int mdb_pwalk(const char *name, mdb_walk_cb_t func, void *data, uintptr_t addr);
Initiate a local walk starting at addr using the walker specified by name, and invoke the callback function func at each step. If addr is NULL, a global walk is performed (that is, the mdb_pwalk() invocation is equivalent to the identical call to mdb_walk() without the trailing addr parameter). This function returns 0 for success, or -1 for error. The mdb_pwalk() function fails if the walker itself returns a fatal error, or if the specified walker name is not known to the debugger. The walker name may be scoped using the backquote (`) operator if there are naming conflicts. The data parameter is an opaque argument that has meaning only to the caller; it is passed back to func at each step of the walk.