Basile Starynkevitch <bas...@starynkevitch.net> writes: > In my MELT branch I have now some corrputed memory (maybe because I am > inserting a pass at the wrong place in the pass tree). At some point, I call > bb_debug, and it crashes because the field bb_next contains 0x101 (which is > not a valid adress). > > So I need to understand who is writing the 0x101 in that field. > > How do you folks debug such issues. > > An obvious strategy is to use the hardware watchpoint feature of GDB. > However, one cannot nicely put a watchpoint on an address which is not > mmap-ed yet. > > But I don't know how to ask gdb to be notified when a given adress is > becoming valid in the address space. Putting a breakpoint on mmap is really > not funny.
I usually put a breakpoint on the allocation routine and make it conditional on returning the address I am interested in. Once that address is returned, I can put a hardware breakpoint on the field value being changed. This approach is only moderately successful in practice. Ian
