[kernel] Add missing zero_ok changes

This change adds some changes I missed as part of the previous (see
da5c1e9) zero_ok change.

src/kernel/syscalls/endpoint.cpp

@@ -28,11 +28,6 @@ endpoint_send(endpoint *self, uint64_t tag, const void * data, size_t data_len)
 j6_status_t
 endpoint_receive(endpoint *self, uint64_t * tag, void * data, size_t * data_len, uint64_t timeout)
 {
-    // Data is marked optional, but we need the length, and if length > 0,
-    // data is not optional.
-    if (!data_len || (*data_len && !data))
-        return j6_err_invalid_arg;
-
     // Use local variables instead of the passed-in pointers, since
     // they may get filled in when the sender is running, which means
     // a different user VM space would be active.

src/kernel/syscalls/handle.cpp

@@ -11,9 +11,6 @@ namespace syscalls {
 j6_status_t
 handle_list(j6_handle_t *handles, size_t *handles_len)
 {
-    if (!handles_len || (*handles_len && !handles))
-        return j6_err_invalid_arg;
-
     process &p = process::current();
     size_t requested = *handles_len;
 
@@ -26,16 +23,12 @@ handle_list(j6_handle_t *handles, size_t *handles_len)
 }
 
 j6_status_t
-handle_clone(j6_handle_t orig, j6_handle_t *clone, uint32_t mask)
+handle_clone(handle *orig, j6_handle_t *clone, uint32_t mask)
 {
-    handle *orig_handle = get_handle<kobject>(orig);
-    if (!orig_handle)
-        return j6_err_invalid_arg;
-
     process &p = process::current();
     *clone = p.add_handle(
-            orig_handle->object,
-            orig_handle->caps() & mask);
+            orig->object,
+            orig->caps() & mask);
 
     return j6_status_ok;
 }

src/kernel/syscalls/process.cpp

@@ -13,7 +13,7 @@ j6_status_t
 process_create(j6_handle_t *self)
 {
     process *p = construct_handle<process>(self);
-    log::debug(logs::task, "Process %llx created", p->koid());
+    log::info(logs::task, "Process %llx created", p->koid());
     return j6_status_ok;
 }
 
@@ -22,7 +22,7 @@ process_kill(process *self)
 {
     process &p = process::current();
 
-    log::debug(logs::task, "Process %llx killed by process %llx", self->koid(), p.koid());
+    log::info(logs::task, "Process %llx killed by process %llx", self->koid(), p.koid());
     self->exit(-1u);
 
     return j6_status_ok;
@@ -32,7 +32,7 @@ j6_status_t
 process_exit(int32_t status)
 {
     process &p = process::current();
-    log::debug(logs::task, "Process %llx exiting with code %d", p.koid(), status);
+    log::info(logs::task, "Process %llx exiting with code %d", p.koid(), status);
 
     p.exit(status);
 
@@ -41,13 +41,12 @@ process_exit(int32_t status)
 }
 
 j6_status_t
-process_give_handle(process *self, j6_handle_t target, j6_handle_t *received)
+process_give_handle(process *self, handle *target, j6_handle_t *received)
 {
-    handle *target_handle = get_handle<kobject>(target);
-    j6_handle_t out = self->add_handle(target_handle->object, target_handle->caps());
-
+    j6_handle_t out = self->add_handle(target->object, target->caps());
     if (received)
         *received = out;
+
     return j6_status_ok;
 }
 

src/kernel/syscalls/system.cpp

@@ -39,11 +39,6 @@ noop()
 j6_status_t
 system_get_log(system *self, void *buffer, size_t *buffer_len)
 {
-    // Buffer is marked optional, but we need the length, and if length > 0,
-    // buffer is not optional.
-    if (!buffer_len || (*buffer_len && !buffer))
-        return j6_err_invalid_arg;
-
     size_t orig_size = *buffer_len;
     *buffer_len = g_logger.get_entry(buffer, *buffer_len);
     if (!g_logger.has_log())