unmap message object used for syscalls

5 files changed, 94 insertions, 40 deletions

diff --git a/sys/message.c b/sys/message.c
index 7c871ce..c87487b 100644
--- a/sys/message.c
+++ b/sys/message.c
@@ -1,15 +1,54 @@
 #include "message.h"
+#include "api/error.h"
+#include "errno.h"
+#include "hal/memory.h"
 #include "hal/obj.h"
+#include "lib/printf.h"
 
-void *
-message_data(jove_owned_obj_t *obj)
+int
+message_hasmap(jove_owned_obj_t *obj)
 {
-    uintptr_t objptr = (uintptr_t)obj_deref(obj);
-    return (void*)(objptr & ~0xFFF);
+    return obj_getvalue(obj) & 1;
 }
 
-size_t 
-message_len(jove_owned_obj_t *obj)
+uintptr_t
+message_unmap(jove_owned_obj_t *obj, jove_owned_obj_t *pagedir)
 {
-    return (obj_getvalue(obj) & 0xFFF) << 12;
+    if(message_hasmap(obj) == 0) {
+        kprintf("Message %p doesn't have a map\n", obj_getvalue(obj));
+        return -ENOMAP;
+    }
+    uintptr_t vptr = obj->locked.value & ~0xFFFULL;
+    uintptr_t *mapping = pagedir_get_mapping(pagedir, vptr);
+
+    pagedir_mapping_set_present(mapping, false);
+    pagedir_invlpg(vptr);
+
+    obj_setvalue(obj, *mapping);
+    return vptr;
+}
+
+void 
+message_remap(jove_owned_obj_t *message, jove_owned_obj_t *pagedir, uintptr_t vptr)
+{
+    if(message_hasmap(message)) {
+        errno = -EHASMAP;
+        return;
+    }
+
+    uintmax_t *mapping = pagedir_get_mapping(pagedir, vptr);
+
+    *mapping = obj_getvalue(message) | 1;
+    pagedir_invlpg(vptr);
+
+    obj_setvalue(message, vptr | 1);
+}
+
+uintptr_t message_getdata(jove_owned_obj_t *message)
+{
+    if(message_hasmap(message))
+        return obj_getvalue(message) & ~0xFFFULL;
+
+    uintptr_t message_val = obj_getvalue(message);
+    return pagedir_ident_from_mapping(&message_val);
 }
diff --git a/sys/message.h b/sys/message.h
index 2ae6e03..97d0f71 100644
--- a/sys/message.h
+++ b/sys/message.h
@@ -3,11 +3,13 @@
 
 #include "hal/obj.h"
 
-#define MESSAGE_MAX_PAGES (1<<12)
-#define MESSAGE_MAX_BYTES (MESSAGE_MAX_PAGES * 0x1000)
+
 #define MESSAGE_ALIGN 0x1000
 
-void *message_data(jove_owned_obj_t *obj);
-size_t message_len(jove_owned_obj_t *obj);
+int message_hasmap(jove_owned_obj_t *message);
+uintptr_t message_unmap(jove_owned_obj_t *message, jove_owned_obj_t *pagedir);
+void message_remap(jove_owned_obj_t *message, jove_owned_obj_t *pagedir, uintptr_t vptr);
+
+uintptr_t message_getdata(jove_owned_obj_t *message);
 
 #endif
diff --git a/sys/syscall.c b/sys/syscall.c
index 1c9af45..7207708 100644
--- a/sys/syscall.c
+++ b/sys/syscall.c
@@ -1,5 +1,6 @@
 #include "sys/syscall.h"
 #include "arch/x86_64/hal/obj.h"
+#include "hal/memory.h"
 #include "hal/smp.h"
 #include "proc/process.h"
 #include "jove.h"
@@ -27,7 +28,7 @@ int
 _syscall_handle_generic(syscall_context_t *ctx)
 {
     pcb_t *pcb = obj_deref(ctx->pcb);
-    klogf("Process %i encountered stub syscall on object %P\n", pcb_pid(pcb), ctx->header->path, ctx->header->pathlen);
+    klogf("Process %i encountered stub syscall on object %P\n", pcb_getpid(pcb), ctx->header->path, ctx->header->pathlen);
     return -EBADOBJ;
 }
 
@@ -92,35 +93,38 @@ syscall_handler(uintmax_t message_path_raw, uint16_t message_pathlen)
 
     if(ctx.message.obj == NULL) {
         klogf("Process %i failed to get message %P : %s\n",
-                pcb_pid(pcb), message_path, message_pathlen, errstr(errno));
+                pcb_getpid(pcb), message_path, message_pathlen, errstr(errno));
         sysret = -errno;
         goto release_return;
     }
 
     if(obj_gettype(ctx.message.obj) != JOVE_OBJ_MESSAGE) {
         klogf("Process %i tried to call syscall with invalid object %P\n", 
-                pcb_pid(pcb), message_path, message_pathlen);
+                pcb_getpid(pcb), message_path, message_pathlen);
         sysret = -EBADOBJ;
         goto release_return;
     }
 
     if((ctx.message.permissions & JOVE_PERM_READ) == 0) {
         klogf("Process %i tried to call syscall with message object %P without read permissions\n",
-                pcb_pid(pcb), message_path, message_pathlen);
+                pcb_getpid(pcb), message_path, message_pathlen);
         sysret = -EPERM;
         goto release_return;
     }
 
