[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.

assets/grammars/definitions.g

@@ -2,7 +2,7 @@ start: import_statement* (object|interface)+
 
 import_statement: "import" PATH
 
-object: description? "object" name options? super? "{" uid cname? method* "}"
+object: description? "object" name options? super? "{" uid cname? capabilities? method* "}"
 
 interface: description? "interface" name options? "{" uid interface_param* "}"
 
@@ -14,6 +14,8 @@ uid: "uid" UID
 
 cname: "cname" IDENTIFIER
 
+capabilities: "capabilities" "[" IDENTIFIER+ "]"
+
 super: ":" name
 
 function: description? "function" name options? ("{" param* "}")?

definitions/objects/channel.def

@@ -1,14 +1,20 @@
 object channel : kobject {
     uid 3ea38b96aa0e54c8
 
-    method create [constructor] 
+    capabilities [
-    method close [destructor]
+        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
+    }
 }

scripts/definitions/context.py

@@ -68,6 +68,14 @@ class Context:
         from .types import ObjectRef
         ObjectRef.connect(objects)
 
+        for obj in objects.values():
+            for method in obj.methods:
+                caps = method.options.get("cap", list())
+                for cap in caps:
+                    if not cap in obj.caps:
+                        from .errors import UnknownCapError
+                        raise UnknownCapError(f"Unknown capability {cap} on {obj.name}::{method.name}")
+
         self.objects.update(objects)
         self.interfaces.update(interfaces)
 

scripts/definitions/errors.py

@@ -1,2 +1,3 @@
 class InvalidType(Exception): pass
 class UnknownTypeError(Exception): pass
+class UnknownCapError(Exception): pass

scripts/definitions/generate.py

@@ -1,62 +0,0 @@
-def generate_template(template, outfile, **kwargs):
-    from hashlib import md5
-    from os import makedirs
-    from os.path import dirname, exists
-
-    content = template.render(**kwargs)
-    h = md5(content.encode('utf-8')).hexdigest()
-
-    if exists(outfile):
-        existing = open(outfile, 'r').read().encode('utf-8')
-        if md5(existing).hexdigest() == h:
-            return False
-
-    makedirs(dirname(outfile), exist_ok=True)
-    open(outfile, 'w').write(content)
-
-    return True
-
-def generate(ctx, outdir, template_type):
-    from os.path import basename, join, split, splitext
-    from jinja2 import Environment, PackageLoader
-
-    for name, interface in ctx.interfaces.items():
-        base = "_".join(sorted(interface.options))
-
-        path = join("templates", base, template_type)
-        env = Environment(
-            loader = PackageLoader('definitions', package_path=path),
-            trim_blocks = True, lstrip_blocks = True)
-
-        env.filters
-
-        for template_name in env.list_templates():
-            template = env.get_template(template_name)
-
-            basepath, filename = split(template_name)
-            filename, ext = splitext(filename)
-
-            if filename == "_object_":
-                for obj in ctx.objects.values():
-                    outfile = join(outdir, basepath, obj.name + ext)
-                    wrote = generate_template(
-                                template, outfile,
-                                filename=obj.name + ext,
-                                basepath=basepath,
-                                object=obj,
-                                interface=interface,
-                                objects=ctx.objects)
-
-                    if wrote and ctx.verbose:
-                        print(f"Writing {outfile}")
-
-            else:
-                outfile = join(outdir, template_name)
-                wrote = generate_template(
-                            template, outfile,
-                            filename=basename(template_name),
-                            interface=interface,
-                            objects=ctx.objects)
-
-                if wrote and ctx.verbose:
-                    print(f"Writing {outfile}")

scripts/definitions/transformer.py

@@ -1,12 +1,13 @@
 from .parser import Transformer, v_args
 
 def get_opts(args):
-    from .types import CName, Description, Options, Type, UID
+    from .types import Caps, CName, Description, Options, Type, UID
 
     kinds = {
         Description: "desc",
         Options: "opts",
         CName: "cname",
+        Caps: "caps",
         UID: "uid",
         Type: "typename",
     }
@@ -112,6 +113,10 @@ class DefTransformer(Transformer):
         from .types import Options
         return Options([str(s) for s in args])
 
+    def capabilities(self, args):
+        from .types import Caps
+        return Caps([str(s) for s in args])
+
     def description(self, s):
         from .types import Description
         return Description("\n".join(s))
@@ -140,6 +145,9 @@ class DefTransformer(Transformer):
     def COMMENT(self, s):
         return s[2:].strip()
 
+    def OPTION(self, s):
+        return str(s)
+
     def IDENTIFIER(self, s):
         return str(s)
 

scripts/definitions/types/__init__.py

@@ -5,16 +5,13 @@ def _indent(x):
 class CName(str): pass
 class Description(str): pass
 class Import(str): pass
+class Caps(list): pass
 
 class Options(dict):
     def __init__(self, opts = tuple()):
         for opt in opts:
             parts = opt.split(":", 1)
-            self[parts[0]] = "".join(parts[1:])
+            self[parts[0]] = self.get(parts[0], []) + ["".join(parts[1:])]
-
-    def __str__(self):
-        if not self: return ""
-        return "[{}]".format(" ".join(self.keys()))
 
 class UID(int):
     def __str__(self):

scripts/definitions/types/function.py

@@ -43,6 +43,11 @@ class Param:
         self.options = opts
         self.desc = desc
 
+        self.caps = set()
+        for key, values in opts.items():
+            if key == "cap":
+                self.caps.update(values)
+
     def __str__(self):
         return "param {} {} {}  {}".format(
                 self.name, repr(self.type), self.options, self.desc or "")

scripts/definitions/types/object.py

@@ -1,8 +1,8 @@
 from . import _indent
-from . import Options
+from . import Caps, Options
 
 class Object:
-    def __init__(self, name, uid, typename=None, opts=Options(), desc="", children=tuple(), cname=None):
+    def __init__(self, name, uid, typename=None, opts=Options(), caps=Caps(), desc="", children=tuple(), cname=None):
         self.name = name
         self.uid = uid
         self.options = opts
@@ -11,6 +11,8 @@ class Object:
         self.methods = children
         self.cname = cname or name
 
+        self.caps = set(caps)
+
         from . import ObjectRef
         self.__ref = ObjectRef(name)
 

src/kernel/kernel.module

@@ -53,6 +53,7 @@ kernel = module("kernel",
         "syscalls.inc.cog",
         "syscalls/channel.cpp",
         "syscalls/endpoint.cpp",
+        "syscalls/handle.cpp",
         "syscalls/object.cpp",
         "syscalls/process.cpp",
         "syscalls/system.cpp",

src/kernel/objects/channel.h

@@ -2,6 +2,7 @@
 /// \file channel.h
 /// Definition of channel objects and related functions
 
+#include <j6/caps.h>
 #include <j6/signals.h>
 #include <util/bip_buffer.h>
 #include <util/counted.h>
@@ -17,7 +18,7 @@ class channel :
 {
 public:
     /// Capabilities on a newly constructed channel handle
-    constexpr static j6_cap_t creation_caps = 0;
+    constexpr static j6_cap_t creation_caps = j6_cap_channel_all;
 
     channel();
     virtual ~channel();

src/kernel/objects/endpoint.h

@@ -2,6 +2,7 @@
 /// \file endpoint.h
 /// Definition of endpoint kobject types
 
+#include <j6/caps.h>
 #include <j6/signals.h>
 #include <util/spinlock.h>
 #include <util/vector.h>
@@ -16,7 +17,7 @@ class endpoint :
 {
 public:
     /// Capabilities on a newly constructed endpoint handle
-    constexpr static j6_cap_t creation_caps = 0;
+    constexpr static j6_cap_t creation_caps = j6_cap_endpoint_all;
 
     endpoint();
     virtual ~endpoint();

