[PATCH 0/5] riscv: Use READ_ONCE()/WRITE_ONCE() for pte accesses

* [PATCH 0/5] riscv: Use READ_ONCE()/WRITE_ONCE() for pte accesses
@ 2023-10-02 15:10 Alexandre Ghiti
  2023-10-02 15:10 ` [PATCH 1/5] riscv: Use WRITE_ONCE() when setting page table entries Alexandre Ghiti
                   ` (5 more replies)
  0 siblings, 6 replies; 14+ messages in thread
From: Alexandre Ghiti @ 2023-10-02 15:10 UTC (permalink / raw)
  To: Ryan Roberts, Alexander Potapenko, Marco Elver, Dmitry Vyukov,
	Paul Walmsley, Palmer Dabbelt, Albert Ou, Anup Patel,
	Atish Patra, Ard Biesheuvel, Andrey Ryabinin, Andrey Konovalov,
	Vincenzo Frascino, kasan-dev, linux-riscv, linux-kernel, kvm,
	kvm-riscv, linux-efi, linux-mm
  Cc: Alexandre Ghiti

This series is a follow-up for riscv of a recent series from Ryan [1] which
converts all direct dereferences of pte_t into a ptet_get() access.

The goal here for riscv is to use READ_ONCE()/WRITE_ONCE() for all page
table entries accesses to avoid any compiler transformation when the
hardware can concurrently modify the page tables entries (A/D bits for
example).

I went a bit further and added pud/p4d/pgd_get() helpers as such concurrent
modifications can happen too at those levels.

[1] https://lore.kernel.org/all/20230612151545.3317766-1-ryan.roberts@arm.com/

Alexandre Ghiti (5):
  riscv: Use WRITE_ONCE() when setting page table entries
  mm: Introduce pudp/p4dp/pgdp_get() functions
  riscv: mm: Only compile pgtable.c if MMU
  riscv: Suffix all page table entry pointers with 'p'
  riscv: Use accessors to page table entries instead of direct
    dereference

 arch/riscv/include/asm/kfence.h     |   6 +-
 arch/riscv/include/asm/kvm_host.h   |   2 +-
 arch/riscv/include/asm/pgalloc.h    |  86 ++++++++++----------
 arch/riscv/include/asm/pgtable-64.h |  26 +++---
 arch/riscv/include/asm/pgtable.h    |  33 ++------
 arch/riscv/kernel/efi.c             |   2 +-
 arch/riscv/kvm/mmu.c                |  44 +++++-----
 arch/riscv/mm/Makefile              |   3 +-
 arch/riscv/mm/fault.c               |  38 ++++-----
 arch/riscv/mm/hugetlbpage.c         |  80 +++++++++----------
 arch/riscv/mm/init.c                |  30 +++----
 arch/riscv/mm/kasan_init.c          | 119 ++++++++++++++--------------
 arch/riscv/mm/pageattr.c            |  74 +++++++++--------
 arch/riscv/mm/pgtable.c             |  71 +++++++++++------
 include/linux/pgtable.h             |  21 +++++
 15 files changed, 334 insertions(+), 301 deletions(-)

-- 
2.39.2

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