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kernel: mmu: fix assigning unaligned addr to page frame

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In do_page_fault(), the incoming page fault address is not
aligned, and it was unconditionally assigned to the page
frame virtual address field. If the backing store simply
returns the virtual address without processing in
k_mem_paging_backing_store_location_get(), this unaligned
address will be passed to arch_mem_page_out(). On x86,
it is further passed to range_map() which asserts if
the physical address is not page aligned. So align
the address to page size before assigning it to the page
frame virtual address field.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This commit is contained in:
Daniel Leung 2021-07-16 15:27:27 -07:00 • committed by Christopher Friedt
commit c38634fa33
1 changed files with 3 additions and 1 deletions
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4
kernel/mmu.c
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@ -1288,7 +1288,9 @@ static bool do_page_fault(void *addr, bool pin)
pf->flags |= Z_PAGE_FRAME_PINNED;
}
pf->flags |= Z_PAGE_FRAME_MAPPED;
pf->addr = addr;
pf->addr = UINT_TO_POINTER(POINTER_TO_UINT(addr)
& ~(CONFIG_MMU_PAGE_SIZE - 1));
arch_mem_page_in(addr, z_page_frame_to_phys(pf));
k_mem_paging_backing_store_page_finalize(pf, page_in_location);
out: