add basic scheduler logic. rename init rootdir indexes

7 files changed, 214 insertions, 16 deletions

diff --git a/sys/link.c b/sys/link.c
index 45c118a..04a15cf 100644
--- a/sys/link.c
+++ b/sys/link.c
@@ -1,5 +1,6 @@
 #include "link.h"
 #include "arch/x86_64/hal/obj.h"
+#include "sys/objdir.h"
 #include "hal/memory.h"
 #include "lib/printf.h"
 #include "jove.h"
diff --git a/sys/objdir.c b/sys/objdir.c
new file mode 100644
index 0000000..c448e85
--- /dev/null
+++ b/sys/objdir.c
@@ -0,0 +1,114 @@
+#include "api/error.h"
+#include "arch/x86_64/hal/obj.h"
+#include "hal/memory.h"
+#include "hal/obj.h"
+#include "lib/string.h"
+#include "jove.h"
+#include <errno.h>
+
+int
+objdir_new(jove_owned_obj_t *untyped_obj)
+{
+    jove_untyped_t *untyped = obj_deref(untyped_obj);
+    if((uintptr_t)untyped & (JOVE_OBJDIR_SIZE - 1)) return -EALIGN;
+    if(untyped->limit != JOVE_OBJDIR_SIZE) return -EBADSIZE;
+
+    memset(untyped, 0, JOVE_OBJDIR_SIZE);
+    obj_settype(untyped_obj, JOVE_OBJ_OBJDIR);
+    return 0;
+}
+
+jove_obj_t
+objdir_peeklocal(
+        jove_owned_obj_t *objdir_obj, 
+        uint16_t entry)
+{
+    if(obj_gettype(objdir_obj) != JOVE_OBJ_OBJDIR) {
+        errno = EBADOBJ;
+        return (jove_obj_t) { 0 };
+    }
+    if(entry >= JOVE_OBJDIR_ENTRIES) {
+        errno = EBADPATH;
+        return (jove_obj_t) { 0 };
+    }
+
+    jove_objdir_t *objtab = obj_deref(objdir_obj);
+    return objtab->entries[entry];
+}
+
+jove_owned_obj_t*
+objdir_getlocal(
+        jove_owned_obj_t *objdir_obj, 
+        uint16_t entry)
+{
+    if(obj_gettype(objdir_obj) != JOVE_OBJ_OBJDIR) {
+        reterr(EBADOBJ);
+    }
+    if(entry >= JOVE_OBJDIR_ENTRIES) {
+        reterr(EBADPATH);
+    }
+
+    jove_objdir_t *objtab = obj_deref(objdir_obj);
+    return obj_take(&objtab->entries[entry]);
+}
+
+jove_owned_obj_t*
+objdir_trygetlocal(
+        jove_owned_obj_t *objdir_obj, 
+        uint16_t entry)
+{
+    if(obj_gettype(objdir_obj) != JOVE_OBJ_OBJDIR) {
+        reterr(EBADOBJ);
+    }
+    if(entry >= JOVE_OBJDIR_ENTRIES) {
+        reterr(EBADPATH);
+    }
+
+    jove_objdir_t *objtab = obj_deref(objdir_obj);
+    return obj_trytake(&objtab->entries[entry]);
+}
+
+jove_owned_obj_t*
+objdir_getobj(
+        jove_owned_obj_t *objdir_obj, 
+        const uint16_t *path, 
+        size_t path_len)
+{
+    errno = 0;
+    if(path_len == 0) {
+        return objdir_obj;
+    }
+    {
+        jove_owned_obj_t *child_objdir = objdir_getlocal(objdir_obj, path[0]);
+        if(child_objdir == 0) {
+            reterr(EBADPATH);
+        }
+
+        jove_owned_obj_t *target_obj = objdir_getobj(child_objdir, path + 1, path_len - 1);
+        obj_release(child_objdir);
+        return target_obj;
+    }
+}
+
+jove_owned_obj_t*
+objdir_trygetobj(
+        jove_owned_obj_t *objdir_obj, 
+        const uint16_t *path, 
+        size_t path_len)
+{
+    errno = 0;
+    if(path_len == 0) {
+        return objdir_obj;
+    }
+    {
+        jove_owned_obj_t *child_objdir = objdir_trygetlocal(objdir_obj, path[0]);
+        if(child_objdir == 0) {
+            return 0;
+        }
+
+        jove_owned_obj_t *target_obj = objdir_trygetobj(child_objdir, path + 1, path_len - 1);
+        obj_release(child_objdir);
+        return target_obj;
+    }
+}
+
diff --git a/sys/objdir.h b/sys/objdir.h
new file mode 100644
index 0000000..54e9618
--- /dev/null
+++ b/sys/objdir.h
@@ -0,0 +1,27 @@
+#ifndef _JOVE_SYS_OBJDIR_H
+#define _JOVE_SYS_OBJDIR_H 1
+
+#include "hal/obj.h"
+
+int objdir_new(jove_owned_obj_t *untyped_obj);
+/*Returns the n'th entry of the object directory passed.
+ * If the passed object is not an objdir, returns NULL and sets errno to EBADOBJ.
+ * If the passed entry index is out of bounds, returns NULL and sets errno to EOOB.*/
+jove_owned_obj_t *objdir_getlocal(jove_owned_obj_t *objdir_obj, uint16_t entry);
+/*Same as objdir_getlocal except does not block if entry obj is taken.*/
+jove_owned_obj_t *objdir_trygetlocal(jove_owned_obj_t *objdir_obj, uint16_t entry);
+jove_obj_t objdir_peeklocal(jove_owned_obj_t *objdir_obj, uint16_t entry);
+
+/*Recursively seeks through an object directory for an object following the passed
+ * path variable.
+ * If the path length is zero, returns the passed object.
+ * If the passed object is not an objdir, returns NULL and sets errno to EBADOBJ.
+ * If any object excluding the object at the end of the path is not an objdir,
+ * returns NULL and sets errno to EBADOBJ.
+ * If any entry in the path is out of bounds, returns NULL and sets errno to EBADOBJ.*/
+jove_owned_obj_t *objdir_getobj(jove_owned_obj_t *objdir_obj, const uint16_t *path, size_t path_len);
+/*Same as objdir_getobj but does not block if child objects are locked.*/
+jove_owned_obj_t *objdir_trygetobj(jove_owned_obj_t *objdir_obj, const uint16_t *path, size_t path_len);
+
+
+#endif
diff --git a/sys/syscall.c b/sys/syscall.c
index 05eeb58..0c40418 100644
--- a/sys/syscall.c
+++ b/sys/syscall.c
@@ -87,6 +87,7 @@ syscall_handler(uintmax_t message_path_raw, uint16_t message_pathlen)
 
