[PATCH bpf-next v3 2/6] riscv, bpf: Support riscv jit to provide bpf_line_info
From: Pu Lehui <pulehui@huawei.com>
Date: 2022-05-30 08:58:52
Also in:
bpf, linux-riscv, lkml
Subsystem:
bpf jit for risc-v (32-bit), bpf jit for risc-v (64-bit), bpf [general] (safe dynamic programs and tools), risc-v architecture, the rest · Maintainers:
Luke Nelson, Xi Wang, Björn Töpel, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
Add support for riscv jit to provide bpf_line_info. We need to consider the prologue offset in ctx->offset, but unlike x86 and arm64, ctx->offset of riscv does not provide an extra slot for the prologue, so here we just calculate the len of prologue and add it to ctx->offset at the end. Both RV64 and RV32 have been tested. Signed-off-by: Pu Lehui <pulehui@huawei.com> --- arch/riscv/net/bpf_jit.h | 1 + arch/riscv/net/bpf_jit_core.c | 8 +++++++- 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/net/bpf_jit.h b/arch/riscv/net/bpf_jit.h
index 2a3715bf29fe..d926e0f7ef57 100644
--- a/arch/riscv/net/bpf_jit.h
+++ b/arch/riscv/net/bpf_jit.h@@ -69,6 +69,7 @@ struct rv_jit_context { struct bpf_prog *prog; u16 *insns; /* RV insns */ int ninsns; + int body_len; int epilogue_offset; int *offset; /* BPF to RV */ int nexentries;
diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c
index be743d700aa7..737baf8715da 100644
--- a/arch/riscv/net/bpf_jit_core.c
+++ b/arch/riscv/net/bpf_jit_core.c@@ -44,7 +44,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) unsigned int prog_size = 0, extable_size = 0; bool tmp_blinded = false, extra_pass = false; struct bpf_prog *tmp, *orig_prog = prog; - int pass = 0, prev_ninsns = 0, i; + int pass = 0, prev_ninsns = 0, prologue_len, i; struct rv_jit_data *jit_data; struct rv_jit_context *ctx;
@@ -95,6 +95,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) prog = orig_prog; goto out_offset; } + ctx->body_len = ctx->ninsns; bpf_jit_build_prologue(ctx); ctx->epilogue_offset = ctx->ninsns; bpf_jit_build_epilogue(ctx);
@@ -161,6 +162,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) if (!prog->is_func || extra_pass) { bpf_jit_binary_lock_ro(jit_data->header); + prologue_len = ctx->epilogue_offset - ctx->body_len; + for (i = 0; i < prog->len; i++) + ctx->offset[i] = ninsns_rvoff(prologue_len + + ctx->offset[i]); + bpf_prog_fill_jited_linfo(prog, ctx->offset); out_offset: kfree(ctx->offset); kfree(jit_data);
--
2.25.1