That's just _odd_. The call chain actually has kmap() in it, and kmap
does:
if (!PageHighMem(page))
return page_address(page);
return kmap_high(page);
so if it's the one at line 319, which says
BUG_ON(!PageHighMem(page));
then I wonder what happened to that PageHighMem() test of the page in
between..
Ahh.. Not the same "page". It looks like it's in the
flush_all_zero_pkmaps() path, and it's clearing some _other_ page in the
pkmap table in order to make room for the new one. So the page that causes
problems is from here:
page = pte_page(pkmap_page_table[i]);
rather than the one we're trying to map.
Not that it explains the BUG_ON(). We should only insert page table
entries into the pkmap_page_table[] array in map_new_virtual(), which in
turn is only called from kmap_high(), which in turn means that *those*
pages have also gine through the PageHighMem() test.
So it sounds like we either
- have corruption in pkmap_page_table[]
- or pte_page() doesn't reverse mk_pte(page) propely, and one or the
other is broken.
Does anybody know if the fc9 x86-32 kernel is built with PAE enabled?
Might this be another PAE bit-masking bug and thus possibly fixed by the
PTE_MASK changes?
Linus
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