Commit e5e7a8f2 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

selftests/bpf: add few verifier scale tests 



Add 3 basic tests that stress verifier scalability.

test_verif_scale1.c calls non-inlined jhash() function 90 times on
different position in the packet.
This test simulates network packet parsing.
jhash function is ~140 instructions and main program is ~1200 insns.

test_verif_scale2.c force inlines jhash() function 90 times.
This program is ~15k instructions long.

test_verif_scale3.c calls non-inlined jhash() function 90 times on
But this time jhash has to process 32-bytes from the packet
instead of 14-bytes in tests 1 and 2.
jhash function is ~230 insns and main program is ~1200 insns.

$ test_progs -s
can be used to see verifier stats.

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent da11b417

tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c

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// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook

#include <test_progs.h>

static int libbpf_debug_print(enum libbpf_print_level level,

			      const char *format, va_list args)

{

	if (level != LIBBPF_DEBUG)

		return 0;



	if (!strstr(format, "verifier log"))

		return 0;

	return vfprintf(stderr, "%s", args);

}



static int check_load(const char *file)

{

	struct bpf_prog_load_attr attr;

	struct bpf_object *obj;

	int err, prog_fd;



	memset(&attr, 0, sizeof(struct bpf_prog_load_attr));

	attr.file = file;

	attr.prog_type = BPF_PROG_TYPE_SCHED_CLS;

	attr.log_level = 4;

	err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);

	bpf_object__close(obj);

	if (err)

		error_cnt++;

	return err;

}



void test_bpf_verif_scale(void)

{

	const char *file1 = "./test_verif_scale1.o";

	const char *file2 = "./test_verif_scale2.o";

	const char *file3 = "./test_verif_scale3.o";

	int err;



	if (verifier_stats)

		libbpf_set_print(libbpf_debug_print);



	err = check_load(file1);

	err |= check_load(file2);

	err |= check_load(file3);

	if (!err)

		printf("test_verif_scale:OK\n");

	else

		printf("test_verif_scale:FAIL\n");

}

tools/testing/selftests/bpf/progs/test_jhash.h

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// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook



typedef unsigned int u32;



static __attribute__((always_inline)) u32 rol32(u32 word, unsigned int shift)

{

	return (word << shift) | (word >> ((-shift) & 31));

}



#define __jhash_mix(a, b, c)			\

{						\

	a -= c;  a ^= rol32(c, 4);  c += b;	\

	b -= a;  b ^= rol32(a, 6);  a += c;	\

	c -= b;  c ^= rol32(b, 8);  b += a;	\

	a -= c;  a ^= rol32(c, 16); c += b;	\

	b -= a;  b ^= rol32(a, 19); a += c;	\

	c -= b;  c ^= rol32(b, 4);  b += a;	\

}



#define __jhash_final(a, b, c)			\

{						\

	c ^= b; c -= rol32(b, 14);		\

	a ^= c; a -= rol32(c, 11);		\

	b ^= a; b -= rol32(a, 25);		\

	c ^= b; c -= rol32(b, 16);		\

	a ^= c; a -= rol32(c, 4);		\

	b ^= a; b -= rol32(a, 14);		\

	c ^= b; c -= rol32(b, 24);		\

}



#define JHASH_INITVAL		0xdeadbeef



static ATTR

u32 jhash(const void *key, u32 length, u32 initval)

{

	u32 a, b, c;

	const unsigned char *k = key;



	a = b = c = JHASH_INITVAL + length + initval;



	while (length > 12) {

		a += *(volatile u32 *)(k);

		b += *(volatile u32 *)(k + 4);

		c += *(volatile u32 *)(k + 8);

		__jhash_mix(a, b, c);

		length -= 12;

		k += 12;

	}

	switch (length) {

	case 12: c += (u32)k[11]<<24;

	case 11: c += (u32)k[10]<<16;

	case 10: c += (u32)k[9]<<8;

	case 9:  c += k[8];

	case 8:  b += (u32)k[7]<<24;

	case 7:  b += (u32)k[6]<<16;

	case 6:  b += (u32)k[5]<<8;

	case 5:  b += k[4];

	case 4:  a += (u32)k[3]<<24;

	case 3:  a += (u32)k[2]<<16;

	case 2:  a += (u32)k[1]<<8;

	case 1:  a += k[0];

		 c ^= a;

		 __jhash_final(a, b, c);

	case 0: /* Nothing left to add */

		break;

	}



	return c;

}

tools/testing/selftests/bpf/progs/test_verif_scale1.c

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// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook

#include <linux/bpf.h>

#include "bpf_helpers.h"

#define ATTR __attribute__((noinline))

#include "test_jhash.h"



SEC("scale90_noinline")

int balancer_ingress(struct __sk_buff *ctx)

{

	void *data_end = (void *)(long)ctx->data_end;

	void *data = (void *)(long)ctx->data;

	void *ptr;

	int ret = 0, nh_off, i = 0;



	nh_off = 14;



	/* pragma unroll doesn't work on large loops */



#define C do { \

	ptr = data + i; \

	if (ptr + nh_off > data_end) \

		break; \

	ctx->tc_index = jhash(ptr, nh_off, ctx->cb[0] + i++); \

	} while (0);

#define C30 C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;

	C30;C30;C30; /* 90 calls */

	return 0;

}

char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/test_verif_scale2.c

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// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook

#include <linux/bpf.h>

#include "bpf_helpers.h"

#define ATTR __attribute__((always_inline))

#include "test_jhash.h"



SEC("scale90_inline")

int balancer_ingress(struct __sk_buff *ctx)

{

	void *data_end = (void *)(long)ctx->data_end;

	void *data = (void *)(long)ctx->data;

	void *ptr;

	int ret = 0, nh_off, i = 0;



	nh_off = 14;



	/* pragma unroll doesn't work on large loops */



#define C do { \

	ptr = data + i; \

	if (ptr + nh_off > data_end) \

		break; \

	ctx->tc_index = jhash(ptr, nh_off, ctx->cb[0] + i++); \

	} while (0);

#define C30 C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;

	C30;C30;C30; /* 90 calls */

	return 0;

}

char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/progs/test_verif_scale3.c

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// SPDX-License-Identifier: GPL-2.0

// Copyright (c) 2019 Facebook

#include <linux/bpf.h>

#include "bpf_helpers.h"

#define ATTR __attribute__((noinline))

#include "test_jhash.h"



SEC("scale90_noinline32")

int balancer_ingress(struct __sk_buff *ctx)

{

	void *data_end = (void *)(long)ctx->data_end;

	void *data = (void *)(long)ctx->data;

	void *ptr;

	int ret = 0, nh_off, i = 0;



	nh_off = 32;



	/* pragma unroll doesn't work on large loops */



#define C do { \

	ptr = data + i; \

	if (ptr + nh_off > data_end) \

		break; \

	ctx->tc_index = jhash(ptr, nh_off, ctx->cb[0] + i++); \

	} while (0);

#define C30 C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;

	C30;C30;C30; /* 90 calls */

	return 0;

}

char _license[] SEC("license") = "GPL";

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