diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2024-03-07 17:08:01 -0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-03-11 15:37:24 -0700 |
| commit | 2fe99eb0ccf2bb73df65ebcbbf2f2ff70e63547b (patch) | |
| tree | 9bc8df3820cfa576dfbff871acff07e3145e1e1d /include/linux/bpf.h | |
| parent | 667a86ad9b71d934c444eec193cf3508016f35c5 (diff) | |
bpf: Add x86-64 JIT support for PROBE_MEM32 pseudo instructions.
Add support for [LDX | STX | ST], PROBE_MEM32, [B | H | W | DW] instructions.
They are similar to PROBE_MEM instructions with the following differences:
- PROBE_MEM has to check that the address is in the kernel range with
src_reg + insn->off >= TASK_SIZE_MAX + PAGE_SIZE check
- PROBE_MEM doesn't support store
- PROBE_MEM32 relies on the verifier to clear upper 32-bit in the register
- PROBE_MEM32 adds 64-bit kern_vm_start address (which is stored in %r12 in the prologue)
Due to bpf_arena constructions such %r12 + %reg + off16 access is guaranteed
to be within arena virtual range, so no address check at run-time.
- PROBE_MEM32 allows STX and ST. If they fault the store is a nop.
When LDX faults the destination register is zeroed.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240308010812.89848-4-alexei.starovoitov@gmail.com
Diffstat (limited to 'include/linux/bpf.h')
| -rw-r--r-- | include/linux/bpf.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ea6ab6e0eef9..8904d1606125 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1458,6 +1458,7 @@ struct bpf_prog_aux { bool xdp_has_frags; bool exception_cb; bool exception_boundary; + struct bpf_arena *arena; /* BTF_KIND_FUNC_PROTO for valid attach_btf_id */ const struct btf_type *attach_func_proto; /* function name for valid attach_btf_id */ |