Re: ntfs.ko needs unknown symbol end_iomem (under uml)

Re: ntfs.ko needs unknown symbol end_iomem (under uml)

[Yura Pakhuchiy]

Hi,

Anton Altaparmakov wrote:
> On Thu, 2004-10-21 at 14:53, Yura Pakhuchiy wrote:
> 
>>Hi Anton,
>>
>>When I compile ntfs as module for UML I receive during build:
>>*** Warning: "end_iomem" [fs/ntfs/ntfs.ko] undefined!
>>
>>It's ntfs bug or uml bug? Or am I doing something wrong?
> 
> 
> UML is broken.  It defines VMALLOC_START to ((end_iomem +
> VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)) but it clearly does not export
> end_iomem to modules which means modules cannot use VMALLOC_START.
> 
> But ntfs uses VMALLOC_START to determine if a pointer is in kmalloc()-ed
> memory or vmalloc()-ed memory so if you want to build it as a module you
> need to fix uml to export end_iomem, i.e. by for example adding:
> 
> EXPORT_SYMBOL(end_iomem);
> 
> after the end_iomem definition in arch/um/kernel/um_arch.c and the
> reconfiguring, recbuilding the kernel.
> 
> You may wish to report this to LKML / the UML maintainer (after you have
> made sure that this does actually fix it).
> 
> Best regards,
> 
> 	Anton

I didn't find UML maintainer in MAINTAINERS, so I send this to
linux-kernel@vger.kernel.org.

I added line that Anton suggested and it's fixed above bug. Patch below.

Best regards,
	Yura


--- ntfs-2.6-devel/arch/um/kernel/um_arch.c     2004-10-19 20:50:05.000000000 +0300
+++ ntfs-2.6-yura/arch/um/kernel/um_arch.c      2004-10-21 17:14:18.000000000 +0300
@@ -300,6 +300,7 @@ static void __init uml_postsetup(void)
  /* Set during early boot */
  unsigned long brk_start;
  unsigned long end_iomem;
+EXPORT_SYMBOL(end_iomem);

  #define MIN_VMALLOC (32 * 1024 * 1024)