Re: [Valgrind-users] Marking blocks as write-once/grow-only

[Julian S. <js...@ac...>]

> Is it possible for the DRD/Helgrind tools to detect this sort of
> double-write access behaviour?

Both of them should be able to detect a write-vs-write race, if
that's what you mean.

> Could I instrument QEMU so it marked the
> codegen buffer as one that should only grow upwards (modulo-patchable
> bits) so if anything re-wrote the buffer it could trigger an error?

This is confusing.  Both tools are able to detect races at a byte level
granularity.  If you can show that QEMU doesn't race on individual writes
to its code buffer, isn't that good enough from a correctness perspective?

J