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    SubjectRe: [PATCH] Read THREAD_CPUTIME clock from other processes.
    On 01/07, Roland McGrath wrote:
    > This can certainly be enhanced, but it opens some cans of worms about the
    > security question. It is probably still considered an unsafe information
    > leak to let every process examine every other process's thread clocks.

    Yes, I was worried about possible security issues too. But, it seems,
    /proc/pid/task/tid/stat (do_task_stat) shows ->utime/stime anyway.
    And /proc/schedstat shows sum_exec_runtime.

    > I'll leave that judgement to security folks.


    > As well as the information leak, it is most certainly a DoS attack vector
    > to allow one process to set CPU timers an another process or its threads.

    No, the suggested change doesn't go that far, afaics. It only modifies
    check_clock: this affects clock_getres and clock_set (which does nothing),
    and posix_cpu_clock_get: affects clock_gettime().


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