     ctx.pcb = process_current();
     pcb_t *pcb = obj_deref(ctx.pcb);
+
     ctx.objdir = lockstack_push(&ctx.lockstack, obj_take(pcb_getrootdir(pcb)));
 
     ctx.message = link_try_traverse_objdir(
@@ -113,8 +114,8 @@ syscall_handler(uintmax_t message_path_raw, uint16_t message_pathlen)
         goto release_return;
     }
 
-    uintptr_t message_vptr = message_unmap(ctx.message.obj,
-            (jove_owned_obj_t*)pcb_getpagedir(pcb));
+    jove_owned_obj_t *pagedir = lockstack_push(&ctx.lockstack, pcb_getpagedir(ctx.objdir));
+    uintptr_t message_vptr = message_unmap(ctx.message.obj, pagedir);
 
     size_t messagelen = 0x1000;
     void *messagedata = (void*)message_getdata(ctx.message.obj);
@@ -135,27 +136,31 @@ syscall_handler(uintmax_t message_path_raw, uint16_t message_pathlen)
     ctx.target = link_try_traverse_objdir(
         ctx.objdir, &ctx.lockstack, ctx.header->pathlen, ctx.header->path);
 
-    if(ctx.target.obj != 0) {
-        sysret = _syscall_handle_switch(&ctx);
-    }else{
-        //Check if we're trying to reference the PCB. If we are, we should set it as the target
-        //regardless of lock.
-        if(ctx.header->pathlen == 1 &&
-            objdir_peeklocal(ctx.objdir, ctx.header->path[0]).data == ctx.pcb->locked.data)
-        {
-            ctx.target = (jove_perm_obj_t) { .permissions = 0xFF, .obj = ctx.pcb };
-            sysret = _syscall_handle_switch(&ctx);
-
+    if(ctx.target.obj == 0) {
+        //Check if we're trying to reference objects we've already locked in this function. 
+        //If we are, we should set it as the target regardless of lock, 
+        //since we're the ones with the lock already.
+        if(ctx.header->pathlen == 1) {
+            if(ctx.header->path[0] == PCB_ROOTDIR_SELF_I)
+                ctx.target = (jove_perm_obj_t) { .permissions = 0xFF, .obj = ctx.pcb };
+            else if(ctx.header->path[0] == PCB_ROOTDIR_PAGEDIR_I)
+                ctx.target = (jove_perm_obj_t) { .permissions = 0xFF, .obj = pagedir };
+            else
+                goto fail_target_busy;
         }else{
+fail_target_busy:
             //Could not find payload target in pcb rootdir.
             klogf("Process %i tried to call syscall with bad target path %P : %s\n", 
                     pcb_getpid(pcb), header->path, header->pathlen, errstr(errno));
             sysret = -errno;
+            goto remap_return;
         }
     }
 
