Commit 4831b779 authored Dec 10, 2017 by Andy Lutomirski Committed by Ingo Molnar Dec 22, 2017

x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode

If something goes wrong with pagetable setup, vsyscall=native will
accidentally fall back to emulation.  Make it warn and fail so that we
notice.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 49275fef

arch/x86/entry/vsyscall/vsyscall_64.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -139,6 +139,10 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)

		WARN_ON_ONCE(address != regs->ip);

		/* This should be unreachable in NATIVE mode. */
		if (WARN_ON(vsyscall_mode == NATIVE))
		return false;

		if (vsyscall_mode == NONE) {
		warn_bad_vsyscall(KERN_INFO, regs,
		"vsyscall attempted with vsyscall=none");