As noted by David:
pte_page() is a macro defined as follows;
include/asm-sh/pgtable.h
#define pte_page(x) phys_to_page(pte_val(x)&PTE_PHYS_MASK)
include/asm-sh/page.h
#define phys_to_page(phys) (pfn_to_page(phys >> PAGE_SHIFT))
So as you can see the phys_to_page() macro doesn't wrap the 'phys'
parameter in parentheses so we end up with;
pte_val(x)&PTE_PHYS_MASK >> PAGE_SHIFT
Which is not what we wanted as '>>' has a higher precedence than bitwise
AND. I dug into the git repository and I believe this bug was added with
this commit (104b8deaa5);
2006-03-27 KAMEZAWA Hiroyuki [PATCH] unify pfn_to_page: sh pfn_to_page
-#define phys_to_page(phys) (mem_map + (((phys)-__MEMORY_START) >>
PAGE_SHIFT))
-#define page_to_phys(page) (((page - mem_map) << PAGE_SHIFT) +
__MEMORY_START)
+#define phys_to_page(phys) (pfn_to_page(phys >> PAGE_SHIFT))
+#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
Reported-by: David ADDISON <david.addison@st.com>
Reported-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
afca035745