Hi, On 1/15/23 16:06, Michael Ellerman wrote: > Geoff Levand <ge...@infradead.org> writes: >> On 1/9/23 09:41, Christophe Leroy wrote: >>> >>> >>> Le 03/01/2023 à 18:51, Geoff Levand a écrit : >>>> Commit fdacae8a84024474afff234bdd1dbe19ad597a10 (powerpc: Activate >>>> CONFIG_STRICT_KERNEL_RWX by default) causes ps3_hpte_updateboltedpp() >>>> to be called. Change the panic statment in ps3_hpte_updateboltedpp() >>>> to a pr_info statement so that bootup can continue. >>> >>> But if I understand correctly, it means that CONFIG_STRICT_KERNEL_RWX >>> won't work then. >>> >>> So, shouldn't we keep the panic and forbid CONFIG_STRICT_KERNEL_RWX on PS3 ? >> >> mmu_hash_ops.updateboltedpp returns void, so I can't return an error code to >> indicate the feature is not supported. > > We could change that in the medium term. > >> I could do something like this in arch/powerpc/Kconfig: >> >> - select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || >> 40x) && !HIBERNATION >> + select ARCH_HAS_STRICT_KERNEL_RWX if (PPC_BOOK3S || PPC_8xx || >> 40x) && !PPC_PS3 && !HIBERNATION >> >> But then the ppc64_defconfig would be built without STRICT_KERNEL_RWX. > > Yeah that would be a pity. > > We could do the above and disable PS3 in ppc64_defconfig, allowing > ppc64_defconfig to still have STRICT_KERNEL_RWX.
I really want to keep PS3 included in ppc64_defconfig. Not that I expect anyone to boot a ppc64_defconfig kernel on PS3, but that is one of the 'standard' configs that is built by some automated builders, and generally by anyone doing changes to the powerpc arch, and I want to keep getting those build tests for PS3. > I assume actual PS3 users would use a ps3_defconfig anyway right? Yeah, a derivative of it. They are most likely are using 'Jailbreak' firmware that allows them to run Linux in the gameos partition. > Relatedly are there any actual PS3 users left? ;) It seems there are more users now than a few years ago. I think they buy PS5s to play the latest games, and use their old console to mess around with Linux. I generally get a private inquiry every 3 or 4 weeks. Usually asking how to update their kernel, or how to install a modern distro. >> What other 'clean' way is there? > > If we want to have a multi-platform kernel image that can boot on PS3 > and other platforms, and have strict kernel RWX, then we need some > runtime logic to deal with that. > > I'd rather not do that though, because it adds complexity to deal with a > pretty obscure corner case, and I suspect no one really boots a > ppc64_defconfig on actual PS3 hardware these days. > > So my preference is we disable PS3 in ppc64_defconfig, and make PS3 > incompatible with STRICT_KERNEL_RWX. As mentioned, I'd really like to keep PS3 included in ppc64_defconfig. My original patch that basically just ignores the call to mmu_hash_ops.updateboltedpp allows that, and I haven't experienced any problems with it yet. My preference would be to keep PS3 in ppc64_defconfig, and either apply my original patch, or I keep that patch in my ps3-linux repo on kernel.org. Then, if we end up adding runtime support for RWX I then fixup PS3 to use that. -Geoff
