[bpf-next,v2,0/2] bpf,riscv: Add support for BPF Arena

Message

Puranjay Mohan March 25, 2024, 3:54 p.m. UTC

Changes in V2
V1: https://lore.kernel.org/bpf/[e-mail]/
- Used S7 in place of S11 for storing the kernel_vm_start
- Used 17 in place of 16 for DONT_CLEAR marker
- Remove an unused variable
- Removed some misleading information from the commit message.

This series adds the support for PROBE_MEM32 and bpf_addr_space_cast
instructions to the RISCV BPF JIT. These two instructions allow the
enablement of BPF Arena.

All arena related selftests are passing:

  root@rv-tester:~/bpf# uname -p
  riscv64
  root@rv-tester:~/bpf# ./test_progs -a "*arena*"
  #3/1     arena_htab/arena_htab_llvm:OK
  #3/2     arena_htab/arena_htab_asm:OK
  #3       arena_htab:OK
  #4/1     arena_list/arena_list_1:OK
  #4/2     arena_list/arena_list_1000:OK
  #4       arena_list:OK
  #434/1   verifier_arena/basic_alloc1:OK
  #434/2   verifier_arena/basic_alloc2:OK
  #434/3   verifier_arena/basic_alloc3:OK
  #434/4   verifier_arena/iter_maps1:OK
  #434/5   verifier_arena/iter_maps2:OK
  #434/6   verifier_arena/iter_maps3:OK
  #434     verifier_arena:OK
  Summary: 3/10 PASSED, 0 SKIPPED, 0 FAILED

This needs the patch[1] that adds the insn_is_cast_user() helper to build.
It also  needs the following patches/commits [2][3] to work correctly.

[1] https://lore.kernel.org/bpf/[e-mail]/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=f7f5d1808b1b66935a24dd796dd1a0612ca9c147
[3] https://lore.kernel.org/bpf/[e-mail]/

Puranjay Mohan (2):
  bpf,riscv: Implement PROBE_MEM32 pseudo instructions
  bpf,riscv: Implement bpf_addr_space_cast instruction

 arch/riscv/net/bpf_jit.h        |   2 +
 arch/riscv/net/bpf_jit_comp64.c | 207 +++++++++++++++++++++++++++++++-
 arch/riscv/net/bpf_jit_core.c   |   2 +
 3 files changed, 208 insertions(+), 3 deletions(-)