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9585116ba0
get_vm_area always returns an area with an adjacent guard page. That guard page is included in vm_struct.size. iounmap uses vm_struct.size to determine how much address space needs to have change_page_attr applied to it, which will BUG if applied to the guard page. This patch adds a helper function - get_vm_area_size() in linux/vmalloc.h - to return the actual size of a vm area, and uses it to make iounmap do the right thing. There are probably other places which should be using get_vm_area_size(). Thanks to Dave Young <hidave.darkstar@gmail.com> for debugging the problem. [ Andi, it wasn't clear to me whether x86_64 needs the same fix. ] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
91 lines
2.7 KiB
C
91 lines
2.7 KiB
C
#ifndef _LINUX_VMALLOC_H
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#define _LINUX_VMALLOC_H
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#include <linux/spinlock.h>
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#include <asm/page.h> /* pgprot_t */
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struct vm_area_struct;
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/* bits in vm_struct->flags */
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#define VM_IOREMAP 0x00000001 /* ioremap() and friends */
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#define VM_ALLOC 0x00000002 /* vmalloc() */
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#define VM_MAP 0x00000004 /* vmap()ed pages */
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#define VM_USERMAP 0x00000008 /* suitable for remap_vmalloc_range */
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#define VM_VPAGES 0x00000010 /* buffer for pages was vmalloc'ed */
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/* bits [20..32] reserved for arch specific ioremap internals */
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/*
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* Maximum alignment for ioremap() regions.
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* Can be overriden by arch-specific value.
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*/
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#ifndef IOREMAP_MAX_ORDER
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#define IOREMAP_MAX_ORDER (7 + PAGE_SHIFT) /* 128 pages */
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#endif
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struct vm_struct {
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/* keep next,addr,size together to speedup lookups */
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struct vm_struct *next;
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void *addr;
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unsigned long size;
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unsigned long flags;
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struct page **pages;
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unsigned int nr_pages;
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unsigned long phys_addr;
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};
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/*
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* Highlevel APIs for driver use
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*/
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extern void *vmalloc(unsigned long size);
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extern void *vmalloc_user(unsigned long size);
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extern void *vmalloc_node(unsigned long size, int node);
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extern void *vmalloc_exec(unsigned long size);
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extern void *vmalloc_32(unsigned long size);
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extern void *vmalloc_32_user(unsigned long size);
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extern void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);
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extern void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask,
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pgprot_t prot);
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extern void vfree(void *addr);
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extern void *vmap(struct page **pages, unsigned int count,
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unsigned long flags, pgprot_t prot);
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extern void vunmap(void *addr);
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extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
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unsigned long pgoff);
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void vmalloc_sync_all(void);
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/*
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* Lowlevel-APIs (not for driver use!)
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*/
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static inline size_t get_vm_area_size(const struct vm_struct *area)
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{
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/* return actual size without guard page */
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return area->size - PAGE_SIZE;
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}
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extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);
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extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
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unsigned long start, unsigned long end);
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extern struct vm_struct *get_vm_area_node(unsigned long size,
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unsigned long flags, int node,
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gfp_t gfp_mask);
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extern struct vm_struct *remove_vm_area(void *addr);
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extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
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struct page ***pages);
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extern void unmap_kernel_range(unsigned long addr, unsigned long size);
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/* Allocate/destroy a 'vmalloc' VM area. */
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extern struct vm_struct *alloc_vm_area(size_t size);
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extern void free_vm_area(struct vm_struct *area);
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/*
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* Internals. Dont't use..
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*/
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extern rwlock_t vmlist_lock;
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extern struct vm_struct *vmlist;
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#endif /* _LINUX_VMALLOC_H */
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