• David S. Miller's avatar
    sparc64: Fix pcr_ops initialization and usage bugs. · 8bccf5b3
    David S. Miller authored
    Christopher reports that perf_event_print_debug() can crash in uniprocessor
    builds.  The crash is due to pcr_ops being NULL.
    
    This happens because pcr_arch_init() is only invoked by smp_cpus_done() which
    only executes in SMP builds.
    
    init_hw_perf_events() is closely intertwined with pcr_ops being setup properly,
    therefore:
    
    1) Call pcr_arch_init() early on from init_hw_perf_events(), instead of
       from smp_cpus_done().
    
    2) Do not hook up a PMU type if pcr_ops is NULL after pcr_arch_init().
    
    3) Move init_hw_perf_events to a later initcall so that it we will be
       sure to invoke pcr_arch_init() after all cpus are brought up.
    
    Finally, guard the one naked sequence of pcr_ops dereferences in
    __global_pmu_self() with an appropriate NULL check.
    Reported-by: default avatarChristopher Alexander Tobias Schulze <cat.schulze@alice-dsl.net>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    8bccf5b3
smp_64.c 35.5 KB