make syscall use non-locking mutexes

9 files changed, 68 insertions, 9 deletions

diff --git a/arch/x86_64/hal/idt.h b/arch/x86_64/hal/idt.h
index 2aa759b..19c9e4c 100644
--- a/arch/x86_64/hal/idt.h
+++ b/arch/x86_64/hal/idt.h
@@ -66,7 +66,7 @@ struct int_stackframe
 struct int_user_handle
 {
     uintmax_t pid;
-    void *handle;
+    int (*handle)(struct int_stackframe*);
 };
 extern struct int_user_handle __int_user_handles[IDT_ENTRIES];
 
diff --git a/arch/x86_64/hal/obj.c b/arch/x86_64/hal/obj.c
index af0491a..cb0e13d 100644
--- a/arch/x86_64/hal/obj.c
+++ b/arch/x86_64/hal/obj.c
@@ -16,6 +16,18 @@ obj_take(jove_obj_t *obj)
     return (jove_owned_obj_t*)obj;
 }
 
+jove_owned_obj_t*
+obj_trytake(jove_obj_t *obj)
+{
+    if((uintptr_t)obj < IDENT_VIRT_BASE) {
+        reterr(EBADOBJ);
+    }
+    if(try_take_mutex(&obj->lock)) {
+        reterr(EBUSY);
+    }
+    return (jove_owned_obj_t*)obj;
+}
+
 jove_obj_t*
 obj_release(jove_owned_obj_t *obj)
 {
@@ -97,16 +109,32 @@ objdir_getlocal(
 }
 
 jove_owned_obj_t*
+objdir_trygetlocal(
+        jove_owned_obj_t *objdir_obj, 
+        uint16_t entry)
+{
+    if(obj_gettype_linked(objdir_obj) != JOVE_OBJ_OBJDIR) {
+        reterr(EBADOBJ);
+    }
+    if(entry >= JOVE_OBJDIR_ENTRIES) {
+        reterr(EBADPATH);
+    }
+
+    jove_objdir_t *objtab = obj_deref_linked(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;
     }
     {
-        errno = 0;
         jove_owned_obj_t *child_objdir = objdir_getlocal(objdir_obj, path[0]);
         if(child_objdir == 0) {
             reterr(EBADPATH);
@@ -118,3 +146,25 @@ objdir_getobj(
     }
 }
 
+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/arch/x86_64/hal/obj.h b/arch/x86_64/hal/obj.h
index deea2be..4364348 100644
--- a/arch/x86_64/hal/obj.h
+++ b/arch/x86_64/hal/obj.h
@@ -17,7 +17,7 @@ typedef union jove_obj
     struct {
         uint8_t type;
         atomic_flag lock;
-        /*Raw value or pointer to a data-structure located in kernel memory.*/
+        /*Raw value or pointer to a data-structure located in identity memory.*/
         uint64_t value : 48;
     };
     uintmax_t data;
@@ -32,7 +32,7 @@ typedef struct jove_locked_obj
 } jove_owned_obj_t;
 
 /*Object directories are always 1 page wide. Since an object inside the directory
- * is a pointer width, on x86_64 that is 512 entries per directory.*/
+ * in this arch is a pointer width, that is 512 entries per directory.*/
 #define JOVE_OBJDIR_SIZE 0x1000
 #define JOVE_OBJDIR_ENTRIES (JOVE_OBJDIR_SIZE / sizeof(jove_obj_t))
 
diff --git a/arch/x86_64/hal/process.c b/arch/x86_64/hal/process.c
index 0155919..f30d703 100644
--- a/arch/x86_64/hal/process.c
+++ b/arch/x86_64/hal/process.c
@@ -37,7 +37,7 @@ pcb_pid(pcb_t *pcb)
 jove_owned_obj_t*
 pcb_rootdir(pcb_t *pcb)
 {
-    return pcb->rootdir;
+    return obj_take(pcb->rootdir);
 }
 
 void
diff --git a/arch/x86_64/hal/process.h b/arch/x86_64/hal/process.h
index c3530bf..f903153 100644
--- a/arch/x86_64/hal/process.h
+++ b/arch/x86_64/hal/process.h
@@ -7,7 +7,7 @@
 typedef struct process_control_block
 {
     pid_t pid;
-    jove_owned_obj_t *rootdir;
+    jove_obj_t *rootdir;
     jove_owned_obj_t *iopb;
     uintptr_t pml4;
 
diff --git a/arch/x86_64/lock.c b/arch/x86_64/lock.c
index b010ee6..a34cee6 100644
--- a/arch/x86_64/lock.c
+++ b/arch/x86_64/lock.c
@@ -11,6 +11,13 @@ take_mutex(atomic_flag *lock)
     }
 }
 
+int
+try_take_mutex(atomic_flag *lock)
+{
+    if(_kernel_panic_unlock) return 1;
+    return atomic_flag_test_and_set(lock);
+}
+
 void
 release_mutex(atomic_flag *lock)
 {
diff --git a/arch/x86_64/lock.h b/arch/x86_64/lock.h
index 609ea39..3592ea1 100644
--- a/arch/x86_64/lock.h
+++ b/arch/x86_64/lock.h
@@ -4,6 +4,8 @@
 #include <stdatomic.h>
 
 void take_mutex(atomic_flag *lock);
+int try_take_mutex(atomic_flag *lock);
+
 void release_mutex(atomic_flag *lock);
 
 #endif
diff --git a/arch/x86_64/main.c b/arch/x86_64/main.c
index 7266155..a35a465 100644
--- a/arch/x86_64/main.c
+++ b/arch/x86_64/main.c
@@ -1,3 +1,4 @@
+#include "api/init.h"
 #include "jove.h"
 #include "init.h"
 #include "lib/string.h"
@@ -19,9 +20,7 @@
 int errno = 0;
 
 PAGEALIGN jove_objdir_t _rootdir;
-
-jove_owned_obj_t s_rootdir_obj;
-void *_rootdir_obj = &s_rootdir_obj;
+void *_rootdir_obj = &_rootdir.entries[ROOTDIR_DIR_I];
 
 static void kernel_process_entry(void);
 
diff --git a/arch/x86_64/sys/init.c b/arch/x86_64/sys/init.c
index 8823df2..c55eabe 100644
--- a/arch/x86_64/sys/init.c
+++ b/arch/x86_64/sys/init.c
@@ -171,6 +171,7 @@ init_setup(void)
     pcb_t *pcb = obj_deref(pcb_obj);
 
     obj_release(pcb_obj);
+    obj_release(_rootdir_obj);
 
     uintptr_t usp = 0x00007FFFFFFFFFF8;
     uintptr_t uip = init_ehdr->e_entry;