* Wilco Dijkstra: >> For userland, I would like to eventually copy the OpenBSD approach for >> architectures which have some form of PC-relative addressing: we can >> have multiple random canaries in (RELRO) .rodata in sufficiently close >> to the code that needs them (assuming that we have split .rodata). At >> least for x86-64, I expect this to be a small win. It's also a slight >> hardening improvement if the reference canary is not stored in writable >> memory. > > On AArch64 hardware pointer signing already provides a free and more robust > implementation of stack canaries, so we could change -fstack-protector to > use that when pointer signing is enabled.
I expected to use both because not all AArch64 implementations support pointer signing, and we'd use the stack protector to get some coverage for the legacy implementations. (I'm still waiting for a request to enable pointer signing in Fedora rawhide, BTW.) Thanks, Florian
