gcc-4.9.1 generating different code between two successive builds

Andrew Haley aph@redhat.com
Thu Dec 31 10:17:00 GMT 2015


On 30/12/15 15:33, Georg-Johann Lay wrote:

> Some parts of the compiler use the address of objects to compute
> hashes, but I don't remember which part(s) actually do this.  That
> technique can lead to different code for different runs of the
> compiler even on the same system.  This is hard to reproduce as it
> depends on how the OS is supplying memory, and it might depend on
> the "history" of the machine and the actual OS.

... and many Linux kernels deliberately randomize memory layout to
provide some protection from buffer overflow attacks.

Andrew.



More information about the Gcc mailing list