Here are several improvements and bug fixes for the MIPS eBPF JIT.
The main change is the addition of support for JLT, JLE, JSLT and JSLE
ops, that were recently added.
Also fix WARN output when used with preemptable kernel, and a small
cleanup/optimization in the use of BPF_OP(insn->code).
I suggest that the whole thing go via the BPF/net-next path as there
are dependencies on code that is not yet merged to Linus' tree.
Still pending are changes to reduce stack usage when the verifier can
determine the maximum stack size.
David Daney (3):
MIPS,bpf: Fix using smp_processor_id() in preemptible splat.
MIPS,bpf: Implement JLT, JLE, JSLT and JSLE ops in the eBPF JIT.
MIPS,bpf: Cache value of BPF_OP(insn->code) in eBPF JIT.
arch/mips/net/ebpf_jit.c | 162 ++++++++++++++++++++++++++++++-----------------
1 file changed, 103 insertions(+), 59 deletions(-)
--
2.9.5
The code looks a little cleaner if we replace BPF_OP(insn->code) with
the local variable bpf_op. Caching the value this way also saves 300
bytes (about 1%) in the code size of the JIT.
Signed-off-by: David Daney <[email protected]>
---
arch/mips/net/ebpf_jit.c | 67 ++++++++++++++++++++++++------------------------
1 file changed, 34 insertions(+), 33 deletions(-)
diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c
index c1e21cb..44ddc12 100644
--- a/arch/mips/net/ebpf_jit.c
+++ b/arch/mips/net/ebpf_jit.c
@@ -670,6 +670,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
unsigned int target;
u64 t64;
s64 t64s;
+ int bpf_op = BPF_OP(insn->code);
switch (insn->code) {
case BPF_ALU64 | BPF_ADD | BPF_K: /* ALU64_IMM */
@@ -758,13 +759,13 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, sll, dst, dst, 0);
if (insn->imm == 1) {
/* div by 1 is a nop, mod by 1 is zero */
- if (BPF_OP(insn->code) == BPF_MOD)
+ if (bpf_op == BPF_MOD)
emit_instr(ctx, addu, dst, MIPS_R_ZERO, MIPS_R_ZERO);
break;
}
gen_imm_to_reg(insn, MIPS_R_AT, ctx);
emit_instr(ctx, divu, dst, MIPS_R_AT);
- if (BPF_OP(insn->code) == BPF_DIV)
+ if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
else
emit_instr(ctx, mfhi, dst);
@@ -786,13 +787,13 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
if (insn->imm == 1) {
/* div by 1 is a nop, mod by 1 is zero */
- if (BPF_OP(insn->code) == BPF_MOD)
+ if (bpf_op == BPF_MOD)
emit_instr(ctx, addu, dst, MIPS_R_ZERO, MIPS_R_ZERO);
break;
}
gen_imm_to_reg(insn, MIPS_R_AT, ctx);
emit_instr(ctx, ddivu, dst, MIPS_R_AT);
- if (BPF_OP(insn->code) == BPF_DIV)
+ if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
else
emit_instr(ctx, mfhi, dst);
@@ -817,7 +818,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, dinsu, dst, MIPS_R_ZERO, 32, 32);
did_move = false;
if (insn->src_reg == BPF_REG_10) {
- if (BPF_OP(insn->code) == BPF_MOV) {
+ if (bpf_op == BPF_MOV) {
emit_instr(ctx, daddiu, dst, MIPS_R_SP, MAX_BPF_STACK);
did_move = true;
} else {
@@ -827,7 +828,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
} else if (get_reg_val_type(ctx, this_idx, insn->src_reg) == REG_32BIT) {
int tmp_reg = MIPS_R_AT;
- if (BPF_OP(insn->code) == BPF_MOV) {
+ if (bpf_op == BPF_MOV) {
tmp_reg = dst;
did_move = true;
}
@@ -835,7 +836,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, dinsu, tmp_reg, MIPS_R_ZERO, 32, 32);
src = MIPS_R_AT;
}
- switch (BPF_OP(insn->code)) {
+ switch (bpf_op) {
case BPF_MOV:
if (!did_move)
emit_instr(ctx, daddu, dst, src, MIPS_R_ZERO);
@@ -867,7 +868,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, beq, src, MIPS_R_ZERO, b_off);
emit_instr(ctx, movz, MIPS_R_V0, MIPS_R_ZERO, src);
emit_instr(ctx, ddivu, dst, src);
- if (BPF_OP(insn->code) == BPF_DIV)
+ if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
else
emit_instr(ctx, mfhi, dst);
@@ -911,7 +912,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
if (ts == REG_64BIT || ts == REG_32BIT_ZERO_EX) {
int tmp_reg = MIPS_R_AT;
- if (BPF_OP(insn->code) == BPF_MOV) {
+ if (bpf_op == BPF_MOV) {
tmp_reg = dst;
did_move = true;
