1 /* quick and dirty hack to grab credential backtrace info from kernel via sysctl.
2 * sysctl is only defined if xnu is built with DEBUG_CRED defined.
3 * The current version of this is used to target a specific credential and gather
4 * backtrace info on all references and unreferences.
5 */
6
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <fcntl.h>
10 #include <limits.h>
11 #include <string.h>
12 #include <errno.h>
13 #include <unistd.h>
14 #include <sys/stat.h>
15 #include <sys/types.h>
16 #include <sys/sysctl.h>
17 #include <bsm/audit.h>
18
19 /* bad! this is replicated in kern_credential.c. make sure they stay in sync!
20 * Or better yet have commone header file?
21 */
22 #define MAX_STACK_DEPTH 8
23 struct cred_backtrace {
24 int depth;
25 uint32_t stack[MAX_STACK_DEPTH];
26 };
27 typedef struct cred_backtrace cred_backtrace;
28
29 struct cred_debug_buffer {
30 int next_slot;
31 cred_backtrace stack_buffer[1];
32 };
33 typedef struct cred_debug_buffer cred_debug_buffer;
34
35
main(int argc,char * argv[])36 main( int argc, char *argv[] )
37 {
38 int err, i, j;
39 size_t len;
40 char *my_bufferp = NULL;
41 cred_debug_buffer *bt_buffp;
42 cred_backtrace *btp;
43
44 /* get size of buffer we will need */
45 len = 0;
46 err = sysctlbyname( "kern.cred_bt", NULL, &len, NULL, 0 );
47 if (err != 0) {
48 printf( "sysctl failed \n" );
49 printf( "\terrno %d - \"%s\" \n", errno, strerror( errno ));
50 return;
51 }
52
53 /* get a buffer for our back traces */
54 my_bufferp = malloc( len );
55 if (my_bufferp == NULL) {
56 printf( "malloc error %d - \"%s\" \n", errno, strerror( errno ));
57 return;
58 }
59 err = sysctlbyname( "kern.cred_bt", my_bufferp, &len, NULL, 0 );
60 if (err != 0) {
61 printf( "sysctl 2 failed \n" );
62 printf( "\terrno %d - \"%s\" \n", errno, strerror( errno ));
63 return;
64 }
65
66 bt_buffp = (cred_debug_buffer *) my_bufferp;
67 btp = &bt_buffp->stack_buffer[0];
68
69 printf("number of traces %d \n", bt_buffp->next_slot);
70 for (i = 0; i < bt_buffp->next_slot; i++, btp++) {
71 printf("[%d] ", i);
72 for (j = 0; j < btp->depth; j++) {
73 printf("%p ", btp->stack[j]);
74 }
75 printf("\n");
76 }
77
78 return;
79 }
80