Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752246AbdDLFDN (ORCPT ); Wed, 12 Apr 2017 01:03:13 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:33224 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751564AbdDLFDJ (ORCPT ); Wed, 12 Apr 2017 01:03:09 -0400 From: Hoeun Ryu To: Andrew Morton , Andrey Ryabinin , Andreas Dilger , Vlastimil Babka , Michal Hocko , Chris Wilson , Ingo Molnar , zijun_hu , Matthew Wilcox , Thomas Garnier , "Kirill A. Shutemov" Cc: linux-arch@vger.kernel.org, Hoeun Ryu , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH] mm: add VM_STATIC flag to vmalloc and prevent from removing the areas Date: Wed, 12 Apr 2017 14:01:59 +0900 Message-Id: <1491973350-26816-1-git-send-email-hoeun.ryu@gmail.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2386 Lines: 67 vm_area_add_early/vm_area_register_early() are used to reserve vmalloc area during boot process and those virtually mapped areas are never unmapped. So `OR` VM_STATIC flag to the areas in vmalloc_init() when importing existing vmlist entries and prevent those areas from being removed from the rbtree by accident. Signed-off-by: Hoeun Ryu --- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 9 ++++++--- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 46991ad..3df53fc 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -19,6 +19,7 @@ struct notifier_block; /* in notifier.h */ #define VM_UNINITIALIZED 0x00000020 /* vm_struct is not fully initialized */ #define VM_NO_GUARD 0x00000040 /* don't add guard page */ #define VM_KASAN 0x00000080 /* has allocated kasan shadow memory */ +#define VM_STATIC 0x00000200 /* bits [20..32] reserved for arch specific ioremap internals */ /* diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 8ef8ea1..fb5049a 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1262,7 +1262,7 @@ void __init vmalloc_init(void) /* Import existing vmlist entries. */ for (tmp = vmlist; tmp; tmp = tmp->next) { va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT); - va->flags = VM_VM_AREA; + va->flags = VM_VM_AREA | VM_STATIC; va->va_start = (unsigned long)tmp->addr; va->va_end = va->va_start + tmp->size; va->vm = tmp; @@ -1480,7 +1480,7 @@ struct vm_struct *remove_vm_area(const void *addr) might_sleep(); va = find_vmap_area((unsigned long)addr); - if (va && va->flags & VM_VM_AREA) { + if (va && va->flags & VM_VM_AREA && likely(!(va->flags & VM_STATIC))) { struct vm_struct *vm = va->vm; spin_lock(&vmap_area_lock); @@ -1510,7 +1510,7 @@ static void __vunmap(const void *addr, int deallocate_pages) area = remove_vm_area(addr); if (unlikely(!area)) { - WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", + WARN(1, KERN_ERR "Trying to vfree() nonexistent or static vm area (%p)\n", addr); return; } @@ -2708,6 +2708,9 @@ static int s_show(struct seq_file *m, void *p) if (v->phys_addr) seq_printf(m, " phys=%pa", &v->phys_addr); + if (v->flags & VM_STATIC) + seq_puts(m, " static"); + if (v->flags & VM_IOREMAP) seq_puts(m, " ioremap"); -- 2.7.4