}
@@ -919,7 +920,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, sll, tmp_reg, src, 0);
src = MIPS_R_AT;
}
- switch (BPF_OP(insn->code)) {
+ switch (bpf_op) {
case BPF_MOV:
if (!did_move)
emit_instr(ctx, addu, dst, src, MIPS_R_ZERO);
@@ -950,7 +951,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, beq, src, MIPS_R_ZERO, b_off);
emit_instr(ctx, movz, MIPS_R_V0, MIPS_R_ZERO, src);
emit_instr(ctx, divu, dst, src);
- if (BPF_OP(insn->code) == BPF_DIV)
+ if (bpf_op == BPF_DIV)
emit_instr(ctx, mflo, dst);
else
emit_instr(ctx, mfhi, dst);
@@ -977,7 +978,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
break;
case BPF_JMP | BPF_JEQ | BPF_K: /* JMP_IMM */
case BPF_JMP | BPF_JNE | BPF_K: /* JMP_IMM */
- cmp_eq = (BPF_OP(insn->code) == BPF_JEQ);
+ cmp_eq = (bpf_op == BPF_JEQ);
dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
if (dst < 0)
return dst;
@@ -1012,18 +1013,18 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
emit_instr(ctx, sll, MIPS_R_AT, dst, 0);
dst = MIPS_R_AT;
}
- if (BPF_OP(insn->code) == BPF_JSET) {
+ if (bpf_op == BPF_JSET) {
emit_instr(ctx, and, MIPS_R_AT, dst, src);
cmp_eq = false;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
- } else if (BPF_OP(insn->code) == BPF_JSGT || BPF_OP(insn->code) == BPF_JSLE) {
+ } else if (bpf_op == BPF_JSGT || bpf_op == 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;
- if (BPF_OP(insn->code) == BPF_JSGT)
+ if (bpf_op == BPF_JSGT)
emit_instr(ctx, blez, MIPS_R_AT, b_off);
else
emit_instr(ctx, bgtz, MIPS_R_AT, b_off);
@@ -1033,18 +1034,18 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
b_off = b_imm(this_idx + insn->off + 1, ctx);
if (is_bad_offset(b_off))
return -E2BIG;
- if (BPF_OP(insn->code) == BPF_JSGT)
+ if (bpf_op == 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 || BPF_OP(insn->code) == BPF_JSLT) {
+ } else if (bpf_op == BPF_JSGE || bpf_op == BPF_JSLT) {
emit_instr(ctx, slt, MIPS_R_AT, dst, src);
- cmp_eq = BPF_OP(insn->code) == BPF_JSGE;
+ cmp_eq = bpf_op == BPF_JSGE;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
- } else if (BPF_OP(insn->code) == BPF_JGT || BPF_OP(insn->code) == BPF_JLE) {
+ } else if (bpf_op == BPF_JGT || bpf_op == 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);
@@ -1052,16 +1053,16 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
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 = BPF_OP(insn->code) == BPF_JGT;
+ cmp_eq = bpf_op == BPF_JGT;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
- } else if (BPF_OP(insn->code) == BPF_JGE || BPF_OP(insn->code) == BPF_JLT) {
+ } else if (bpf_op == BPF_JGE || bpf_op == BPF_JLT) {
emit_instr(ctx, sltu, MIPS_R_AT, dst, src);
- cmp_eq = BPF_OP(insn->code) == BPF_JGE;
+ cmp_eq = bpf_op == BPF_JGE;
dst = MIPS_R_AT;
src = MIPS_R_ZERO;
} else { /* JNE/JEQ case */
- cmp_eq = (BPF_OP(insn->code) == BPF_JEQ);
+ cmp_eq = (bpf_op == BPF_JEQ);
}
jeq_common:
/*
@@ -1122,7 +1123,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
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);
+ cmp_eq = (bpf_op == BPF_JSGE);
dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
if (dst < 0)
return dst;
@@ -1132,7 +1133,7 @@ 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;
- switch (BPF_OP(insn->code)) {
+ switch (bpf_op) {
case BPF_JSGT:
emit_instr(ctx, blez, dst, b_off);
break;
@@ -1152,7 +1153,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
b_off = b_imm(this_idx + insn->off + 1, ctx);
if (is_bad_offset(b_off))
return -E2BIG;
- switch (BPF_OP(insn->code)) {
+ switch (bpf_op) {
case BPF_JSGT:
emit_instr(ctx, bgtz, dst, b_off);
break;
@@ -1173,14 +1174,14 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
* only "LT" compare available, so we must use imm + 1
* to generate "GT" and imm -1 to generate LE
*/
- if (BPF_OP(insn->code) == BPF_JSGT)
+ if (bpf_op == BPF_JSGT)
t64s = insn->imm + 1;
- else if (BPF_OP(insn->code) == BPF_JSLE)
+ else if (bpf_op == BPF_JSLE)
