• Namhyung Kim's avatar
    tools lib traceevent: Honor operator priority · 3201f0dc
    Namhyung Kim authored
    Currently it ignores operator priority and just sets processed args as a
    right operand.  But it could result in priority inversion in case that
    the right operand is also a operator arg and its priority is lower.
    
    For example, following print format is from new kmem events.
    
      "page=%p", REC->pfn != -1UL ? (((struct page *)(0xffffea0000000000UL)) + (REC->pfn)) : ((void *)0)
    
    But this was treated as below:
    
      REC->pfn != ((null - 1UL) ? ((struct page *)0xffffea0000000000UL + REC->pfn) : (void *) 0)
    
    In this case, the right arg was '?' operator which has lower priority.
    But it just sets the whole arg so making the output confusing - page was
    always 0 or 1 since that's the result of logical operation.
    
    With this patch, it can handle it properly like following:
    
      ((REC->pfn != (null - 1UL)) ? ((struct page *)0xffffea0000000000UL + REC->pfn) : (void *) 0)
    Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
    Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: Joonsoo Kim <js1304@gmail.com>
    Cc: Minchan Kim <minchan@kernel.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: linux-mm@kvack.org
    Link: http://lkml.kernel.org/r/1428298576-9785-10-git-send-email-namhyung@kernel.org
    [ Replaced 'swap' with 'rotate' in a comment as requested by Steve and agreed by Namhyung ]
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    3201f0dc
event-parse.c 140 KB