From: Yonghong Song <yhs@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>, <bpf@ietf.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Fangrui Song <maskray@google.com>, <kernel-team@fb.com>
Subject: [PATCH bpf-next v3 08/17] bpf: Add kernel/bpftool asm support for new instructions
Date: Wed, 19 Jul 2023 17:01:47 -0700 [thread overview]
Message-ID: <20230720000147.105988-1-yhs@fb.com> (raw)
In-Reply-To: <20230720000103.99949-1-yhs@fb.com>
Add asm support for new instructions so kernel verifier and bpftool
xlated insn dumps can have proper asm syntax for new instructions.
Signed-off-by: Yonghong Song <yhs@fb.com>
---
kernel/bpf/disasm.c | 57 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 51 insertions(+), 6 deletions(-)
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
index 7b4afb7d96db..d7bff608f299 100644
--- a/kernel/bpf/disasm.c
+++ b/kernel/bpf/disasm.c
@@ -87,6 +87,17 @@ const char *const bpf_alu_string[16] = {
[BPF_END >> 4] = "endian",
};
+const char *const bpf_alu_sign_string[16] = {
+ [BPF_DIV >> 4] = "s/=",
+ [BPF_MOD >> 4] = "s%=",
+};
+
+const char *const bpf_movsx_string[4] = {
+ [0] = "(s8)",
+ [1] = "(s16)",
+ [3] = "(s32)",
+};
+
static const char *const bpf_atomic_alu_string[16] = {
[BPF_ADD >> 4] = "add",
[BPF_AND >> 4] = "and",
@@ -101,6 +112,12 @@ static const char *const bpf_ldst_string[] = {
[BPF_DW >> 3] = "u64",
};
+static const char *const bpf_ldsx_string[] = {
+ [BPF_W >> 3] = "s32",
+ [BPF_H >> 3] = "s16",
+ [BPF_B >> 3] = "s8",
+};
+
static const char *const bpf_jmp_string[16] = {
[BPF_JA >> 4] = "jmp",
[BPF_JEQ >> 4] = "==",
@@ -128,6 +145,26 @@ static void print_bpf_end_insn(bpf_insn_print_t verbose,
insn->imm, insn->dst_reg);
}
+static void print_bpf_bswap_insn(bpf_insn_print_t verbose,
+ void *private_data,
+ const struct bpf_insn *insn)
+{
+ verbose(private_data, "(%02x) r%d = bswap%d r%d\n",
+ insn->code, insn->dst_reg,
+ insn->imm, insn->dst_reg);
+}
+
+static bool is_sdiv_smod(const struct bpf_insn *insn)
+{
+ return (BPF_OP(insn->code) == BPF_DIV || BPF_OP(insn->code) == BPF_MOD) &&
+ insn->off == 1;
+}
+
+static bool is_movsx(const struct bpf_insn *insn)
+{
+ return BPF_OP(insn->code) == BPF_MOV && insn->off != 0;
+}
+
void print_bpf_insn(const struct bpf_insn_cbs *cbs,
const struct bpf_insn *insn,
bool allow_ptr_leaks)
@@ -138,7 +175,7 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs,
if (class == BPF_ALU || class == BPF_ALU64) {
if (BPF_OP(insn->code) == BPF_END) {
if (class == BPF_ALU64)
- verbose(cbs->private_data, "BUG_alu64_%02x\n", insn->code);
+ print_bpf_bswap_insn(verbose, cbs->private_data, insn);
else
print_bpf_end_insn(verbose, cbs->private_data, insn);
} else if (BPF_OP(insn->code) == BPF_NEG) {
@@ -147,17 +184,20 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs,
insn->dst_reg, class == BPF_ALU ? 'w' : 'r',
insn->dst_reg);
} else if (BPF_SRC(insn->code) == BPF_X) {
- verbose(cbs->private_data, "(%02x) %c%d %s %c%d\n",
+ verbose(cbs->private_data, "(%02x) %c%d %s %s%c%d\n",
insn->code, class == BPF_ALU ? 'w' : 'r',
insn->dst_reg,
- bpf_alu_string[BPF_OP(insn->code) >> 4],
+ is_sdiv_smod(insn) ? bpf_alu_sign_string[BPF_OP(insn->code) >> 4]
+ : bpf_alu_string[BPF_OP(insn->code) >> 4],
+ is_movsx(insn) ? bpf_movsx_string[(insn->off >> 3) - 1] : "",
class == BPF_ALU ? 'w' : 'r',
insn->src_reg);
} else {
verbose(cbs->private_data, "(%02x) %c%d %s %d\n",
insn->code, class == BPF_ALU ? 'w' : 'r',
insn->dst_reg,
- bpf_alu_string[BPF_OP(insn->code) >> 4],
+ is_sdiv_smod(insn) ? bpf_alu_sign_string[BPF_OP(insn->code) >> 4]
+ : bpf_alu_string[BPF_OP(insn->code) >> 4],
insn->imm);
}
} else if (class == BPF_STX) {
@@ -218,13 +258,15 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs,
verbose(cbs->private_data, "BUG_st_%02x\n", insn->code);
}
} else if (class == BPF_LDX) {
- if (BPF_MODE(insn->code) != BPF_MEM) {
+ if (BPF_MODE(insn->code) != BPF_MEM && BPF_MODE(insn->code) != BPF_MEMSX) {
verbose(cbs->private_data, "BUG_ldx_%02x\n", insn->code);
return;
}
verbose(cbs->private_data, "(%02x) r%d = *(%s *)(r%d %+d)\n",
insn->code, insn->dst_reg,
- bpf_ldst_string[BPF_SIZE(insn->code) >> 3],
+ BPF_MODE(insn->code) == BPF_MEM ?
