static inline void bpf_prog_put(struct bpf_prog *prog)
{
}
+static inline struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
#endif /* CONFIG_BPF_SYSCALL */
/* verifier prototypes for helper functions called from eBPF programs */
u64 (*clock)(void);
perf_overflow_handler_t overflow_handler;
void *overflow_handler_context;
+#ifdef CONFIG_BPF_SYSCALL
+ perf_overflow_handler_t orig_overflow_handler;
+ struct bpf_prog *prog;
+#endif
#ifdef CONFIG_EVENT_TRACING
struct trace_event_call *tp_event;
int page;
};
+struct bpf_perf_event_data_kern {
+ struct pt_regs *regs;
+ struct perf_sample_data *data;
+};
+
#ifdef CONFIG_CGROUP_PERF
/*
header-y += blkpg.h
header-y += blktrace_api.h
header-y += bpf_common.h
+header-y += bpf_perf_event.h
header-y += bpf.h
header-y += bpqether.h
header-y += bsg.h
BPF_PROG_TYPE_SCHED_ACT,
BPF_PROG_TYPE_TRACEPOINT,
BPF_PROG_TYPE_XDP,
+ BPF_PROG_TYPE_PERF_EVENT,
};
#define BPF_PSEUDO_MAP_FD 1
--- /dev/null
+/* 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.
+ */
+#ifndef _UAPI__LINUX_BPF_PERF_EVENT_H__
+#define _UAPI__LINUX_BPF_PERF_EVENT_H__
+
+#include <linux/types.h>
+#include <linux/ptrace.h>
+
+struct bpf_perf_event_data {
+ struct pt_regs regs;
+ __u64 sample_period;
+};
+
+#endif /* _UAPI__LINUX_BPF_PERF_EVENT_H__ */
if (err)
return err;
- if (BPF_SIZE(insn->code) != BPF_W) {
+ if (BPF_SIZE(insn->code) != BPF_W &&
+ BPF_SIZE(insn->code) != BPF_DW) {
insn_idx++;
continue;
}
return 0;
}
+static int check_map_prog_compatibility(struct bpf_map *map,
+ struct bpf_prog *prog)
+
+{
+ if (prog->type == BPF_PROG_TYPE_PERF_EVENT &&
+ (map->map_type == BPF_MAP_TYPE_HASH ||
+ map->map_type == BPF_MAP_TYPE_PERCPU_HASH) &&
+ (map->map_flags & BPF_F_NO_PREALLOC)) {
+ verbose("perf_event programs can only use preallocated hash map\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
/* look for pseudo eBPF instructions that access map FDs and
* replace them with actual map pointers
*/
{
struct bpf_insn *insn = env->prog->insnsi;
int insn_cnt = env->prog->len;
- int i, j;
+ int i, j, err;
for (i = 0; i < insn_cnt; i++, insn++) {
if (BPF_CLASS(insn->code) == BPF_LDX &&
return PTR_ERR(map);
}
+ err = check_map_prog_compatibility(map, env->prog);
+ if (err) {
+ fdput(f);
+ return err;
+ }
+
/* store map pointer inside BPF_LD_IMM64 instruction */
insn[0].imm = (u32) (unsigned long) map;
insn[1].imm = ((u64) (unsigned long) map) >> 32;
for (i = 0; i < insn_cnt; i++, insn++) {
u32 insn_delta, cnt;
- if (insn->code == (BPF_LDX | BPF_MEM | BPF_W))
+ if (insn->code == (BPF_LDX | BPF_MEM | BPF_W) ||
+ insn->code == (BPF_LDX | BPF_MEM | BPF_DW))
type = BPF_READ;
- else if (insn->code == (BPF_STX | BPF_MEM | BPF_W))
+ else if (insn->code == (BPF_STX | BPF_MEM | BPF_W) ||
+ insn->code == (BPF_STX | BPF_MEM | BPF_DW))
type = BPF_WRITE;
else
continue;
irq_work_queue(&event->pending);
}
- event->overflow_handler(event, data, regs);
+ READ_ONCE(event->overflow_handler)(event, data, regs);
if (*perf_event_fasync(event) && event->pending_kill) {
event->pending_wakeup = 1;
ftrace_profile_free_filter(event);
}
+#ifdef CONFIG_BPF_SYSCALL
+static void bpf_overflow_handler(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ struct bpf_perf_event_data_kern ctx = {
+ .data = data,
+ .regs = regs,
+ };
+ int ret = 0;
+
+ preempt_disable();
+ if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
+ goto out;
+ rcu_read_lock();
