[v6,07/14] arm: Use STACK_TOP when computing mmap base address
diff mbox series

Message ID 20190808061756.19712-8-alex@ghiti.fr
State New
Headers show
Series
  • Provide generic top-down mmap layout functions
Related show

Commit Message

Alex 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 <alex@ghiti.fr>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
---
 arch/arm/mm/mmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch
diff mbox series

diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index bff3d00bda5b..0b94b674aa91 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -19,7 +19,7 @@ 
 
 /* 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)
@@ -51,7 +51,7 @@  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);
 }
 
 /*