src/kernel/objects/handle.h

@@ -9,34 +9,40 @@ namespace obj {
 
 struct handle
 {
-    inline handle(j6_handle_t in_id, kobject *in_object, j6_cap_t in_caps) :
+    // A j6_handle_t is an id in the low 32 bits, caps in bits 32-55, and type in 56-63
-        id {in_id}, object {in_object}, caps {in_caps} {
+    static inline j6_handle_t make_id(j6_handle_t id, j6_cap_t caps, kobject *obj) {
+        return (id & 0xffffffffull) |
+            static_cast<j6_handle_t>(caps) << 32 |
+            static_cast<j6_handle_t>(obj ? obj->get_type() : kobject::type::none) << 56;
+    }
+
+    inline handle(j6_handle_t in_id, kobject *in_obj, j6_cap_t caps) :
+        id {make_id(in_id, caps, in_obj)}, object {in_obj} {
         if (object) object->handle_retain();
     }
 
     inline handle(const handle &other) :
-        id {other.id}, object {other.object}, caps {other.caps} {
+        id {other.id}, object {other.object} {
         if (object) object->handle_retain();
     }
 
     inline handle(handle &&other) :
-        id {other.id}, object {other.object}, caps {other.caps} {
+        id {other.id}, object {other.object} {
         other.id = 0;
-        other.caps = 0;
         other.object = nullptr;
     }
 
     inline handle & operator=(const handle &other) {
         if (object) object->handle_release();
-        id = other.id; caps = other.caps; object = other.object;
+        id = other.id; object = other.object;
         if (object) object->handle_retain();
         return *this;
     }
 
     inline handle & operator=(handle &&other) {
         if (object) object->handle_release();
-        id = other.id; caps = other.caps; object = other.object;
+        id = other.id; object = other.object;
-        other.id = other.caps = 0; other.object = nullptr;
+        other.id = 0; other.object = nullptr;
         return *this;
     }
 
@@ -44,12 +50,14 @@ struct handle
         if (object) object->handle_release();
     }
 
+    inline j6_cap_t caps() const { return id >> 32; }
+
     inline bool has_cap(j6_cap_t test) const {
-        return (caps & test) == test;
+        return (caps() & test) == test;
     }
 
     inline kobject::type type() const {
-        return object->get_type();
+        return static_cast<kobject::type>(id >> 56);
     }
 
     inline int compare(const handle &o) {
@@ -75,7 +83,6 @@ struct handle
     inline const kobject * as<kobject>() const { return object; }
 
     j6_handle_t id;
-    j6_cap_t caps;
     kobject *object;
 };
 

src/kernel/objects/kobject.h

@@ -16,7 +16,7 @@ class kobject
 {
 public:
     /// Types of kernel objects.
-    enum class type : uint16_t
+    enum class type : uint8_t
     {
 #define OBJECT_TYPE( name, val ) name = val,
 #include <j6/tables/object_types.inc>

src/kernel/objects/process.cpp

@@ -22,8 +22,7 @@ process::process() :
     m_next_handle {1},
     m_state {state::running}
 {
-    j6_handle_t self = add_handle(this, process::self_caps);
+    m_self_handle = add_handle(this, process::self_caps);
-    kassert(self == self_handle(), "Process self-handle is not 1");
 }
 
 // The "kernel process"-only constructor
@@ -129,9 +128,10 @@ process::add_handle(kobject *obj, j6_cap_t caps)
     if (!obj)
         return j6_handle_invalid;
 
-    j6_handle_t id = m_next_handle++;
+    handle h {m_next_handle++, obj, caps};
-    m_handles.insert(id, {id, obj, caps});
+    j6_handle_t id = h.id;
 
+    m_handles.insert(id, h);
     return id;
 }
 
@@ -147,4 +147,16 @@ process::lookup_handle(j6_handle_t id)
     return m_handles.find(id);
 }
 
