Re: L4Re: Identifying the source location of a program exception
Jean Wolter <[email protected]>
| Newsgroups | gmane.comp.micro-kernel.l4.devel |
|---|---|
| Message-ID | <[email protected]> |
On 31/07/2020 01:23, Paul Boddie wrote: > And if I look in the objdump output, at least on some occasions, I can find an > instruction which would be causing the exception. The code looks like this: > > 100490f: 49 8b 04 24 mov (%r12),%rax > 1004913: 4c 89 ee mov %r13,%rsi > 1004916: 31 d2 xor %edx,%edx > 1004918: 4c 89 e7 mov %r12,%rdi > 100491b: ff 50 70 callq *0x70(%rax) > > It is at this final instruction that the exception occurs, and the offset is > as reported, too. > > The awkward thing here, though, is that the offending instruction is a virtual > method call within the same instance: > > this->flush_flexpage(flexpage); This looks like a pointer to an object is null. Is there any chance that the method containing the "this->flush_flexpage(flexpage);" is a method, that is not virtual? And that you invoked the method on a pointer to an object and that the pointer is a nullptr? A simple test whether "this" is null could shed some light on this ... best regards, Jean -- [email protected] - Tel. 0351-41 888 618 http://www.kernkonzept.com Kernkonzept GmbH. Sitz: Dresden. Amtsgericht Dresden, HRB 31129. Geschäftsführer: Dr.-Ing. Michael Hohmuth _______________________________________________ l4-hackers mailing list [email protected] http://os.inf.tu-dresden.de/mailman/listinfo/l4-hackers