-    size_t messagelen = message_len(ctx.message.obj);
-    void *messagedata = message_data(ctx.message.obj);
+    uintptr_t message_vptr = message_unmap(ctx.message.obj,
+            (jove_owned_obj_t*)pcb_pagedir(pcb));
+
+    size_t messagelen = 0x1000;
+    void *messagedata = (void*)message_getdata(ctx.message.obj);
     struct syscall_header *header = messagedata;
 
     size_t bytes_needed = sizeof(struct syscall_header) + header->pathlen * 2;
     if(bytes_needed > messagelen) {
         //Target path exceeds message length.
-        klogf("Process %i tried to call syscall with target path too big for message.\n", pcb_pid(pcb));
+        klogf("Process %i tried to call syscall with target path too big for message.\n", pcb_getpid(pcb));
         sysret = -ETOOSMALL;
-        goto release_return;
+        goto remap_return;
     }
 
     ctx.header = header;
@@ -128,17 +132,29 @@ syscall_handler(uintmax_t message_path_raw, uint16_t message_pathlen)
     ctx.payload = (void*)((uintptr_t)header + bytes_needed);
 
     ctx.target = link_try_traverse_objdir(
-            ctx.objdir, &ctx.lockstack, ctx.header->pathlen, ctx.header->path);
-
-    if(ctx.target.obj == 0) {
-        //Could not find payload target in pcb rootdir.
-        klogf("Process %i tried to call syscall with bad target path %P : %s\n", 
-                pcb_pid(pcb), header->path, header->pathlen, errstr(errno));
-        sysret = -errno;
-        goto release_return;
+        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);
+
+        }else{
+            //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;
+        }
     }
 
-    sysret = _syscall_handle_switch(&ctx);
+remap_return:
+    message_remap(ctx.message.obj, (jove_owned_obj_t*)pcb_pagedir(pcb), message_vptr);
 
 release_return:
     lockstack_popall(&ctx.lockstack);
diff --git a/sys/syscall_initrd_file.c b/sys/syscall_initrd_file.c
index 8e34488..904039d 100644
--- a/sys/syscall_initrd_file.c
+++ b/sys/syscall_initrd_file.c
@@ -8,16 +8,17 @@
 int
 s_syscall_initrd_file_name(
         jove_owned_obj_t *initrd_file,
-        jove_owned_obj_t *message)
+        jove_owned_obj_t *message,
+        void *message_data)
 {
     const char *filename = initrd_file_name(initrd_file);
     size_t filename_len = strlen(filename);
 
-    size_t bytes_left = message_len(message);
+    size_t bytes_left = 0x1000;
     size_t bytes_needed = filename_len + sizeof(struct syscall_initrd_file_name_ret);
 
     CHECK_TOOSMALL(bytes_needed, bytes_left, "Message is too small for file name.");
-    struct syscall_initrd_file_name_ret *payload = message_data(message);
+    struct syscall_initrd_file_name_ret *payload = message_data;
 
     payload->len = filename_len;
     memcpy(payload->c_str, filename, filename_len);
@@ -34,6 +35,7 @@ int
 s_syscall_initrd_file_read(
         jove_owned_obj_t *initrd_file,
         jove_owned_obj_t *message,
+        void *message_data,
         size_t bytes_left,
         void *payload_data)
 {
@@ -44,7 +46,7 @@ s_syscall_initrd_file_read(
 
     struct syscall_initrd_file_read *payload = payload_data;
     bytes_needed = payload->read_size;
-    bytes_left = message_len(message);
+    bytes_left = 0x1000;
 
     //Ensure that the message is big enough to hold the read file data.
     CHECK_TOOSMALL(bytes_needed, bytes_left,
@@ -67,8 +69,7 @@ s_syscall_initrd_file_read(
         return -ETOOBIG;
     }
     
-    void *read_data = message_data(message);
-    memcpy(read_data, file_data + payload->start_index, payload->read_size);
+    memcpy(message_data, file_data + payload->start_index, payload->read_size);
     return 0;
 }
 
@@ -79,7 +80,7 @@ _syscall_handle_initrd_file(syscall_context_t *ctx)
         case SYSCALL_INITRD_FILE_NAME:
             if(ctx->target.permissions & SYSCALL_PERM_INITRD_FILE_NAME)
                 return s_syscall_initrd_file_name(
-                        ctx->target.obj, ctx->message.obj);
+                        ctx->target.obj, ctx->message.obj, (void*)ctx->header);
             return -EPERM;
         
         case SYSCALL_INITRD_FILE_SIZE:
@@ -90,7 +91,7 @@ _syscall_handle_initrd_file(syscall_context_t *ctx)
         case SYSCALL_INITRD_FILE_READ:
             if(ctx->target.permissions & SYSCALL_PERM_INITRD_FILE_READ)
                 return s_syscall_initrd_file_read(
-                        ctx->target.obj, ctx->message.obj, ctx->bytes_left, ctx->payload);
+                        ctx->target.obj, ctx->message.obj, (void*)ctx->header, ctx->bytes_left, ctx->payload);
             return -EPERM;
         default:
             return -EBADCALL;
diff --git a/sys/syscall_message.c b/sys/syscall_message.c
index 5edf33f..6c5fb8f 100644
--- a/sys/syscall_message.c
+++ b/sys/syscall_message.c
@@ -6,10 +6,6 @@ int
 _syscall_handle_message(syscall_context_t *ctx)
 {
     switch(ctx->header->callid) {
-        case SYSCALL_OBJDIR_OBJTYPE:
-            if(ctx->target.permissions & SYSCALL_PERM_OBJDIR_OBJTYPE)
-                return message_len(ctx->message.obj);
-            return -EPERM;
         default:
             return -EBADCALL;
     }