* [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs
@ 2019-02-22 22:36 Jiong Wang
2019-02-22 22:36 ` [PATCH bpf 1/2] nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K Jiong Wang
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Jiong Wang @ 2019-02-22 22:36 UTC (permalink / raw)
To: alexei.starovoitov, daniel; +Cc: netdev, oss-drivers, Jiong Wang
code-gen for BPF_ALU | BPF_XOR | BPF_K is wrong when imm is -1, also high
32-bit of 64-bit register should always be cleared.
This set fixed both bugs.
Jiong Wang (2):
nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K
nfp: bpf: fix ALU32 high bits clearance bug
drivers/net/ethernet/netronome/nfp/bpf/jit.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
--
2.7.4
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH bpf 1/2] nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K
2019-02-22 22:36 [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs Jiong Wang
@ 2019-02-22 22:36 ` Jiong Wang
2019-02-22 22:36 ` [PATCH bpf 2/2] nfp: bpf: fix ALU32 high bits clearance bug Jiong Wang
2019-02-22 23:09 ` [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs Daniel Borkmann
2 siblings, 0 replies; 4+ messages in thread
From: Jiong Wang @ 2019-02-22 22:36 UTC (permalink / raw)
To: alexei.starovoitov, daniel; +Cc: netdev, oss-drivers, Jiong Wang
The intended optimization should be A ^ 0 = A, not A ^ -1 = A.
Fixes: cd7df56ed3e6 ("nfp: add BPF to NFP code translator")
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
---
drivers/net/ethernet/netronome/nfp/bpf/jit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index e23ca90..a096965 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -2309,7 +2309,7 @@ static int xor_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int xor_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
- return wrp_alu32_imm(nfp_prog, meta, ALU_OP_XOR, !~meta->insn.imm);
+ return wrp_alu32_imm(nfp_prog, meta, ALU_OP_XOR, !meta->insn.imm);
}
static int and_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH bpf 2/2] nfp: bpf: fix ALU32 high bits clearance bug
2019-02-22 22:36 [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs Jiong Wang
2019-02-22 22:36 ` [PATCH bpf 1/2] nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K Jiong Wang
@ 2019-02-22 22:36 ` Jiong Wang
2019-02-22 23:09 ` [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs Daniel Borkmann
2 siblings, 0 replies; 4+ messages in thread
From: Jiong Wang @ 2019-02-22 22:36 UTC (permalink / raw)
To: alexei.starovoitov, daniel; +Cc: netdev, oss-drivers, Jiong Wang
NFP BPF JIT compiler is doing a couple of small optimizations when jitting
ALU imm instructions, some of these optimizations could save code-gen, for
example:
A & -1 = A
A | 0 = A
A ^ 0 = A
However, for ALU32, high 32-bit of the 64-bit register should still be
cleared according to ISA semantics.
Fixes: cd7df56ed3e6 ("nfp: add BPF to NFP code translator")
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
---
drivers/net/ethernet/netronome/nfp/bpf/jit.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
index a096965..0a868c8 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -1291,15 +1291,10 @@ wrp_alu64_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
static int
wrp_alu32_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
- enum alu_op alu_op, bool skip)
+ enum alu_op alu_op)
{
const struct bpf_insn *insn = &meta->insn;
- if (skip) {
- meta->skip = true;
- return 0;
- }
-
wrp_alu_imm(nfp_prog, insn->dst_reg * 2, alu_op, insn->imm);
wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2 + 1), 0);
@@ -2309,7 +2304,7 @@ static int xor_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int xor_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
- return wrp_alu32_imm(nfp_prog, meta, ALU_OP_XOR, !meta->insn.imm);
+ return wrp_alu32_imm(nfp_prog, meta, ALU_OP_XOR);
}
static int and_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
@@ -2319,7 +2314,7 @@ static int and_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int and_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
- return wrp_alu32_imm(nfp_prog, meta, ALU_OP_AND, !~meta->insn.imm);
+ return wrp_alu32_imm(nfp_prog, meta, ALU_OP_AND);
}
static int or_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
@@ -2329,7 +2324,7 @@ static int or_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int or_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
- return wrp_alu32_imm(nfp_prog, meta, ALU_OP_OR, !meta->insn.imm);
+ return wrp_alu32_imm(nfp_prog, meta, ALU_OP_OR);
}
static int add_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
@@ -2339,7 +2334,7 @@ static int add_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int add_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
- return wrp_alu32_imm(nfp_prog, meta, ALU_OP_ADD, !meta->insn.imm);
+ return wrp_alu32_imm(nfp_prog, meta, ALU_OP_ADD);
}
static int sub_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
@@ -2349,7 +2344,7 @@ static int sub_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
static int sub_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
- return wrp_alu32_imm(nfp_prog, meta, ALU_OP_SUB, !meta->insn.imm);
+ return wrp_alu32_imm(nfp_prog, meta, ALU_OP_SUB);
}
static int mul_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs
2019-02-22 22:36 [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs Jiong Wang
2019-02-22 22:36 ` [PATCH bpf 1/2] nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K Jiong Wang
2019-02-22 22:36 ` [PATCH bpf 2/2] nfp: bpf: fix ALU32 high bits clearance bug Jiong Wang
@ 2019-02-22 23:09 ` Daniel Borkmann
2 siblings, 0 replies; 4+ messages in thread
From: Daniel Borkmann @ 2019-02-22 23:09 UTC (permalink / raw)
To: Jiong Wang, alexei.starovoitov; +Cc: netdev, oss-drivers
On 02/22/2019 11:36 PM, Jiong Wang wrote:
> code-gen for BPF_ALU | BPF_XOR | BPF_K is wrong when imm is -1, also high
> 32-bit of 64-bit register should always be cleared.
>
> This set fixed both bugs.
>
> Jiong Wang (2):
> nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K
> nfp: bpf: fix ALU32 high bits clearance bug
>
> drivers/net/ethernet/netronome/nfp/bpf/jit.c | 17 ++++++-----------
> 1 file changed, 6 insertions(+), 11 deletions(-)
>
Applied, thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-02-22 23:09 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-02-22 22:36 [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs Jiong Wang
2019-02-22 22:36 ` [PATCH bpf 1/2] nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K Jiong Wang
2019-02-22 22:36 ` [PATCH bpf 2/2] nfp: bpf: fix ALU32 high bits clearance bug Jiong Wang
2019-02-22 23:09 ` [PATCH bpf 0/2] nfp: bpf: fix two ALU32 code-gen bugs Daniel Borkmann
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