+size_t
+process::list_handles(j6_handle_t *handles, size_t len)
+{
+    for (const auto &i : m_handles) {
+        if (len-- == 0)
+            break;
+        *handles++ = i.key;
+    }
+
+    return m_handles.count();
+}
+
 } // namespace obj

src/kernel/objects/process.h

@@ -2,6 +2,7 @@
 /// \file process.h
 /// Definition of process kobject types
 
+#include <j6/caps.h>
 #include <util/map.h>
 #include <util/vector.h>
 
@@ -17,10 +18,10 @@ class process :
 {
 public:
     /// Capabilities on a newly constructed process handle
-    constexpr static j6_cap_t creation_caps = 0;
+    constexpr static j6_cap_t creation_caps = j6_cap_process_all;
 
     /// Capabilities on a process to itself
-    constexpr static j6_cap_t self_caps = 0;
+    constexpr static j6_cap_t self_caps = j6_cap_process_all;
 
     /// Top of memory area where thread stacks are allocated
     constexpr static uintptr_t stacks_top = 0x0000800000000000;
@@ -74,13 +75,19 @@ public:
     /// \returns     Pointer to the handle struct, or null if not found
     handle * lookup_handle(j6_handle_t handle);
 
+    /// Get the list of handle ids this process owns
+    /// \arg handles  Pointer to an array of handles to copy into
+    /// \arg len      Size of the array
+    /// \returns      Total number of handles (may be more than number copied)
+    size_t list_handles(j6_handle_t *handles, size_t len);
+
     /// Inform the process of an exited thread
     /// \args th  The thread which has exited
     /// \returns  True if this thread ending has ended the process
     bool thread_exited(thread *th);
 
     /// Get the handle for this process to refer to itself
-    inline j6_handle_t self_handle() const { return 1; }
+    inline j6_handle_t self_handle() const { return m_self_handle; }
 
     /// Get the process object that owns kernel threads and the
     /// kernel address space
@@ -95,6 +102,7 @@ private:
     // This constructor is called by create_kernel_process
     process(page_table *kpml4);
 
+    j6_handle_t m_self_handle;
     int32_t m_return_code;
 
     vm_space m_space;

src/kernel/objects/system.h

@@ -2,6 +2,7 @@
 /// \file system.h
 /// Definition of kobject type representing the system
 
+#include <j6/caps.h>
 #include "objects/kobject.h"
 
 namespace obj {
@@ -11,7 +12,7 @@ class system :
 {
 public:
     /// Capabilities on system given to init
-    constexpr static j6_cap_t init_caps = 0;
+    constexpr static j6_cap_t init_caps = j6_cap_system_all;
 
     static constexpr kobject::type type = kobject::type::system;
 

src/kernel/objects/thread.h

@@ -2,6 +2,7 @@
 /// \file thread.h
 /// Definition of thread kobject types
 
+#include <j6/caps.h>
 #include <util/enum_bitfields.h>
 #include <util/linked_list.h>
 #include <util/spinlock.h>
@@ -60,10 +61,10 @@ class thread :
 {
 public:
     /// Capabilities on a newly constructed thread handle
-    constexpr static j6_cap_t creation_caps = 0;
+    constexpr static j6_cap_t creation_caps = j6_cap_thread_all;
 
     /// Capabilities the parent process gets on new thread handles
-    constexpr static j6_cap_t parent_caps = 0;
+    constexpr static j6_cap_t parent_caps = j6_cap_thread_all;
 
     enum class state : uint8_t {
         ready    = 0x01,

src/kernel/objects/vm_area.h

@@ -5,6 +5,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include <j6/caps.h>
 #include <j6/signals.h>
 #include <util/vector.h>
 #include <util/enum_bitfields.h>
@@ -34,7 +35,7 @@ class vm_area :
 {
 public:
     /// Capabilities on a newly constructed vma handle
-    constexpr static j6_cap_t creation_caps = 0;
+    constexpr static j6_cap_t creation_caps = j6_cap_vma_all;
 
     static constexpr kobject::type type = kobject::type::vma;
 

src/kernel/syscall_verify.cpp.cog

@@ -2,6 +2,7 @@
 
 #include <stdint.h>
 #include <arch/memory.h>
+#include <j6/caps.h>
 #include <j6/errors.h>
 #include <j6/types.h>
 #include <util/counted.h>
@@ -36,6 +37,10 @@ using util::buffer;
 /*[[[cog code generation
 cbool = {True: "true", False: "false"}
 
