[kernel] Add capabilities to handles

This change finally adds capabilities to handles. Included changes:

- j6_handle_t is now again 64 bits, with the highest 8 bits being a type
  code, and the next highest 24 bits being the capability mask, so that
  programs can check type/caps without calling the kernel.
- The definitions grammar now includes a `capabilities [ ]` section on
  objects, to list what capabilities are relevant.
- j6/caps.h is auto-generated from object capability lists
- init_libj6 again sets __handle_self and __handle_sys, this is a bit
  of a hack.
- A new syscall, j6_handle_list, will return the list of existing
  handles owned by the calling process.
- syscall_verify.cpp.cog now actually checks that the needed
  capabilities exist on handles before allowing the call.

definitions/objects/channel.def

@@ -1,14 +1,20 @@
 object channel : kobject {
     uid 3ea38b96aa0e54c8
 
-    method create [constructor] 
-    method close [destructor]
+    capabilities [
+        send
+        receive
+        close
+    ]
 
-    method send {
+    method create [constructor] 
+    method close [destructor cap:close]
+
+    method send [cap:send] {
         param data buffer [inout]
     }
 
-    method receive {
+    method receive [cap:receive] {
         param data buffer [out]
     }
 }

definitions/objects/endpoint.def

@@ -4,18 +4,23 @@
 object endpoint : kobject {
     uid c5882f24a4c03b7e
 
+    capabilities [
+        send
+        receive
+    ]
+
     method create [constructor]
 
     # Send a message on a channel. Blocks until the message
     # is received.
-    method send {
+    method send [cap:send] {
         param tag uint64
         param data buffer
     }
 
     # Receieve a message on a channel. Blocks until a message
     # is available.
-    method receive {
+    method receive [cap:receive] {
         param tag uint64 [out]
         param data buffer [out optional]
         param timeout uint64    # Receive timeout in nanoseconds
@@ -24,7 +29,7 @@ object endpoint : kobject {
     # Send a message on a channel and then await a new message.
     # Equivalent to calling send and then recieve, as a single
     # operation.
-    method sendrecv {
+    method sendrecv [cap:send cap:receive] {
         param tag uint64 [inout]
         param data buffer [inout]
         param timeout uint64      # Receive timeout in nanoseconds

definitions/objects/process.def

@@ -6,11 +6,16 @@ import "objects/kobject.def"
 object process : kobject {
     uid 0c69ee0b7502ba31
 
+    capabilities [
+        kill
+        create_thread
+    ]
+
     # Create a new empty process
     method create [constructor]
 
     # Stop all threads and exit the given process
-    method kill [destructor]
+    method kill [destructor cap:kill]
 
     # Stop all threads and exit the current process
     method exit [static] {

definitions/objects/system.def

@@ -6,21 +6,28 @@ import "objects/vma.def"
 object system : kobject {
     uid fa72506a2cf71a30
 
+    capabilities [
+        get_log
+        bind_irq
+        map_phys
+        change_iopl
+    ]
+
     # Get a log line from the kernel log
-    method get_log {
+    method get_log [cap:get_log] {
         param buffer buffer [out optional]   # Buffer for the log message data structure
     }
 
     # Ask the kernel to send this process messages whenever
     # the given IRQ fires
-    method bind_irq {
+    method bind_irq [cap:bind_irq] {
         param dest object endpoint  # Endpoint that will receive messages
         param irq uint              # IRQ number to bind
     }
 
     # Create a VMA and map an area of physical memory into it,
     # also mapping that VMA into the current process
-    method map_phys {
+    method map_phys [cap:map_phys] {
         param area object vma [out] # Receives a handle to the VMA created
         param phys address          # The physical address of the area
         param size size             # Size of the area, in pages
@@ -29,7 +36,7 @@ object system : kobject {
 
     # Request the kernel change the IOPL for this process. The only values
     # that make sense are 0 and 3.
-    method request_iopl {
+    method request_iopl [cap:change_iopl] {
         param iopl uint             # The IOPL to set for this process
     }
 }

definitions/objects/thread.def

@@ -1,13 +1,17 @@
 object thread : kobject {
     uid 11f23e593d5761bd
 
+    capabilities [
+        kill
+    ]
+
     method create [constructor] {
-        param process object process
+        param process object process [cap:create_thread]
         param stack_top address
         param entrypoint address
     }
 
-    method kill [destructor]
+    method kill [destructor cap:kill]
 
     method exit [static] {
         param status int32

definitions/objects/vma.def

@@ -4,27 +4,33 @@ object vma : kobject {
     uid d6a12b63b3ed3937
     cname vm_area
 
+    capabilities [
+        map
+        unmap
+        resize
+    ]
+
     method create [constructor] {
         param size size
         param flags uint32
     }
 
-    method create_map [constructor] {
+    method create_map [constructor cap:map] {
         param size size
         param address address
         param flags uint32
     }
 
-    method map {
+    method map [cap:map] {
         param process object process
         param address address
     }
 
-    method unmap {
+    method unmap [cap:unmap] {
         param process object process
     }
 
-    method resize {
+    method resize [cap:resize] {
         param size size [inout]
     }
 }

definitions/syscalls.def

@@ -1,9 +1,11 @@
-import "objects/system.def"
 import "objects/kobject.def"
-import "objects/process.def"
-import "objects/thread.def"
+
 import "objects/channel.def"
 import "objects/endpoint.def"
+import "objects/event.def"
+import "objects/process.def"
+import "objects/system.def"
+import "objects/thread.def"
 import "objects/vma.def"
 
 interface syscalls [syscall] {
@@ -11,6 +13,7 @@ interface syscalls [syscall] {
 
     expose object system
     expose object kobject
+    expose object event
     expose object process
     expose object thread
     expose object channel
@@ -24,4 +27,11 @@ interface syscalls [syscall] {
     function log {
         param message string
     }
+
+    # Get a list of handles owned by this process. If the
+    # supplied list is not big enough, will set the size
+    # needed in `size` and return j6_err_insufficient
+    function handle_list {
+        param handles object kobject [list inout optional] # A list of handles to be filled
+    }
 }