diff options
| author | Sami Tolvanen <samitolvanen@google.com> | 2023-09-30 00:11:58 +0300 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-01-24 18:07:43 +0300 |
| commit | 7df1ff5a5cd615815bc6fb4a3a981e9746935e59 (patch) | |
| tree | 3c3fa9c7d7bb51a8eeef4de5eeb1de471fed4802 /arch/riscv/mm | |
| parent | 71a5849aedaa9ea028fc51ee74576cad61954743 (diff) | |
| download | linux-7df1ff5a5cd615815bc6fb4a3a981e9746935e59.tar.xz | |
riscv: mm: Update mmap_rnd_bits_max
ARCH_MMAP_RND_BITS_MAX is based on Sv39, which leaves a few
potential bits of mmap randomness on the table if we end up enabling
4/5-level paging. Update mmap_rnd_bits_max to take the final address
space size into account. This increases mmap_rnd_bits_max from 24 to
33 with Sv48/57.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230929211155.3910949-6-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/mm')
| -rw-r--r-- | arch/riscv/mm/init.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 32cad6a65ccd..c55915554836 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -767,6 +767,11 @@ static int __init print_no5lvl(char *p) } early_param("no5lvl", print_no5lvl); +static void __init set_mmap_rnd_bits_max(void) +{ + mmap_rnd_bits_max = MMAP_VA_BITS - PAGE_SHIFT - 3; +} + /* * There is a simple way to determine if 4-level is supported by the * underlying hardware: establish 1:1 mapping in 4-level page table mode @@ -1081,6 +1086,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) set_satp_mode(dtb_pa); + set_mmap_rnd_bits_max(); #endif /* |