+ ret = BPF_PROG_RUN(event->prog, (void *)&ctx);
+ rcu_read_unlock();
+out:
+ __this_cpu_dec(bpf_prog_active);
+ preempt_enable();
+ if (!ret)
+ return;
+
+ event->orig_overflow_handler(event, data, regs);
+}
+
+static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd)
+{
+ struct bpf_prog *prog;
+
+ if (event->overflow_handler_context)
+ /* hw breakpoint or kernel counter */
+ return -EINVAL;
+
+ if (event->prog)
+ return -EEXIST;
+
+ prog = bpf_prog_get_type(prog_fd, BPF_PROG_TYPE_PERF_EVENT);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+
+ event->prog = prog;
+ event->orig_overflow_handler = READ_ONCE(event->overflow_handler);
+ WRITE_ONCE(event->overflow_handler, bpf_overflow_handler);
+ return 0;
+}
+
+static void perf_event_free_bpf_handler(struct perf_event *event)
+{
+ struct bpf_prog *prog = event->prog;
+
+ if (!prog)
+ return;
+
+ WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler);
+ event->prog = NULL;
+ bpf_prog_put(prog);
+}
+#else
+static int perf_event_set_bpf_handler(struct perf_event *event, u32 prog_fd)
+{
+ return -EOPNOTSUPP;
+}
+static void perf_event_free_bpf_handler(struct perf_event *event)
+{
+}
+#endif
+
static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)
{
bool is_kprobe, is_tracepoint;
struct bpf_prog *prog;
+ if (event->attr.type == PERF_TYPE_HARDWARE ||
+ event->attr.type == PERF_TYPE_SOFTWARE)
+ return perf_event_set_bpf_handler(event, prog_fd);
+
if (event->attr.type != PERF_TYPE_TRACEPOINT)
return -EINVAL;
{
struct bpf_prog *prog;
+ perf_event_free_bpf_handler(event);
+
if (!event->tp_event)
return;
if (!overflow_handler && parent_event) {
overflow_handler = parent_event->overflow_handler;
context = parent_event->overflow_handler_context;
+#ifdef CONFIG_BPF_SYSCALL
+ if (overflow_handler == bpf_overflow_handler) {
+ struct bpf_prog *prog = bpf_prog_inc(parent_event->prog);
+
+ if (IS_ERR(prog)) {
+ err = PTR_ERR(prog);
+ goto err_ns;
+ }
+ event->prog = prog;
+ event->orig_overflow_handler =
+ parent_event->orig_overflow_handler;
+ }
+#endif
}
if (overflow_handler) {
/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
+ * 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
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/bpf.h>
+#include <linux/bpf_perf_event.h>
#include <linux/filter.h>
#include <linux/uaccess.h>
#include <linux/ctype.h>
.type = BPF_PROG_TYPE_TRACEPOINT,
};
+static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
+ enum bpf_reg_type *reg_type)
+{
+ if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
+ return false;
+ if (type != BPF_READ)
+ return false;
+ if (off % size != 0)
+ return false;
+ if (off == offsetof(struct bpf_perf_event_data, sample_period)) {
+ if (size != sizeof(u64))
+ return false;
+ } else {
+ if (size != sizeof(long))
+ return false;
+ }
+ return true;
+}
+
+static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, int dst_reg,
+ int src_reg, int ctx_off,
+ struct bpf_insn *insn_buf,
+ struct bpf_prog *prog)
+{
+ struct bpf_insn *insn = insn_buf;
+
+ switch (ctx_off) {
+ case offsetof(struct bpf_perf_event_data, sample_period):
+ BUILD_BUG_ON(FIELD_SIZEOF(struct perf_sample_data, period) != sizeof(u64));
+ *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct bpf_perf_event_data_kern, data)),
+ dst_reg, src_reg,
+ offsetof(struct bpf_perf_event_data_kern, data));
+ *insn++ = BPF_LDX_MEM(BPF_DW, dst_reg, dst_reg,