+ bpf_ldst_string[BPF_SIZE(insn->code) >> 3] :
+ bpf_ldsx_string[BPF_SIZE(insn->code) >> 3],
insn->src_reg, insn->off);
} else if (class == BPF_LD) {
if (BPF_MODE(insn->code) == BPF_ABS) {
@@ -279,6 +321,9 @@ void print_bpf_insn(const struct bpf_insn_cbs *cbs,
} else if (insn->code == (BPF_JMP | BPF_JA)) {
verbose(cbs->private_data, "(%02x) goto pc%+d\n",
insn->code, insn->off);
+ } else if (insn->code == (BPF_JMP32 | BPF_JA)) {
+ verbose(cbs->private_data, "(%02x) gotol pc%+d\n",
+ insn->code, insn->imm);
} else if (insn->code == (BPF_JMP | BPF_EXIT)) {
verbose(cbs->private_data, "(%02x) exit\n", insn->code);
} else if (BPF_SRC(insn->code) == BPF_X) {
--
2.34.1
next prev parent reply other threads:[~2023-07-20 0:02 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 0:01 [PATCH bpf-next v3 00/17] bpf: Support new insns from cpu v4 Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 01/17] bpf: Support new sign-extension load insns Yonghong Song
2023-07-20 20:33 ` Eduard Zingerman
2023-07-24 4:03 ` [Bpf] " Yonghong Song
2023-07-24 4:03 ` Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 02/17] bpf: Support new sign-extension mov insns Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 03/17] bpf: Handle sign-extenstin ctx member accesses Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 04/17] bpf: Support new unconditional bswap instruction Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 05/17] bpf: Support new signed div/mod instructions Yonghong Song
2023-07-20 0:01 ` [Bpf] " Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 06/17] bpf: Fix jit blinding with new sdiv/smov insns Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 07/17] bpf: Support new 32bit offset jmp instruction Yonghong Song
2023-07-20 0:01 ` Yonghong Song [this message]
2023-07-21 14:36 ` [PATCH bpf-next v3 08/17] bpf: Add kernel/bpftool asm support for new instructions Quentin Monnet
2023-07-21 14:36 ` [Bpf] " Quentin Monnet
2023-07-20 0:01 ` [PATCH bpf-next v3 09/17] selftests/bpf: Fix a test_verifier failure Yonghong Song
2023-07-20 0:01 ` [PATCH bpf-next v3 10/17] selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing Yonghong Song
2023-07-20 0:02 ` [PATCH bpf-next v3 11/17] selftests/bpf: Add unit tests for new sign-extension load insns Yonghong Song
2023-07-20 6:31 ` [Bpf] " Yonghong Song
2023-07-20 6:31 ` Yonghong Song
2023-07-20 6:36 ` [Bpf] " Yonghong Song
2023-07-20 6:36 ` Yonghong Song
2023-07-20 0:02 ` [PATCH bpf-next v3 12/17] selftests/bpf: Add unit tests for new sign-extension mov insns Yonghong Song
2023-07-20 0:02 ` [PATCH bpf-next v3 13/17] selftests/bpf: Add unit tests for new bswap insns Yonghong Song
2023-07-20 0:02 ` [PATCH bpf-next v3 14/17] selftests/bpf: Add unit tests for new sdiv/smod insns Yonghong Song
2023-07-20 0:02 ` [PATCH bpf-next v3 15/17] selftests/bpf: Add unit tests for new gotol insn Yonghong Song
2023-07-20 0:02 ` [Bpf] " Yonghong Song
2023-07-20 0:02 ` [PATCH bpf-next v3 16/17] selftests/bpf: Test ldsx with more complex cases Yonghong Song
2023-07-20 0:02 ` [PATCH bpf-next v3 17/17] docs/bpf: Add documentation for new instructions Yonghong Song
2023-07-20 20:35 ` [PATCH bpf-next v3 00/17] bpf: Support new insns from cpu v4 Eduard Zingerman
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