<div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small">So have here awkward behaving of code. </div><div><br></div><div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small">I have a block of code where originally was `dprintk` for debugging and everything was fine.</div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small">But when I tried to remove it (for the sanity of debug output) kernel crashed. (Both with `.configure.py --debug`)</div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small">I can't see why this is happing and most importantly WHY IS THIS HAPPENING?</div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small">both `print` and `dprintk` should not apply any change.</div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><div class="gmail_default">This is a copy of the issue: <a href="https://gitlab.mff.cuni.cz/teaching/nswi004/2020/team-please_dont/-/issues/15">https://gitlab.mff.cuni.cz/teaching/nswi004/2020/team-please_dont/-/issues/15</a></div><div class="gmail_default">related to branch <a href="https://gitlab.mff.cuni.cz/teaching/nswi004/2020/team-please_dont/-/tree/bugfix/K-15">https://gitlab.mff.cuni.cz/teaching/nswi004/2020/team-please_dont/-/tree/bugfix/K-15</a></div></div><br></div><div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><span style="font-family:Arial,Helvetica,sans-serif">file: `heap.c/search_heap_size`</span></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><span class="gmail_default"></span></div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><span style="font-family:Arial,Helvetica,sans-serif">When running with `dprintk`, code will run smoothly and the result is expected.<br> </span><span style="font-family:Arial,Helvetica,sans-serif">```c</span></div>*((int*)scanner) = 0xC0FFEE;<br>dprintk("Scanning: 0x%x (%x)\n", scanner, *((int*)scanner));<br>if(*((int*)scanner) != 0xC0FFEE)<br>```<br><span class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"></span><br>``` shell<br>[DEBUG src/mm/heap.c:24 search_heap_size()] Scanning: 0x800fb130 (c0ffee)<br>[DEBUG src/mm/heap.c:24 search_heap_size()] Scanning: 0x800fc130 (c0ffee)<br>[DEBUG src/mm/heap.c:24 search_heap_size()] Scanning: 0x800fd130 (c0ffee)<br>[DEBUG src/mm/heap.c:24 search_heap_size()] Scanning: 0x800fe130 (c0ffee)<br>[DEBUG src/mm/heap.c:24 search_heap_size()] Scanning: 0x800ff130 (c0ffee)<br>[DEBUG src/mm/heap.c:24 search_heap_size()] Scanning: 0x80100130 (c0ffee)<br>[DEBUG src/mm/heap.c:27 search_heap_size()] NonMatch: 0x80100130 (ffffffff)<br>[DEBUG src/mm/heap.c:149 heap_init()] heap_begin: 0x80001130<br>[DEBUG src/mm/heap.c:150 heap_init()] heap_end:  0x800ff130<br>[DEBUG src/mm/heap.c:151 heap_init()] heap size: 1016 bytes<br>Hello world!<br><msim> Alert: XHLT: Machine halt<br><br>Cycles: 229951<br>```<br><br><br><br><span class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"></span>
<span class="gmail_default" style="font-family:verdana,sans-serif"></span>When running **Without** `dprintk`, code will fail during the process.  <br>```c<br>*((int*)scanner) = 0xC0FFEE;<br>//dprintk("Scanning: 0x%x (%x)\n", scanner, *((int*)scanner));<br>if(*((int*)scanner) != 0xC0FFEE)<br>```<br><span class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"></span><br>``` shell<br><msim> Alert: XRD: Register dump<br>processor 0<br>  0         0  at         0  v0 ffffffffc0000f20  v1      c0ffee  a0         0<br> a1         0  a2         0  a3         0  t0         0  t1         0<br> t2         0  t3         0  t4         0  t5         0  t6         0<br> t7         0  s0         0  s1         0  s2         0  s3         0<br> s4         0  s5         0  s6         0  s7         0  t8         0<br> t9         0  k0       ff01  k1         0  gp ffffffff80000000  sp ffffffff800003e8<br> fp         0  ra ffffffff80000440  pc ffffffff80000180  lo         0  hi         0<br><msim> Alert: XINT: Interactive mode<br>[msim]<br><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small"><span style="font-family:Arial,Helvetica,sans-serif">```</span></div><br></div><div><br></div>-- <br><div dir="ltr" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><span style="font-size:12.8px"><font face="georgia, serif"><br></font></span></div><div><font face="georgia, serif"><span style="font-size:12.8px">S pozdravem JiÅà Pelc</span></font></div><div><font face="georgia, serif"><span style="font-size:12.8px">Matematicko-fyzikálnà fakulta</span></font></div><div><font face="georgia, serif"><span style="font-size:12.8px">Univerzita Karlova</span></font></div></div></div></div></div></div>