTE_MODIFIED; return 0; } static int vmap_pmd_range(pud_t *pud, unsigned long addr, - unsigned long end, pgprot_t prot, struct page **pages, int *nr) + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) { pmd_t *pmd; unsigned long next; - pmd = pmd_alloc(&init_mm, pud, addr); + pmd = pmd_alloc_track(&init_mm, pud, addr, mask); if (!pmd) return -ENOMEM; do { next = pmd_addr_end(addr, end); - if (vmap_pte_range(pmd, addr, next, prot, pages, nr)) + if (vmap_pte_range(pmd, addr, next, prot, pages, nr, mask)) return -ENOMEM; } while (pmd++, addr = next, addr != end); return 0; } static int vmap_pud_range(p4d_t *p4d, unsigned long addr, - unsigned long end, pgprot_t prot, struct page **pages, int *nr) + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) { pud_t *pud; unsigned long next; - pud = pud_alloc(&init_mm, p4d, addr); + pud = pud_alloc_track(&init_mm, p4d, addr, mask); if (!pud) return -ENOMEM; do { next = pud_addr_end(addr, end); - if (vmap_pmd_range(pud, addr, next, prot, pages, nr)) + if (vmap_pmd_range(pud, addr, next, prot, pages, nr, mask)) return -ENOMEM; } while (pud++, addr = next, addr != end); return 0; } static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, - unsigned long end, pgprot_t prot, struct page **pages, int *nr) + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) { p4d_t *p4d; unsigned long next; - p4d = p4d_alloc(&init_mm, pgd, addr); + p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); if (!p4d) return -ENOMEM; do { next = p4d_addr_end(addr, end); - if (vmap_pud_range(p4d, addr, next, prot, pages, nr)) + if (vmap_pud_range(p4d, addr, next, prot, pages, nr, mask)) return -ENOMEM; } while (p4d++, addr = next, addr != end); return 0; @@ -234,16 +270,20 @@ static int vmap_page_range_noflush(unsigned long start, unsigned long end, unsigned long addr = start; int err = 0; int nr = 0; + pgtbl_mod_mask mask = 0; BUG_ON(addr >= end); pgd = pgd_offset_k(addr); do { next = pgd_addr_end(addr, end); - err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr); + err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr, &mask); if (err) return err; } while (pgd++, addr = next, addr != end); + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) + arch_sync_kernel_mappings(start, end); + return nr; }