On Wed, Jul 16, 2025 at 09:22:19PM +0000, Qing Zhao wrote:
> Yes, the above solution could also resolve the undefined behavior issue. We
> can certainly go
> with this approach.
Another option is to use .ACCESS_WITH_SIZE (with different flags compared to
the FAM cases) solely on reads from the pointer, and then objsz pass taking
the indirection into account. I.e. when you see some pointer dereferenced
and the pointer originates in .ACCESS_WITH_SIZE with that flag, take it as
size of what the pointer points at rather than the FAM way. Still,
.ACCESS_WITH_SIZE first argument should be the pointer value, not its
address, and you should never instrument stores to the pointer, only reads
from it.
So, f->p = whatever; doesn't get .ACCESS_WITH_SIZE,
_1 = f->p; gets it and then f->p[a] is
_2 = _1 p+ off;
MEM_REF[_2]
opr similar.
Jakub
