title: Unable to handle kernel paging request at virtual address - Kernel OOPS
body: <p>I've had a kernel OOPS the other day running speaker-test on my Freescale i.MX233. Presumably happened after an attempted SIGTERM on speaker-test (it could be any other time, ). After the OOPS I could see waiting for IO running at all unused cpu time. The process invoking speaker-test couldn't be terminated either. Tried SIGKILL as well. "ps ax" was also hanging after execution.</p>
  
  <p>Luckily I've managed to extract the OOPS from the messages. I've searched all over the internet but couldn't really explain everything that I'm seeing in this OOPS.</p>
  
  <p>What I really can't figure out is what can actually cause this and how can I backtrace it to a specific driver. The mxs audio drivers are built-in in the kernel, so it won't be visible in the drivers list. The driver itself has been heavily modified, on request I can share parts of it.</p>
  
  <p>So the kernel addresses are starting at 0xc0000000, but why is the process stack part of the kernel memory address region? Isn't that supposed to be starting downwards from kernel addresses?</p>
  
  <p>Speaker-test in use is 1.0.11rc2, but I presume even if the program would end abruptly the sound architecture would close everything properly. This version of speaker-test doesn't handle signals and is not attempting to close gracefully, just gives up.</p>
  
  <p>What region would 0xe1a0a024 be? Is that an ARM instruction perhaps? Meaning this will a stack overflow somewhere? I know the memory mapped registers reside in 0x80000000. What region is "pgd = c39dc000" in? Is that kernel stack?</p>
  
  <p>Is it possible to get more stack dump the next time on an OOPS, so that I can possibly go further? I can change the kernel if that's necessary (I guess the I should just go to the OOPS printer to get more), but is there a configuration for this?</p>
  
  <p>Any ideas? Any helps is greatly appreciated, I'm looking at this for 2 days now.</p>
  
