Re: [PATCH v10 08/15] x86/vsyscall: Reorganize the page fault emulation code

Sohil Mehta
2025-10-30T19:28:59Z

Thank you for taking a look at these patches.

On 10/30/2025 9:58 AM, Andy Lutomirski wrote:

> So I think all that's needed is to update "[PATCH v10 10/15] x86/vsyscall: Add vsyscall emulation for #GP" to check user_64bit_mode(regs) for the vsyscall case. (As submitted, unless I missed something while composing the patches in my head, it's only checking user_mode(regs), and I think it's worth the single extra line of code to make the result a tiny bit more robust.)

I probably don't understand all the nuances here. But, the goal of the
check seems to ensure a 32-bit process running on a 64-bit kernel
doesn't ever go through this vsyscall emulation code, right?

I guess a user_64bit_mode(regs) check wouldn't harm. I'll add it when
the vsyscall series is posted.