diff options
| author | Andi Kleen <ak@suse.de> | 2005-05-20 14:27:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-20 15:48:20 -0700 |
| commit | 4057923614e2868a865aa6c6e3bc53542c818d4d (patch) | |
| tree | 0a6a2b492eaa11897538a06655685474b961df44 | |
| parent | 7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9 (diff) | |
| download | lwn-4057923614e2868a865aa6c6e3bc53542c818d4d.tar.gz lwn-4057923614e2868a865aa6c6e3bc53542c818d4d.zip | |
[PATCH] i386: Fix race in iounmap
We need to hold the vmlist_lock while doing change_page_attr, otherwise we
could reset someone else's mapping.
Requires previous patch to add __remove_vm_area
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/i386/mm/ioremap.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/i386/mm/ioremap.c b/arch/i386/mm/ioremap.c index db06f7399913..ab542792b27b 100644 --- a/arch/i386/mm/ioremap.c +++ b/arch/i386/mm/ioremap.c @@ -238,19 +238,21 @@ void iounmap(volatile void __iomem *addr) addr < phys_to_virt(ISA_END_ADDRESS)) return; - p = remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr)); + write_lock(&vmlist_lock); + p = __remove_vm_area((void *) (PAGE_MASK & (unsigned long __force) addr)); if (!p) { - printk("__iounmap: bad address %p\n", addr); - return; + printk("iounmap: bad address %p\n", addr); + goto out_unlock; } if ((p->flags >> 20) && p->phys_addr < virt_to_phys(high_memory) - 1) { - /* p->size includes the guard page, but cpa doesn't like that */ change_page_attr(virt_to_page(__va(p->phys_addr)), p->size >> PAGE_SHIFT, PAGE_KERNEL); global_flush_tlb(); } +out_unlock: + write_unlock(&vmlist_lock); kfree(p); } |