Skip to content

Commit

Permalink
MIPS, bpf: Implement JLT, JLE, JSLT and JSLE ops in the eBPF JIT.
Browse files Browse the repository at this point in the history 
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
David Daney authored and David S. Miller committed Aug 21, 2017
1 parent 8d8d18c commit a67b375
Showing 1 changed file with 72 additions and 29 deletions.
101 changes: 72 additions & 29 deletions arch/mips/net/ebpf_jit.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -990,8 +990,12 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
goto jeq_common;
case BPF_JMP | BPF_JEQ | BPF_X: /* JMP_REG */
case BPF_JMP | BPF_JNE | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_X:
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP | BPF_JSGE | BPF_X:
case BPF_JMP | BPF_JLT | BPF_X:
case BPF_JMP | BPF_JLE | BPF_X:
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JSET | BPF_X:
Expand All @@ -1013,41 +1017,47 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
cmp_eq = false;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
} else if (BPF_OP(insn->code) == BPF_JSGT) {
} else if (BPF_OP(insn->code) == BPF_JSGT || BPF_OP(insn->code) == BPF_JSLE) {
emit_instr(ctx, dsubu, MIPS_R_AT, dst, src);
if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) {
b_off = b_imm(exit_idx, ctx);
if (is_bad_offset(b_off))
return -E2BIG;
emit_instr(ctx, blez, MIPS_R_AT, b_off);
if (BPF_OP(insn->code) == BPF_JSGT)
emit_instr(ctx, blez, MIPS_R_AT, b_off);
else
emit_instr(ctx, bgtz, MIPS_R_AT, b_off);
emit_instr(ctx, nop);
return 2; /* We consumed the exit. */
}
b_off = b_imm(this_idx + insn->off + 1, ctx);
if (is_bad_offset(b_off))
return -E2BIG;
emit_instr(ctx, bgtz, MIPS_R_AT, b_off);
if (BPF_OP(insn->code) == BPF_JSGT)
emit_instr(ctx, bgtz, MIPS_R_AT, b_off);
else
emit_instr(ctx, blez, MIPS_R_AT, b_off);
emit_instr(ctx, nop);
break;
} else if (BPF_OP(insn->code) == BPF_JSGE) {
} else if (BPF_OP(insn->code) == BPF_JSGE || BPF_OP(insn->code) == BPF_JSLT) {
emit_instr(ctx, slt, MIPS_R_AT, dst, src);
cmp_eq = true;
cmp_eq = BPF_OP(insn->code) == BPF_JSGE;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
} else if (BPF_OP(insn->code) == BPF_JGT) {
} else if (BPF_OP(insn->code) == BPF_JGT || BPF_OP(insn->code) == BPF_JLE) {
/* dst or src could be AT */
emit_instr(ctx, dsubu, MIPS_R_T8, dst, src);
emit_instr(ctx, sltu, MIPS_R_AT, dst, src);
/* SP known to be non-zero, movz becomes boolean not */
emit_instr(ctx, movz, MIPS_R_T9, MIPS_R_SP, MIPS_R_T8);
emit_instr(ctx, movn, MIPS_R_T9, MIPS_R_ZERO, MIPS_R_T8);
emit_instr(ctx, or, MIPS_R_AT, MIPS_R_T9, MIPS_R_AT);
cmp_eq = true;
cmp_eq = BPF_OP(insn->code) == BPF_JGT;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
} else if (BPF_OP(insn->code) == BPF_JGE) {
} else if (BPF_OP(insn->code) == BPF_JGE || BPF_OP(insn->code) == BPF_JLT) {
emit_instr(ctx, sltu, MIPS_R_AT, dst, src);
cmp_eq = true;
cmp_eq = BPF_OP(insn->code) == BPF_JGE;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
} else { /* JNE/JEQ case */
Expand Down Expand Up @@ -1110,6 +1120,8 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
break;
case BPF_JMP | BPF_JSGT | BPF_K: /* JMP_IMM */
case BPF_JMP | BPF_JSGE | BPF_K: /* JMP_IMM */
case BPF_JMP | BPF_JSLT | BPF_K: /* JMP_IMM */
case BPF_JMP | BPF_JSLE | BPF_K: /* JMP_IMM */
cmp_eq = (BPF_OP(insn->code) == BPF_JSGE);
dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
if (dst < 0)
Expand All @@ -1120,65 +1132,92 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
b_off = b_imm(exit_idx, ctx);
if (is_bad_offset(b_off))
return -E2BIG;
if (cmp_eq)
emit_instr(ctx, bltz, dst, b_off);
else
switch (BPF_OP(insn->code)) {
case BPF_JSGT:
emit_instr(ctx, blez, dst, b_off);
break;
case BPF_JSGE:
emit_instr(ctx, bltz, dst, b_off);
break;
case BPF_JSLT:
emit_instr(ctx, bgez, dst, b_off);
break;
case BPF_JSLE:
emit_instr(ctx, bgtz, dst, b_off);
break;
}
emit_instr(ctx, nop);
return 2; /* We consumed the exit. */
}
b_off = b_imm(this_idx + insn->off + 1, ctx);
if (is_bad_offset(b_off))
return -E2BIG;
if (cmp_eq)
emit_instr(ctx, bgez, dst, b_off);
else
switch (BPF_OP(insn->code)) {
case BPF_JSGT:
emit_instr(ctx, bgtz, dst, b_off);
break;
case BPF_JSGE:
emit_instr(ctx, bgez, dst, b_off);
break;
case BPF_JSLT:
emit_instr(ctx, bltz, dst, b_off);
break;
case BPF_JSLE:
emit_instr(ctx, blez, dst, b_off);
break;
}
emit_instr(ctx, nop);
break;
}
/*
* only "LT" compare available, so we must use imm + 1
* to generate "GT"
* to generate "GT" and imm -1 to generate LE
*/
t64s = insn->imm + (cmp_eq ? 0 : 1);
if (BPF_OP(insn->code) == BPF_JSGT)
t64s = insn->imm + 1;
else if (BPF_OP(insn->code) == BPF_JSLE)
t64s = insn->imm + 1;
else
t64s = insn->imm;

