mips uses a top-down layout by default that fits the generic functions. At the same time, this commit allows to fix problem uncovered and not fixed for mips here: https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1429066.html Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx> --- arch/mips/include/asm/processor.h | 4 +-- arch/mips/mm/mmap.c | 57 ------------------------------- 2 files changed, 2 insertions(+), 59 deletions(-) diff --git a/arch/mips/include/asm/processor.h b/arch/mips/include/asm/processor.h index aca909bd7841..f8e04962b52d 100644 --- a/arch/mips/include/asm/processor.h +++ b/arch/mips/include/asm/processor.h @@ -30,9 +30,9 @@ extern unsigned int vced_count, vcei_count; /* - * MIPS does have an arch_pick_mmap_layout() + * MIPS uses the default implementation of topdown mmap layout. */ -#define HAVE_ARCH_PICK_MMAP_LAYOUT 1 +#define ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT #ifdef CONFIG_32BIT #ifdef CONFIG_KVM_GUEST diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index 2f616ebeb7e0..61e65a69bb09 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -20,33 +20,6 @@ unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); -/* gap between mmap and stack */ -#define MIN_GAP (128*1024*1024UL) -#define MAX_GAP ((TASK_SIZE)/6*5) - -static int mmap_is_legacy(struct rlimit *rlim_stack) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlim_stack->rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack) -{ - unsigned long gap = rlim_stack->rlim_cur; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(TASK_SIZE - gap - rnd); -} - #define COLOUR_ALIGN(addr, pgoff) \ ((((addr) + shm_align_mask) & ~shm_align_mask) + \ (((pgoff) << PAGE_SHIFT) & shm_align_mask)) @@ -144,36 +117,6 @@ unsigned long arch_get_unmapped_area_topdown(struct file *filp, addr0, len, pgoff, flags, DOWN); } -unsigned long arch_mmap_rnd(void) -{ - unsigned long rnd; - -#ifdef CONFIG_COMPAT - if (TASK_IS_32BIT_ADDR) - rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); - else -#endif /* CONFIG_COMPAT */ - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - - return rnd << PAGE_SHIFT; -} - -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) -{ - unsigned long random_factor = 0UL; - - if (current->flags & PF_RANDOMIZE) - random_factor = arch_mmap_rnd(); - - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - } -} - static inline unsigned long brk_rnd(void) { unsigned long rnd = get_random_long(); -- 2.20.1
