Linus Torvalds writes: (Summary)
I actually think there may be two issues here:
I actually think there may be two issues here:
- vsyscall isn't even used much - if any - any more - vsyscall isn't even used much - if any - any more - the vsyscall emulation works fine without _PAGE_USER, since the whole point is that we take a fault on it and then emulate. That would be an insane combination.
combination.
So the only possibly difference would be a user mode program that actually looks at the vsyscall page, which sounds unlikely to be an issue.
I actually think there may be two issues here:
- vsyscall isn't even used much - if any - any more - vsyscall isn't even used much - if any - any more - the vsyscall emulation works fine without _PAGE_USER, since the whole point is that we take a fault on it and then emulate. That would be an insane combination.
combination.
So the only possibly difference would be a user mode program that actually looks at the vsyscall page, which sounds unlikely to be an issue.