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<p class="MsoNormal">Hello LTTng devs,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am experiencing a strange problem with what I believe is corrupt metadata. This is seen on v2.6.0 of LTTng.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">If I try and parse recovered traces using Babeltrace, it fails with a segmentation fault.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">nbryan@meteorubuntu-OptiPlex-7010:/data/nbryan/Meteor/altera_trace$ babeltrace --help<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">BabelTrace Trace Viewer and Converter 1.0.0-rc1<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">nbryan@meteorubuntu-OptiPlex-7010:/data/nbryan/Meteor/altera_trace$ babeltrace auto-20150304-091109/<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Segmentation fault (core dumped)<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I thought it may be worth a look at the metadata file and I observed the following (these are just three examples):<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Environment:<o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">env {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> hostname = "socfpga_cyclone5";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> domain = "kernel";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> sysname = "Linux";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> kernel_release = "3.10.31-ltsi-05035-g801a40f";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> kernel_version = "#3 SMP Tue Mar 3 17:31:45 GMT 2015";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> tracer_name = "lttng-modules";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> tracer_major = 2;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> tracer_minor = 6;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> tracer_patchlevel = 0;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">};<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">event {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> name = "syscall_exit_recvmmsg";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> id = 921;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> stream_id = 0;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> fields := struct {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 1; encoding = none; base = 10; } _ret;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signe Wu?)2Ndn d = 0; encoding = none; base = 16; } _mmsg;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 0; encoding = none; base = 16; } _timeout;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> };<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">};<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Decoded binary values:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">00h,00h,00h,57h,1Dh,D1h,75h,3Fh,ADh,A9h,29h,32h,BEh,C8h,4Eh,B9h,64h,99h,8Fh,14h,89h,6Eh,AEh,00h,00h,00h,00h,E8h,7Fh,00h,00h,00h,80h,00h,00h,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">00h,00h,00h,01h,08h<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">event {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> name = "syscall_exit_getcpu";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> id = 903;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> stream_id = 0;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> fields := struct {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 1; encoding = none; base = 10; } _ret;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 0; encoding = none; base = 16; } _cpup;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 0; encoding = none; base = 16; } _nodep;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 0; encoding = none; base = Wu?)2Ndn 16; } _tcache;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> };<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">};<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Decoded binary values:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">00h,00h,00h,57h,1Dh,D1h,75h,3Fh,ADh,A9h,29h,32h,BEh,C8h,4Eh,B9h,64h,99h,8Fh,14h,89h,6Eh,AEh,00h,00h,00h,00h,E8h,7Fh,00h,00h,00h,80h,00h,00h,00h,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">00h,00h,01h,08h<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">event {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> name = "syscall_exit_fstatat64";<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> id = 886;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> stream_id = 0;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> fields := struct {<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 1; encoding = none; base = 10; } _ret;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 1; encod Wu?)2Ndn ing = none; base = 10; } _dfd;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> string _filename;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 0; encoding = none; base = 16; } _statbuf;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> integer { size = 32; align = 32; signed = 1; encoding = none; base = 10; } _flag;<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""> };<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">};<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">Decoded binary values:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">00h,00h,00h,57h,1Dh,D1h,75h,3Fh,ADh,A9h,29h,32h,BEh,C8h,4Eh,B9h,64h,99h,8Fh,14h,89h,6Eh,AEh,00h,00h,00h,00h,E8h,7Fh,00h,00h,00h,80h,00h,00h,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">00h,00h,00h,01h,08h<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In a metadata file containing 7200 lines, I see this corruption 74 times.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I also notice that the header of the metadata file contains something very similar:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-family:"Courier New"">57h,1Dh,D1h,75h,3Fh,ADh,A9h,29h,32h,BEh,C8h,4Eh,B9h,64h,99h,8Fh,14h,89h,6Eh,AEh,00h,00h,00h,00h,D8h,27h,00h,00h,00h,80h,00h,00h,00h,00h,00h,01h,08h<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This appears identical to the other instances, less the first three 00h bytes.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Now it may be intentional to squirt binary data into what is essentially a text file, but it looks suspicious. Can anyone shed any light on what is happening here?<o:p></o:p></p>
<p class="MsoNormal">Is the metadata file supposed to have any binary data in it at all?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Neil.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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