+    sysret = _syscall_handle_switch(&ctx);
+
 remap_return:
-    message_remap(ctx.message.obj, (jove_owned_obj_t*)pcb_getpagedir(pcb), message_vptr);
+    message_remap(ctx.message.obj, pagedir, message_vptr);
 
 release_return:
     lockstack_popall(&ctx.lockstack);
diff --git a/sys/syscall.h b/sys/syscall.h
index 6387d79..946417c 100644
--- a/sys/syscall.h
+++ b/sys/syscall.h
@@ -4,6 +4,7 @@
 #include "config.h"
 #include "api/syscall.h"
 #include "hal/obj.h"
+#include "sys/objdir.h"
 #include "lockstack.h"
 #include "link.h"
 #include <stdint.h>
diff --git a/sys/syscall_pcb.c b/sys/syscall_pcb.c
index b77be95..a37e4bb 100644
--- a/sys/syscall_pcb.c
+++ b/sys/syscall_pcb.c
@@ -1,14 +1,21 @@
 #include "api/error.h"
+#include "jove.h"
 #include "lib/printf.h"
+#include "proc/process.h"
+#include "proc/scheduler.h"
 #include "syscall.h"
+#include "errno.h"
 
 int
 s_syscall_pcb_yield(jove_owned_obj_t *pcb_obj,
         size_t bytes_left,
         void *payload_data)
 {
-    kprintf("%s: Stub!\n", __func__);
-    return 0;
+    size_t bytes_needed = sizeof(pid_t);
+    CHECK_TOOSMALL(bytes_needed, bytes_left, "Message too small for payload");
+
+    pid_t subject_pid = *((pid_t*)payload_data);
+    return scheduler_yield(subject_pid);
 }
 
 int
diff --git a/sys/syscall_untyped.c b/sys/syscall_untyped.c
index 8fe592d..1ec21c7 100644
--- a/sys/syscall_untyped.c
+++ b/sys/syscall_untyped.c
@@ -2,6 +2,7 @@
 #include "hal/memory.h"
 #include "jove.h"
 #include "lib/printf.h"
+#include "proc/process.h"
 #include "syscall.h"
 
 static int
@@ -73,6 +74,27 @@ s_syscall_untyped_merge(
     return sysret;
 }
 
+int
+s_syscall_untyped_retype_pcb(jove_owned_obj_t *untyped_obj,
+        lockstack_t *lockstack,
+        jove_owned_obj_t *rootdir,
+        struct syscall_header *header)
+{
+    jove_untyped_t *untyped = obj_deref(untyped_obj);
+    CHECK_TOOSMALL(PCB_MINSIZE, untyped->limit, "Untyped object too small for PCB");
+
+    jove_perm_obj_t objdir_obj = link_try_traverse_objdir(
+        rootdir, lockstack, header->pathlen - 1, header->path);
+    if(errno) {
+        klogf("Unable to retrieve parent objdir at %P\n",
+                header->path, header->pathlen - 1);
+        return -errno;
+    }
+    CHECK_OBJPERM(objdir_obj, JOVE_PERM_ALL, "New PCB needs full access to it's root objdir!");
+
+    obj_settype(untyped_obj, JOVE_OBJ_PCB);
+    return pcb_new(untyped_obj, untyped->limit, objdir_obj.obj);
+}
 
 int _syscall_handle_untyped(syscall_context_t *ctx)
 {
@@ -99,6 +121,27 @@ int _syscall_handle_untyped(syscall_context_t *ctx)
                         &ctx->lockstack, ctx->objdir, ctx->target.obj, ctx->bytes_left, ctx->payload);
             return -EPERM;
 
+        case SYSCALL_UNTYPED_RETYPE_OBJDIR:
+            if(ctx->target.permissions & SYSCALL_PERM_UNTYPED_RETYPE)
+                return objdir_new(ctx->target.obj);
+            return -EPERM;
+
+        case SYSCALL_UNTYPED_RETYPE_PAGEDIR:
+            if(ctx->target.permissions & SYSCALL_PERM_UNTYPED_RETYPE)
+                return pagedir_new(ctx->target.obj);
+            return -EPERM;
+
+        case SYSCALL_UNTYPED_RETYPE_SHMEMORY:
+            if(ctx->target.permissions & SYSCALL_PERM_UNTYPED_RETYPE)
+                return shmem_new(ctx->target.obj);
+            return -EPERM;
+
+        case SYSCALL_UNTYPED_RETYPE_PCB:
+            if(ctx->target.permissions & SYSCALL_PERM_UNTYPED_RETYPE)
+                return s_syscall_untyped_retype_pcb(
+                        ctx->target.obj, &ctx->lockstack, ctx->objdir, ctx->header);
+            return -EPERM;
+
         default:
             return -EBADCALL;
     }