+def get_caps(opts, type):
+    caps = opts.get("cap", list())
+    return [f"j6_cap_{type.name}_{c}" for c in caps]
+
 for id, scope, method in syscalls.methods:
     if scope:
         name = f"{scope.name}_{method.name}"
@@ -58,7 +63,11 @@ for id, scope, method in syscalls.methods:
         argdefs.append("j6_handle_t self")
         cxxargdefs.append(f"obj::{scope.cname} *self")
         args.append("self_obj")
-        handles.append((f"obj::{scope.cname} *", "self", "self_obj"))
+        handles.append((
+            f"obj::{scope.cname} *",
+            "self",
+            "self_obj",
+            get_caps(method.options, scope)))
 
     for param in method.params:
         needs_obj = param.type.needs_object(param.options)
@@ -73,7 +82,7 @@ for id, scope, method in syscalls.methods:
 
             if needs_obj:
                 oarg = f"{arg}_obj"
-                handles.append((type, arg, oarg))
+                handles.append((type, arg, oarg, get_caps(param.options, param.type.object)))
                 args.append(oarg)
             else:
                 args.append(arg)
@@ -94,12 +103,18 @@ for id, scope, method in syscalls.methods:
         cog.outl( "        return j6_err_invalid_arg;")
         cog.outl()
 
-    for type, inarg, outarg in handles:
+    for type, inarg, outarg, caps in handles:
         if type.endswith('*'):
             type = type[:-1].strip()
 
         cog.outl(f"    obj::handle *{inarg}_handle = get_handle<typename {type}>({inarg});")
         cog.outl(f"    if (!{inarg}_handle) return j6_err_invalid_arg;")
+
+        if caps:
+            allcaps = " | ".join(caps)
+            cog.outl(f"    j6_cap_t {inarg}_caps_req = {allcaps};")
+            cog.outl(f"    if (!{inarg}_handle->has_cap({inarg}_caps_req)) return j6_err_denied;")
+
         cog.outl(f"    {type} *{outarg} = {inarg}_handle->as<typename {type}>();")
         cog.outl(f"    if (!{outarg}) return j6_err_invalid_arg;")
         cog.outl()

src/kernel/syscalls/handle.cpp

@@ -0,0 +1,27 @@
+#include <j6/errors.h>
+#include <j6/types.h>
+
+#include "objects/process.h"
+
+using namespace obj;
+
+namespace syscalls {
+
+j6_status_t
+handle_list(j6_handle_t *handles, size_t *handles_len)
+{
+    if (!handles_len || (*handles_len && !handles))
+        return j6_err_invalid_arg;
+
+    process &p = process::current();
+    size_t requested = *handles_len;
+
+    *handles_len = p.list_handles(handles, requested);
+
+    if (*handles_len < requested)
+        return j6_err_insufficient;
+
+    return j6_status_ok;
+}
+
+} // namespace syscalls

src/libraries/j6/include/j6/caps.h.cog

@@ -0,0 +1,25 @@
+#pragma once
+// vim: ft=cpp
+
+/// \file caps.h
+/// Capability bitfield constants
+
+/*[[[cog code generation
+from definitions.context import Context
+
+ctx = Context(definitions_path)
+ctx.parse("syscalls.def")
+syscalls = ctx.interfaces["syscalls"]
+
+for obj in syscalls.exposes:
+    i = 0
+    for cap in obj.object.caps:
+        name = f"j6_cap_{obj.object.name}_{cap}"
+        cog.outl(f"#define {name:<30} (1 << {i})")
+        i += 1
+
+    name = f"j6_cap_{obj.object.name}_all"
+    cog.outl(f"#define {name:<30} ((1<<{i})-1)")
+    cog.outl()
+]]]*/
+/// [[[end]]]

src/libraries/j6/include/j6/errors.h

@@ -18,4 +18,5 @@
 #define j6_err_not_ready            j6_err(0x0004)
 #define j6_err_insufficient         j6_err(0x0005)
 #define j6_err_timed_out            j6_err(0x0006)
+#define j6_err_denied               j6_err(0x0007)
 

src/libraries/j6/include/j6/types.h

@@ -27,14 +27,16 @@ typedef uint64_t j6_tag_t;
 #define j6_tag_from_irq(x)    ((x) | j6_tag_irq_base)
 #define j6_tag_to_irq(x)      ((x) & ~j6_tag_irq_base)
 
