• Paul Mackerras's avatar
    perf_counter/powerpc: Fix oops on cpus without perf_counter hardware support · f36a1a13
    Paul Mackerras authored
    If we have the powerpc perf_counter backend compiled in, but
    the cpu we are running on is one where we don't support the
    PMU, we currently oops in hw_perf_group_sched_in if we try to
    use any counters, because ppmu is NULL in that case, and we
    unconditionally dereference ppmu.
    
    This fixes the problem by adding a check if ppmu is NULL at the
    beginning of hw_perf_group_sched_in, and also at the beginning
    of the other functions that get called from the perf_counter
    core, i.e. hw_perf_disable, hw_perf_enable, and
    hw_perf_counter_setup.
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: benh@kernel.crashing.org
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    f36a1a13
perf_counter.c 32 KB