vfs: Fix read and write operations panicking for kernel-provided resources

Fixes #48.

1 files changed, 12 insertions, 4 deletions

diff --git a/src/lib/vfs.zig b/src/lib/vfs.zig
index c70a375..f3520be 100644
--- a/src/lib/vfs.zig
+++ b/src/lib/vfs.zig
@@ -150,15 +150,19 @@ pub const ResourceDescriptor = struct {
         self.inode.refs -|= 1;
     }
 
-    pub fn read(self: ResourceDescriptor, proc: *process.Info, buffer: []u8) !noreturn {
+    pub fn read(self: ResourceDescriptor, proc: *process.Info, buffer: []u8) !usize {
         return switch (self.inode.resource.tag) {
             .stream => {
                 const stream = self.inode.resource.data.stream;
 
+                const readFn = stream.readFn orelse return Error.ReadNotSupported;
+                if (self.inode.pid == 0) {
+                    return readFn(buffer.ptr, buffer.len).toErrorUnion();
+                }
+
                 const driver = process.latestThread(self.inode.pid).?;
                 const copy = try driver.copyBuffer(buffer);
 
-                const readFn = stream.readFn orelse return Error.ReadNotSupported;
                 proc.state = .suspended;
                 try call(driver, readFn, .{ copy.ptr, copy.len }, .{
                     .cleanupFn = moveBack,
@@ -174,15 +178,19 @@ pub const ResourceDescriptor = struct {
         };
     }
 
-    pub fn write(self: ResourceDescriptor, proc: *process.Info, bytes: []const u8) !noreturn {
+    pub fn write(self: ResourceDescriptor, proc: *process.Info, bytes: []const u8) !usize {
         return switch (self.inode.resource.tag) {
             .stream => {
                 const stream = self.inode.resource.data.stream;
 
+                const writeFn = stream.writeFn orelse return Error.WriteNotSupported;
+                if (self.inode.pid == 0) {
+                    return writeFn(bytes.ptr, bytes.len).toErrorUnion();
+                }
+
                 const driver = process.latestThread(self.inode.pid).?;
                 const copy = try driver.copyBytes(bytes);
 
-                const writeFn = stream.writeFn orelse return Error.WriteNotSupported;
                 proc.state = .suspended;
                 try call(driver, writeFn, .{ copy.ptr, copy.len }, null, .{
                     .hookFn = crossProcessReturn,