On Wed, Oct 14, 2026 at 10:23:35PM -0700, Iurii Trukhin wrote: > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index cab741a695f5..7bca47269dd5 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -313,6 +313,14 @@ config ARCH_MMAP_RND_BITS_MAX > default 16 if ARM64_16K_PAGES > default 18 > > +# default to 1 TiB (5 bits below ARCH_MMAP_RND_BITS_MAX) on 48-bit and > +# 52-bit VA; smaller VA sizes fall back to ARCH_MMAP_RND_BITS_MIN in > +# arch/Kconfig > +config ARCH_MMAP_RND_BITS > + default 24 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_64K_PAGES > + default 26 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52) && ARM64_16K_PAGES > + default 28 if (ARM64_VA_BITS=48 || ARM64_VA_BITS=52)
This looks fine but I was wondering what ARCH_MMAP_RND_BITS_DEFAULT (and the compat equivalent) is for. It turns out that an int always evaluates to 'n', so not taken into account. It might be worth removing them altogether as a separate patch. No-one seems to be using them. -- Catalin
