• Philippe Gerum's avatar
    lockdep: ipipe: make the logic aware of interrupt pipelining · 393ce342
    Philippe Gerum authored
    The lockdep engine will check for the current interrupt state as part
    of the locking validation process, which must encompass:
    
    - the CPU interrupt state
    - the current pipeline domain
    - the virtual interrupt disable flag
    
    so that we can traverse the tracepoints from any context sanely and
    safely.
    
    In addition trace_hardirqs_on_virt_caller() should be called by the
    arch-dependent code when tracking the interrupt state before returning
    to user-space after a kernel entry (exceptions, IRQ). This makes sure
    that the tracking logic only applies to the root domain, and considers
    the virtual disable flag exclusively.
    
    For instance, the kernel may be entered when interrupts are (only)
    virtually disabled for the root domain (i.e. stalled), and we should
    tell the IRQ tracing logic that IRQs are about to be enabled back only
    if the root domain is unstalled before leaving to user-space. In such
    a context, the state of the interrupt bit in the CPU would be
    irrelevant.
    393ce342
lockdep_internals.h 5.1 KB