diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2024-04-01 19:13:03 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-04-03 10:29:56 -0700 |
| commit | 1ae6921009e5d72787e07ccc04754514ccf6bc99 (patch) | |
| tree | 1ef59b0a783c0ac47d1ba63d5aaa3c932ec9dcd5 /kernel | |
| parent | 7bdbf7446305cb65c510c16d57cde82bc76b234a (diff) | |
bpf: inline bpf_get_smp_processor_id() helper
If BPF JIT supports per-CPU MOV instruction, inline bpf_get_smp_processor_id()
to eliminate unnecessary function calls.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20240402021307.1012571-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index fcb62300f407..17c06f1505e4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -20074,6 +20074,30 @@ patch_map_ops_generic: goto next_insn; } +#ifdef CONFIG_X86_64 + /* Implement bpf_get_smp_processor_id() inline. */ + if (insn->imm == BPF_FUNC_get_smp_processor_id && + prog->jit_requested && bpf_jit_supports_percpu_insn()) { + /* BPF_FUNC_get_smp_processor_id inlining is an + * optimization, so if pcpu_hot.cpu_number is ever + * changed in some incompatible and hard to support + * way, it's fine to back out this inlining logic + */ + insn_buf[0] = BPF_MOV32_IMM(BPF_REG_0, (u32)(unsigned long)&pcpu_hot.cpu_number); + insn_buf[1] = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0); + insn_buf[2] = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0); + cnt = 3; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + goto next_insn; + } +#endif /* Implement bpf_get_func_arg inline. */ if (prog_type == BPF_PROG_TYPE_TRACING && insn->imm == BPF_FUNC_get_func_arg) { |