From 4bb9c5c02153dfc89a6c73a6f32091413805ad7d Mon Sep 17 00:00:00 2001 From: "Pallipadi, Venkatesh" Date: Thu, 12 Mar 2009 17:45:27 -0700 Subject: VM, x86, PAT: Change is_linear_pfn_mapping to not use vm_pgoff Impact: fix false positive PAT warnings - also fix VirtalBox hang Use of vma->vm_pgoff to identify the pfnmaps that are fully mapped at mmap time is broken. vm_pgoff is set by generic mmap code even for cases where drivers are setting up the mappings at the fault time. The problem was originally reported here: http://marc.info/?l=linux-kernel&m=123383810628583&w=2 Change is_linear_pfn_mapping logic to overload VM_INSERTPAGE flag along with VM_PFNMAP to mean full PFNMAP setup at mmap time. Problem also tracked at: http://bugzilla.kernel.org/show_bug.cgi?id=12800 Reported-by: Thomas Hellstrom Tested-by: Frans Pop Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha @intel.com> Cc: Nick Piggin Cc: "ebiederm@xmission.com" Cc: # only for 2.6.29.1, not .28 LKML-Reference: <20090313004527.GA7176@linux-os.sc.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/mm/pat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch/x86/mm/pat.c') diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index e0ab173b6974..21bc1f787ae2 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -641,10 +641,11 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, is_ram = pat_pagerange_is_ram(paddr, paddr + size); /* - * reserve_pfn_range() doesn't support RAM pages. + * reserve_pfn_range() doesn't support RAM pages. Maintain the current + * behavior with RAM pages by returning success. */ if (is_ram != 0) - return -EINVAL; + return 0; ret = reserve_memtype(paddr, paddr + size, want_flags, &flags); if (ret) -- cgit v1.2.3