+ offsetof(struct perf_sample_data, period));
+ break;
+ default:
+ *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct bpf_perf_event_data_kern, regs)),
+ dst_reg, src_reg,
+ offsetof(struct bpf_perf_event_data_kern, regs));
+ *insn++ = BPF_LDX_MEM(bytes_to_bpf_size(sizeof(long)),
+ dst_reg, dst_reg, ctx_off);
+ break;
+ }
+
+ return insn - insn_buf;
+}
+
+static const struct bpf_verifier_ops perf_event_prog_ops = {
+ .get_func_proto = tp_prog_func_proto,
+ .is_valid_access = pe_prog_is_valid_access,
+ .convert_ctx_access = pe_prog_convert_ctx_access,
+};
+
+static struct bpf_prog_type_list perf_event_tl = {
+ .ops = &perf_event_prog_ops,
+ .type = BPF_PROG_TYPE_PERF_EVENT,
+};
+
static int __init register_kprobe_prog_ops(void)
{
bpf_register_prog_type(&kprobe_tl);
bpf_register_prog_type(&tracepoint_tl);
+ bpf_register_prog_type(&perf_event_tl);
return 0;
}
late_initcall(register_kprobe_prog_ops);
hostprogs-y += xdp1
hostprogs-y += xdp2
hostprogs-y += test_current_task_under_cgroup
+hostprogs-y += trace_event
+hostprogs-y += sampleip
test_verifier-objs := test_verifier.o libbpf.o
test_maps-objs := test_maps.o libbpf.o
xdp2-objs := bpf_load.o libbpf.o xdp1_user.o
test_current_task_under_cgroup-objs := bpf_load.o libbpf.o \
test_current_task_under_cgroup_user.o
+trace_event-objs := bpf_load.o libbpf.o trace_event_user.o
+sampleip-objs := bpf_load.o libbpf.o sampleip_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
always += xdp1_kern.o
always += xdp2_kern.o
always += test_current_task_under_cgroup_kern.o
+always += trace_event_kern.o
+always += sampleip_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
HOSTLOADLIBES_xdp1 += -lelf
HOSTLOADLIBES_xdp2 += -lelf
HOSTLOADLIBES_test_current_task_under_cgroup += -lelf
+HOSTLOADLIBES_trace_event += -lelf
+HOSTLOADLIBES_sampleip += -lelf
# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
# make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
(void *) BPF_FUNC_skb_get_tunnel_opt;
static int (*bpf_skb_set_tunnel_opt)(void *ctx, void *md, int size) =
(void *) BPF_FUNC_skb_set_tunnel_opt;
+static unsigned long long (*bpf_get_prandom_u32)(void) =
+ (void *) BPF_FUNC_get_prandom_u32;
/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions
bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0;
bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0;
bool is_xdp = strncmp(event, "xdp", 3) == 0;
+ bool is_perf_event = strncmp(event, "perf_event", 10) == 0;
enum bpf_prog_type prog_type;
char buf[256];
int fd, efd, err, id;
prog_type = BPF_PROG_TYPE_TRACEPOINT;
} else if (is_xdp) {
prog_type = BPF_PROG_TYPE_XDP;
+ } else if (is_perf_event) {
+ prog_type = BPF_PROG_TYPE_PERF_EVENT;
} else {
printf("Unknown event '%s'\n", event);
return -1;
prog_fd[prog_cnt++] = fd;
- if (is_xdp)
+ if (is_xdp || is_perf_event)
return 0;
if (is_socket) {
memcmp(shname_prog, "kretprobe/", 10) == 0 ||
memcmp(shname_prog, "tracepoint/", 11) == 0 ||
memcmp(shname_prog, "xdp", 3) == 0 ||
+ memcmp(shname_prog, "perf_event", 10) == 0 ||
memcmp(shname_prog, "socket", 6) == 0)
load_and_attach(shname_prog, insns, data_prog->d_size);
}
memcmp(shname, "kretprobe/", 10) == 0 ||
memcmp(shname, "tracepoint/", 11) == 0 ||
memcmp(shname, "xdp", 3) == 0 ||
+ memcmp(shname, "perf_event", 10) == 0 ||
memcmp(shname, "socket", 6) == 0)
load_and_attach(shname, data->d_buf, data->d_size);
}
--- /dev/null
+/* Copyright 2016 Netflix, Inc.
