This patch adds JIT blinds support for JMP32.
Reviewed-by: Jakub Kicinski <jakub.kicin...@netronome.com>
Signed-off-by: Jiong Wang <jiong.w...@netronome.com>
---
include/linux/filter.h | 20 ++++++++++++++++++++
kernel/bpf/core.c | 21 +++++++++++++++++++++
2 files changed, 41 insertions(+)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index ad106d8..248dbc5 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -277,6 +277,26 @@ struct sock_reuseport;
.off = OFF, \
.imm = IMM })
+/* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
+
+#define BPF_JMP32_REG(OP, DST, SRC, OFF) \
+ ((struct bpf_insn) { \
+ .code = BPF_JMP32 | BPF_OP(OP) | BPF_X, \
+ .dst_reg = DST, \
+ .src_reg = SRC, \
+ .off = OFF, \
+ .imm = 0 })
+
+/* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
+
+#define BPF_JMP32_IMM(OP, DST, IMM, OFF) \
+ ((struct bpf_insn) { \
+ .code = BPF_JMP32 | BPF_OP(OP) | BPF_K, \
+ .dst_reg = DST, \
+ .src_reg = 0, \
+ .off = OFF, \
+ .imm = IMM })
+
/* Unconditional jumps, goto pc + off16 */
#define BPF_JMP_A(OFF) \
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 199612e..84a8b25 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -935,6 +935,27 @@ static int bpf_jit_blind_insn(const struct bpf_insn *from,
*to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
break;
+ case BPF_JMP32 | BPF_JEQ | BPF_K:
+ case BPF_JMP32 | BPF_JNE | BPF_K:
+ case BPF_JMP32 | BPF_JGT | BPF_K:
+ case BPF_JMP32 | BPF_JLT | BPF_K:
+ case BPF_JMP32 | BPF_JGE | BPF_K:
+ case BPF_JMP32 | BPF_JLE | BPF_K:
+ case BPF_JMP32 | BPF_JSGT | BPF_K:
+ case BPF_JMP32 | BPF_JSLT | BPF_K:
+ case BPF_JMP32 | BPF_JSGE | BPF_K:
+ case BPF_JMP32 | BPF_JSLE | BPF_K:
+ case BPF_JMP32 | BPF_JSET | BPF_K:
+ /* Accommodate for extra offset in case of a backjump. */
+ off = from->off;
+ if (off < 0)
+ off -= 2;
+ *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
+ *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
+ *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
+ off);
+ break;
+
case BPF_LD | BPF_IMM | BPF_DW:
*to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^
aux[1].imm);
*to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
--
2.7.4
