• Dmitry Vyukov's avatar
    kcov: ignore fault-inject and stacktrace · 43e76af8
    Dmitry Vyukov authored
    Don't instrument 3 more files that contain debugging facilities and
    produce large amounts of uninteresting coverage for every syscall.
    
    The following snippets are sprinkled all over the place in kcov traces
    in a debugging kernel.  We already try to disable instrumentation of
    stack unwinding code and of most debug facilities.  I guess we did not
    use fault-inject.c at the time, and stacktrace.c was somehow missed (or
    something has changed in kernel/configs).  This change both speeds up
    kcov (kernel doesn't need to store these PCs, user-space doesn't need to
    process them) and frees trace buffer capacity for more useful coverage.
    
      should_fail
      lib/fault-inject.c:149
      fail_dump
      lib/fault-inject.c:45
    
      stack_trace_save
      kernel/stacktrace.c:124
      stack_trace_consume_entry
      kernel/stacktrace.c:86
      stack_trace_consume_entry
      kernel/stacktrace.c:89
      ... a hundred frames skipped ...
      stack_trace_consume_entry
      kernel/stacktrace.c:93
      stack_trace_consume_entry
      kernel/stacktrace.c:86
    
    Link: http://lkml.kernel.org/r/20200116111449.217744-1-dvyukov@gmail.comSigned-off-by: default avatarDmitry Vyukov <dvyukov@google.com>
    Reviewed-by: default avatarAndrey Konovalov <andreyknvl@google.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    43e76af8
Makefile 4.37 KB