Commit 441cedab authored Jun 26, 2019 by Andy Lutomirski Committed by Thomas Gleixner Jun 28, 2019

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@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/a386925835e49d319e70c4d7404b1f6c3c2e3702.1561610354.git.luto@kernel.org

parent 625b7b7f

arch/x86/entry/vsyscall/vsyscall_64.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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,

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