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Date: Tue, 07 Nov 2006 16:22:02 -0800 From: Jeremy Fitzhardinge <jeremy@...p.org> To: Andrew Morton <akpm@...l.org> CC: Zachary Amsden <zach@...are.com>, Rusty Russell <rusty@...tcorp.com.au>, Linux Kernel Mailing List <linux-kernel@...r.kernel.org> Subject: [PATCH] Fix kunmap_atomic's use of kpte_clear_flush() kunmap_atomic() will call kpte_clear_flush with vaddr/ptep arguments which don't correspond if the vaddr is just a normal lowmem address (ie, not in the KMAP area). This patch makes sure that the pte is only cleared if kmap area was actually used for the mapping. Signed-off-by: Jeremy Fitzhardinge <jeremy@...source.com> Signed-off-by: Rusty Russell <rusty@...tcorp.com.au> Cc: Zachary Amsden <zach@...are.com> =================================================================== --- a/arch/i386/mm/highmem.c +++ b/arch/i386/mm/highmem.c @@ -56,22 +56,20 @@ void kunmap_atomic(void *kvaddr, enum km unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); -#ifdef CONFIG_DEBUG_HIGHMEM - if (vaddr >= PAGE_OFFSET && vaddr < (unsigned long)high_memory) { - pagefault_enable(); - return; - } - - if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx)) - BUG(); -#endif /* * Force other mappings to Oops if they'll try to access this pte * without first remap it. Keeping stale mappings around is a bad idea * also, in case the page changes cacheability attributes or becomes * a protected page in a hypervisor. */ - kpte_clear_flush(kmap_pte-idx, vaddr); + if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx)) + kpte_clear_flush(kmap_pte-idx, vaddr); + else { +#ifdef CONFIG_DEBUG_HIGHMEM + BUG_ON(vaddr < PAGE_OFFSET); + BUG_ON(vaddr >= (unsigned long)high_memory); +#endif + } pagefault_enable(); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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