From: Lennert Buytenhek <buytenh@wantstofly.org>
Date: Mon, 10 Jul 2006 11:45:27 +0000 (-0700)
Subject: [PATCH] make valid_mmap_phys_addr_range() take a pfn
X-Git-Tag: v2.6.18-rc2~144
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=06c67befeeb16f2995c11b0e04a348103ddbfab1;p=pandora-kernel.git

[PATCH] make valid_mmap_phys_addr_range() take a pfn

Newer ARMs have a 40 bit physical address space, but mapping physical
memory above 4G needs a special page table format which we (currently?) do
not use for userspace mappings, so what happens instead is that mapping an
address >= 4G will happily discard the upper bits and wrap.

There is a valid_mmap_phys_addr_range() arch hook where we could check for
>= 4G addresses and deny the mapping, but this hook takes an unsigned long
address:

	static inline int valid_mmap_phys_addr_range(unsigned long addr, size_t size);

And drivers/char/mem.c:mmap_mem() calls it like this:

	static int mmap_mem(struct file * file, struct vm_area_struct * vma)
	{
		size_t size = vma->vm_end - vma->vm_start;

		if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, size))

So that's not much help either.

This patch makes the hook take a pfn instead of a phys address.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

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