[PATCH 3/9] riscv: Constify sys_call_table

From: Jisheng Zhang <jszhang3@mail.ustc.edu.cn>
To: "Paul Walmsley" <paul.walmsley@sifive.com>,
	"Palmer Dabbelt" <palmer@dabbelt.com>,
	"Albert Ou" <aou@eecs.berkeley.edu>,
	"Andrey Ryabinin" <ryabinin.a.a@gmail.com>,
	"Alexander Potapenko" <glider@google.com>,
	"Andrey Konovalov" <andreyknvl@gmail.com>,
	"Dmitry Vyukov" <dvyukov@google.com>,
	" Björn Töpel" <bjorn@kernel.org>,
	"Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"KP Singh" <kpsingh@kernel.org>,
	"Luke Nelson" <luke.r.nels@gmail.com>,
	"Xi Wang" <xi.wang@gmail.com>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	kasan-dev@googlegroups.com, netdev@vger.kernel.org,
	bpf@vger.kernel.org
Subject: [PATCH 3/9] riscv: Constify sys_call_table
Date: Tue, 30 Mar 2021 02:23:24 +0800	[thread overview]
Message-ID: <20210330022324.6737116c@xhacker> (raw)
In-Reply-To: <20210330022144.150edc6e@xhacker>

From: Jisheng Zhang <jszhang@kernel.org>

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@kernel.org>
---
 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


