On 02/10/17 01:05 AM, John Knight wrote: > Hi Dave, > > I finally got a few cycles to work on your suggestions for trying to use > libunwind version 1.1 and 1.0. I have confirmed that libunwind version 1.1 > also SEGVs when compiled for Mips. Same as 1.2. > > As for version 1.0, the source does NOT compile... it fails to compile > tests/Gperf-simple.c with multiple undefined references to _Umips_getcontext. > I have attached an excerpt from make log file for your review. > > I also have one complaint that covers versions 1.1 and 1.2: > The file tests/test-coredump-unwind.c fails to compile on our linux system > (linux 2.6.36)... the issue is that the test relies on the presence of > execinfo.h, and functions backtrace() and backtrace_symbols_fd(). The issue > here is that older linux versions do not have execinfo.h, nor do they have > backtrace() or backtrace_symbols_fd(). If our version of linux had these, > than I would not be looking to implement backtrace() capability with > libunwind. I am not sure I understand why this test uses these, unless to > compare the output of libunwind to the output of glibc's backtrace() > capability. At any rate, we can't use this test and we end up patching the > libunwind test source, effectively removing the inclusion of execinfo.h and > the calls to backtrace() and backtrace_symbols() from the source code just to > get it to compile. It would be VERY NICE if there was a flag that could be > set in the Makefile to skip compiling all of the tests. In our embedded > environment, the tests are not useful anyhow.
Git master now has a --disable-tests, but alas it just missed inclusion in 1.2. Next release though. > At this point, I have pretty much determined that libunwind's mips > implementation is perhaps just a work in progress and not debugged and > working. This might explain why mips was not listed as a supported > architecture in the online documentation; I was kinda afraid of this. As for > me, I really don't know enough of the mips architecture to provide useful > help in debugging this, nor do I have much time available for the activity. > I can tell you it does not work in your current source base (1.2) and also > broken in 1.1. The fact it doesn't compile in 1.0 is also pretty telling for > that release as well. Perhaps the contributor of the mips code to the > libunwind project can help get it to work? If the issues with it cannot be > resolved any time soon, I am afraid I may have to find an alternative way to > implement backtrace on mips... not something I look forward to. I've cc'd a few of the mips committers if they have any suggestions for help. > Thanks for your suggestions and help with this... I will see if I can gleen > any more info from the SEGV fault, but alas, I don't have a lot of hope for > this. I'll see if I can at least determine what function is actually causing > the SEGV... beyond this, not sure how much more I can do. If you do get any more info let us know, I'm out of ideas for now though. Thanks! _______________________________________________ Libunwind-devel mailing list Libunwind-devel@nongnu.org https://lists.nongnu.org/mailman/listinfo/libunwind-devel