-/// Handles are references and capabilities to other objects.
+/// Handles are references and capabilities to other objects. A handle is
-typedef uint32_t j6_handle_t;
+/// an id in the lower 32 bits, a bitfield of capabilities in bits 32-55
+/// and a type id in bits 56-63.
+typedef uint64_t j6_handle_t;
+
+/// Bitfield for storage of capabilities on their own
+typedef uint32_t j6_cap_t;
 
 #define j6_handle_invalid ((j6_handle_t)-1)
 
-/// Bitfield for storage of capabilities
-typedef uint32_t j6_cap_t;
-
 enum j6_object_type {
 #define OBJECT_TYPE( name, val ) j6_object_type_ ## name = val,
 #include <j6/tables/object_types.inc>

src/libraries/j6/init.cpp

@@ -3,45 +3,47 @@
 #ifndef __j6kernel
 
 #include <stdint.h>
+#include <j6/errors.h>
 #include <j6/init.h>
+#include <j6/syscalls.h>
 #include <j6/types.h>
 
-static size_t __initc = 0;
-static struct j6_init_value *__initv = 0;
-
 j6_handle_t __handle_sys = j6_handle_invalid;
 j6_handle_t __handle_self = j6_handle_invalid;
 
-extern "C" void
+namespace {
-_get_init(size_t *initc, struct j6_init_value **initv)
+    constexpr size_t __static_arr_size = 4;
-{
+    j6_handle_t __handle_array[__static_arr_size];
-    if (!initc)
-        return;
 
-    *initc = __initc;
+    static j6_status_t
-    if (initv)
+    __load_handles()
-        *initv = __initv;
+    {
-}
+        size_t count = __static_arr_size;
+        j6_handle_t *handles = __handle_array;
+        j6_status_t s = j6_handle_list(handles, &count);
+
+        if (s != j6_err_insufficient && s != j6_status_ok)
+            return s;
+
+        if (count > __static_arr_size)
+            count = __static_arr_size;
+
+        for (size_t i = 0; i < count; ++i) {
+            uint8_t type = (handles[i] >> 56);
+            if (type == j6_object_type_system && __handle_sys == j6_handle_invalid)
+                __handle_sys = handles[i];
+            else if (type == j6_object_type_process && __handle_self == j6_handle_invalid)
+                __handle_self = handles[i];
+        }
+
+        return s;
+    }
+} // namespace
 
 extern "C" void
 _init_libj6(uint64_t *rsp)
 {
-    uint64_t argc = *rsp++;
+    __load_handles();
-    rsp += argc;
-
-    __initc = *rsp++;
-    __initv = (struct j6_init_value *)rsp;
-
-    for (unsigned i = 0; i < __initc; ++i) {
-        if (__initv[i].type == j6_init_handle_other &&
-            __initv[i].handle.type == j6_object_type_system) {
-            __handle_sys = __initv[i].handle.handle;
-        }
-        else if (__initv[i].type == j6_init_handle_self &&
-            __initv[i].handle.type == j6_object_type_process) {
-            __handle_self = __initv[i].handle.handle;
-        }
-    }
 }
 
