[bpf-next,0/4] Fix up bpf_jit_limit some more

Message

Lorenz Bauer Sept. 24, 2021, 9:55 a.m. UTC

Some more cleanups around bpf_jit_limit to make it readable via sysctl.

Things I'm not sure about:
* Is it OK to expose atomic_long_t bpf_jit_limit like this? The sysctl code
  isn't atomic, but maybe it's fine because it's read only.
* All of the JIT related sysctls are quite restrictive, you have to have
  CAP_SYS_ADMIN / CAP_BPF _and_ be root as well. This makes it problematic
  to scrape these to expose them as metrics. Can we relax this somewhat?

Lorenz

Lorenz Bauer (4):
  bpf: define bpf_jit_alloc_exec_limit for riscv JIT
  bpf: define bpf_jit_alloc_exec_limit for arm64 JIT
  bpf: prevent increasing bpf_jit_limit above max
  bpf: export bpf_jit_current

 arch/arm64/net/bpf_jit_comp.c | 5 +++++
 arch/riscv/net/bpf_jit_core.c | 5 +++++
 include/linux/filter.h        | 2 ++
 kernel/bpf/core.c             | 7 ++++---
 net/core/sysctl_net_core.c    | 9 ++++++++-
 5 files changed, 24 insertions(+), 4 deletions(-)