4 files changed, 54 insertions, 3 deletions

diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index dc8f9df..1909eb7 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -51,11 +51,10 @@ long _syscall_fork(int flags, handle_t __user *fs_front) {
 	child = process_fork(process_current, flags);
 	regs_savereturn(&child->regs, 0);
 
-	if ((flags & FORK_NEWFS) && fs_front) {
+	if (flags & FORK_NEWFS) {
 		struct handle *h;
 		handle_t hid = process_handle_init(process_current, HANDLE_FS_FRONT, &h);
 		if (hid < 0) {
-			// TODO test
 			child->noreap = true;
 			process_kill(child, -EMFILE);
 			SYSCALL_RETURN(-EMFILE);
@@ -87,8 +86,9 @@ handle_t _syscall_open(const char __user *path, long len, int flags) {
 
 	if (PATH_MAX < len)
 		SYSCALL_RETURN(-1);
+	// TODO remove this check - it's not worth it w/ threads
 	if (process_find_free_handle(process_current, 0) < 0)
-		SYSCALL_RETURN(-1);
+		SYSCALL_RETURN(-EMFILE);
 
 	path_buf = kmalloc(len);
 	if (!path_buf) goto fail;
diff --git a/src/user/app/tests/kernel/fdlimit.c b/src/user/app/tests/kernel/fdlimit.c
new file mode 100644
index 0000000..d22af13
--- /dev/null
+++ b/src/user/app/tests/kernel/fdlimit.c
@@ -0,0 +1,49 @@
+#include "../tests.h"
+#include <camellia/flags.h>
+#include <errno.h>
+#include <unistd.h>
+
+static void test_fdlimit_pipe(void) {
+	handle_t ends[2];
+	handle_t h[2] = {-1, -1};
+	for (;;) {
+		handle_t cur = _syscall_open("/", 1, OPEN_READ);
+		if (cur == -EMFILE) break;
+		test(cur >= 0);
+		h[0] = h[1];
+		h[1] = cur;
+	}
+	test(h[0] >= 0); /* we need at least two handles */
+
+	test(_syscall_pipe(ends, 0) == -EMFILE);
+	test(_syscall_open("/", 1, OPEN_READ) == -EMFILE);
+
+	close(h[1]);
+	test(_syscall_pipe(ends, 0) == -EMFILE);
+	test(_syscall_open("/", 1, OPEN_READ) == h[1]);
+	test(_syscall_open("/", 1, OPEN_READ) == -EMFILE);
+
+	close(h[0]);
+	close(h[1]);
+	test(_syscall_pipe(ends, 0) == 0);
+}
+
+static void test_fdlimit_fork(void) {
+	for (;;) {
+		handle_t cur = _syscall_open("/", 1, OPEN_READ);
+		if (cur == -EMFILE) break;
+		test(cur >= 0);
+	}
+
+	if (!_syscall_fork(0, NULL)) _syscall_exit(123);
+
+	test(_syscall_fork(FORK_NEWFS, NULL) == -EMFILE);
+	test(_syscall_await() == 123);
+	test(_syscall_await() == ~0);
+}
+
+void r_k_fdlimit(void) {
+	/* all these tests implicitly test if the vfs returns -EMFILE */
+	run_test(test_fdlimit_pipe);
+	run_test(test_fdlimit_fork);
+}
diff --git a/src/user/app/tests/tests.c b/src/user/app/tests/tests.c
index 29733aa..14225ac 100644
--- a/src/user/app/tests/tests.c
+++ b/src/user/app/tests/tests.c
@@ -36,6 +36,7 @@ int forkpipe(FILE **f, handle_t *h) {
 int main(void) {
 	handle_t reader;
 	if (!forkpipe(&fail_trig, &reader)) {
+		r_k_fdlimit();
 		r_k_fs();
 		r_k_misc();
 		r_k_miscsyscall();
diff --git a/src/user/app/tests/tests.h b/src/user/app/tests/tests.h
index 248303d..e9b06e5 100644
--- a/src/user/app/tests/tests.h
+++ b/src/user/app/tests/tests.h
@@ -7,6 +7,7 @@
 
 void run_test(void (*fn)());
 
+void r_k_fdlimit(void);
 void r_k_fs(void);
 void r_k_misc(void);
 void r_k_miscsyscall(void);