2 files changed, 27 insertions, 9 deletions

diff --git a/src/lib/syscall.zig b/src/lib/syscall.zig
index 5cbc9f2..c124373 100644
--- a/src/lib/syscall.zig
+++ b/src/lib/syscall.zig
@@ -57,12 +57,20 @@ fn open(proc: *process.Info, trap_frame: *trap.Frame) void {
     const path_c: [*:0]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
     const data = trap_frame.general_purpose_registers[11];
 
-    const rd = vfs.openZ(proc, path_c, proc.id, data) catch |err| {
+    const result = vfs.openZ(proc, path_c, data) catch |err| {
         sysexchange.frameReturn(usize, trap_frame, err);
         return;
     };
-    const maybe_handle = proc.createRdHandle(rd);
-    sysexchange.frameReturn(null, trap_frame, maybe_handle);
+
+    switch (result) {
+        .rd => |rd| {
+            const maybe_handle = proc.createRdHandle(rd);
+            sysexchange.frameReturn(usize, trap_frame, maybe_handle);
+        },
+        .data => |result_data| {
+            sysexchange.frameReturn(null, trap_frame, result_data);
+        },
+    }
 }
 
 // close(handle: usize) void
diff --git a/src/lib/vfs.zig b/src/lib/vfs.zig
index 10c961c..f601ddb 100644
--- a/src/lib/vfs.zig
+++ b/src/lib/vfs.zig
@@ -168,6 +168,11 @@ pub const Tree = struct {
     }
 };
 
+pub const OpenResult = union(enum) {
+    rd: ResourceDescriptor,
+    data: usize,
+};
+
 pub const ResourceDescriptor = struct {
     inode: *Inode,
 
@@ -363,26 +368,31 @@ pub fn provideResourceZ(path_c: [*:0]const u8, resource: Resource, pid: u16, opt
     return provideResource(mem.sliceTo(path_c, 0), resource, pid, options);
 }
 
-pub fn open(proc: *process.Info, path: []const u8, pid: u16, data: usize) !ResourceDescriptor {
+pub fn open(proc: *process.Info, path: []const u8, data: usize) !OpenResult {
     const inode = find(path) orelse return Error.NotFound;
     return switch (inode.resource.tag) {
-        .hook => {
+        .hook => blk: {
             const hook = inode.resource.data.hook;
 
+            if (inode.pid == 0) {
+                const result = hook.callback(proc.id, proc.thread_id, data);
+                break :blk .{ .data = try result.toErrorUnion() };
+            }
+
             const driver = process.latestThread(inode.pid).?;
 
             proc.state = .suspended;
-            try call(driver, hook.callback, .{ pid, data }, null, .{
+            try call(driver, hook.callback, .{ proc.id, proc.thread_id, data }, null, .{
                 .hookFn = crossProcessReturn,
                 .context = proc,
             });
         },
-        else => ResourceDescriptor.init(inode),
+        else => .{ .rd = try ResourceDescriptor.init(inode) },
     };
 }
 
-pub fn openZ(proc: *process.Info, path_c: [*:0]const u8, pid: u16, data: usize) !ResourceDescriptor {
-    return open(proc, mem.sliceTo(path_c, 0), pid, data);
+pub fn openZ(proc: *process.Info, path_c: [*:0]const u8, data: usize) !OpenResult {
+    return open(proc, mem.sliceTo(path_c, 0), data);
 }
 
 pub fn openNonHook(path: []const u8) !ResourceDescriptor {