+ *
+ * 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/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
+#include "bpf_helpers.h"
+
+#define MAX_IPS 8192
+
+struct bpf_map_def SEC("maps") ip_map = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(u64),
+ .value_size = sizeof(u32),
+ .max_entries = MAX_IPS,
+};
+
+SEC("perf_event")
+int do_sample(struct bpf_perf_event_data *ctx)
+{
+ u64 ip;
+ u32 *value, init_val = 1;
+
+ ip = ctx->regs.ip;
+ value = bpf_map_lookup_elem(&ip_map, &ip);
+ if (value)
+ *value += 1;
+ else
+ /* E2BIG not tested for this example only */
+ bpf_map_update_elem(&ip_map, &ip, &init_val, BPF_NOEXIST);
+
+ return 0;
+}
+char _license[] SEC("license") = "GPL";
--- /dev/null
+/*
+ * sampleip: sample instruction pointer and frequency count in a BPF map.
+ *
+ * Copyright 2016 Netflix, Inc.
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <assert.h>
+#include <linux/perf_event.h>
+#include <linux/ptrace.h>
+#include <linux/bpf.h>
+#include <sys/ioctl.h>
+#include "libbpf.h"
+#include "bpf_load.h"
+
+#define DEFAULT_FREQ 99
+#define DEFAULT_SECS 5
+#define MAX_IPS 8192
+#define PAGE_OFFSET 0xffff880000000000
+
+static int nr_cpus;
+
+static void usage(void)
+{
+ printf("USAGE: sampleip [-F freq] [duration]\n");
+ printf(" -F freq # sample frequency (Hertz), default 99\n");
+ printf(" duration # sampling duration (seconds), default 5\n");
+}
+
+static int sampling_start(int *pmu_fd, int freq)
+{
+ int i;
+
+ struct perf_event_attr pe_sample_attr = {
+ .type = PERF_TYPE_SOFTWARE,
+ .freq = 1,
+ .sample_period = freq,
+ .config = PERF_COUNT_SW_CPU_CLOCK,
+ .inherit = 1,
+ };
+
+ for (i = 0; i < nr_cpus; i++) {
+ pmu_fd[i] = perf_event_open(&pe_sample_attr, -1 /* pid */, i,
+ -1 /* group_fd */, 0 /* flags */);
+ if (pmu_fd[i] < 0) {
+ fprintf(stderr, "ERROR: Initializing perf sampling\n");
+ return 1;
+ }
+ assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF,
+ prog_fd[0]) == 0);
+ assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0);
+ }
+
+ return 0;
+}
+
+static void sampling_end(int *pmu_fd)
+{
+ int i;
+
+ for (i = 0; i < nr_cpus; i++)
+ close(pmu_fd[i]);
+}
+
+struct ipcount {
+ __u64 ip;
+ __u32 count;
+};
+
+/* used for sorting */
+struct ipcount counts[MAX_IPS];
+
+static int count_cmp(const void *p1, const void *p2)
+{
+ return ((struct ipcount *)p1)->count - ((struct ipcount *)p2)->count;
+}
+
+static void print_ip_map(int fd)
+{
+ struct ksym *sym;
+ __u64 key, next_key;
+ __u32 value;
+ int i, max;
+
+ printf("%-19s %-32s %s\n", "ADDR", "KSYM", "COUNT");
+
+ /* fetch IPs and counts */
+ key = 0, i = 0;
+ while (bpf_get_next_key(fd, &key, &next_key) == 0) {
+ bpf_lookup_elem(fd, &next_key, &value);
+ counts[i].ip = next_key;
+ counts[i++].count = value;
+ key = next_key;
+ }
+ max = i;
+
+ /* sort and print */
+ qsort(counts, max, sizeof(struct ipcount), count_cmp);
+ for (i = 0; i < max; i++) {
+ if (counts[i].ip > PAGE_OFFSET) {
+ sym = ksym_search(counts[i].ip);
+ printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name,
+ counts[i].count);
+ } else {
+ printf("0x%-17llx %-32s %u\n", counts[i].ip, "(user)",
+ counts[i].count);
+ }
+ }
+
+ if (max == MAX_IPS) {
+ printf("WARNING: IP hash was full (max %d entries); ", max);
+ printf("may have dropped samples\n");
+ }
+}
+
+static void int_exit(int sig)
+{
+ printf("\n");
+ print_ip_map(map_fd[0]);
+ exit(0);
+}
+
+int main(int argc, char **argv)
+{
+ char filename[256];
+ int *pmu_fd, opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS;
+
+ /* process arguments */
+ while ((opt = getopt(argc, argv, "F:h")) != -1) {
+ switch (opt) {
+ case 'F':
+ freq = atoi(optarg);
+ break;
+ case 'h':
