[PATCH 3.18 30/49] arm64: make sys_call_table const

From: Greg Kroah-Hartman
Date: Thu May 18 2017 - 09:25:51 EST


3.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mark Rutland <mark.rutland@xxxxxxx>

commit c623b33b4e9599c6ac5076f7db7369eb9869aa04 upstream.

As with x86, mark the sys_call_table const such that it will be placed
in the .rodata section. This will cause attempts to modify the table
(accidental or deliberate) to fail when strict page permissions are in
place. In the absence of strict page permissions, there should be no
functional change.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm64/kernel/sys.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm64/kernel/sys.c
+++ b/arch/arm64/kernel/sys.c
@@ -50,7 +50,7 @@ asmlinkage long sys_mmap(unsigned long a
* The sys_call_table array must be 4K aligned to be accessible from
* kernel/entry.S.
*/
-void *sys_call_table[__NR_syscalls] __aligned(4096) = {
+void * const sys_call_table[__NR_syscalls] __aligned(4096) = {
[0 ... __NR_syscalls - 1] = sys_ni_syscall,
#include <asm/unistd.h>
};