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 "test_utils.h"
8
9 /*
10 * Any change to this structure must be reflected in iBoot / MacEFI / PanicDump / XNU Tests and vice versa.
11 */
12 typedef struct __attribute__((packed)) {
13 uint32_t magic; /* g_valid_magic if valid */
14 uint32_t size; /* Size of the preoslog buffer including the header */
15 uint32_t offset; /* Write pointer. Indicates where in the buffer new log entry would go */
16 uint8_t source; /* Indicates who filled in the buffer (e.g. iboot vs MacEFI) */
17 uint8_t wrapped; /* If equal to 1, the preoslog ring buffer wrapped at least once */
18 char data[]; /* log buffer */
19 } preoslog_header_t;
20
21 static const char* g_sysctl_kern_version = "kern.version";
22 static const char* g_sysctl_kern_preoslog = "kern.preoslog";
23 static const uint32_t g_valid_magic = 'LSOP';
24
25 /*
26 * Defines substrings to look up in preoslog buffer.
27 * To pass the test, one of the entries should match a substring in preoslog buffer.
28 */
29 static const char* g_preoslog_buffer_string[] = {"serial output"};
30
31 static boolean_t
check_for_substrings(const char * string,size_t len)32 check_for_substrings(const char* string, size_t len)
33 {
34 int i;
35 boolean_t res = FALSE;
36
37 for (i = 0; i < (sizeof(g_preoslog_buffer_string) / sizeof(char*)); i++) {
38 res = res || strnstr(string, g_preoslog_buffer_string[i], len) == NULL ? FALSE : TRUE;
39 }
40
41 return res;
42 }
43
44 /*
45 * Valid cases:
46 * 1. Development & Debug iBoot/macEFI provides a preoslog buffer.
47 * 2. Release iBoot/macEFI doesn't provide a presoslog buffer.
48 * 3. Development & Debug xnu provids kern.preoslog sysctl.
49 * 4. Release xnu doesn't provide kern.preoslog sysctl.
50 */
51
52 T_DECL(test_preoslog, "Validate kern.preoslog sysctl has expected log content from the boot loader")
53 {
54 int ret = 0;
55 size_t size = 0;
56 void *buffer = NULL;
57 preoslog_header_t *header = NULL;
58 char tmp = 0;
59 const char *lower_buffer = NULL;
60 size_t lower_buffer_size = 0;
61 const char *upper_buffer = NULL;
62 size_t upper_buffer_size = 0;
63 boolean_t found = FALSE;
64
65 // kern.preoslog is writable
66 ret = sysctlbyname(g_sysctl_kern_preoslog, buffer, &size, &tmp, sizeof(tmp));
67 T_ASSERT_POSIX_SUCCESS(ret, "kern.preoslog write check");
68
69 ret = sysctlbyname(g_sysctl_kern_preoslog, NULL, &size, NULL, 0);
70 if (!is_development_kernel()) {
71 // kern.preoslog mustn't exist on release builds of xnu
72 T_ASSERT_NE(ret, 0, "get size kern.preoslog ret != 0 on release builds");
73 T_ASSERT_POSIX_ERROR(ret, ENOENT, " get size kern.preoslog errno==ENOENT on release builds");
74 return;
75 }
76
77 /*
78 * Everything below is applicable only to development & debug xnu
79 */
80
81 T_ASSERT_POSIX_SUCCESS(ret, "get size for kern.preoslog");
82 if (size == 0) {
83 // No preoslog buffer available, valid case if iboot is release
84 return;
85 }
86
87 buffer = calloc(size, sizeof(char));
88 T_ASSERT_NOTNULL(buffer, "allocate buffer for preoslog");
89
90 ret = sysctlbyname(g_sysctl_kern_preoslog, buffer, &size, NULL, 0);
91 T_ASSERT_POSIX_SUCCESS(ret, "get preoslog buffer");
92
93 header = (preoslog_header_t *)buffer;
94 T_ASSERT_EQ(header->magic, g_valid_magic, "check preoslog header magic - expected %#x, given %#x", g_valid_magic, header->magic);
95 T_ASSERT_EQ(header->size, size, "check preoslog sizes - expected %zu, given %zu", size, header->size);
96 T_ASSERT_LT(header->offset, header->size - sizeof(*header), "check write offset");
97
98 lower_buffer = header->data;
99 lower_buffer_size = header->offset + 1;
100 upper_buffer = lower_buffer + lower_buffer_size;
101 upper_buffer_size = header->size - lower_buffer_size - sizeof(*header);
102 if (header->wrapped) {
103 found = check_for_substrings(upper_buffer, upper_buffer_size);
104 }
105
106 found = found || check_for_substrings(lower_buffer, lower_buffer_size);
107 T_ASSERT_TRUE(found, "Verify buffer content");
108
109 free(buffer);
110 buffer = NULL;
111 header = NULL;
112 }
113