mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 02:30:34 +02:00 
			
		
		
		
	Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 107 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171438.615055994@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
		
			
				
	
	
		
			124 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
 | 
						|
/* Copyright (c) 2016 Facebook
 | 
						|
 */
 | 
						|
#include <stdio.h>
 | 
						|
#include <unistd.h>
 | 
						|
#include <stdlib.h>
 | 
						|
#include <signal.h>
 | 
						|
#include <linux/bpf.h>
 | 
						|
#include <string.h>
 | 
						|
#include <linux/perf_event.h>
 | 
						|
#include <errno.h>
 | 
						|
#include <assert.h>
 | 
						|
#include <stdbool.h>
 | 
						|
#include <sys/resource.h>
 | 
						|
#include "libbpf.h"
 | 
						|
#include "bpf_load.h"
 | 
						|
#include "trace_helpers.h"
 | 
						|
 | 
						|
#define PRINT_RAW_ADDR 0
 | 
						|
 | 
						|
static void print_ksym(__u64 addr)
 | 
						|
{
 | 
						|
	struct ksym *sym;
 | 
						|
 | 
						|
	if (!addr)
 | 
						|
		return;
 | 
						|
	sym = ksym_search(addr);
 | 
						|
	if (!sym) {
 | 
						|
		printf("ksym not found. Is kallsyms loaded?\n");
 | 
						|
		return;
 | 
						|
	}
 | 
						|
 | 
						|
	if (PRINT_RAW_ADDR)
 | 
						|
		printf("%s/%llx;", sym->name, addr);
 | 
						|
	else
 | 
						|
		printf("%s;", sym->name);
 | 
						|
}
 | 
						|
 | 
						|
#define TASK_COMM_LEN 16
 | 
						|
 | 
						|
struct key_t {
 | 
						|
	char waker[TASK_COMM_LEN];
 | 
						|
	char target[TASK_COMM_LEN];
 | 
						|
	__u32 wret;
 | 
						|
	__u32 tret;
 | 
						|
};
 | 
						|
 | 
						|
static void print_stack(struct key_t *key, __u64 count)
 | 
						|
{
 | 
						|
	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
 | 
						|
	static bool warned;
 | 
						|
	int i;
 | 
						|
 | 
						|
	printf("%s;", key->target);
 | 
						|
	if (bpf_map_lookup_elem(map_fd[3], &key->tret, ip) != 0) {
 | 
						|
		printf("---;");
 | 
						|
	} else {
 | 
						|
		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
 | 
						|
			print_ksym(ip[i]);
 | 
						|
	}
 | 
						|
	printf("-;");
 | 
						|
	if (bpf_map_lookup_elem(map_fd[3], &key->wret, ip) != 0) {
 | 
						|
		printf("---;");
 | 
						|
	} else {
 | 
						|
		for (i = 0; i < PERF_MAX_STACK_DEPTH; i++)
 | 
						|
			print_ksym(ip[i]);
 | 
						|
	}
 | 
						|
	printf(";%s %lld\n", key->waker, count);
 | 
						|
 | 
						|
	if ((key->tret == -EEXIST || key->wret == -EEXIST) && !warned) {
 | 
						|
		printf("stackmap collisions seen. Consider increasing size\n");
 | 
						|
		warned = true;
 | 
						|
	} else if (((int)(key->tret) < 0 || (int)(key->wret) < 0)) {
 | 
						|
		printf("err stackid %d %d\n", key->tret, key->wret);
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
static void print_stacks(int fd)
 | 
						|
{
 | 
						|
	struct key_t key = {}, next_key;
 | 
						|
	__u64 value;
 | 
						|
 | 
						|
	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
 | 
						|
		bpf_map_lookup_elem(fd, &next_key, &value);
 | 
						|
		print_stack(&next_key, value);
 | 
						|
		key = next_key;
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
static void int_exit(int sig)
 | 
						|
{
 | 
						|
	print_stacks(map_fd[0]);
 | 
						|
	exit(0);
 | 
						|
}
 | 
						|
 | 
						|
int main(int argc, char **argv)
 | 
						|
{
 | 
						|
	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 | 
						|
	char filename[256];
 | 
						|
	int delay = 1;
 | 
						|
 | 
						|
	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
 | 
						|
	setrlimit(RLIMIT_MEMLOCK, &r);
 | 
						|
 | 
						|
	signal(SIGINT, int_exit);
 | 
						|
	signal(SIGTERM, int_exit);
 | 
						|
 | 
						|
	if (load_kallsyms()) {
 | 
						|
		printf("failed to process /proc/kallsyms\n");
 | 
						|
		return 2;
 | 
						|
	}
 | 
						|
 | 
						|
	if (load_bpf_file(filename)) {
 | 
						|
		printf("%s", bpf_log_buf);
 | 
						|
		return 1;
 | 
						|
	}
 | 
						|
 | 
						|
	if (argc > 1)
 | 
						|
		delay = atoi(argv[1]);
 | 
						|
	sleep(delay);
 | 
						|
	print_stacks(map_fd[0]);
 | 
						|
 | 
						|
	return 0;
 | 
						|
}
 |