  <p>OOPS:</p>
  
  <pre><code>&lt;1&gt;[268811.560000] Unable to handle kernel paging request at virtual address e1a0a024
  &lt;1&gt;[268811.560000] pgd = c39dc000
  &lt;1&gt;[268811.560000] [e1a0a024] *pgd=00000000
  &lt;4&gt;[268811.560000] Internal error: Oops: 5 [#1] PREEMPT
  &lt;4&gt;[268811.560000] Modules linked in: 
  &lt;4&gt;[268811.560000] CPU: 0    Tainted: P            (2.6.31-private #153)
  &lt;4&gt;[268811.560000] PC is at vma_prio_tree_next+0x3c/0x6c
  &lt;4&gt;[268811.560000] LR is at update_mmu_cache+0x120/0x1c4
  &lt;4&gt;[268811.560000] pc : [&lt;c00b98d8&gt;]    lr : [&lt;c00611d4&gt;]    psr: a0000093
  &lt;4&gt;[268811.560000] sp : c39c5de0  ip : c5cfa8f8  fp : c7ce7d80
  &lt;4&gt;[268811.560000] r10: c7ce7d80  r9 : 401fb000  r8 : 401fb000
  &lt;4&gt;[268811.560000] r7 : 00000021  r6 : c5c9b478  r5 : 00000000  r4 : 401fad94
  &lt;4&gt;[268811.560000] r3 : e08f7007  r2 : ea00014d  r1 : c39c5dec  r0 : e1a0a000
  &lt;4&gt;[268811.560000] Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
  &lt;4&gt;[268811.560000] Control: 0005317f  Table: 439dc000  DAC: 00000015
  &lt;4&gt;[268811.560000] Process speaker-test (pid: 1823, stack limit = 0xc39c4270)
  &lt;4&gt;[268811.560000] Stack: (0xc39c5de0 to 0xc39c6000)
  &lt;4&gt;[268811.560000] 5de0: 401fad94 c00611d4 c5f351c0 c7d34c84 00000080 00000000 00000000 c747d3c0 
  &lt;4&gt;[268811.560000] 5e00: 00000021 00000021 00000000 00000000 4507630f c04a4ec0 00000000 c5c9b478 
  &lt;4&gt;[268811.560000] 5e20: 00000000 c00bbc68 c7802060 00000000 00000200 c3a22fec 00000000 00000021 
  &lt;4&gt;[268811.560000] 5e40: 401fb000 c04a4ec0 c5c9b108 c3a22800 c39dd000 c5c9b478 c5c9b478 401fb000 
  &lt;4&gt;[268811.560000] 5e60: 00000000 00000000 c7ce7d80 c00bc69c 00000021 00000000 00000000 00000000 
  &lt;4&gt;[268811.560000] 5e80: 000001fb c39dc000 00000200 000007ec c3a22fec c5c0612c 00000010 00000000 
  &lt;4&gt;[268811.560000] 5ea0: 00000000 c749b0b0 0000000a c03b030c c5de0c00 c5c9b478 c7ce7db4 401fb290 
  &lt;4&gt;[268811.560000] 5ec0: c39c5fb0 c7ce7d80 00000017 c0060a30 c7d34cb8 00000000 00000200 00000000 
  &lt;4&gt;[268811.560000] 5ee0: 00000000 c03b030c 00000006 c03b037c 00000017 c39c5fb0 0000000b 401fb290 
  &lt;4&gt;[268811.560000] 5f00: be93295c c005a228 00000000 00000000 c7ce7d80 c00bc69c 0000000a 00000000 
  &lt;4&gt;[268811.560000] 5f20: 00000000 00000000 000001b0 c39dc000 00000200 000006c0 c3a22ec0 401c3000 
  &lt;4&gt;[268811.560000] 5f40: 00000001 00000000 40025050 c00858f8 00000021 ffffffff c5de0c00 c5c9b948 
  &lt;4&gt;[268811.560000] 5f60: 00000000 c01697e8 00000200 c5de0c00 c5c9b948 c0060ac4 c005af84 be932c38 
  &lt;4&gt;[268811.560000] 5f80: 00000008 00000000 c39c4000 ffffffff 00000006 ffffffff 00000006 be9329e8 
  &lt;4&gt;[268811.560000] 5fa0: be9329e8 0000000c 403004d0 c005ad9c 00000000 00000000 0000000c 00000000 
  &lt;4&gt;[268811.560000] 5fc0: 0000000c 00000006 be9329e8 be9329e8 0000000c 0000000b 403004d0 be93295c 
  &lt;4&gt;[268811.560000] 5fe0: 0000c718 be9328f8 401fa7bc 401fadb8 20000010 ffffffff 00000000 00000000 
  &lt;4&gt;[268811.560000] [&lt;c00b98d8&gt;] (vma_prio_tree_next+0x3c/0x6c) from [&lt;c00611d4&gt;] (update_mmu_cache+0x120/0x1c4)
  &lt;4&gt;[268811.560000] [&lt;c00611d4&gt;] (update_mmu_cache+0x120/0x1c4) from [&lt;c00bbc68&gt;] (__do_fault+0x308/0x3ec)
  &lt;4&gt;[268811.560000] [&lt;c00bbc68&gt;] (__do_fault+0x308/0x3ec) from [&lt;c00bc69c&gt;] (handle_mm_fault+0x298/0xc14)
  &lt;4&gt;[268811.560000] [&lt;c00bc69c&gt;] (handle_mm_fault+0x298/0xc14) from [&lt;c0060a30&gt;] (do_page_fault+0xec/0x234)
  &lt;4&gt;[268811.560000] [&lt;c0060a30&gt;] (do_page_fault+0xec/0x234) from [&lt;c005a228&gt;] (do_DataAbort+0x30/0x90)
  &lt;4&gt;[268811.560000] [&lt;c005a228&gt;] (do_DataAbort+0x30/0x90) from [&lt;c005ad9c&gt;] (ret_from_exception+0x0/0x10)
  &lt;4&gt;[268811.560000] Exception stack(0xc39c5fb0 to 0xc39c5ff8)
  &lt;4&gt;[268811.560000] 5fa0:                                     00000000 00000000 0000000c 00000000 
  &lt;4&gt;[268811.560000] 5fc0: 0000000c 00000006 be9329e8 be9329e8 0000000c 0000000b 403004d0 be93295c 
  &lt;4&gt;[268811.560000] 5fe0: 0000c718 be9328f8 401fa7bc 401fadb8 20000010 ffffffff                   
  &lt;4&gt;[268811.560000] Code: e2430024 e5903030 e3530000 1a000001 (e5903024) 
  &lt;4&gt;[268811.560000] ---[ end trace c70c22c7b9cf390d ]---
  &lt;6&gt;[268811.560000] note: speaker-test[1823] exited with preempt_count 2
  </code></pre>