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[[!tag open_issue_gnumach]]


# IRC, freenode, #hurd, 2012-07-04

    <braunr> yes, we have integer overflows on resident_page_count, but
      luckily, the member is rarely used

See also [[gnumach_vm_object_resident_page_count]].


## IRC, freenode, #hurd, 2013-06-04

    <elmig> this is declared as int on vm_object.h
    <elmig> and as it as counter it's always positive
    <braunr> yes it should be unsigned
    <elmig> ok
    <braunr> but leave it as it is for consistency with the rest
    <elmig> i send patch :)
    <braunr> please no
    <braunr> unless you've fully determined the side effects
    <elmig> i've grepped the vars and saw only comparisons > and = 0
    <elmig> never less than 0
    <braunr> > 0 is the same
    <braunr> well
    <braunr> > not, but >= would be a problem
    <elmig> http://paste.debian.net/plain/8527
    <elmig> asctually no >=0
    <braunr> still, i don't want to change that unless it's strictly necessary
    <braunr> hum, you're grepping ref_count, not resident_page_count
    <elmig> i did both
    <elmig> on resident_page_count theres resident_page_count >= 0
    <elmig> = 0, == 0
    <braunr> this isn't the only possible issue
    <braunr> anyway
    <braunr> for now there is no reason to change anything unless you do a full
      review
    <elmig> only place i see resdent_page_count and page_count being decreased
      it's on vm/vm_resident.c
    <elmig> vm_page_remove() and vm_page_replace()