[PATCH v3 04/10] riscv: Constify sys_call_table

From: Jisheng Zhang
Date: Mon Apr 12 2021 - 12:19:21 EST


From: Jisheng Zhang <jszhang@xxxxxxxxxx>

Constify the sys_call_table so that it will be placed in the .rodata
section. This will cause attempts to modify the table to fail when
strict page permissions are in place.

Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
---
arch/riscv/include/asm/syscall.h | 2 +-
arch/riscv/kernel/syscall_table.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
index 49350c8bd7b0..b933b1583c9f 100644
--- a/arch/riscv/include/asm/syscall.h
+++ b/arch/riscv/include/asm/syscall.h
@@ -15,7 +15,7 @@
#include <linux/err.h>

/* The array of function pointers for syscalls. */
-extern void *sys_call_table[];
+extern void * const sys_call_table[];

/*
* Only the low 32 bits of orig_r0 are meaningful, so we return int.
diff --git a/arch/riscv/kernel/syscall_table.c b/arch/riscv/kernel/syscall_table.c
index f1ead9df96ca..a63c667c27b3 100644
--- a/arch/riscv/kernel/syscall_table.c
+++ b/arch/riscv/kernel/syscall_table.c
@@ -13,7 +13,7 @@
#undef __SYSCALL
#define __SYSCALL(nr, call) [nr] = (call),

-void *sys_call_table[__NR_syscalls] = {
+void * const sys_call_table[__NR_syscalls] = {
[0 ... __NR_syscalls - 1] = sys_ni_syscall,
#include <asm/unistd.h>
};
--
2.31.0