Re: [03/17] is_vmalloc_addr(): Check if an address is within thevmalloc boundaries

From: David Rientjes
Date: Wed Sep 19 2007 - 04:10:54 EST


On Wed, 19 Sep 2007, Anton Altaparmakov wrote:

> > > Index: linux-2.6/include/linux/mm.h
> > > ===================================================================
> > > --- linux-2.6.orig/include/linux/mm.h 2007-09-17 21:46:06.000000000
> > > -0700
> > > +++ linux-2.6/include/linux/mm.h 2007-09-17 23:56:54.000000000 -0700
> > > @@ -1158,6 +1158,14 @@ static inline unsigned long vma_pages(st
> > > return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
> > > }
> > >
> > > +/* Determine if an address is within the vmalloc range */
> > > +static inline int is_vmalloc_addr(const void *x)
> > > +{
> > > + unsigned long addr = (unsigned long)x;
> > > +
> > > + return addr >= VMALLOC_START && addr < VMALLOC_END;
> > > +}
> >
> > This breaks on i386 because VMALLOC_END is defined in terms of PKMAP_BASE
> > in the CONFIG_HIGHMEM case.
>
> That is incorrect. This works perfectly on i386 and on ALL architectures
> supported by Linux. A lot of places in the kernel already do this today
> (mostly hand coded though, eg XFS and NTFS)...
>

Hmm, really?

After applying patches 1-3 in this series and compiling on my i386 with
defconfig, I get this:

In file included from include/linux/suspend.h:11,
from arch/i386/kernel/asm-offsets.c:11:
include/linux/mm.h: In function 'is_vmalloc_addr':
include/linux/mm.h:1166: error: 'PKMAP_BASE' undeclared (first use in this function)
include/linux/mm.h:1166: error: (Each undeclared identifier is reported only once
include/linux/mm.h:1166: error: for each function it appears in.)

so I don't know what you're talking about.
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