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[ Upstream commitf101c56447] When the 52-bit virtual addressing was introduced the select like ARCH_MMAP_RND_BITS_MAX logic was never updated to account for it. Because of that the rnd max bits knob is set to the default value of 18 when ARM64_VA_BITS=52. Fix this by setting ARCH_MMAP_RND_BITS_MAX to the same value that would be used if 48-bit addressing was used. Higher values can't used here because 52-bit addressing is used only if the caller provides a hint to mmap, with a fallback to 48-bit. The knob in question is an upper bound for what the user can set in /proc/sys/vm/mmap_rnd_bits, which in turn is used to determine how many random bits can be inserted into the base address used for mmap allocations. Since 48-bit allocations are legal with ARM64_VA_BITS=52, we need to make sure that the base address is small enough to facilitate this. Fixes:b6d00d47e8("arm64: mm: Introduce 52-bit Kernel VAs") Signed-off-by: Kornel Dulęba <korneld@google.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Link: https://lore.kernel.org/r/20250417114754.3238273-1-korneld@google.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2458 lines
84 KiB
2458 lines
84 KiB