t64s = insn->imm + 1;
else
t64s = insn->imm;
- cmp_eq = BPF_OP(insn->code) == BPF_JSGT || BPF_OP(insn->code) == BPF_JSGE;
+ cmp_eq = bpf_op == BPF_JSGT || bpf_op == BPF_JSGE;
if (t64s >= S16_MIN && t64s <= S16_MAX) {
emit_instr(ctx, slti, MIPS_R_AT, dst, (int)t64s);
src = MIPS_R_AT;
@@ -1197,7 +1198,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
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);
+ cmp_eq = (bpf_op == BPF_JGE);
dst = ebpf_to_mips_reg(ctx, insn, dst_reg_fp_ok);
if (dst < 0)
return dst;
@@ -1205,14 +1206,14 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
* only "LT" compare available, so we must use imm + 1
* to generate "GT" and imm -1 to generate LE
*/
- if (BPF_OP(insn->code) == BPF_JGT)
+ if (bpf_op == BPF_JGT)
t64s = (u64)(u32)(insn->imm) + 1;
- else if (BPF_OP(insn->code) == BPF_JLE)
+ else if (bpf_op == 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;
+ cmp_eq = bpf_op == BPF_JGT || bpf_op == BPF_JGE;
emit_const_to_reg(ctx, MIPS_R_AT, (u64)t64s);
emit_instr(ctx, sltu, MIPS_R_AT, dst, MIPS_R_AT);
--
2.9.5
If the kernel is configured with preemption enabled we were getting
warning stack traces for use of current_cpu_type().
Fix by moving the test between preempt_disable()/preempt_enable() and
caching the results of the CPU type tests for use during code
generation.
Signed-off-by: David Daney <[email protected]>
---
arch/mips/net/ebpf_jit.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c
index 3f87b96..721216b 100644
--- a/arch/mips/net/ebpf_jit.c
+++ b/arch/mips/net/ebpf_jit.c
@@ -113,6 +113,7 @@ struct jit_ctx {
u64 *reg_val_types;
unsigned int long_b_conversion:1;
unsigned int gen_b_offsets:1;
+ unsigned int use_bbit_insns:1;
};
static void set_reg_val_type(u64 *rvt, int reg, enum reg_val_type type)
@@ -655,19 +656,6 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx, int this_idx)
return build_int_epilogue(ctx, MIPS_R_T9);
}
-static bool use_bbit_insns(void)
-{
- switch (current_cpu_type()) {
- case CPU_CAVIUM_OCTEON:
- case CPU_CAVIUM_OCTEON_PLUS:
- case CPU_CAVIUM_OCTEON2:
- case CPU_CAVIUM_OCTEON3:
- return true;
- default:
- return false;
- }
-}
-
static bool is_bad_offset(int b_off)
{
return b_off > 0x1ffff || b_off < -0x20000;
@@ -1198,7 +1186,7 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
if (dst < 0)
return dst;
- if (use_bbit_insns() && hweight32((u32)insn->imm) == 1) {
+ if (ctx->use_bbit_insns && hweight32((u32)insn->imm) == 1) {
if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) {
b_off = b_imm(exit_idx, ctx);
if (is_bad_offset(b_off))
@@ -1853,6 +1841,18 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
memset(&ctx, 0, sizeof(ctx));
+ preempt_disable();
+ switch (current_cpu_type()) {
+ case CPU_CAVIUM_OCTEON:
+ case CPU_CAVIUM_OCTEON_PLUS:
+ case CPU_CAVIUM_OCTEON2:
+ case CPU_CAVIUM_OCTEON3:
+ ctx.use_bbit_insns = 1;
+ default:
+ ctx.use_bbit_insns = 0;
+ }
+ preempt_enable();
+
ctx.offsets = kcalloc(prog->len + 1, sizeof(*ctx.offsets), GFP_KERNEL);
if (ctx.offsets == NULL)
goto out_err;
--
2.9.5
Signed-off-by: David Daney <[email protected]>
---
arch/mips/net/ebpf_jit.c | 101 +++++++++++++++++++++++++++++++++--------------
1 file changed, 72 insertions(+), 29 deletions(-)
diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c
index 721216b..c1e21cb 100644
--- a/arch/mips/net/ebpf_jit.c
+++ b/arch/mips/net/ebpf_jit.c
@@ -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:
@@ -1013,28 +1017,34 @@ 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);
@@ -1042,12 +1052,12 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
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 */
@@ -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)
@@ -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 */
@@ -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;
--
2.9.5
On 08/19/2017 01:40 AM, David Daney wrote:
> Here are several improvements and bug fixes for the MIPS eBPF JIT.
