diff options
| author | Alexei Starovoitov <ast@fb.com> | 2017-05-30 13:31:27 -0700 |
|---|---|---|
| committer | Bruno Martins <bgcngm@gmail.com> | 2024-01-10 14:16:43 +0000 |
| commit | 29da450cb1a0e7215d3136320daa461ea28fd628 (patch) | |
| tree | 5538f200fcc5905e3a8174dbe98725d533739c9b | |
| parent | 1d2bd276c33545f77d64219b555cfed6097102bb (diff) | |
bpf: free up BPF_JMP | BPF_CALL | BPF_X opcode
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.
Change-Id: I1a45b8e3c13848c9689ce288d4862935ede97fa7
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | arch/arm64/net/bpf_jit_comp.c | 2 | ||||
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 2 | ||||
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 2 | ||||
| -rw-r--r-- | include/linux/filter.h | 3 | ||||
| -rw-r--r-- | kernel/bpf/core.c | 2 | ||||
| -rw-r--r-- | kernel/bpf/verifier.c | 2 |
6 files changed, 8 insertions, 5 deletions
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 28699dd66e1e..1b4f8bf6d48e 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -583,7 +583,7 @@ emit_cond_jmp: 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/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 98599503923e..992ee13ccccc 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1046,7 +1046,7 @@ 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/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 140109e8a818..4d3b0540279f 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -855,7 +855,7 @@ 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 d64498da2a0c..22e9bd1cf047 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -53,6 +53,9 @@ 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 + /* BPF program can access up to 512 bytes of stack space. */ #define MAX_BPF_STACK 512 diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 2cb991abf6c3..a012b6c7918e 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -604,7 +604,7 @@ static unsigned int __bpf_prog_run(const struct sk_buff *ctx, const struct bpf_i [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 78bdfbefd996..0bdb7c1b558d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3496,7 +3496,7 @@ 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; /* instead of changing every JIT dealing with tail_call * emit two extra insns: |