[PATCH net-next 1/9] bpf: free up BPF_JMP | BPF_CALL | BPF_X opcode
From: Alexei Starovoitov <hidden>
Date: 2017-05-30 20:31:43
Subsystem:
arm64 port (aarch64 architecture), bpf jit for arm64, bpf jit for powerpc (32-bit and 64-bit), bpf jit for s390, bpf jit for sparc (32-bit and 64-bit), bpf jit for x86 64-bit, bpf [core], bpf [general] (safe dynamic programs and tools), linux for powerpc (32-bit and 64-bit), s390 architecture, sparc + ultrasparc (sparc/sparc64), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Catalin Marinas, Will Deacon, Daniel Borkmann, Alexei Starovoitov, Puranjay Mohan, Hari Bathini, Christophe Leroy, Ilya Leoshkevich, Heiko Carstens, Vasily Gorbik, David S. Miller, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Madhavan Srinivasan, Michael Ellerman, Alexander Gordeev, "David S. Miller", Andreas Larsson, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
free up BPF_JMP | BPF_CALL | BPF_X opcode to be used by actual indirect call by register and use kernel internal opcode to mark call instruction into bpf_tail_call() helper. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> --- arch/arm64/net/bpf_jit_comp.c | 2 +- arch/powerpc/net/bpf_jit_comp64.c | 2 +- arch/s390/net/bpf_jit_comp.c | 2 +- arch/sparc/net/bpf_jit_comp_64.c | 2 +- arch/x86/net/bpf_jit_comp.c | 2 +- include/linux/filter.h | 3 +++ kernel/bpf/core.c | 2 +- kernel/bpf/verifier.c | 2 +- 8 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 71f930501ade..b1d38eeb24f6 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c@@ -586,7 +586,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) break; } /* tail call */ - case BPF_JMP | BPF_CALL | BPF_X: + case BPF_JMP | BPF_TAIL_CALL: if (emit_bpf_tail_call(ctx)) return -EFAULT; break;
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index aee2bb817ac6..a01366584a4b 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c@@ -938,7 +938,7 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, /* * Tail call */ - case BPF_JMP | BPF_CALL | BPF_X: + case BPF_JMP | BPF_TAIL_CALL: ctx->seen |= SEEN_TAILCALL; bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]); break;
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 6e97a2e3fd8d..42ad3832586c 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c@@ -991,7 +991,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i } break; } - case BPF_JMP | BPF_CALL | BPF_X: + case BPF_JMP | BPF_TAIL_CALL: /* * Implicit input: * B1: pointer to ctx
diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c
index 21de77419f48..4a52d34facf9 100644
--- a/arch/sparc/net/bpf_jit_comp_64.c
+++ b/arch/sparc/net/bpf_jit_comp_64.c@@ -1217,7 +1217,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) } /* tail call */ - case BPF_JMP | BPF_CALL |BPF_X: + case BPF_JMP | BPF_TAIL_CALL: emit_tail_call(ctx); break;
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index f58939393eef..fec12eaa0dec 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c@@ -877,7 +877,7 @@ xadd: if (is_imm8(insn->off)) } break; - case BPF_JMP | BPF_CALL | BPF_X: + case BPF_JMP | BPF_TAIL_CALL: emit_bpf_tail_call(&prog); break;
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 62d948f80730..a20ba40fcb73 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h@@ -57,6 +57,9 @@ struct bpf_prog_aux; #define BPF_REG_AX MAX_BPF_REG #define MAX_BPF_JIT_REG (MAX_BPF_REG + 1) +/* unused opcode to mark special call to bpf_tail_call() helper */ +#define BPF_TAIL_CALL 0xf0 + /* As per nm, we expose JITed images as text (code) section for * kallsyms. That way, tools like perf can find it to match * addresses.
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index dedf367f59bb..339289402b96 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c@@ -824,7 +824,7 @@ static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, /* Call instruction */ [BPF_JMP | BPF_CALL] = &&JMP_CALL, - [BPF_JMP | BPF_CALL | BPF_X] = &&JMP_TAIL_CALL, + [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL, /* Jumps */ [BPF_JMP | BPF_JA] = &&JMP_JA, [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 339c8a1371de..28113d0e8e92 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -3469,7 +3469,7 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) * that doesn't support bpf_tail_call yet */ insn->imm = 0; - insn->code |= BPF_X; + insn->code = BPF_JMP | BPF_TAIL_CALL; continue; }
--
2.9.3