>
> The main change is the addition of support for JLT, JLE, JSLT and JSLE
> ops, that were recently added.
>
> Also fix WARN output when used with preemptable kernel, and a small
> cleanup/optimization in the use of BPF_OP(insn->code).
>
> I suggest that the whole thing go via the BPF/net-next path as there
> are dependencies on code that is not yet merged to Linus' tree.
Yes, this would be via net-next.
> Still pending are changes to reduce stack usage when the verifier can
> determine the maximum stack size.
Awesome, thanks a lot!
From: David Daney <[email protected]>
Date: Fri, 18 Aug 2017 16:40:30 -0700
> I suggest that the whole thing go via the BPF/net-next path as there
> are dependencies on code that is not yet merged to Linus' tree.
What kind of dependency? On networking or MIPS changes?
If the dependency is on MIPS changes, then if I cannot apply this as
it will break the net-next build on MIPS. You should merge this
via the MIPS tree, where the dependencies are, in that case.
Please clarify what is specifically happening here.
Thanks.
On 08/21/2017 05:06 AM, David Miller wrote:
> From: David Daney <[email protected]>
> Date: Fri, 18 Aug 2017 16:40:30 -0700
>
>> I suggest that the whole thing go via the BPF/net-next path as there
>> are dependencies on code that is not yet merged to Linus' tree.
>
> What kind of dependency? On networking or MIPS changes?
On networking, David implemented the JLT, JLE, JSLT and JSLE
ops for the JIT in the patch set. Back then the MIPS JIT wasn't
in net-next tree, thus this is basically just a follow-up, so
that we have all covered with JIT support for net-next.
Thanks,
Daniel
From: David Daney <[email protected]>
Date: Fri, 18 Aug 2017 16:40:30 -0700
> Here are several improvements and bug fixes for the MIPS eBPF JIT.
>
> The main change is the addition of support for JLT, JLE, JSLT and JSLE
> ops, that were recently added.
>
> Also fix WARN output when used with preemptable kernel, and a small
> cleanup/optimization in the use of BPF_OP(insn->code).
>
> I suggest that the whole thing go via the BPF/net-next path as there
> are dependencies on code that is not yet merged to Linus' tree.
>
> Still pending are changes to reduce stack usage when the verifier can
> determine the maximum stack size.
Applied to net-next.
From: Daniel Borkmann <[email protected]>
Date: Mon, 21 Aug 2017 10:24:23 +0200
> On 08/21/2017 05:06 AM, David Miller wrote:
>> From: David Daney <[email protected]>
>> Date: Fri, 18 Aug 2017 16:40:30 -0700
>>
>>> I suggest that the whole thing go via the BPF/net-next path as there
>>> are dependencies on code that is not yet merged to Linus' tree.
>>
>> What kind of dependency? On networking or MIPS changes?
>
> On networking, David implemented the JLT, JLE, JSLT and JSLE
> ops for the JIT in the patch set. Back then the MIPS JIT wasn't
> in net-next tree, thus this is basically just a follow-up, so
> that we have all covered with JIT support for net-next.
Ok, that makes sense, thanks for explaining.