 #endif // __j6kernel

src/libraries/j6/j6.module

@@ -5,6 +5,7 @@ j6 = module("j6",
     includes = [ "include" ],
     sources = [
         "init.cpp",
+        "include/j6/caps.h.cog",
         "include/j6/syscalls.h.cog",
         "include/j6/sysconf.h.cog",
         "syscalls.s.cog",
@@ -18,6 +19,7 @@ sysconf = join(source_root, "definitions/sysconf.yaml")
 definitions = glob('definitions/**/*.def', recursive=True)
 
 j6.add_depends([
+        "include/j6/caps.h.cog",
         "include/j6/syscalls.h.cog",
         "syscalls.s.cog",
     ], definitions)

src/libraries/libc/j6libc/sbrk.c

@@ -3,7 +3,7 @@
 #include <j6/syscalls.h>
 //void *sbrk(intptr_t) __attribute__ ((weak));
 
-static j6_handle_t __core_handle = 0;
+static j6_handle_t __core_handle = j6_handle_invalid;
 static intptr_t __core_size = 0;
 
 static const uintptr_t __core_base = 0x1c0000000;

src/user/drv.uart/main.cpp

@@ -18,8 +18,8 @@ extern "C" {
     int main(int, const char **);
 }
 
-constexpr j6_handle_t handle_self = 1;
+extern j6_handle_t __handle_self;
-constexpr j6_handle_t handle_sys = 2;
+extern j6_handle_t __handle_sys;
 
 struct entry
 {
@@ -76,13 +76,13 @@ log_pump_proc()
     void *message_buffer = nullptr;
     char stringbuf[300];
 
-    j6_status_t result = j6_system_request_iopl(handle_sys, 3);
+    j6_status_t result = j6_system_request_iopl(__handle_sys, 3);
     if (result != j6_status_ok)
         return;
 
     while (true) {
         size_t size = buffer_size;
-        j6_status_t s = j6_system_get_log(handle_sys, message_buffer, &size);
+        j6_status_t s = j6_system_get_log(__handle_sys, message_buffer, &size);
 
         if (s == j6_err_insufficient) {
             free(message_buffer);
@@ -96,7 +96,7 @@ log_pump_proc()
 
         if (size == 0) {
             j6_signal_t sigs = 0;
-            j6_kobject_wait(handle_sys, j6_signal_system_has_log, &sigs);
+            j6_kobject_wait(__handle_sys, j6_signal_system_has_log, &sigs);
             continue;
         }
 
@@ -121,7 +121,7 @@ main(int argc, const char **argv)
     j6_handle_t endp = j6_handle_invalid;
     j6_status_t result = j6_status_ok;
 
-    result = j6_system_request_iopl(handle_sys, 3);
+    result = j6_system_request_iopl(__handle_sys, 3);
     if (result != j6_status_ok)
         return result;
 
@@ -129,11 +129,11 @@ main(int argc, const char **argv)
     if (result != j6_status_ok)
         return result;
 
-    result = j6_system_bind_irq(handle_sys, endp, 3);
+    result = j6_system_bind_irq(__handle_sys, endp, 3);
     if (result != j6_status_ok)
         return result;
 
-    result = j6_system_bind_irq(handle_sys, endp, 4);
+    result = j6_system_bind_irq(__handle_sys, endp, 4);
     if (result != j6_status_ok)
         return result;
 
@@ -153,7 +153,7 @@ main(int argc, const char **argv)
     sp[0] = sp[1] = 0;
 
     j6_handle_t child = j6_handle_invalid;
-    result = j6_thread_create(&child, handle_self, stack_top - 0x10, reinterpret_cast<uintptr_t>(&log_pump_proc));
+    result = j6_thread_create(&child, __handle_self, stack_top - 0x10, reinterpret_cast<uintptr_t>(&log_pump_proc));
     if (result != j6_status_ok)
         return result;
 

src/user/drv.uefi_fb/main.cpp

@@ -37,7 +37,6 @@ main(int argc, const char **argv)
 
     size_t initc = 0;
     j6_init_value *initv = nullptr;
-    _get_init(&initc, &initv);
 
     j6_init_framebuffer *fb = nullptr;
     for (unsigned i = 0; i < initc; ++i) {

src/user/srv.init/loader.cpp

@@ -12,8 +12,8 @@
 using bootproto::module_flags;
 using bootproto::module_program;
 
