kernel/proc: introduce child ids for telling children apart

5 files changed, 23 insertions, 12 deletions

diff --git a/src/kernel/proc.c b/src/kernel/proc.c
index 71d1f44..85992d5 100644
--- a/src/kernel/proc.c
+++ b/src/kernel/proc.c
@@ -26,7 +26,9 @@ struct process *process_seed(void *data, size_t datalen) {
 	process_first->state = PS_RUNNING;
 	process_first->pages = pagedir_new();
 	process_first->mount = vfs_mount_seed();
-	process_first->id    = next_pid++;
+	process_first->globalid = next_pid++;
+	process_first->cid = 1;
+	process_first->nextcid = 1;
 	process_first->_handles = kzalloc(sizeof(struct handle) * HANDLE_MAX);
 
 	// map .shared
@@ -68,7 +70,11 @@ struct process *process_fork(struct process *parent, int flags) {
 	child->parent  = parent;
 	parent->child  = child;
 
-	child->id = next_pid++;
+	if (parent->nextcid == 0)
+		panic_unimplemented();
+	child->cid = parent->nextcid++;
+	child->nextcid = 1;
+	child->globalid = next_pid++;
 
 	if ((flags & FORK_NEWFS) == 0 && parent->controlled) {
 		child->controlled = parent->controlled;
diff --git a/src/kernel/proc.h b/src/kernel/proc.h
index 780c8ee..0ae811e 100644
--- a/src/kernel/proc.h
+++ b/src/kernel/proc.h
@@ -51,7 +51,9 @@ struct process {
 	struct handle **_handles; /* points to struct handle *[HANDLE_MAX] */
 	uint64_t *handles_refcount; /* works just like pages_refcount */
 
-	uint32_t id; /* only for debugging, don't expose to userland */
+	uint32_t cid; /* child id. unique amongst all of this process' siblings */
+	uint32_t nextcid; /* the child id to assign to the next spawned child */
+	uint32_t globalid; /* only for debugging, don't expose to userland */
 	bool noreap;
 
 	/* allocated once, the requests from WAITS4FS get stored here */
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index 37a0ce3..62acf5f 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -76,7 +76,7 @@ long _syscall_fork(int flags, handle_t __user *fs_front) {
 			virt_cpy_to(process_current->pages, fs_front, &hid, sizeof hid);
 		}
 	}
-	SYSCALL_RETURN(1);
+	SYSCALL_RETURN(child->cid);
 }
 
 handle_t _syscall_open(const char __user *path, long len, int flags) {
@@ -379,12 +379,13 @@ long _syscall_execbuf(void __user *ubuf, size_t len) {
 }
 
 void _syscall_debug_klog(const void __user *buf, size_t len) {
-	(void)buf; (void)len;
-	// static char kbuf[256];
-	// if (len >= sizeof(kbuf)) len = sizeof(kbuf) - 1;
-	// virt_cpy_from(process_current->pages, kbuf, buf, len);
-	// kbuf[len] = '\0';
-	// kprintf("[klog] %x\t%s\n", process_current->id, kbuf);
+	if (false) {
+		static char kbuf[256];
+		if (len >= sizeof(kbuf)) len = sizeof(kbuf) - 1;
+		virt_cpy_from(process_current->pages, kbuf, buf, len);
+		kbuf[len] = '\0';
+		kprintf("[klog] %x\t%s\n", process_current->globalid, kbuf);
+	}
 }
 
 long _syscall(long num, long a, long b, long c, long d, long e) {
diff --git a/src/shared/include/camellia/syscalls.h b/src/shared/include/camellia/syscalls.h
index 634583b..2450fff 100644
--- a/src/shared/include/camellia/syscalls.h
+++ b/src/shared/include/camellia/syscalls.h
@@ -47,7 +47,7 @@ long _syscall_await(void);
  * @param flags FORK_NOREAP, FORK_NEWFS
  * @param fs_front requires FORK_NEWFS. the front handle to the new fs is put there
  *
- * @return 0 in the child, a meaningless positive value in the parent.
+ * @return 0 in the child, the CID in the parent.
  */
 long _syscall_fork(int flags, handle_t __user *fs_front);
 
diff --git a/src/user/app/init/init.c b/src/user/app/init/init.c
index b97b483..04380a6 100644
--- a/src/user/app/init/init.c
+++ b/src/user/app/init/init.c
@@ -83,9 +83,11 @@ int main(void) {
 	}
 	close(killswitch_pipe[1]);
 
-	if (fork()) {
+	long cid = fork();
+	if (cid > 0) {
 		/* used to trigger a kernel bug
 		 * 7c96f9c03502e0c60f23f4c550d12a629f3b3daf */
+		printf("main at cid %u\n", cid);
 		_syscall_await();
 		exit(1);
 	}