kernel/arch/powerpc/include/asm/book3s/64/pgtable.h, branch linux-6.2.y

mm: remove unused savedwrite infrastructure

2022-11-30T23:58:49Z

NUMA hinting no longer uses savedwrite, let's rip it out. ... and while at it, drop __pte_write() and __pmd_write() on ppc64. Link: https://lkml.kernel.org/r/20221108174652.198904-7-david@redhat.com Signed-off-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Anshuman Khandual Cc: Dave Chinner Cc: Hugh Dickins Cc: Linus Torvalds Cc: Mel Gorman Cc: Michael Ellerman Cc: Mike Rapoport Cc: Nadav Amit Cc: Nicholas Piggin Cc: Peter Xu Cc: Vlastimil Babka Signed-off-by: Andrew Morton

powerpc/64s: Enable KFENCE on book3s64

2022-09-28T09:22:10Z

KFENCE support was added for ppc32 in commit 90cbac0e995d ("powerpc: Enable KFENCE for PPC32"). Enable KFENCE on ppc64 architecture with hash and radix MMUs. It uses the same mechanism as debug pagealloc to protect/unprotect pages. All KFENCE kunit tests pass on both MMUs. KFENCE memory is initially allocated using memblock but is later marked as SLAB allocated. This necessitates the change to __pud_free to ensure that the KFENCE pages are freed appropriately. Based on previous work by Christophe Leroy and Jordan Niethe. Signed-off-by: Nicholas Miehlbradt Reviewed-by: Russell Currey Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220926075726.2846-4-nicholas@linux.ibm.com

powerpc/mm: Make PAGE_KERNEL_xxx macros grep-friendly

2022-09-26T10:58:18Z

Avoid multi-lines to help getting a complete view when using grep. They still remain under the 100 chars limit. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/3bc3f5a51949ee7f52dba36677db23d4337c7995.1662544980.git.christophe.leroy@csgroup.eu

powerpc/mm: Reduce redundancy in pgtable.h

2022-09-26T10:58:18Z

PAGE_KERNEL_TEXT, PAGE_KERNEL_EXEC and PAGE_AGP are the same for all powerpcs. Remove duplicated definitions. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/92254499430d13d99e4a4d7e9ad8e8284cb35380.1662544974.git.christophe.leroy@csgroup.eu

powerpc/mm/64s: Drop p4d_leaf()

2022-09-26T10:58:18Z

Because 64-bit Book3S uses pgtable-nop4d.h, the P4D is folded into the PGD. So P4D entries are actually PGD entries, or vice versa. The other way to think of it is that the P4D is a single entry page table below the PGD. Zero bits of the address are needed to index into the P4D, therefore a P4D entry maps the same size address space as a PGD entry. As explained in the previous commit, there are no huge page sizes supported directly at the PGD level on 64-bit Book3S, so there are also no huge page sizes supported at the P4D level. Therefore p4d_is_leaf() can never be true, so drop the definition and fallback to the default implementation that always returns false. Reviewed-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220903123640.719846-2-mpe@ellerman.id.au

powerpc/64s: add pte_needs_flush and huge_pmd_needs_flush

2022-09-08T01:11:18Z

Allow PTE changes to avoid flushing the TLB when access permissions are being relaxed, the dirty bit is being set, and the accessed bit is being changed. Relaxing access permissions and setting dirty and accessed bits do not require a flush because the MMU will re-load the PTE and notice the updates (it may also cause a spurious fault). Clearing the accessed bit does not require a flush because of the imprecise PTE accessed bit accounting that is already performed, as documented in ptep_clear_flush_young(). This reduces TLB flushing for some mprotect(2) calls. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Reviewed-by: Christophe Leroy Link: https://lore.kernel.org/r/20220901110334.1618913-1-npiggin@gmail.com

powerpc/mm: Support execute-only memory on the Radix MMU

2022-08-26T01:02:21Z

Add support for execute-only memory (XOM) for the Radix MMU by using an execute-only mapping, as opposed to the RX mapping used by powerpc's other MMUs. The Hash MMU already supports XOM through the execute-only pkey, which is a separate mechanism shared with x86. A PROT_EXEC-only mapping will map to RX, and then the pkey will be applied on top of it. mmap() and mprotect() consumers in userspace should observe the same behaviour on Hash and Radix despite the differences in implementation. Replacing the vma_is_accessible() check in access_error() with a read check should be functionally equivalent for non-Radix MMUs, since it follows write and execute checks. For Radix, the change enables detecting faults on execute-only mappings where vma_is_accessible() would return true. Signed-off-by: Russell Currey Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220817050640.406017-1-ruscur@russell.cc

docs: rename Documentation/vm to Documentation/mm

2022-06-27T19:52:53Z

so it will be consistent with code mm directory and with Documentation/admin-guide/mm and won't be confused with virtual machines. Signed-off-by: Mike Rapoport Suggested-by: Matthew Wilcox Tested-by: Ira Weiny Acked-by: Jonathan Corbet Acked-by: Wu XiangCheng

Merge tag 'powerpc-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2022-05-28T18:27:17Z

