Re: [PATCH v5 2/2] Add user-mode only option to unprivileged_userfaultfd sysctl knob

2020-10-23 Thread Lokesh Gidra
On Fri, Oct 23, 2020 at 7:48 PM Andrea Arcangeli wrote: > > Hello everyone, > > On Sat, Oct 10, 2020 at 11:24:56PM -0700, Lokesh Gidra wrote: > > With this change, when the knob is set to 0, it allows unprivileged > > users to call userfaultfd, like when it is set to 1, but with the > > restrictio

Re: [PATCH v5 2/2] Add user-mode only option to unprivileged_userfaultfd sysctl knob

2020-10-23 Thread Andrea Arcangeli
Hello everyone, On Sat, Oct 10, 2020 at 11:24:56PM -0700, Lokesh Gidra wrote: > With this change, when the knob is set to 0, it allows unprivileged > users to call userfaultfd, like when it is set to 1, but with the > restriction that page faults from only user-mode can be handled. > In this mode,

[PATCH v5 2/2] Add user-mode only option to unprivileged_userfaultfd sysctl knob

2020-10-10 Thread Lokesh Gidra
With this change, when the knob is set to 0, it allows unprivileged users to call userfaultfd, like when it is set to 1, but with the restriction that page faults from only user-mode can be handled. In this mode, an unprivileged user (without SYS_CAP_PTRACE capability) must pass UFFD_USER_MODE_ONLY