From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Fri, 19 Feb 2016 16:46:06 +0000 Subject: [PATCH v2 0/5] arm64: kernel: Add support for User Access Override In-Reply-To: References: <1454684330-892-1-git-send-email-james.morse@arm.com> <20160218180313.GE2538@e104818-lin.cambridge.arm.com> Message-ID: <20160219164606.GD12864@e104818-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Feb 19, 2016 at 03:38:44PM +0000, Peter Maydell wrote: > On 18 February 2016 at 18:03, Catalin Marinas wrote: > > On Fri, Feb 05, 2016 at 02:58:45PM +0000, James Morse wrote: > >> James Morse (5): > >> arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macro > >> arm64: add ARMv8.2 id_aa64mmfr2 boiler plate > >> arm64: kernel: Add support for User Access Override > >> arm64: cpufeature: Test 'matches' pointer to find the end of the list > >> arm64: kernel: Don't toggle PAN on systems with UAO > > > > Patches applied with an additional fixup on top for removing > > get_thread_info(). > > Just to let you know, unfortunately this series breaks booting the > kernel on QEMU. We didn't implement the parts of the ID register > space that the ARM ARM documents as "reserved, RAZ", and so when > the kernel touches ID_AA64MMFR2 (new in v8.2) QEMU hands it an > UNDEF. This is obviously a bug in QEMU, and I just sent out a patch > for it: http://patchwork.ozlabs.org/patch/585237/ -- but of course > that doesn't do anything for all the buggy QEMUs already in the field. > > This is more of a heads-up than a demand that you Do Something, > but perhaps somebody has a clever idea... Only if Qemu had its own MIDR/REVIDR ;) (and patch the instruction like other errata workarounds). -- Catalin