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    <p>DobrÃ½ den.<br>

    </p>

    <div class="moz-cite-prefix">On 11/26/18 1:56 PM, SlÃ¡vka IvaniÄovÃ¡

      wrote:<br>

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cite="mid:CAPJCgrkvzauQovuzuAQhHOuM8_gxxGPDbxn+cP55w_s=TUPEDQ@mail.gmail.com">

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                                <div dir="ltr">ZdravÃm, vedel by mi,

                                  prosÃm, niekto objasniÅ¥ zopÃ¡r vecÃ k

                                  tÃ©me System calls z OperaÄnÃ½ch

                                  systÃ©mov?Â 

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                                  <div>V sÃºbore kernel/proc/sys_thread.c

                                    je fukciaÂ sys_thread_join (uintptr_t

                                    tid, void **thread_retval), ktorÃ¡ mÃ¡

                                    spojiÅ¥ thread (join a thread).Â </div>

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                                  <div>ChÃ¡pem to tak, Å¾e fukciaÂ robÃ

                                    nasledovnÃ©:</div>

                                  <div>// check that the tid pointer

                                    points to a safely mapped user

                                    memory,</div>

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                                    <div><span style="white-space:pre-wrap">      </span>if

                                      (tid != NULL &&

                                      !vma_check_user((void*)tid,

                                      sizeof(struct uthread))) {</div>

                                    <div><span style="white-space:pre-wrap">              </span>return

                                      ENOMEM;</div>

                                    <div><span style="white-space:pre-wrap">      </span>}</div>

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    <p>KoukÃ¡m do komentÃ¡ÅÅ¯ a tam ÅÃ¡dil tiskaÅskÃ½ Å¡otek, protoÅ¾e oba

      komentÃ¡Åe ÅÃkajÃ to stejnÃ© a vztahujÃ se k thread_retval. Z

      principu je tid pointer do kernelovÃ© pamÄti (vizte funkci

      sys_thread_create).<br>

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    <blockquote type="cite"

cite="mid:CAPJCgrkvzauQovuzuAQhHOuM8_gxxGPDbxn+cP55w_s=TUPEDQ@mail.gmail.com">

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                                <div dir="ltr">Mojou otÃ¡zkou je, Äi je

                                  potrebnÃ© v tejto fukciÃ prechÃ¡dzaÅ¥

                                  zoznam process->uthread_list a

                                  porovnaÅ¥, Äi sa uthreadÂ nachÃ¡dza v

                                  zozname.</div>

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    <p>Je potÅeba zajistit, Å¾e userspacovÃ½ proces nezkouÅ¡Ã napÅ. Äekat

      na vlÃ¡kno jinÃ©ho procesu popÅ., obecnÄji, jestli nepodstrÄil tid,

      kterÃ½ je nesmyslnÃ½.</p>

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    - VH<br>

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