samples/bpf: add bpf map stress test

this test calls bpf programs from different contexts:
from inside of slub, from rcu, from pretty much everywhere,
since it kprobes all spin_lock functions.
It stresses the bpf hash and percpu map pre-allocation,
deallocation logic and call_rcu mechanisms.
User space part adding more stress by walking and deleting map elements.

Note that due to nature bpf_load.c the earlier kprobe+bpf programs are
already active while loader loads new programs, creates new kprobes and
attaches them.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov 2016-03-08 15:07:52 -08:00 committed by David S. Miller
parent e28e87ed47
commit 9d8b612d88
3 changed files with 113 additions and 0 deletions

View file

@ -17,6 +17,7 @@ hostprogs-y += tracex6
hostprogs-y += trace_output
hostprogs-y += lathist
hostprogs-y += offwaketime
hostprogs-y += spintest
test_verifier-objs := test_verifier.o libbpf.o
test_maps-objs := test_maps.o libbpf.o
@ -34,6 +35,7 @@ tracex6-objs := bpf_load.o libbpf.o tracex6_user.o
trace_output-objs := bpf_load.o libbpf.o trace_output_user.o
lathist-objs := bpf_load.o libbpf.o lathist_user.o
offwaketime-objs := bpf_load.o libbpf.o offwaketime_user.o
spintest-objs := bpf_load.o libbpf.o spintest_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
@ -50,6 +52,7 @@ always += trace_output_kern.o
always += tcbpf1_kern.o
always += lathist_kern.o
always += offwaketime_kern.o
always += spintest_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
@ -67,6 +70,7 @@ HOSTLOADLIBES_tracex6 += -lelf
HOSTLOADLIBES_trace_output += -lelf -lrt
HOSTLOADLIBES_lathist += -lelf
HOSTLOADLIBES_offwaketime += -lelf
HOSTLOADLIBES_spintest += -lelf
# point this to your LLVM backend with bpf support
LLC=$(srctree)/tools/bpf/llvm/bld/Debug+Asserts/bin/llc

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@ -0,0 +1,59 @@
/* Copyright (c) 2016, Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(long),
.value_size = sizeof(long),
.max_entries = 1024,
};
struct bpf_map_def SEC("maps") my_map2 = {
.type = BPF_MAP_TYPE_PERCPU_HASH,
.key_size = sizeof(long),
.value_size = sizeof(long),
.max_entries = 1024,
};
#define PROG(foo) \
int foo(struct pt_regs *ctx) \
{ \
long v = ctx->ip, *val; \
\
val = bpf_map_lookup_elem(&my_map, &v); \
bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
bpf_map_update_elem(&my_map2, &v, &v, BPF_ANY); \
bpf_map_delete_elem(&my_map2, &v); \
return 0; \
}
/* add kprobes to all possible *spin* functions */
SEC("kprobe/spin_unlock")PROG(p1)
SEC("kprobe/spin_lock")PROG(p2)
SEC("kprobe/mutex_spin_on_owner")PROG(p3)
SEC("kprobe/rwsem_spin_on_owner")PROG(p4)
SEC("kprobe/spin_unlock_irqrestore")PROG(p5)
SEC("kprobe/_raw_spin_unlock_irqrestore")PROG(p6)
SEC("kprobe/_raw_spin_unlock_bh")PROG(p7)
SEC("kprobe/_raw_spin_unlock")PROG(p8)
SEC("kprobe/_raw_spin_lock_irqsave")PROG(p9)
SEC("kprobe/_raw_spin_trylock_bh")PROG(p10)
SEC("kprobe/_raw_spin_lock_irq")PROG(p11)
SEC("kprobe/_raw_spin_trylock")PROG(p12)
SEC("kprobe/_raw_spin_lock")PROG(p13)
SEC("kprobe/_raw_spin_lock_bh")PROG(p14)
/* and to inner bpf helpers */
SEC("kprobe/htab_map_update_elem")PROG(p15)
SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)
SEC("kprobe/htab_map_alloc")PROG(p17)
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;

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@ -0,0 +1,50 @@
#include <stdio.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <string.h>
#include <assert.h>
#include <sys/resource.h>
#include "libbpf.h"
#include "bpf_load.h"
int main(int ac, char **argv)
{
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
long key, next_key, value;
char filename[256];
struct ksym *sym;
int i;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
setrlimit(RLIMIT_MEMLOCK, &r);
if (load_kallsyms()) {
printf("failed to process /proc/kallsyms\n");
return 2;
}
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
}
for (i = 0; i < 5; i++) {
key = 0;
printf("kprobing funcs:");
while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0) {
bpf_lookup_elem(map_fd[0], &next_key, &value);
assert(next_key == value);
sym = ksym_search(value);
printf(" %s", sym->name);
key = next_key;
}
if (key)
printf("\n");
key = 0;
while (bpf_get_next_key(map_fd[0], &key, &next_key) == 0)
bpf_delete_elem(map_fd[0], &next_key);
sleep(1);
}
return 0;
}