Messages in this thread Patch in this message | | | From | Andy Lutomirski <> | Subject | [PATCH PTI v3 06/10] x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode | Date | Tue, 12 Dec 2017 07:56:41 -0800 |
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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> --- arch/x86/entry/vsyscall/vsyscall_64.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c index bc88a0540347..a06f2ae09ad6 100644 --- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -138,6 +138,10 @@ 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"); -- 2.13.6
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