Dear all, "hardened usercopy" does not work correctly on ia64. And deactivating it with `hardened_usercopy=off` in the kernel commandline seems to make no real difference for specific Itanium 2 CPUs, namely: * Madison (in rx4640 with zx1) * Montvale (in rx2660, rx3600 and rx6600 with zx2) ...which can't successfully complete kernel boot with and w/o `hardened_usercopy=off`. If "hardened usercopy" is deactivated in the kernel configuration instead it seems to allow Montvales to complete kernel boot successfully. @Pedro: Please correct me if I understood you wrongly here. * Montecitos (in rx2620 with zx1 and rx2660 with zx2) instead seem to work much better (both kernel boot and userland operation) with `hardened_usercopy=off`. They don't work w/o `hardened_usercopy=off`, though (rx2620 needs to be checked, true for rx2660). * Tukwilas (in rx2800 i2) seem to be not affected by this bug at all. **** I compiled the stack traces of the machines I tested on [1]. [1]: https://pastebin.com/raw/AKfZrjWi Please also see the originating "Re: rx2660 + debian" thread on Debian's ia64 mailing list ([2]), and specifically [3] where Pedro and Sergei start to dissect this problem. [4] shows that usercopy problems already seem to exist in Linux 4.19 (for Montvales in rx2660 with zx2)! [2]: https://lists.debian.org/debian-ia64/2022/04/threads.html [3]: https://lists.debian.org/debian-ia64/2022/04/msg00021.html [4]: https://lists.debian.org/debian-ia64/2022/04/msg00022.html **** If you need more information, please let me know. I haven't yet created a bug report on "bugzilla.kernel.org" for this. Does this need any more information than what I just wrote above? Cheers, Frank