-extern j6_handle_t handle_self;
+extern j6_handle_t __handle_self;
-extern j6_handle_t handle_system;
+extern j6_handle_t __handle_sys;
 
 constexpr uintptr_t load_addr_base = 0xf8000000;
 constexpr size_t stack_size = 0x10000;
@@ -28,13 +28,13 @@ load_program(const module_program &prog, char *err_msg)
     }
 
     j6_handle_t elf_vma = j6_handle_invalid;
-    j6_status_t res = j6_system_map_phys(handle_system, &elf_vma, prog.base_address, prog.size, 0);
+    j6_status_t res = j6_system_map_phys(__handle_sys, &elf_vma, prog.base_address, prog.size, 0);
     if (res != j6_status_ok) {
         sprintf(err_msg, "  ** error loading program '%s': creating physical vma: %lx", prog.filename, res);
         return false;
     }
 
-    res = j6_vma_map(elf_vma, handle_self, prog.base_address);
+    res = j6_vma_map(elf_vma, __handle_self, prog.base_address);
     if (res != j6_status_ok) {
         sprintf(err_msg, "  ** error loading program '%s': mapping vma: %lx", prog.filename, res);
         return false;
@@ -55,7 +55,7 @@ load_program(const module_program &prog, char *err_msg)
         return false;
     }
 
-    res = j6_process_give_handle(proc, handle_system, nullptr);
+    res = j6_process_give_handle(proc, __handle_sys, nullptr);
     if (res != j6_status_ok) {
         sprintf(err_msg, "  ** error loading program '%s': giving system handle: %lx", prog.filename, res);
         return false;
@@ -90,7 +90,7 @@ load_program(const module_program &prog, char *err_msg)
             return false;
         }
 
-        res = j6_vma_unmap(sub_vma, handle_self);
+        res = j6_vma_unmap(sub_vma, __handle_self);
         if (res != j6_status_ok) {
             sprintf(err_msg, "  ** error loading program '%s': unmapping sub vma: %lx", prog.filename, res);
             return false;
@@ -115,7 +115,7 @@ load_program(const module_program &prog, char *err_msg)
         return false;
     }
 
-    res = j6_vma_unmap(stack_vma, handle_self);
+    res = j6_vma_unmap(stack_vma, __handle_self);
     if (res != j6_status_ok) {
         sprintf(err_msg, "  ** error loading program '%s': unmapping stack vma: %lx", prog.filename, res);
         return false;
@@ -128,7 +128,7 @@ load_program(const module_program &prog, char *err_msg)
         return false;
     }
 
-    res = j6_vma_unmap(elf_vma, handle_self);
+    res = j6_vma_unmap(elf_vma, __handle_self);
     if (res != j6_status_ok) {
         sprintf(err_msg, "  ** error loading program '%s': unmapping elf vma: %lx", prog.filename, res);
         return false;

src/user/srv.init/main.cpp

@@ -1,6 +1,9 @@
 #include <stdio.h>
+#include <stdlib.h>
 
+#include <j6/errors.h>
 #include <j6/syscalls.h>
+#include <j6/types.h>
 #include <bootproto/init.h>
 
 #include "loader.h"
@@ -16,15 +19,15 @@ extern "C" {
 
 uintptr_t _arg_modules_phys;   // This gets filled in in _start
 
-j6_handle_t handle_self   = 1; // Self program handle is always 1
+extern j6_handle_t __handle_self;
-j6_handle_t handle_system = 2; // boot protocol is that init gets the system as handle 2
+extern j6_handle_t __handle_sys;
 
 int
 main(int argc, const char **argv)
 {
     j6_log("srv.init starting");
 
-    modules mods = modules::load_modules(_arg_modules_phys, handle_system, handle_self);
+    modules mods = modules::load_modules(_arg_modules_phys, __handle_sys, __handle_self);
 
     for (auto &mod : mods.of_type(module_type::program)) {
         auto &prog = static_cast<const module_program&>(mod);