Re: [Valgrind-users] Strange 'Invalid read' and 'Invalid write' errors

[Jason E. <ja...@ca...>]

Christoph Bartoschek wrote:
> Do you have the traceback with debug information and the code that produces 
> the erorr? You could check right after allocation from the system that the 
> whole range is accessible with valgrinds macros.

Thank you for your suggestion; it helped me find my mistake.  Valgrind 
did have the whole range marked as accessible, and writes/reads worked 
fine to begin with.  The problem was that in another place I was calling 
MALLOC_FREELIKE_BLOCK(ptr, size), but the second argument is redzone 
size, not allocation size.  This deallocated object was close enough to 
the large object for the erroneous redzone to overlap.  Whoops.

Thank you everyone for your help.

Jason