Pull powerpc updates from Michael Ellerman: - Convert to the generic mmap support (ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) - Add support for outline-only KASAN with 64-bit Radix MMU (P9 or later) - Increase SIGSTKSZ and MINSIGSTKSZ and add support for AT_MINSIGSTKSZ - Enable the DAWR (Data Address Watchpoint) on POWER9 DD2.3 or later - Drop support for system call instruction emulation - Many other small features and fixes Thanks to Alexey Kardashevskiy, Alistair Popple, Andy Shevchenko, Bagas Sanjaya, Bjorn Helgaas, Bo Liu, Chen Huang, Christophe Leroy, Colin Ian King, Daniel Axtens, Dwaipayan Ray, Fabiano Rosas, Finn Thain, Frank Rowand, Fuqian Huang, Guilherme G. Piccoli, Hangyu Hua, Haowen Bai, Haren Myneni, Hari Bathini, He Ying, Jason Wang, Jiapeng Chong, Jing Yangyang, Joel Stanley, Julia Lawall, Kajol Jain, Kevin Hao, Krzysztof Kozlowski, Laurent Dufour, Lv Ruyi, Madhavan Srinivasan, Magali Lemes, Miaoqian Lin, Minghao Chi, Nathan Chancellor, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Oscar Salvador, Pali Rohár, Paul Mackerras, Peng Wu, Qing Wang, Randy Dunlap, Reza Arbab, Russell Currey, Sohaib Mohamed, Vaibhav Jain, Vasant Hegde, Wang Qing, Wang Wensheng, Xiang wangx, Xiaomeng Tong, Xu Wang, Yang Guang, Yang Li, Ye Bin, YueHaibing, Yu Kuai, Zheng Bin, Zou Wei, and Zucheng Zheng. * tag 'powerpc-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (200 commits) powerpc/64: Include cache.h directly in paca.h powerpc/64s: Only set HAVE_ARCH_UNMAPPED_AREA when CONFIG_PPC_64S_HASH_MMU is set powerpc/xics: Include missing header powerpc/powernv/pci: Drop VF MPS fixup powerpc/fsl_book3e: Don't set rodata RO too early powerpc/microwatt: Add mmu bits to device tree powerpc/powernv/flash: Check OPAL flash calls exist before using powerpc/powermac: constify device_node in of_irq_parse_oldworld() powerpc/powermac: add missing g5_phy_disable_cpu1() declaration selftests/powerpc/pmu: fix spelling mistake "mis-match" -> "mismatch" powerpc: Enable the DAWR on POWER9 DD2.3 and above powerpc/64s: Add CPU_FTRS_POWER10 to ALWAYS mask powerpc/64s: Add CPU_FTRS_POWER9_DD2_2 to CPU_FTRS_ALWAYS mask powerpc: Fix all occurences of "the the" selftests/powerpc/pmu/ebb: remove fixed_instruction.S powerpc/platforms/83xx: Use of_device_get_match_data() powerpc/eeh: Drop redundant spinlock initialization powerpc/iommu: Add missing of_node_put in iommu_init_early_dart powerpc/pseries/vas: Call misc_deregister if sysfs init fails powerpc/papr_scm: Fix leaking nvdimm_events_map elements ...

powerpc: Book3S 64-bit outline-only KASAN support

2022-05-22T05:58:29Z

Implement a limited form of KASAN for Book3S 64-bit machines running under the Radix MMU, supporting only outline mode. - Enable the compiler instrumentation to check addresses and maintain the shadow region. (This is the guts of KASAN which we can easily reuse.) - Require kasan-vmalloc support to handle modules and anything else in vmalloc space. - KASAN needs to be able to validate all pointer accesses, but we can't instrument all kernel addresses - only linear map and vmalloc. On boot, set up a single page of read-only shadow that marks all iomap and vmemmap accesses as valid. - Document KASAN in powerpc docs. Background ---------- KASAN support on Book3S is a bit tricky to get right: - It would be good to support inline instrumentation so as to be able to catch stack issues that cannot be caught with outline mode. - Inline instrumentation requires a fixed offset. - Book3S runs code with translations off ("real mode") during boot, including a lot of generic device-tree parsing code which is used to determine MMU features. [ppc64 mm note: The kernel installs a linear mapping at effective address c000...-c008.... This is a one-to-one mapping with physical memory from 0000... onward. Because of how memory accesses work on powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the same memory both with translations on (accessing as an 'effective address'), and with translations off (accessing as a 'real address'). This works in both guests and the hypervisor. For more details, see s5.7 of Book III of version 3 of the ISA, in particular the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this KASAN implementation currently only supports Radix.] - Some code - most notably a lot of KVM code - also runs with translations off after boot. - Therefore any offset has to point to memory that is valid with translations on or off. One approach is just to give up on inline instrumentation. This way boot-time checks can be delayed until after the MMU is set is up, and we can just not instrument any code that runs with translations off after booting. Take this approach for now and require outline instrumentation. Previous attempts allowed inline instrumentation. However, they came with some unfortunate restrictions: only physically contiguous memory could be used and it had to be specified at compile time. Maybe we can do better in the future. [paulus@ozlabs.org - Rebased onto 5.17. Note that a kernel with CONFIG_KASAN=y will crash during boot on a machine using HPT translation because not all the entry points to the generic KASAN code are protected with a call to kasan_arch_is_ready().] Originally-by: Balbir Singh # ppc64 out-of-line radix version Signed-off-by: Daniel Axtens Signed-off-by: Paul Mackerras [mpe: Update copyright year and comment formatting] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo