Messages in this thread | | | Date | Thu, 5 Nov 2020 12:39:55 -0800 | From | Martin KaFai Lau <> | Subject | Re: [PATCH bpf-next v4 1/9] bpf: Allow LSM programs to use bpf spin locks |
| |
On Thu, Nov 05, 2020 at 03:47:47PM +0100, KP Singh wrote: > From: KP Singh <kpsingh@google.com> > > Usage of spin locks was not allowed for tracing programs due to > insufficient preemption checks. The verifier does not currently prevent > LSM programs from using spin locks, but the helpers are not exposed > via bpf_lsm_func_proto. > > Based on the discussion in [1], non-sleepable LSM programs should be > able to use bpf_spin_{lock, unlock}. > > Sleepable LSM programs can be preempted which means that allowng spin > locks will need more work (disabling preemption and the verifier > ensuring that no sleepable helpers are called when a spin lock is held). > > [1]: https://lore.kernel.org/bpf/20201103153132.2717326-1-kpsingh@chromium.org/T/#md601a053229287659071600d3483523f752cd2fb > > Signed-off-by: KP Singh <kpsingh@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com>
| |