diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/Kconfig | 29 | ||||
| -rw-r--r-- | arch/arm64/mm/mmap.c | 8 |
2 files changed, 35 insertions, 2 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 4d5b416e2e4b..6be3fa2310ee 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -52,6 +52,8 @@ config ARM64 select HAVE_ARCH_JUMP_LABEL select HAVE_ARCH_KASAN if SPARSEMEM_VMEMMAP && !(ARM64_16K_PAGES && ARM64_VA_BITS_48) select HAVE_ARCH_KGDB + select HAVE_ARCH_MMAP_RND_BITS + select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_BPF_JIT @@ -107,6 +109,33 @@ config ARCH_PHYS_ADDR_T_64BIT config MMU def_bool y +config ARCH_MMAP_RND_BITS_MIN + default 14 if ARM64_64K_PAGES + default 16 if ARM64_16K_PAGES + default 18 + +# max bits determined by the following formula: +# VA_BITS - PAGE_SHIFT - 3 +config ARCH_MMAP_RND_BITS_MAX + default 19 if ARM64_VA_BITS=36 + default 24 if ARM64_VA_BITS=39 + default 27 if ARM64_VA_BITS=42 + default 30 if ARM64_VA_BITS=47 + default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES + default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES + default 33 if ARM64_VA_BITS=48 + default 14 if ARM64_64K_PAGES + default 16 if ARM64_16K_PAGES + default 18 + +config ARCH_MMAP_RND_COMPAT_BITS_MIN + default 7 if ARM64_64K_PAGES + default 9 if ARM64_16K_PAGES + default 11 + +config ARCH_MMAP_RND_COMPAT_BITS_MAX + default 16 + config NO_IOPORT_MAP def_bool y if !PCI diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index ed177475dd8c..4c893b5189dd 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -51,8 +51,12 @@ unsigned long arch_mmap_rnd(void) { unsigned long rnd; - rnd = (unsigned long)get_random_int() & STACK_RND_MASK; - +#ifdef CONFIG_COMPAT + if (test_thread_flag(TIF_32BIT)) + rnd = (unsigned long)get_random_int() & ((1 << mmap_rnd_compat_bits) - 1); + else +#endif + rnd = (unsigned long)get_random_int() & ((1 << mmap_rnd_bits) - 1); return rnd << PAGE_SHIFT; } |