Re: Error: freeing invalid memtype

From: Pallipadi, Venkatesh
Date: Mon Mar 23 2009 - 15:07:52 EST


On Sat, Mar 21, 2009 at 04:05:48PM -0700, Kevin Winchester wrote:
> Pallipadi, Venkatesh wrote:
> > Kevin,
> >
> > Can you please send me the output of
> > # cat /debug/x86/pat_memtype_list
> >
> > (with debugfs mounted at /debug) as soon as you login into X and also
> > when you start seeing these errors with etracer and glxinfo.
> >
>
> Here is the output before attempting to run glxinfo:
> : :
> : :
>
> Does that help track down the problem? I am about to try disabling PAT
> in my config to see if that fixes things.
>

Can you please try the patch below and let me whether it helps.

Thanks,
Venki

x86, PAT: Change vma prot in pci_mmap to reflect inherited prot

While looking at the issue in the thread
http://marc.info/?l=dri-devel&m=123606627824556&w=2
noticed a bug in pci PAT code and memory type setting.

pci mmap code did not set the proper protection in vma, when it
inherited protection in reserve_memtype. This bug only affects
the case where there exists a WC mapping before X does an mmap
with /proc or /sys pci interface. This will cause X userlevel
mmap from /proc or /sysfs to fail on fork.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>

diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 5ead808..f234a37 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -319,6 +319,9 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
return -EINVAL;
}
flags = new_flags;
+ vma->vm_page_prot = __pgprot(
+ (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK) |
+ flags);
}

if (((vma->vm_pgoff < max_low_pfn_mapped) ||
--
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