Messages in this thread | | | Date | Wed, 06 Oct 2004 13:34:50 -0400 | From | Neil Horman <> | Subject | Re: [PATCH] RFC. User space backtrace on segv |
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Alex Bennee wrote: > Hi, > > I hacked up this little patch to dump the stack and attempt to generate > a back-trace for errant user-space tasks. > > What: > > Generates a back-trace of the user application on (in this case) a segv > caused by an unaligned access. This particular patch is against 2.4.22 > on the SH which is what I'm working with but there no reason it couldn't > be more generalised. > > How: > > Its not the most intelligent approach as it basically walks up the stack > reading values and seeing if the address corresponds to one of the > processes executable VMA's. If it matches it assumes its the return > address treats that section as a "frame" > > Why: > > I work with embedded systems and for a myriad of reasons doing a full > core dump of the crashing task is a pain. Often just knowing the > immediate call stack and local variables is enough to look at what went > wrong with objdump -S. > > Questions: > > Have I replicated anything that is already hidden in the code base? > Would this be useful (as a CONFIG_ option) for embedded systems? >
IIRC, there is already a backtrace function defined for most arches in the c library. in execinfo.h there is a family of backtrace functions that can unwind the stack fairly well for most arches, and store the trace in a post SIGSEGV-safe fashion.
Neil
-- /*************************************************** *Neil Horman *Software Engineer *Red Hat, Inc. *nhorman@redhat.com *gpg keyid: 1024D / 0x92A74FA1 *http://pgp.mit.edu ***************************************************/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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