Commit-ID: 441cedab2dfca18fe4983cbc795de04536ed421e
Gitweb: https://git.kernel.org/tip/441cedab2dfca18fe4983cbc795de04536ed421e
Author: Andy Lutomirski <luto@xxxxxxxxxx>
AuthorDate: Wed, 26 Jun 2019 21:45:08 -0700
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 28 Jun 2019 00:04:40 +0200
x86/vsyscall: Add __ro_after_init to global variables
The vDSO is only configurable by command-line options, so make its
global variables __ro_after_init. This seems highly unlikely to
ever stop an exploit, but it's nicer anyway.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Florian Weimer <fweimer@xxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Kernel Hardening <kernel-hardening@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/a386925835e49d319e70c4d7404b1f6c3c2e3702.1561610354.git.luto@xxxxxxxxxx
---
arch/x86/entry/vsyscall/vsyscall_64.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 9c58ab807aeb..07003f3f1bfc 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -42,7 +42,7 @@
#define CREATE_TRACE_POINTS
#include "vsyscall_trace.h"
-static enum { EMULATE, XONLY, NONE } vsyscall_mode =
+static enum { EMULATE, XONLY, NONE } vsyscall_mode __ro_after_init =
#ifdef CONFIG_LEGACY_VSYSCALL_NONE
NONE;
#elif defined(CONFIG_LEGACY_VSYSCALL_XONLY)
@@ -305,7 +305,7 @@ static const char *gate_vma_name(struct vm_area_struct *vma)
static const struct vm_operations_struct gate_vma_ops = {
.name = gate_vma_name,
};
-static struct vm_area_struct gate_vma = {
+static struct vm_area_struct gate_vma __ro_after_init = {
.vm_start = VSYSCALL_ADDR,
.vm_end = VSYSCALL_ADDR + PAGE_SIZE,
.vm_page_prot = PAGE_READONLY_EXEC,
|