xref: /xnu-11215/tests/preoslog.c (revision 5c2921b0)
1 #include <darwintest.h>
2 #include <darwintest_utils.h>
3 #include <sys/sysctl.h>
4 #include <string.h>
5 #include <errno.h>
6 
7 #include <sys/preoslog.h>
8 #include "test_utils.h"
9 
10 static const char* g_sysctl_kern_version = "kern.version";
11 static const char* g_sysctl_kern_preoslog = "kern.preoslog";
12 static const uint32_t g_valid_magic = 'LSOP';
13 
14 /*
15  * Defines substrings to look up in preoslog buffer.
16  * To pass the test, one of the entries should match a substring in preoslog buffer.
17  */
18 static const char* g_preoslog_buffer_string[] = {"serial output"};
19 
20 static boolean_t
check_for_substrings(const char * string,size_t len)21 check_for_substrings(const char* string, size_t len)
22 {
23 	int i;
24 	boolean_t res = FALSE;
25 
26 	for (i = 0; i < (sizeof(g_preoslog_buffer_string) / sizeof(char*)); i++) {
27 		res = res || strnstr(string, g_preoslog_buffer_string[i], len) == NULL ? FALSE : TRUE;
28 	}
29 
30 	return res;
31 }
32 
33 /*
34  *       Valid cases:
35  *       1. Development & Debug iBoot/macEFI provides a preoslog buffer.
36  *       2. Release iBoot/macEFI doesn't provide a presoslog buffer.
37  *       3. Development & Debug xnu provids kern.preoslog sysctl.
38  *       4. Release xnu doesn't provide kern.preoslog sysctl.
39  */
40 
41 T_DECL(test_preoslog, "Validate kern.preoslog sysctl has expected log content from the boot loader")
42 {
43 	int ret = 0;
44 	size_t size = 0;
45 	void *buffer = NULL;
46 	preoslog_header_t *header = NULL;
47 	char tmp = 0;
48 	const char *lower_buffer = NULL;
49 	size_t lower_buffer_size = 0;
50 	const char *upper_buffer = NULL;
51 	size_t upper_buffer_size = 0;
52 	boolean_t found = FALSE;
53 
54 	// kern.preoslog is writable
55 	ret = sysctlbyname(g_sysctl_kern_preoslog, buffer, &size, &tmp, sizeof(tmp));
56 	T_ASSERT_POSIX_SUCCESS(ret, "kern.preoslog write check");
57 
58 	ret = sysctlbyname(g_sysctl_kern_preoslog, NULL, &size, NULL, 0);
59 	if (!is_development_kernel()) {
60 		// kern.preoslog mustn't exist on release builds of xnu
61 		T_ASSERT_NE(ret, 0, "get size kern.preoslog ret != 0 on release builds");
62 		T_ASSERT_POSIX_ERROR(ret, ENOENT, " get size kern.preoslog errno==ENOENT on release builds");
63 		return;
64 	}
65 
66 	/*
67 	 * Everything below is applicable only to development & debug xnu
68 	 */
69 
70 	T_ASSERT_POSIX_SUCCESS(ret, "get size for kern.preoslog");
71 	if (size == 0) {
72 		// No preoslog buffer available, valid case if iboot is release
73 		return;
74 	}
75 
76 	buffer = calloc(size, sizeof(char));
77 	T_ASSERT_NOTNULL(buffer, "allocate buffer for preoslog");
78 
79 	ret = sysctlbyname(g_sysctl_kern_preoslog, buffer, &size, NULL, 0);
80 	T_ASSERT_POSIX_SUCCESS(ret, "get preoslog buffer");
81 
82 	header = (preoslog_header_t *)buffer;
83 	T_ASSERT_EQ(header->magic, g_valid_magic, "check preoslog header magic - expected %#x, given %#x", g_valid_magic, header->magic);
84 	T_ASSERT_EQ(header->size, size, "check preoslog sizes - expected %zu, given %zu", size, header->size);
85 	T_ASSERT_LT(header->offset, header->size - sizeof(*header), "check write offset");
86 
87 	lower_buffer = header->data;
88 	lower_buffer_size = header->offset + 1;
89 	upper_buffer = lower_buffer + lower_buffer_size;
90 	upper_buffer_size = header->size - lower_buffer_size - sizeof(*header);
91 	if (header->wrapped) {
92 		found = check_for_substrings(upper_buffer, upper_buffer_size);
93 	}
94 
95 	found = found || check_for_substrings(lower_buffer, lower_buffer_size);
96 	T_ASSERT_TRUE(found, "Verify buffer content");
97 
98 	free(buffer);
99 	buffer = NULL;
100 	header = NULL;
101 }
102