Building on the work of Christophe, Aneesh and Balbir, I've ported KASAN to the e6500, a 64-bit Book3E processor which doesn't have a hashed page table. It applies on top of Christophe's series, v9, plus the proposed new version of patch 2.
It requires some changes to the KASAN core; we use the less ugly outline readiness check patch proposed by Christophe. The KASAN shadow area is mapped into vmemmap space: 0x8000 0400 0000 0000 to 0x8000 0600 0000 0000. To do this we require that vmemmap be disabled. (This is the default in the kernel config that QorIQ provides for the machine in their SDK anyway - they use flat memory.) Only outline instrumentation is supported and only KASAN_MINIMAL works. Only the kernel linear mapping (0xc000...) is checked. The vmalloc and ioremap areas (also in 0x800...) are all mapped to a zero page. As with the Book3S hash series, this requires overriding the memory <-> shadow mapping. Also, as with both previous 64-bit series, early instrumentation is not supported. KVM, kexec and xmon have not been tested. Thanks to those who have done the heavy lifting over the past several years: - Christophe's 32 bit series: https://lists.ozlabs.org/pipermail/linuxppc-dev/2019-February/185379.html - Aneesh's Book3S hash series: https://lwn.net/Articles/655642/ - Balbir's Book3S radix series: https://patchwork.ozlabs.org/patch/795211/ While useful if you have an Book3E device, this is mostly intended as a warm-up exercise for reviving Aneesh's series for book3s hash. I expect that the changes to the KASAN core will be required for that too, but I'll check against the book3s version before I send a non-RFC version. Once I do that I'll revisit the vmemmap decision as well. Changes from RFCv1: - Use Christophe's new version of outline readiness check - Rebase on top of Christophe's v9 + the proposed changes to string/memory functions Regards, Daniel Daniel Axtens (4): kasan: do not open-code addr_has_shadow kasan: allow architectures to manage the memory-to-shadow mapping kasan: allow architectures to provide an outline readiness check powerpc: KASAN for 64bit Book3E arch/powerpc/Kconfig | 1 + arch/powerpc/Kconfig.debug | 2 +- arch/powerpc/include/asm/kasan.h | 73 +++++++++++++++++++- arch/powerpc/mm/Makefile | 2 + arch/powerpc/mm/kasan/Makefile | 1 + arch/powerpc/mm/kasan/kasan_init_book3e_64.c | 53 ++++++++++++++ include/linux/kasan.h | 6 ++ mm/kasan/generic.c | 6 +- mm/kasan/generic_report.c | 2 +- mm/kasan/kasan.h | 6 +- mm/kasan/report.c | 6 +- mm/kasan/tags.c | 3 +- 12 files changed, 149 insertions(+), 12 deletions(-) create mode 100644 arch/powerpc/mm/kasan/kasan_init_book3e_64.c -- 2.19.1
