1 #include "evsel.h"
2 #include "tests.h"
3 #include "thread_map.h"
4 #include "cpumap.h"
5 #include "debug.h"
6 
7 int test__openat_syscall_event_on_all_cpus(void)
8 {
9 	int err = -1, fd, cpu;
10 	struct cpu_map *cpus;
11 	struct perf_evsel *evsel;
12 	unsigned int nr_openat_calls = 111, i;
13 	cpu_set_t cpu_set;
14 	struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
15 	char sbuf[STRERR_BUFSIZE];
16 
17 	if (threads == NULL) {
18 		pr_debug("thread_map__new\n");
19 		return -1;
20 	}
21 
22 	cpus = cpu_map__new(NULL);
23 	if (cpus == NULL) {
24 		pr_debug("cpu_map__new\n");
25 		goto out_thread_map_delete;
26 	}
27 
28 	CPU_ZERO(&cpu_set);
29 
30 	evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
31 	if (evsel == NULL) {
32 		if (tracefs_configured())
33 			pr_debug("is tracefs mounted on /sys/kernel/tracing?\n");
34 		else if (debugfs_configured())
35 			pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
36 		else
37 			pr_debug("Neither tracefs or debugfs is enabled in this kernel\n");
38 		goto out_thread_map_delete;
39 	}
40 
41 	if (perf_evsel__open(evsel, cpus, threads) < 0) {
42 		pr_debug("failed to open counter: %s, "
43 			 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
44 			 strerror_r(errno, sbuf, sizeof(sbuf)));
45 		goto out_evsel_delete;
46 	}
47 
48 	for (cpu = 0; cpu < cpus->nr; ++cpu) {
49 		unsigned int ncalls = nr_openat_calls + cpu;
50 		/*
51 		 * XXX eventually lift this restriction in a way that
52 		 * keeps perf building on older glibc installations
53 		 * without CPU_ALLOC. 1024 cpus in 2010 still seems
54 		 * a reasonable upper limit tho :-)
55 		 */
56 		if (cpus->map[cpu] >= CPU_SETSIZE) {
57 			pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
58 			continue;
59 		}
60 
61 		CPU_SET(cpus->map[cpu], &cpu_set);
62 		if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
63 			pr_debug("sched_setaffinity() failed on CPU %d: %s ",
64 				 cpus->map[cpu],
65 				 strerror_r(errno, sbuf, sizeof(sbuf)));
66 			goto out_close_fd;
67 		}
68 		for (i = 0; i < ncalls; ++i) {
69 			fd = openat(0, "/etc/passwd", O_RDONLY);
70 			close(fd);
71 		}
72 		CPU_CLR(cpus->map[cpu], &cpu_set);
73 	}
74 
75 	/*
76 	 * Here we need to explicitely preallocate the counts, as if
77 	 * we use the auto allocation it will allocate just for 1 cpu,
78 	 * as we start by cpu 0.
79 	 */
80 	if (perf_evsel__alloc_counts(evsel, cpus->nr) < 0) {
81 		pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
82 		goto out_close_fd;
83 	}
84 
85 	err = 0;
86 
87 	for (cpu = 0; cpu < cpus->nr; ++cpu) {
88 		unsigned int expected;
89 
90 		if (cpus->map[cpu] >= CPU_SETSIZE)
91 			continue;
92 
93 		if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
94 			pr_debug("perf_evsel__read_on_cpu\n");
95 			err = -1;
96 			break;
97 		}
98 
99 		expected = nr_openat_calls + cpu;
100 		if (evsel->counts->cpu[cpu].val != expected) {
101 			pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
102 				 expected, cpus->map[cpu], evsel->counts->cpu[cpu].val);
103 			err = -1;
104 		}
105 	}
106 
107 	perf_evsel__free_counts(evsel);
108 out_close_fd:
109 	perf_evsel__close_fd(evsel, 1, threads->nr);
110 out_evsel_delete:
111 	perf_evsel__delete(evsel);
112 out_thread_map_delete:
113 	thread_map__delete(threads);
114 	return err;
115 }
116