cmp_eq = BPF_OP(insn->code) == BPF_JSGT || BPF_OP(insn->code) == BPF_JSGE;
if (t64s >= S16_MIN && t64s <= S16_MAX) {
emit_instr(ctx, slti, MIPS_R_AT, dst, (int)t64s);
src = MIPS_R_AT;
dst = MIPS_R_ZERO;
cmp_eq = true;
goto jeq_common;
}
emit_const_to_reg(ctx, MIPS_R_AT, (u64)t64s);
emit_instr(ctx, slt, MIPS_R_AT, dst, MIPS_R_AT);
src = MIPS_R_AT;
dst = MIPS_R_ZERO;
cmp_eq = true;
goto jeq_common;

case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JLT | BPF_K:
case BPF_JMP | BPF_JLE | BPF_K:
cmp_eq = (BPF_OP(insn->code) == BPF_JGE);
dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
if (dst < 0)
return dst;
/*
* only "LT" compare available, so we must use imm + 1
* to generate "GT"
* to generate "GT" and imm -1 to generate LE
*/
t64s = (u64)(u32)(insn->imm) + (cmp_eq ? 0 : 1);
if (t64s >= 0 && t64s <= S16_MAX) {
emit_instr(ctx, sltiu, MIPS_R_AT, dst, (int)t64s);
src = MIPS_R_AT;
dst = MIPS_R_ZERO;
cmp_eq = true;
goto jeq_common;
}
if (BPF_OP(insn->code) == BPF_JGT)
t64s = (u64)(u32)(insn->imm) + 1;
else if (BPF_OP(insn->code) == BPF_JLE)
t64s = (u64)(u32)(insn->imm) + 1;
else
t64s = (u64)(u32)(insn->imm);

cmp_eq = BPF_OP(insn->code) == BPF_JGT || BPF_OP(insn->code) == BPF_JGE;

emit_const_to_reg(ctx, MIPS_R_AT, (u64)t64s);
emit_instr(ctx, sltu, MIPS_R_AT, dst, MIPS_R_AT);
src = MIPS_R_AT;
dst = MIPS_R_ZERO;
cmp_eq = true;
goto jeq_common;

case BPF_JMP | BPF_JSET | BPF_K: /* JMP_IMM */
Expand Down Expand Up @@ -1712,10 +1751,14 @@ static int reg_val_propagate_range(struct jit_ctx *ctx, u64 initial_rvt,
case BPF_JEQ:
case BPF_JGT:
case BPF_JGE:
case BPF_JLT:
case BPF_JLE:
case BPF_JSET:
case BPF_JNE:
case BPF_JSGT:
case BPF_JSGE:
case BPF_JSLT:
case BPF_JSLE:
if (follow_taken) {
rvt[idx] |= RVT_BRANCH_TAKEN;
idx += insn->off;
Expand Down

0 comments on commit a67b375

Please sign in to comment.