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Date:   Tue, 13 Apr 2021 00:13:28 +0800
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>,
        " =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?=" <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>, Anup Patel <anup@brainfault.org>
Cc:     linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 04/10] riscv: Constify sys_call_table
Message-ID: <20210413001328.288b2e87@xhacker>
In-Reply-To: <20210413001110.7209bae6@xhacker>
References: <20210413001110.7209bae6@xhacker>
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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>
Reviewed-by: Anup Patel <anup@brainfault.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