1 files changed, 27 insertions, 0 deletions
diff --git a/src/lib/syscall.zig b/src/lib/syscall.zig
index 37cfb00..ee47a6b 100644
--- a/src/lib/syscall.zig
+++ b/src/lib/syscall.zig
@@ -13,6 +13,12 @@ pub const Error = error{
     UnknownSyscall,
 };
 
+fn setUserMemoryAccess(enable: bool) void {
+    var sstatus = instructions.sstatus.read();
+    sstatus.supervisor_user_memory_access = @bitCast(enable);
+    instructions.sstatus.write(sstatus);
+}
+
 pub fn handler(proc: *process.Info, trap_frame: *trap.Frame) !void {
     switch (trap_frame.general_purpose_registers[17]) {
         100000 => uprint(trap_frame),
@@ -45,6 +51,9 @@ fn uprint(trap_frame: *const trap.Frame) void {
 
 // open(path_c: [*:0]const u8, data: usize) Result(usize) // fixme: Kernel panic if null pointer
 fn open(proc: *process.Info, trap_frame: *trap.Frame) void {
+    setUserMemoryAccess(true);
+    defer setUserMemoryAccess(false);
+
     const path_c: [*:0]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
     const data = trap_frame.general_purpose_registers[11];
 
@@ -73,6 +82,9 @@ fn close(proc: *process.Info, trap_frame: *const trap.Frame) void {
 //     writeFn: ?vfs.Stream.WriteFn,
 // ) Result(void)
 fn provideStream(trap_frame: *trap.Frame) void {
+    setUserMemoryAccess(true);
+    defer setUserMemoryAccess(false);
+
     const path_c: [*:0]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
     const readFn: ?vfs.Stream.ReadFn = @ptrFromInt(trap_frame.general_purpose_registers[11]);
     const writeFn: ?vfs.Stream.WriteFn = @ptrFromInt(trap_frame.general_purpose_registers[12]);
@@ -93,6 +105,9 @@ fn provideStream(trap_frame: *trap.Frame) void {
 //     closeFn: ?vfs.File.CloseFn,
 // ) Result(void)
 fn provideFile(trap_frame: *trap.Frame) void {
+    setUserMemoryAccess(true);
+    defer setUserMemoryAccess(false);
+
     const path_c: [*:0]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
     const openFn: vfs.File.OpenFn = @ptrFromInt(trap_frame.general_purpose_registers[11]);
     const readFn: ?vfs.File.ReadFn = @ptrFromInt(trap_frame.general_purpose_registers[12]);
@@ -114,6 +129,9 @@ fn provideFile(trap_frame: *trap.Frame) void {
 //     callback: vfs.Hook.Callback,
 // ) Result(void)
 fn provideHook(trap_frame: *trap.Frame) void {
+    setUserMemoryAccess(true);
+    defer setUserMemoryAccess(false);
+
     const path_c: [*:0]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
     const callback: vfs.Hook.Callback = @ptrFromInt(trap_frame.general_purpose_registers[11]);
 
@@ -144,6 +162,9 @@ fn mkdir(trap_frame: *trap.Frame) void {
 //     removeFn: vfs.DirHook.RemoveFn,
 // ) Result(void)
 fn provideDirHook(trap_frame: *trap.Frame) void {
+    setUserMemoryAccess(true);
+    defer setUserMemoryAccess(false);
+
     const path_c: [*:0]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[10]);
     const provideFn: vfs.DirHook.ProvideFn = @ptrFromInt(trap_frame.general_purpose_registers[11]);
     const findFn: vfs.DirHook.FindFn = @ptrFromInt(trap_frame.general_purpose_registers[12]);
@@ -168,6 +189,9 @@ fn remove(trap_frame: *const trap.Frame) void {
 
 // read(handle: usize, buffer: [*]u8, len: usize) Result(usize)
 fn read(proc: *const process.Info, trap_frame: *trap.Frame) void {
+    setUserMemoryAccess(true);
+    defer setUserMemoryAccess(false);
+
     const handle = trap_frame.general_purpose_registers[10];
     const buffer: [*]u8 = @ptrFromInt(trap_frame.general_purpose_registers[11]);
     const len = trap_frame.general_purpose_registers[12];
@@ -181,6 +205,9 @@ fn read(proc: *const process.Info, trap_frame: *trap.Frame) void {
 
 // write(handle: usize, bytes: [*]const u8, len: usize) Result(usize)
 fn write(proc: *const process.Info, trap_frame: *trap.Frame) void {
+    setUserMemoryAccess(true);
+    defer setUserMemoryAccess(false);
+
     const handle = trap_frame.general_purpose_registers[10];
     const bytes: [*]const u8 = @ptrFromInt(trap_frame.general_purpose_registers[11]);
     const len = trap_frame.general_purpose_registers[12];