+ default:
+ usage();
+ return 0;
+ }
+ }
+ if (argc - optind == 1)
+ secs = atoi(argv[optind]);
+ if (freq == 0 || secs == 0) {
+ usage();
+ return 1;
+ }
+
+ /* initialize kernel symbol translation */
+ if (load_kallsyms()) {
+ fprintf(stderr, "ERROR: loading /proc/kallsyms\n");
+ return 2;
+ }
+
+ /* create perf FDs for each CPU */
+ nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+ pmu_fd = malloc(nr_cpus * sizeof(int));
+ if (pmu_fd == NULL) {
+ fprintf(stderr, "ERROR: malloc of pmu_fd\n");
+ return 1;
+ }
+
+ /* load BPF program */
+ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+ if (load_bpf_file(filename)) {
+ fprintf(stderr, "ERROR: loading BPF program (errno %d):\n",
+ errno);
+ if (strcmp(bpf_log_buf, "") == 0)
+ fprintf(stderr, "Try: ulimit -l unlimited\n");
+ else
+ fprintf(stderr, "%s", bpf_log_buf);
+ return 1;
+ }
+ signal(SIGINT, int_exit);
+
+ /* do sampling */
+ printf("Sampling at %d Hertz for %d seconds. Ctrl-C also ends.\n",
+ freq, secs);
+ if (sampling_start(pmu_fd, freq) != 0)
+ return 1;
+ sleep(secs);
+ sampling_end(pmu_fd);
+ free(pmu_fd);
+
+ /* output sample counts */
+ print_ip_map(map_fd[0]);
+
+ return 0;
+}
--- /dev/null
+/* 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/ptrace.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
+#include <uapi/linux/perf_event.h>
+#include "bpf_helpers.h"
+
+struct key_t {
+ char comm[TASK_COMM_LEN];
+ u32 kernstack;
+ u32 userstack;
+};
+
+struct bpf_map_def SEC("maps") counts = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(struct key_t),
+ .value_size = sizeof(u64),
+ .max_entries = 10000,
+};
+
+struct bpf_map_def SEC("maps") stackmap = {
+ .type = BPF_MAP_TYPE_STACK_TRACE,
+ .key_size = sizeof(u32),
+ .value_size = PERF_MAX_STACK_DEPTH * sizeof(u64),
+ .max_entries = 10000,
+};
+
+#define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
+#define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)
+
+SEC("perf_event")
+int bpf_prog1(struct bpf_perf_event_data *ctx)
+{
+ char fmt[] = "CPU-%d period %lld ip %llx";
+ u32 cpu = bpf_get_smp_processor_id();
+ struct key_t key;
+ u64 *val, one = 1;
+
+ if (ctx->sample_period < 10000)
+ /* ignore warmup */
+ return 0;
+ bpf_get_current_comm(&key.comm, sizeof(key.comm));
+ key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
+ key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
+ if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
+ bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
+ ctx->regs.ip);
+ return 0;
+ }
+
+ val = bpf_map_lookup_elem(&counts, &key);
+ if (val)
+ (*val)++;
+ else
+ bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--- /dev/null
+/* 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 <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <sys/ioctl.h>
+#include <linux/perf_event.h>
+#include <linux/bpf.h>
+#include <signal.h>
+#include <assert.h>
+#include <errno.h>
+#include <sys/resource.h>
+#include "libbpf.h"
+#include "bpf_load.h"
+
+#define SAMPLE_FREQ 50
+
+static bool sys_read_seen, sys_write_seen;
+
+static void print_ksym(__u64 addr)
+{
+ struct ksym *sym;
+
+ if (!addr)
+ return;
+ sym = ksym_search(addr);
+ printf("%s;", sym->name);
+ if (!strcmp(sym->name, "sys_read"))
+ sys_read_seen = true;
+ else if (!strcmp(sym->name, "sys_write"))
+ sys_write_seen = true;
+}
+
+static void print_addr(__u64 addr)
+{
+ if (!addr)
+ return;
+ printf("%llx;", addr);
+}
+
+#define TASK_COMM_LEN 16
+
+struct key_t {
+ char comm[TASK_COMM_LEN];
+ __u32 kernstack;
+ __u32 userstack;
+};
+
+static void print_stack(struct key_t *key, __u64 count)
+{
+ __u64 ip[PERF_MAX_STACK_DEPTH] = {};
+ static bool warned;
+ int i;
+
