diff mbox series

[3/4] mips: Use generic mmap top-down layout

Message ID 20190322074225.22282-4-alex@ghiti.fr (mailing list archive)
State Superseded
Headers show
Series Provide generic top-down mmap layout functions | expand

Commit Message

Alexandre Ghiti March 22, 2019, 7:42 a.m. UTC 
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@vger.kernel.org/msg1429066.html

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
---
 arch/mips/include/asm/processor.h |  4 +--
 arch/mips/mm/mmap.c               | 57 -------------------------------
 2 files changed, 2 insertions(+), 59 deletions(-)
diff mbox series

Patch

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();