From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x225RC4ri0vQAzdd7ktE0B366tl+OuB8x3i/bd9RQaUgwsc+INcTF8ivCfPmGaynfLbUAynWl ARC-Seal: i=1; a=rsa-sha256; t=1518319305; cv=none; d=google.com; s=arc-20160816; b=EFnOxLZGPjSsmdhZB9eawm8swLcKu9aN8SNqHPjPIi2DgjopB/Y9VhYejp/JcKfQhT X6HZtuowofYJVIsmDl8nJO+/30bZ1pFWT9v/blaEv5BW3yrcxzS6ByyZ+ZwRo+f/7oNq 3Hmq2hK5jmfFBnfRnSs+gnuhNP6WsfvtdUqoXXz+Twce7gQ35ADlz4GrjRwDxlqfNegF m8jn4rF3EJ2nGemyo6XbJRAXEs7eWEuWv5qkOWNhbtexz6C2u0XQh7appNAyHDVEdEWt oVyxaf3iWu4bo96l24Ouk0G9DcE3EmvCCIJl1fcTWFE3oQwqLBUZziIfn8KnX83RfjK1 sHyA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:references:in-reply-to:message-id:date:subject:cc:to :from:delivered-to:list-id:list-subscribe:list-unsubscribe:list-help :list-post:precedence:mailing-list:arc-authentication-results; bh=MQdgs6ujP7LWDZGNv/WHuQlAySLcoOwNL8AuKWrbq/c=; b=ZfEgnRuNDjOVVgjr+Wnnd/zEJiU8XQLXxg4aXrexQznVO2JVRcbNgG8uEOszNb91IO pFXHG/orNytgbSW90HRlTr14JC8FKWmQmB6cuzy10k1ftT21gXZhBLlvSKCYykHwbIei WJFsBzd9nLf7qxlWJtqBdg9Rr0+xm1a5/n0IV3uiCnVyvIkvFSvf7HrWf2LtAj6b7QPH XVRIb9DmPXBvRpYEhdB1Fo/2sZjSPIT/l5nYmSnmyUp0HvruqD8QXxCejjAkK8NwcJck 5ez/7vzNC/lqMOxEqEKuegg+r3g7qKsyevHgIROunKZafACvbweyUJvfaIePk6zHYx4n NYNg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-11699-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-11699-gregkh=linuxfoundation.org@lists.openwall.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-11699-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-11699-gregkh=linuxfoundation.org@lists.openwall.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: From: Igor Stoppa To: , , , , , , , CC: , , , , , Igor Stoppa Subject: [PATCH 3/6] struct page: add field for vm_struct Date: Sun, 11 Feb 2018 05:19:17 +0200 Message-ID: <20180211031920.3424-4-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20180211031920.3424-1-igor.stoppa@huawei.com> References: <20180211031920.3424-1-igor.stoppa@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.122.225.51] X-CFilter-Loop: Reflected X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1592073184128407406?= X-GMAIL-MSGID: =?utf-8?q?1592073184128407406?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: When a page is used for virtual memory, it is often necessary to obtian a handler to the corresponding vm_struct, which refers to the virtually continuous area generated when invoking vmalloc. The struct page has a "mapping" field, which can be re-used, to store a pointer to the parent area. This will avoid more expensive searches. As example, the function find_vm_area is reimplemented, to take advantage of the newly introduced field. Signed-off-by: Igor Stoppa --- include/linux/mm_types.h | 1 + mm/vmalloc.c | 18 +++++++++++++----- 2 files changed, 14 insertions(+), 5 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index fd1af6b9591d..c3a4825e10c0 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -84,6 +84,7 @@ struct page { void *s_mem; /* slab first object */ atomic_t compound_mapcount; /* first tail page */ /* page_deferred_list().next -- second tail page */ + struct vm_struct *area; }; /* Second double word */ diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 673942094328..9404ffd0ee98 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1466,13 +1466,16 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, */ struct vm_struct *find_vm_area(const void *addr) { - struct vmap_area *va; + struct page *page; - va = find_vmap_area((unsigned long)addr); - if (va && va->flags & VM_VM_AREA) - return va->vm; + if (unlikely(!is_vmalloc_addr(addr))) + return NULL; - return NULL; + page = vmalloc_to_page(addr); + if (unlikely(!page)) + return NULL; + + return page->area; } /** @@ -1536,6 +1539,7 @@ static void __vunmap(const void *addr, int deallocate_pages) struct page *page = area->pages[i]; BUG_ON(!page); + page->area = NULL; __free_pages(page, 0); } @@ -1744,6 +1748,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, const void *caller) { struct vm_struct *area; + unsigned int i; void *addr; unsigned long real_size = size; @@ -1769,6 +1774,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, kmemleak_vmalloc(area, size, gfp_mask); + for (i = 0; i < area->nr_pages; i++) + area->pages[i]->area = area; + return addr; fail: -- 2.14.1