I've spent much of today (thanks to poor Android native debugging) tracking down a crash on Android that seems to be this. If libc.so's _Unwind_Backtrace() gets called, I get the same crash:

#​00 pc 00097122 libc++_shared.so (unw_get_proc_info+93)
#​01 pc 000992ab libc++_shared.so (_Unwind_GetLanguageSpecificData+10)
#​02 pc 00094c0f libc++_shared.so (__gxx_personality_v0+46)
#​03 pc 0003c630 /system/lib/libc.so (__gnu_Unwind_Backtrace+152)
#​04 pc 0003cb44 /system/lib/libc.so (_Unwind_Backtrace+20)

This happens due to system libraries that only link to libc.so calling _Unwind_Backtrace.

I haven't found any workaround for this, so I'll revert back to gnuc++ for now (and jump some other hoops for a library that doesn't work with that gnuc++, which was the reason I was trying to use this in the first place). This is the repro I isolated, FWIW:

#include <unwind.h>
#include <dlfcn.h>

static _Unwind_Reason_Code test(struct _Unwind_Context *c, void *p) { return _URC_NO_REASON; }

void go()
{
void *libc = dlopen("libc.so", RTLD_LAZY);
void *_Unwind_Backtrace = dlsym(libc, "_Unwind_Backtrace");

typedef _Unwind_Reason_Code (*p_Unwind_Backtrace)(_Unwind_Trace_Fn, void *);
((p_Unwind_Backtrace) _Unwind_Backtrace)(test, NULL);

try {
	throw runtime_error("");
} catch(runtime_error &e) {
}

}

This should be fixed now that http://reviews.llvm.org/rL262178 and http://reviews.llvm.org/rL263010 have landed. Please try it out!