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    Subject[Patch v3 01/14] x86/ioremap: Fix page aligned size calculation in __ioremap_caller()
    Date
    Current code re-calculates the size after aligning the starting and
    ending physical addresses on a page boundary. But the re-calculation
    also embeds the masking of high order bits that exceed the size of
    the physical address space (via PHYSICAL_PAGE_MASK). If the masking
    removes any high order bits, the size calculation results in a huge
    value that is likely to immediately fail.

    Fix this by re-calculating the page-aligned size first. Then mask any
    high order bits using PHYSICAL_PAGE_MASK.

    Signed-off-by: Michael Kelley <mikelley@microsoft.com>
    ---
    arch/x86/mm/ioremap.c | 8 +++++++-
    1 file changed, 7 insertions(+), 1 deletion(-)

    diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
    index 78c5bc6..6453fba 100644
    --- a/arch/x86/mm/ioremap.c
    +++ b/arch/x86/mm/ioremap.c
    @@ -217,9 +217,15 @@ static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
    * Mappings have to be page-aligned
    */
    offset = phys_addr & ~PAGE_MASK;
    - phys_addr &= PHYSICAL_PAGE_MASK;
    + phys_addr &= PAGE_MASK;
    size = PAGE_ALIGN(last_addr+1) - phys_addr;

    + /*
    + * Mask out any bits not part of the actual physical
    + * address, like memory encryption bits.
    + */
    + phys_addr &= PHYSICAL_PAGE_MASK;
    +
    retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
    pcm, &new_pcm);
    if (retval) {
    --
    1.8.3.1
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