[v6,10/14] mips: Use STACK_TOP when computing mmap base address

Commit Message

Alexandre Ghiti Aug. 8, 2019, 6:17 a.m. UTC

mmap base address must be computed wrt stack top address, using TASK_SIZE
is wrong since STACK_TOP and TASK_SIZE are not equivalent.

Signed-off-by: Alexandre Ghiti <[e-mail]>
Acked-by: Kees Cook <[e-mail]>
Acked-by: Paul Burton <[e-mail]>
Reviewed-by: Luis Chamberlain <[e-mail]>
---
 arch/mips/mm/mmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c
index f5c778113384..a7e84b2e71d7 100644
--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
@@ -22,7 +22,7 @@  EXPORT_SYMBOL(shm_align_mask);
 
 /* gap between mmap and stack */
 #define MIN_GAP		(128*1024*1024UL)
-#define MAX_GAP		((TASK_SIZE)/6*5)
+#define MAX_GAP		((STACK_TOP)/6*5)
 #define STACK_RND_MASK	(0x7ff >> (PAGE_SHIFT - 12))
 
 static int mmap_is_legacy(struct rlimit *rlim_stack)
@@ -54,7 +54,7 @@  static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack)
 	else if (gap > MAX_GAP)
 		gap = MAX_GAP;
 
-	return PAGE_ALIGN(TASK_SIZE - gap - rnd);
+	return PAGE_ALIGN(STACK_TOP - gap - rnd);
 }
 
 #define COLOUR_ALIGN(addr, pgoff)				\