• Thomas Gleixner's avatar
    x86/ioperm: Move TSS bitmap update to exit to user work · 22fe5b04
    Thomas Gleixner authored
    There is no point to update the TSS bitmap for tasks which use I/O bitmaps
    on every context switch. It's enough to update it right before exiting to
    user space.
    
    That reduces the context switch bitmap handling to invalidating the io
    bitmap base offset in the TSS when the outgoing task has TIF_IO_BITMAP
    set. The invaldiation is done on purpose when a task with an IO bitmap
    switches out to prevent any possible leakage of an activated IO bitmap.
    
    It also removes the requirement to update the tasks bitmap atomically in
    ioperm().
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    22fe5b04
process.c 24.9 KB