+ printf("%3lld %s;", count, key->comm);
+ if (bpf_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
+ printf("---;");
+ } else {
+ for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+ print_ksym(ip[i]);
+ }
+ printf("-;");
+ if (bpf_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
+ printf("---;");
+ } else {
+ for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+ print_addr(ip[i]);
+ }
+ printf("\n");
+
+ if (key->kernstack == -EEXIST && !warned) {
+ printf("stackmap collisions seen. Consider increasing size\n");
+ warned = true;
+ } else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
+ printf("err stackid %d %d\n", key->kernstack, key->userstack);
+ }
+}
+
+static void int_exit(int sig)
+{
+ kill(0, SIGKILL);
+ exit(0);
+}
+
+static void print_stacks(void)
+{
+ struct key_t key = {}, next_key;
+ __u64 value;
+ __u32 stackid = 0, next_id;
+ int fd = map_fd[0], stack_map = map_fd[1];
+
+ sys_read_seen = sys_write_seen = false;
+ while (bpf_get_next_key(fd, &key, &next_key) == 0) {
+ bpf_lookup_elem(fd, &next_key, &value);
+ print_stack(&next_key, value);
+ bpf_delete_elem(fd, &next_key);
+ key = next_key;
+ }
+
+ if (!sys_read_seen || !sys_write_seen) {
+ printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
+ int_exit(0);
+ }
+
+ /* clear stack map */
+ while (bpf_get_next_key(stack_map, &stackid, &next_id) == 0) {
+ bpf_delete_elem(stack_map, &next_id);
+ stackid = next_id;
+ }
+}
+
+static void test_perf_event_all_cpu(struct perf_event_attr *attr)
+{
+ int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+ int *pmu_fd = malloc(nr_cpus * sizeof(int));
+ int i;
+
+ /* open perf_event on all cpus */
+ for (i = 0; i < nr_cpus; i++) {
+ pmu_fd[i] = perf_event_open(attr, -1, i, -1, 0);
+ if (pmu_fd[i] < 0) {
+ printf("perf_event_open failed\n");
+ goto all_cpu_err;
+ }
+ assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
+ assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0);
+ }
+ system("dd if=/dev/zero of=/dev/null count=5000k");
+ print_stacks();
+all_cpu_err:
+ for (i--; i >= 0; i--)
+ close(pmu_fd[i]);
+ free(pmu_fd);
+}
+
+static void test_perf_event_task(struct perf_event_attr *attr)
+{
+ int pmu_fd;
+
+ /* open task bound event */
+ pmu_fd = perf_event_open(attr, 0, -1, -1, 0);
+ if (pmu_fd < 0) {
+ printf("perf_event_open failed\n");
+ return;
+ }
+ assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
+ assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
+ system("dd if=/dev/zero of=/dev/null count=5000k");
+ print_stacks();
+ close(pmu_fd);
+}
+
+static void test_bpf_perf_event(void)
+{
+ struct perf_event_attr attr_type_hw = {
+ .sample_freq = SAMPLE_FREQ,
+ .freq = 1,
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_CPU_CYCLES,
+ .inherit = 1,
+ };
+ struct perf_event_attr attr_type_sw = {
+ .sample_freq = SAMPLE_FREQ,
+ .freq = 1,
+ .type = PERF_TYPE_SOFTWARE,
+ .config = PERF_COUNT_SW_CPU_CLOCK,
+ .inherit = 1,
+ };
+
+ test_perf_event_all_cpu(&attr_type_hw);
+ test_perf_event_task(&attr_type_hw);
+ test_perf_event_all_cpu(&attr_type_sw);
+ test_perf_event_task(&attr_type_sw);
+}
+
+
+int main(int argc, char **argv)
+{
+ struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+ char filename[256];
+
+ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+ setrlimit(RLIMIT_MEMLOCK, &r);
+
+ signal(SIGINT, int_exit);
+
+ if (load_kallsyms()) {
+ printf("failed to process /proc/kallsyms\n");
+ return 1;
+ }
+
+ if (load_bpf_file(filename)) {
+ printf("%s", bpf_log_buf);
+ return 2;
+ }
+
+ if (fork() == 0) {
+ read_trace_pipe();
+ return 0;
+ }
+ test_bpf_perf_event();
+
+ int_exit(0);
+ return 0;
+}
projects / cascardo / linux.git / commitdiff