mips: use STACK_TOP when computing mmap base address

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

Link: http://lkml.kernel.org/r/[e-mail]
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]>
Cc: Albert Ou <[e-mail]>
Cc: Alexander Viro <[e-mail]>
Cc: Catalin Marinas <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: James Hogan <[e-mail]>
Cc: Palmer Dabbelt <[e-mail]>
Cc: Ralf Baechle <[e-mail]>
Cc: Russell King <[e-mail]>
Cc: Will Deacon <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/mips/mm/mmap.c

···
 
 /* 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)
···
 	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)				\