diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2024-03-07 17:08:00 -0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-03-11 15:37:24 -0700 |
| commit | 667a86ad9b71d934c444eec193cf3508016f35c5 (patch) | |
| tree | 1517fb859cd443cd74b02dbf3d3684cb29a40f40 | |
| parent | 317460317a02a1af512697e6e964298dedd8a163 (diff) | |
bpf: Disasm support for addr_space_cast instruction.
LLVM generates rX = addr_space_cast(rY, dst_addr_space, src_addr_space)
instruction when pointers in non-zero address space are used by the bpf
program. Recognize this insn in uapi and in bpf disassembler.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240308010812.89848-3-alexei.starovoitov@gmail.com
| -rw-r--r-- | include/uapi/linux/bpf.h | 4 | ||||
| -rw-r--r-- | kernel/bpf/disasm.c | 10 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 4 |
3 files changed, 18 insertions, 0 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index e30d943db8a4..3c42b9f1bada 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1339,6 +1339,10 @@ enum { */ #define BPF_PSEUDO_KFUNC_CALL 2 +enum bpf_addr_space_cast { + BPF_ADDR_SPACE_CAST = 1, +}; + /* flags for BPF_MAP_UPDATE_ELEM command */ enum { BPF_ANY = 0, /* create new element or update existing */ diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c index 82b2dbdd048f..bd2e2dd04740 100644 --- a/kernel/bpf/disasm.c +++ b/kernel/bpf/disasm.c @@ -166,6 +166,12 @@ static bool is_movsx(const struct bpf_insn *insn) (insn->off == 8 || insn->off == 16 || insn->off == 32); } +static bool is_addr_space_cast(const struct bpf_insn *insn) +{ + return insn->code == (BPF_ALU64 | BPF_MOV | BPF_X) && + insn->off == BPF_ADDR_SPACE_CAST; +} + void print_bpf_insn(const struct bpf_insn_cbs *cbs, const struct bpf_insn *insn, bool allow_ptr_leaks) @@ -184,6 +190,10 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs, insn->code, class == BPF_ALU ? 'w' : 'r', insn->dst_reg, class == BPF_ALU ? 'w' : 'r', insn->dst_reg); + } else if (is_addr_space_cast(insn)) { + verbose(cbs->private_data, "(%02x) r%d = addr_space_cast(r%d, %d, %d)\n", + insn->code, insn->dst_reg, + insn->src_reg, ((u32)insn->imm) >> 16, (u16)insn->imm); } else if (BPF_SRC(insn->code) == BPF_X) { verbose(cbs->private_data, "(%02x) %c%d %s %s%c%d\n", insn->code, class == BPF_ALU ? 'w' : 'r', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index e30d943db8a4..3c42b9f1bada 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1339,6 +1339,10 @@ enum { */ #define BPF_PSEUDO_KFUNC_CALL 2 +enum bpf_addr_space_cast { + BPF_ADDR_SPACE_CAST = 1, +}; + /* flags for BPF_MAP_UPDATE_ELEM command */ enum { BPF_ANY = 0, /* create new element or update existing */ |