int sdt_init(void)
{ int ret;
ret = misc_register(&sdt_dev);
if (ret) {
printk(KERN_WARNING "sdt: Unable to register misc device\n");
return ret;
}
sdt_attach();
dtrace_printf("sdt loaded: /dev/sdt now available\n");
initted = 1;
return 0;
}
void sdt_init( void )
{
if (0 == gSDTInited)
{
int majdevno = cdevsw_add(SDT_MAJOR, &sdt_cdevsw);
if (majdevno < 0) {
printf("sdt_init: failed to allocate a major number!\n");
gSDTInited = 0;
return;
}
if (dtrace_sdt_probes_restricted()) {
return;
}
if (MH_MAGIC_KERNEL != _mh_execute_header.magic) {
g_sdt_kernctl.mod_address = (vm_address_t)NULL;
g_sdt_kernctl.mod_size = 0;
} else {
kernel_mach_header_t *mh;
struct load_command *cmd;
kernel_segment_command_t *orig_ts = NULL, *orig_le = NULL;
struct symtab_command *orig_st = NULL;
kernel_nlist_t *sym = NULL;
char *strings;
unsigned int i;
g_sdt_mach_module.sdt_nprobes = 0;
g_sdt_mach_module.sdt_probes = NULL;
g_sdt_kernctl.mod_address = (vm_address_t)&g_sdt_mach_module;
g_sdt_kernctl.mod_size = 0;
strncpy((char *)&(g_sdt_kernctl.mod_modname), "mach_kernel", KMOD_MAX_NAME);
g_sdt_kernctl.mod_next = NULL;
g_sdt_kernctl.mod_stale = NULL;
g_sdt_kernctl.mod_id = 0;
g_sdt_kernctl.mod_loadcnt = 1;
g_sdt_kernctl.mod_loaded = 1;
g_sdt_kernctl.mod_flags = 0;
g_sdt_kernctl.mod_nenabled = 0;
mh = &_mh_execute_header;
cmd = (struct load_command*) &mh[1];
for (i = 0; i < mh->ncmds; i++) {
if (cmd->cmd == LC_SEGMENT_KERNEL) {
kernel_segment_command_t *orig_sg = (kernel_segment_command_t *) cmd;
if (LIT_STRNEQL(orig_sg->segname, SEG_TEXT))
orig_ts = orig_sg;
else if (LIT_STRNEQL(orig_sg->segname, SEG_LINKEDIT))
orig_le = orig_sg;
else if (LIT_STRNEQL(orig_sg->segname, ""))
orig_ts = orig_sg; /* kexts have a single unnamed segment */
}
else if (cmd->cmd == LC_SYMTAB)
orig_st = (struct symtab_command *) cmd;
cmd = (struct load_command *) ((uintptr_t) cmd + cmd->cmdsize);
}
if ((orig_ts == NULL) || (orig_st == NULL) || (orig_le == NULL))
return;
sym = (kernel_nlist_t *)(orig_le->vmaddr + orig_st->symoff - orig_le->fileoff);
strings = (char *)(orig_le->vmaddr + orig_st->stroff - orig_le->fileoff);
for (i = 0; i < orig_st->nsyms; i++) {
uint8_t n_type = sym[i].n_type & (N_TYPE | N_EXT);
char *name = strings + sym[i].n_un.n_strx;
const char *prev_name;
unsigned long best;
unsigned int j;
/* Check that the symbol is a global and that it has a name. */
if (((N_SECT | N_EXT) != n_type && (N_ABS | N_EXT) != n_type))
continue;
if (0 == sym[i].n_un.n_strx) /* iff a null, "", name. */
continue;
/* Lop off omnipresent leading underscore. */
if (*name == '_')
name += 1;
if (strncmp(name, DTRACE_PROBE_PREFIX, sizeof(DTRACE_PROBE_PREFIX) - 1) == 0) {
sdt_probedesc_t *sdpd = kmem_alloc(sizeof(sdt_probedesc_t), KM_SLEEP);
int len = strlen(name) + 1;
sdpd->sdpd_name = kmem_alloc(len, KM_SLEEP);
strncpy(sdpd->sdpd_name, name, len); /* NUL termination is ensured. */
prev_name = "<unknown>";
best = 0;
/*
* Find the symbol immediately preceding the sdt probe site just discovered,
* that symbol names the function containing the sdt probe.
*/
for (j = 0; j < orig_st->nsyms; j++) {
uint8_t jn_type = sym[j].n_type & (N_TYPE | N_EXT);
char *jname = strings + sym[j].n_un.n_strx;
if (((N_SECT | N_EXT) != jn_type && (N_ABS | N_EXT) != jn_type))
continue;
if (0 == sym[j].n_un.n_strx) /* iff a null, "", name. */
continue;
if (*jname == '_')
jname += 1;
if (*(unsigned long *)sym[i].n_value <= (unsigned long)sym[j].n_value)
continue;
if ((unsigned long)sym[j].n_value > best) {
best = (unsigned long)sym[j].n_value;
prev_name = jname;
}
}
sdpd->sdpd_func = kmem_alloc((len = strlen(prev_name) + 1), KM_SLEEP);
strncpy(sdpd->sdpd_func, prev_name, len); /* NUL termination is ensured. */
sdpd->sdpd_offset = *(unsigned long *)sym[i].n_value;
#if defined(__arm__)
/* PR8353094 - mask off thumb-bit */
sdpd->sdpd_offset &= ~0x1U;
#elif defined(__arm64__)
sdpd->sdpd_offset &= ~0x1LU;
#endif /* __arm__ */
#if 0
printf("sdt_init: sdpd_offset=0x%lx, n_value=0x%lx, name=%s\n",
sdpd->sdpd_offset, *(unsigned long *)sym[i].n_value, name);
#endif
sdpd->sdpd_next = g_sdt_mach_module.sdt_probes;
g_sdt_mach_module.sdt_probes = sdpd;
} else {
prev_name = name;
}
}
}
sdt_attach( (dev_info_t *)(uintptr_t)majdevno, DDI_ATTACH );
gSDTInited = 1;
} else
panic("sdt_init: called twice!\n");
}
