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authorAndi Kleen <ak@suse.de>2005-05-20 17:27:57 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-05-20 18:48:20 -0400
commit7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9 (patch)
tree0e9f799c3882dce14b49356c6db10bb6f4ba1713 /mm
parentc4d1fcf3a2ea89b6d6221fa8b4588c77aff50995 (diff)
[PATCH] x86_64: Fixed guard page handling again in iounmap
Caused oopses again. Also fix potential mismatch in checking if change_page_attr was needed. To do it without races I needed to change mm/vmalloc.c to export a __remove_vm_area that does not take vmlist lock. Noticed by Terence Ripperda and based on a patch of his. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/vmalloc.c33
1 files changed, 20 insertions, 13 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2bd83e5c2bbf..8ff16a1eee6a 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -248,31 +248,20 @@ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
248 return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END); 248 return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END);
249} 249}
250 250
251/** 251/* Caller must hold vmlist_lock */
252 * remove_vm_area - find and remove a contingous kernel virtual area 252struct vm_struct *__remove_vm_area(void *addr)
253 *
254 * @addr: base address
255 *
256 * Search for the kernel VM area starting at @addr, and remove it.
257 * This function returns the found VM area, but using it is NOT safe
258 * on SMP machines.
259 */
260struct vm_struct *remove_vm_area(void *addr)
261{ 253{
262 struct vm_struct **p, *tmp; 254 struct vm_struct **p, *tmp;
263 255
264 write_lock(&vmlist_lock);
265 for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) { 256 for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) {
266 if (tmp->addr == addr) 257 if (tmp->addr == addr)
267 goto found; 258 goto found;
268 } 259 }
269 write_unlock(&vmlist_lock);
270 return NULL; 260 return NULL;
271 261
272found: 262found:
273 unmap_vm_area(tmp); 263 unmap_vm_area(tmp);
274 *p = tmp->next; 264 *p = tmp->next;
275 write_unlock(&vmlist_lock);
276 265
277 /* 266 /*
278 * Remove the guard page. 267 * Remove the guard page.
@@ -281,6 +270,24 @@ found:
281 return tmp; 270 return tmp;
282} 271}
283 272
273/**
274 * remove_vm_area - find and remove a contingous kernel virtual area
275 *
276 * @addr: base address
277 *
278 * Search for the kernel VM area starting at @addr, and remove it.
279 * This function returns the found VM area, but using it is NOT safe
280 * on SMP machines, except for its size or flags.
281 */
282struct vm_struct *remove_vm_area(void *addr)
283{
284 struct vm_struct *v;
285 write_lock(&vmlist_lock);
286 v = __remove_vm_area(addr);
287 write_unlock(&vmlist_lock);
288 return v;
289}
290
284void __vunmap(void *addr, int deallocate_pages) 291void __vunmap(void *addr, int deallocate_pages)
285{ 292{
286 struct vm_struct *area; 293 struct vm_struct *area;