misc: minor bugs and comments

sprinkle a little bit of commenting throughout the codebase.  hopefully
i dont regret what i've written

- clone: bottom of stack is passed through
- print: write newline at end of message
- initcall: functions return void type

very basic net startup.  hopefully i dont regret implementing the
websocket protocol myself in a language as holy as C.

1 files changed, 10 insertions, 2 deletions

diff --git a/init/subsys.c b/init/subsys.c
index 0435f1a..62ee54e 100644
--- a/init/subsys.c
+++ b/init/subsys.c
@@ -21,7 +21,9 @@ struct subsystem_info {
 
 int __subsystem_entry(struct subsystem_info *info)
 {
-
+    /* entry point from clone(). we setup the process name so we know
+       what we are looking at from a glance in a ps view or htop or
+       whatever. */
     char *name = malloc(16 * sizeof(char));
     snprintf(name, 16, NAME_SHORTHAND ": %s", info->fn_name);
     name[15] = '\0';
@@ -30,6 +32,7 @@ int __subsystem_entry(struct subsystem_info *info)
 
     int ret = info->fn();
 
+    /* we are expected to free info before  exiting */
     free(info);
 
     return ret;
@@ -37,15 +40,20 @@ int __subsystem_entry(struct subsystem_info *info)
 
 int __impl_start_subsystem(char *fn_name, int (*fn)(void))
 {
+    /* because CLONE_VM is being set, our stack is not duplicated and
+       therefore we need to map a stack */
     void *stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_GROWSDOWN | MAP_STACK | MAP_PRIVATE, -1, 0);
     if((long)stack < 0)
         die("subsys mmap:");
 
+    /* the libc gods have graced us with the ability to pass one (1) arg
+       to the function. struct required. the absence of a free is not a
+       memory leak because we free it above. */
     struct subsystem_info *info = malloc(sizeof(struct subsystem_info));
     info->fn_name = fn_name;
     info->fn = fn;
 
-    int pid = clone((int (*)(void *))__subsystem_entry, stack, CLONE_FILES | CLONE_VM, info);
+    int pid = clone((int (*)(void *))__subsystem_entry, (void *)((long)stack + STACK_SIZE), CLONE_FILES | CLONE_VM, info);
     if(pid < 0) {
         munmap(stack, STACK_SIZE);
         die("subsys clone:");