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>
This commit is contained in:
Alexei Starovoitov 2015-07-20 20:34:19 -07:00 committed by David S. Miller
parent 4e10df9a60
commit 4d9c5c53ac
3 changed files with 98 additions and 3 deletions

View File

@ -177,6 +177,7 @@ noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
{
return 0;
}
EXPORT_SYMBOL_GPL(__bpf_call_base);
/**
* __bpf_prog_run - run eBPF program on a given context

View File

@ -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 @@ static int bpf_fill_ja(struct bpf_test *self)
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 @@ static struct bpf_test tests[] = {
{ { 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 @@ static int __run_one(const struct bpf_prog *fp, const void *data,
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;

View File

@ -1457,6 +1457,7 @@ const struct bpf_func_proto bpf_skb_vlan_push_proto = {
.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 @@ const struct bpf_func_proto bpf_skb_vlan_pop_proto = {
.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)
{