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author | Andi Kleen <ak@suse.de> | 2005-05-20 14:27:57 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-20 15:48:20 -0700 |
commit | 7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9 (patch) | |
tree | 0e9f799c3882dce14b49356c6db10bb6f4ba1713 /mm | |
parent | c4d1fcf3a2ea89b6d6221fa8b4588c77aff50995 (diff) | |
download | linux-7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9.tar.gz linux-7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9.tar.bz2 linux-7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9.zip |
[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.c | 33 |
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) return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END); } -/** - * remove_vm_area - find and remove a contingous kernel virtual area - * - * @addr: base address - * - * Search for the kernel VM area starting at @addr, and remove it. - * This function returns the found VM area, but using it is NOT safe - * on SMP machines. - */ -struct vm_struct *remove_vm_area(void *addr) +/* Caller must hold vmlist_lock */ +struct vm_struct *__remove_vm_area(void *addr) { struct vm_struct **p, *tmp; - write_lock(&vmlist_lock); for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) { if (tmp->addr == addr) goto found; } - write_unlock(&vmlist_lock); return NULL; found: unmap_vm_area(tmp); *p = tmp->next; - write_unlock(&vmlist_lock); /* * Remove the guard page. @@ -281,6 +270,24 @@ found: return tmp; } +/** + * remove_vm_area - find and remove a contingous kernel virtual area + * + * @addr: base address + * + * Search for the kernel VM area starting at @addr, and remove it. + * This function returns the found VM area, but using it is NOT safe + * on SMP machines, except for its size or flags. + */ +struct vm_struct *remove_vm_area(void *addr) +{ + struct vm_struct *v; + write_lock(&vmlist_lock); + v = __remove_vm_area(addr); + write_unlock(&vmlist_lock); + return v; +} + void __vunmap(void *addr, int deallocate_pages) { struct vm_struct *area; |