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| author | Palmer Dabbelt <palmer@rivosinc.com> | 2023-11-08 07:08:35 -0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-11-08 07:08:35 -0800 |
| commit | 05942f780ac6a70e5859fc41d5700e2ca43c4867 (patch) | |
| tree | fb65a54091250323e07984a30ecde53bf9af2642 /arch/riscv/mm/init.c | |
| parent | 55e0bf49a0d0387d682d696e41cada071f516075 (diff) | |
| parent | 311cd2f6e25380cff0abc2884dc6a3d33bc9b5c3 (diff) | |
Merge patch series "riscv: Fix set_memory_XX() and set_direct_map_XX()"
Alexandre Ghiti <alexghiti@rivosinc.com> says:
Those 2 patches fix the set_memory_XX() and set_direct_map_XX() APIs, which
in turn fix STRICT_KERNEL_RWX and memfd_secret(). Those were broken since the
permission changes were not applied to the linear mapping because the linear
mapping is mapped using hugepages and walk_page_range_novma() does not split
such mappings.
To fix that, patch 1 disables PGD mappings in the linear mapping as it is
hard to propagate changes at this level in *all* the page tables, this has the
downside of disabling PMD mapping for sv32 and PUD (1GB) mapping for sv39 in
the linear mapping (for specific kernels, we could add a Kconfig to enable
ARCH_HAS_SET_DIRECT_MAP and STRICT_KERNEL_RWX if needed, I'm pretty sure we'll
discuss that).
patch 2 implements the split of the huge linear mappings so that
walk_page_range_novma() can properly apply the permissions. The whole split is
protected with mmap_sem in write mode, but I'm wondering if that's enough,
any opinion on that is appreciated.
* b4-shazam-merge:
riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings
riscv: Don't use PGD entries for the linear mapping
Link: https://lore.kernel.org/r/20231108075930.7157-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/mm/init.c')
| -rw-r--r-- | arch/riscv/mm/init.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index eed1758720c9..b0cc28f7595f 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -666,16 +666,16 @@ void __init create_pgd_mapping(pgd_t *pgdp, static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size) { - if (!(pa & (PGDIR_SIZE - 1)) && !(va & (PGDIR_SIZE - 1)) && size >= PGDIR_SIZE) - return PGDIR_SIZE; - - if (!(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE) + if (pgtable_l5_enabled && + !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE) return P4D_SIZE; - if (!(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE) + if (pgtable_l4_enabled && + !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE) return PUD_SIZE; - if (!(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE) + if (IS_ENABLED(CONFIG_64BIT) && + !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE) return PMD_SIZE; return PAGE_SIZE; |