Unverified Commit 71a5849a authored Sep 29, 2023 by Sami Tolvanen Committed by Palmer Dabbelt Jan 24, 2024

mm: Change mmap_rnd_bits_max to __ro_after_init



Allow mmap_rnd_bits_max to be updated on architectures that
determine virtual address space size at runtime instead of relying
on Kconfig options by changing it from const to __ro_after_init.

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/20230929211155.3910949-5-samitolvanen@google.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

parent 6613476e

include/linux/mm.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -86,7 +86,7 @@ extern int sysctl_legacy_va_layout;

		#ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
		extern const int mmap_rnd_bits_min;
		extern const int mmap_rnd_bits_max;
		extern int mmap_rnd_bits_max __ro_after_init;
		extern int mmap_rnd_bits __read_mostly;
		#endif
		#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS

mm/mmap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -64,7 +64,7 @@

		#ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
		const int mmap_rnd_bits_min = CONFIG_ARCH_MMAP_RND_BITS_MIN;
		const int mmap_rnd_bits_max = CONFIG_ARCH_MMAP_RND_BITS_MAX;
		int mmap_rnd_bits_max __ro_after_init = CONFIG_ARCH_MMAP_RND_BITS_MAX;
		int mmap_rnd_bits __read_mostly = CONFIG_ARCH_MMAP_RND_BITS;
		#endif
		#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS