1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020, Oracle and/or its affiliates. */
3 
4 #include <test_progs.h>
5 
6 #include "trace_printk.lskel.h"
7 
8 #define TRACEBUF	"/sys/kernel/debug/tracing/trace_pipe"
9 #define SEARCHMSG	"testing,testing"
10 
11 void serial_test_trace_printk(void)
12 {
13 	struct trace_printk_lskel__bss *bss;
14 	int err = 0, iter = 0, found = 0;
15 	struct trace_printk_lskel *skel;
16 	char *buf = NULL;
17 	FILE *fp = NULL;
18 	size_t buflen;
19 
20 	skel = trace_printk_lskel__open();
21 	if (!ASSERT_OK_PTR(skel, "trace_printk__open"))
22 		return;
23 
24 	ASSERT_EQ(skel->rodata->fmt[0], 'T', "skel->rodata->fmt[0]");
25 	skel->rodata->fmt[0] = 't';
26 
27 	err = trace_printk_lskel__load(skel);
28 	if (!ASSERT_OK(err, "trace_printk__load"))
29 		goto cleanup;
30 
31 	bss = skel->bss;
32 
33 	err = trace_printk_lskel__attach(skel);
34 	if (!ASSERT_OK(err, "trace_printk__attach"))
35 		goto cleanup;
36 
37 	fp = fopen(TRACEBUF, "r");
38 	if (!ASSERT_OK_PTR(fp, "fopen(TRACEBUF)"))
39 		goto cleanup;
40 
41 	/* We do not want to wait forever if this test fails... */
42 	fcntl(fileno(fp), F_SETFL, O_NONBLOCK);
43 
44 	/* wait for tracepoint to trigger */
45 	usleep(1);
46 	trace_printk_lskel__detach(skel);
47 
48 	if (!ASSERT_GT(bss->trace_printk_ran, 0, "bss->trace_printk_ran"))
49 		goto cleanup;
50 
51 	if (!ASSERT_GT(bss->trace_printk_ret, 0, "bss->trace_printk_ret"))
52 		goto cleanup;
53 
54 	/* verify our search string is in the trace buffer */
55 	while (getline(&buf, &buflen, fp) >= 0 || errno == EAGAIN) {
56 		if (strstr(buf, SEARCHMSG) != NULL)
57 			found++;
58 		if (found == bss->trace_printk_ran)
59 			break;
60 		if (++iter > 1000)
61 			break;
62 	}
63 
64 	if (!ASSERT_EQ(found, bss->trace_printk_ran, "found"))
65 		goto cleanup;
66 
67 cleanup:
68 	trace_printk_lskel__destroy(skel);
69 	free(buf);
70 	if (fp)
71 		fclose(fp);
72 }
73