1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <inttypes.h>
4 /* For the CPU_* macros */
5 #include <pthread.h>
6 
7 #include <sys/types.h>
8 #include <sys/stat.h>
9 #include <fcntl.h>
10 #include <api/fs/fs.h>
11 #include <linux/err.h>
12 #include <linux/string.h>
13 #include <api/fs/tracing_path.h>
14 #include "evsel.h"
15 #include "tests.h"
16 #include "thread_map.h"
17 #include <perf/cpumap.h>
18 #include "debug.h"
19 #include "stat.h"
20 #include "util/counts.h"
21 
22 static int test__openat_syscall_event_on_all_cpus(struct test_suite *test __maybe_unused,
23 						  int subtest __maybe_unused)
24 {
25 	int err = -1, fd, idx;
26 	struct perf_cpu cpu;
27 	struct perf_cpu_map *cpus;
28 	struct evsel *evsel;
29 	unsigned int nr_openat_calls = 111, i;
30 	cpu_set_t cpu_set;
31 	struct perf_thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
32 	char sbuf[STRERR_BUFSIZE];
33 	char errbuf[BUFSIZ];
34 
35 	if (threads == NULL) {
36 		pr_debug("thread_map__new\n");
37 		return -1;
38 	}
39 
40 	cpus = perf_cpu_map__new(NULL);
41 	if (cpus == NULL) {
42 		pr_debug("perf_cpu_map__new\n");
43 		goto out_thread_map_delete;
44 	}
45 
46 	CPU_ZERO(&cpu_set);
47 
48 	evsel = evsel__newtp("syscalls", "sys_enter_openat");
49 	if (IS_ERR(evsel)) {
50 		tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
51 		pr_debug("%s\n", errbuf);
52 		goto out_cpu_map_delete;
53 	}
54 
55 	if (evsel__open(evsel, cpus, threads) < 0) {
56 		pr_debug("failed to open counter: %s, "
57 			 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
58 			 str_error_r(errno, sbuf, sizeof(sbuf)));
59 		goto out_evsel_delete;
60 	}
61 
62 	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
63 		unsigned int ncalls = nr_openat_calls + idx;
64 		/*
65 		 * XXX eventually lift this restriction in a way that
66 		 * keeps perf building on older glibc installations
67 		 * without CPU_ALLOC. 1024 cpus in 2010 still seems
68 		 * a reasonable upper limit tho :-)
69 		 */
70 		if (cpu.cpu >= CPU_SETSIZE) {
71 			pr_debug("Ignoring CPU %d\n", cpu.cpu);
72 			continue;
73 		}
74 
75 		CPU_SET(cpu.cpu, &cpu_set);
76 		if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
77 			pr_debug("sched_setaffinity() failed on CPU %d: %s ",
78 				 cpu.cpu,
79 				 str_error_r(errno, sbuf, sizeof(sbuf)));
80 			goto out_close_fd;
81 		}
82 		for (i = 0; i < ncalls; ++i) {
83 			fd = openat(0, "/etc/passwd", O_RDONLY);
84 			close(fd);
85 		}
86 		CPU_CLR(cpu.cpu, &cpu_set);
87 	}
88 
89 	evsel->core.cpus = perf_cpu_map__get(cpus);
90 
91 	err = 0;
92 
93 	perf_cpu_map__for_each_cpu(cpu, idx, cpus) {
94 		unsigned int expected;
95 
96 		if (cpu.cpu >= CPU_SETSIZE)
97 			continue;
98 
99 		if (evsel__read_on_cpu(evsel, idx, 0) < 0) {
100 			pr_debug("evsel__read_on_cpu\n");
101 			err = -1;
102 			break;
103 		}
104 
105 		expected = nr_openat_calls + idx;
106 		if (perf_counts(evsel->counts, idx, 0)->val != expected) {
107 			pr_debug("evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
108 				 expected, cpu.cpu, perf_counts(evsel->counts, idx, 0)->val);
109 			err = -1;
110 		}
111 	}
112 
113 	evsel__free_counts(evsel);
114 out_close_fd:
115 	perf_evsel__close_fd(&evsel->core);
116 out_evsel_delete:
117 	evsel__delete(evsel);
118 out_cpu_map_delete:
119 	perf_cpu_map__put(cpus);
120 out_thread_map_delete:
121 	perf_thread_map__put(threads);
122 	return err;
123 }
124 
125 DEFINE_SUITE("Detect openat syscall event on all cpus", openat_syscall_event_on_all_cpus);
126