From 4057923614e2868a865aa6c6e3bc53542c818d4d Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 20 May 2005 14:27:57 -0700 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/mm/ioremap.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/i386/mm/ioremap.c b/arch/i386/mm/ioremap.c index db06f739991..ab542792b27 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); } -- 2.46.0