diff options
| author | Puranjay Mohan <[email protected]> | 2024-03-24 18:32:26 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <[email protected]> | 2024-03-25 09:10:51 -0700 |
| commit | 770546ae9f4c1ae1ebcaf0874f0dd9631d77ec97 (patch) | |
| tree | 3a7bbdf305e2c5ab7154fdd2c40216f17f3e4e69 | |
| parent | a8497506cd2c0fc90a64f6f5d2744a0ddb2c81eb (diff) | |
bpf: implement insn_is_cast_user() helper for JITs
Implement a helper function to check if an instruction is
addr_space_cast from as(0) to as(1). Use this helper in the x86 JIT.
Other JITs can use this helper when they add support for this instruction.
Signed-off-by: Puranjay Mohan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 3 | ||||
| -rw-r--r-- | include/linux/filter.h | 10 |
2 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 4900b1ee019f..3b639d6f2f54 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1351,8 +1351,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image break; case BPF_ALU64 | BPF_MOV | BPF_X: - if (insn->off == BPF_ADDR_SPACE_CAST && - insn->imm == 1U << 16) { + if (insn_is_cast_user(insn)) { if (dst_reg != src_reg) /* 32-bit mov */ emit_mov_reg(&prog, false, dst_reg, src_reg); diff --git a/include/linux/filter.h b/include/linux/filter.h index c0d51bff8f96..44934b968b57 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -228,6 +228,16 @@ static inline bool insn_is_zext(const struct bpf_insn *insn) return insn->code == (BPF_ALU | BPF_MOV | BPF_X) && insn->imm == 1; } +/* addr_space_cast from as(0) to as(1) is for converting bpf arena pointers + * to pointers in user vma. + */ +static inline bool insn_is_cast_user(const struct bpf_insn *insn) +{ + return insn->code == (BPF_ALU64 | BPF_MOV | BPF_X) && + insn->off == BPF_ADDR_SPACE_CAST && + insn->imm == 1U << 16; +} + /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ #define BPF_LD_IMM64(DST, IMM) \ BPF_LD_IMM64_RAW(DST, 0, IMM) |