[PATCH v2 0/4] Fix up bpf_jit_limit some more

[Lorenz Bauer <lmb@cloudflare.com>]

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

Jakub raised the point that a sysctl toggle is UAPI and therefore
can't be easily changed later on. I tried to find another place to stick
the info, but couldn't find a good one. All the current BPF knobs are in
sysctl.

There are examples of read only sysctls:
$ sudo find /proc/sys -perm 0444 | wc -l
90

There are no examples of sysctls with mode 0400 however:
$ sudo find /proc/sys -perm 0400 | wc -l
0

Thoughts?

Changes in v2:
* riscv not sparcv (Luke)
* Expose bpf_jit_current in bytes, not pages (Nicholas)

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

 Documentation/admin-guide/sysctl/net.rst |  6 ++++++
 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               | 26 +++++++++++++++++++++++-
 6 files changed, 47 insertions(+), 4 deletions(-)

-- 
2.30.2