diff options
-rw-r--r-- | arch/arm/Kconfig | 9 | ||||
-rw-r--r-- | arch/arm/mm/mmap.c | 3 |
2 files changed, 10 insertions, 2 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 6d3dff00c3b..fd46f716a9b 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -22,6 +22,7 @@ config ARM select HARDIRQS_SW_RESEND select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL select HAVE_ARCH_KGDB + select HAVE_ARCH_MMAP_RND_BITS if MMU select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_BPF_JIT @@ -279,6 +280,14 @@ config MMU Select if you want MMU-based virtualised addressing space support by paged memory management. If unsure, say 'Y'. +config ARCH_MMAP_RND_BITS_MIN + default 8 + +config ARCH_MMAP_RND_BITS_MAX + default 14 if PAGE_OFFSET=0x40000000 + default 15 if PAGE_OFFSET=0x80000000 + default 16 + # # The "ARM system type" choice list is ordered alphabetically by option # text. Please add new entries in the option alphabetic order. diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 5ef506c6f49..2761c861300 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -173,10 +173,9 @@ void arch_pick_mmap_layout(struct mm_struct *mm) { unsigned long random_factor = 0UL; - /* 8 bits of randomness in 20 address space bits */ if ((current->flags & PF_RANDOMIZE) && !(current->personality & ADDR_NO_RANDOMIZE)) - random_factor = (get_random_int() % (1 << 8)) << PAGE_SHIFT; + random_factor = (get_random_int() & ((1 << mmap_rnd_bits) - 1)) << PAGE_SHIFT; if (mmap_is_legacy()) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; |