test_bpf: add bpf_skb_vlan_push/pop() tests
improve accuracy of timing in test_bpf and add two stress tests:
- {skb->data[0], get_smp_processor_id} repeated 2k times
- {skb->data[0], vlan_push} x 68 followed by {skb->data[0], vlan_pop} x 68
1st test is useful to test performance of JIT implementation of BPF_LD_ABS
together with BPF_CALL instructions.
2nd test is stressing skb_vlan_push/pop logic together with skb->data access
via BPF_LD_ABS insn which checks that re-caching of skb->data is done correctly.
In order to call bpf_skb_vlan_push() from test_bpf.ko have to add
three export_symbol_gpl.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index bf38f5e..fafa741 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -177,6 +177,7 @@
{
return 0;
}
+EXPORT_SYMBOL_GPL(__bpf_call_base);
/**
* __bpf_prog_run - run eBPF program on a given context
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 9198f28..8b5e66f 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -18,6 +18,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/filter.h>
+#include <linux/bpf.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
@@ -355,6 +356,81 @@
return __bpf_fill_ja(self, 12, 9);
}
+static int bpf_fill_ld_abs_get_processor_id(struct bpf_test *self)
+{
+ unsigned int len = BPF_MAXINSNS;
+ struct sock_filter *insn;
+ int i;
+
+ insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL);
+ if (!insn)
+ return -ENOMEM;
+
+ for (i = 0; i < len - 1; i += 2) {
+ insn[i] = __BPF_STMT(BPF_LD | BPF_B | BPF_ABS, 0);
+ insn[i + 1] = __BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
+ SKF_AD_OFF + SKF_AD_CPU);
+ }
+
+ insn[len - 1] = __BPF_STMT(BPF_RET | BPF_K, 0xbee);
+
+ self->u.ptr.insns = insn;
+ self->u.ptr.len = len;
+
+ return 0;
+}
+
+#define PUSH_CNT 68
+/* test: {skb->data[0], vlan_push} x 68 + {skb->data[0], vlan_pop} x 68 */
+static int bpf_fill_ld_abs_vlan_push_pop(struct bpf_test *self)
+{
+ unsigned int len = BPF_MAXINSNS;
+ struct bpf_insn *insn;
+ int i = 0, j, k = 0;
+
+ insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL);
+ if (!insn)
+ return -ENOMEM;
+
+ insn[i++] = BPF_MOV64_REG(R6, R1);
+loop:
+ for (j = 0; j < PUSH_CNT; j++) {
+ insn[i++] = BPF_LD_ABS(BPF_B, 0);
+ insn[i] = BPF_JMP_IMM(BPF_JNE, R0, 0x34, len - i - 2);
+ i++;
+ insn[i++] = BPF_MOV64_REG(R1, R6);
+ insn[i++] = BPF_MOV64_IMM(R2, 1);
+ insn[i++] = BPF_MOV64_IMM(R3, 2);
+ insn[i++] = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ bpf_skb_vlan_push_proto.func - __bpf_call_base);
+ insn[i] = BPF_JMP_IMM(BPF_JNE, R0, 0, len - i - 2);
+ i++;
+ }
+
+ for (j = 0; j < PUSH_CNT; j++) {
+ insn[i++] = BPF_LD_ABS(BPF_B, 0);
+ insn[i] = BPF_JMP_IMM(BPF_JNE, R0, 0x34, len - i - 2);
+ i++;
+ insn[i++] = BPF_MOV64_REG(R1, R6);
+ insn[i++] = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ bpf_skb_vlan_pop_proto.func - __bpf_call_base);
+ insn[i] = BPF_JMP_IMM(BPF_JNE, R0, 0, len - i - 2);
+ i++;
+ }
+ if (++k < 5)
+ goto loop;
+
+ for (; i < len - 1; i++)
+ insn[i] = BPF_ALU32_IMM(BPF_MOV, R0, 0xbef);
+
+ insn[len - 1] = BPF_EXIT_INSN();
+
+ self->u.ptr.insns = insn;
+ self->u.ptr.len = len;
+
+ return 0;
+}
+
static struct bpf_test tests[] = {
{
"TAX",
@@ -4398,6 +4474,22 @@
{ { 0, 0xababcbac } },
.fill_helper = bpf_fill_maxinsns11,
},
+ {
+ "BPF_MAXINSNS: ld_abs+get_processor_id",
+ { },
+ CLASSIC,
+ { },
+ { { 1, 0xbee } },
+ .fill_helper = bpf_fill_ld_abs_get_processor_id,
+ },
+ {
+ "BPF_MAXINSNS: ld_abs+vlan_push/pop",
+ { },
+ INTERNAL,
+ { 0x34 },
+ { { 1, 0xbef } },
+ .fill_helper = bpf_fill_ld_abs_vlan_push_pop,
+ },
};
static struct net_device dev;
@@ -4551,14 +4643,14 @@
u64 start, finish;
int ret = 0, i;
- start = ktime_to_us(ktime_get());
+ start = ktime_get_ns();
for (i = 0; i < runs; i++)
ret = BPF_PROG_RUN(fp, data);
- finish = ktime_to_us(ktime_get());
+ finish = ktime_get_ns();
- *duration = (finish - start) * 1000ULL;
+ *duration = finish - start;
do_div(*duration, runs);
return ret;
diff --git a/net/core/filter.c b/net/core/filter.c
index 5033807..786722a 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1457,6 +1457,7 @@
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
};
+EXPORT_SYMBOL_GPL(bpf_skb_vlan_push_proto);
static u64 bpf_skb_vlan_pop(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
{
@@ -1471,6 +1472,7 @@
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
+EXPORT_SYMBOL_GPL(bpf_skb_vlan_pop_proto);
bool bpf_helper_changes_skb_data(void *func)
{
