+ return (unsigned char *) &proc->p_comm; /* Return pointer to the proc name */
+
+}
+
+#define STACKSHOT_SUBSYS_LOCK() lck_mtx_lock(&stackshot_subsys_mutex)
+#define STACKSHOT_SUBSYS_UNLOCK() lck_mtx_unlock(&stackshot_subsys_mutex)
+#ifdef __i386__
+#define TRAP_DEBUGGER __asm__ volatile("int3");
+#endif
+#ifdef __ppc__
+#define TRAP_DEBUGGER __asm__ volatile("tw 4,r3,r3");
+#endif
+
+#define SANE_TRACEBUF_SIZE 2*1024*1024
+
+/* Initialize the mutex governing access to the stack snapshot subsystem */
+__private_extern__ void
+stackshot_lock_init( void )
+{
+ stackshot_subsys_lck_grp_attr = lck_grp_attr_alloc_init();
+
+ stackshot_subsys_lck_grp = lck_grp_alloc_init("stackshot_subsys_lock", stackshot_subsys_lck_grp_attr);
+
+ stackshot_subsys_lck_attr = lck_attr_alloc_init();
+
+ lck_mtx_init(&stackshot_subsys_mutex, stackshot_subsys_lck_grp, stackshot_subsys_lck_attr);
+}
+
+/*
+ * stack_snapshot: Obtains a coherent set of stack traces for all threads
+ * on the system, tracing both kernel and user stacks
+ * where available. Uses machine specific trace routines
+ * for ppc, ppc64 and x86.
+ * Inputs: uap->pid - process id of process to be traced, or -1
+ * for the entire system
+ * uap->tracebuf - address of the user space destination
+ * buffer
+ * uap->tracebuf_size - size of the user space trace buffer
+ * uap->options - various options, including the maximum
+ * number of frames to trace.
+ * Outputs: EPERM if the caller is not privileged
+ * EINVAL if the supplied trace buffer isn't sanely sized
+ * ENOMEM if we don't have enough memory to satisfy the
+ * request
+ * ENOENT if the target pid isn't found
+ * ENOSPC if the supplied buffer is insufficient
+ * *retval contains the number of bytes traced, if successful
+ * and -1 otherwise. If the request failed due to
+ * tracebuffer exhaustion, we copyout as much as possible.
+ */
+int
+stack_snapshot(struct proc *p, register struct stack_snapshot_args *uap, register_t *retval) {
+ int error = 0;
+
+ if ((error = suser(kauth_cred_get(), &p->p_acflag)))
+ return(error);
+
+ return stack_snapshot2(uap->pid, uap->tracebuf, uap->tracebuf_size,
+ uap->options, retval);
+}
+
+int
+stack_snapshot2(pid_t pid, user_addr_t tracebuf, uint32_t tracebuf_size, uint32_t options, register_t *retval)
+{
+ int error = 0;
+ unsigned bytesTraced = 0;
+
+ *retval = -1;
+/* Serialize tracing */
+ STACKSHOT_SUBSYS_LOCK();
+
+ if ((tracebuf_size <= 0) || (tracebuf_size > SANE_TRACEBUF_SIZE)) {
+ error = EINVAL;
+ goto error_exit;
+ }
+
+ MALLOC(stackshot_snapbuf, void *, tracebuf_size, M_TEMP, M_WAITOK);
+
+ if (stackshot_snapbuf == NULL) {
+ error = ENOMEM;
+ goto error_exit;
+ }
+/* Preload trace parameters*/
+ kdp_snapshot_preflight(pid, stackshot_snapbuf, tracebuf_size, options);
+
+/* Trap to the debugger to obtain a coherent stack snapshot; this populates
+ * the trace buffer
+ */
+ TRAP_DEBUGGER;
+
+ bytesTraced = kdp_stack_snapshot_bytes_traced();
+
+ if (bytesTraced > 0) {
+ if ((error = copyout(stackshot_snapbuf, tracebuf,
+ ((bytesTraced < tracebuf_size) ?
+ bytesTraced : tracebuf_size))))
+ goto error_exit;
+ *retval = bytesTraced;
+ }
+ else {
+ error = ENOENT;
+ goto error_exit;
+ }
+
+ error = kdp_stack_snapshot_geterror();
+ if (error == -1) {
+ error = ENOSPC;
+ *retval = -1;
+ goto error_exit;
+ }
projects / apple / xnu.git / blobdiff