Back to the same fs0 bug point as before, but environment, disjoint utcb addresses

and passing of utcb address information via the environment are implemented.

src/arch/arm/exception.c

@@ -82,22 +82,22 @@ int check_aborts(u32 faulted_pc, u32 fsr, u32 far)
 	int ret = 0;
 
 	if (is_prefetch_abort(fsr)) {
-		dprintk("Prefetch abort @ ", faulted_pc);
+//		dprintk("Prefetch abort @ ", faulted_pc);
 		return 0;
 	}
 
 	switch (fsr & ARM_FSR_MASK) {
 	/* Aborts that are expected on page faults: */
 	case DABT_PERM_PAGE:
-		dprintk("Page permission fault @ ", far);
+//		dprintk("Page permission fault @ ", far);
 		ret = 0;
 		break;
 	case DABT_XLATE_PAGE:
-		dprintk("Page translation fault @ ", far);
+//		dprintk("Page translation fault @ ", far);
 		ret = 0;
 		break;
 	case DABT_XLATE_SECT:
-		dprintk("Section translation fault @ ", far);
+//		dprintk("Section translation fault @ ", far);
 		ret = 0;
 		break;
 
@@ -166,7 +166,7 @@ int check_aborts(u32 faulted_pc, u32 fsr, u32 far)
 void data_abort_handler(u32 faulted_pc, u32 fsr, u32 far)
 {
 	set_abort_type(fsr, ARM_DABT);
-	dprintk("Data abort @ PC: ", faulted_pc);
+//	dprintk("Data abort @ PC: ", faulted_pc);
 	if (check_aborts(faulted_pc, fsr, far) < 0) {
 		printascii("This abort can't be handled by any pager.\n");
 		goto error;

tasks/libl4/src/arm/syscalls.S

@@ -8,8 +8,7 @@
 #include <l4/generic/space.h>
 
 	.macro	utcb_address	rx
-		mov	\rx, #L4_KIP_ADDRESS
-		add	\rx, \rx, #UTCB_KIP_OFFSET
+		ldr	\rx, =utcb
 		ldr	\rx, [\rx]
 	.endm
 

tasks/libl4/src/init.c

@@ -47,10 +47,10 @@ void __l4_init(void)
 
 	/* Initialise utcb only if we're not the pager */
 	if (self_tid() != PAGER_TID) {
-		utcb = *(struct utcb **)(USER_AREA_END - 8);
+		/* FIXME: C library should give the environ pointer for this */
+		utcb = *(struct utcb **)(USER_AREA_END - PAGE_SIZE);
 		printf("UTCB Read from userspace as: 0x%x\n",
 		(unsigned long)utcb);
 	}
-
 }
 

tasks/mm0/include/env.h

@@ -1,6 +1,6 @@
 #ifndef __MM0_ENV__
 #define __MM0_ENV__
 
-int task_prepare_env_file(struct tcb *t);
+int task_prepare_environment(struct tcb *t);
 
 #endif

tasks/mm0/include/task.h

@@ -63,10 +63,6 @@ struct tcb {
 	/* UTCB address */
 	unsigned long utcb_address;
 
-	/* Temporary storage for environment data */
-	void *env_data;
-	unsigned long env_size;
-
 	/* Per-task environment file */
 	struct vm_file *env_file;
 

tasks/mm0/src/env.c

@@ -13,34 +13,47 @@
  *
  * Copyright (C) 2008 Bahadir Balban
  */
+#include <l4lib/types.h>
 #include <l4/lib/list.h>
-#include <vm_area.h>
-#include <kmalloc/kmalloc.h>
-#include <task.h>
 #include <l4/api/kip.h>
 #include <l4/api/errno.h>
+#include <kmalloc/kmalloc.h>
+#include <vm_area.h>
 #include <string.h>
 #include <file.h>
+#include <task.h>
+
+struct envdata {
+	struct list_head list;
+	void *env_data;
+	int env_size;
+	int id;
+};
+LIST_HEAD(env_list);
 
 /* Copies environment data into provided page. */
 int task_env_pager_read_page(struct vm_file *f, unsigned long f_off_pfn,
 			     void *dest_page)
 {
-	struct tcb *t = find_task(f->vnum);
+	struct envdata *env;
 
-	if (!t) {
-		printf("%s: No such task tid: %d, to copy environment for.\n",
-		       __TASKNAME__,  f->vnum);
-		return -EINVAL;
-	}
+	list_for_each_entry(env, &env_list, list)
+		if (env->id == f->vnum)
+			goto copyenv;
 
+	printf("%s: No such env id: %d, to copy environment for.\n",
+	       __TASKNAME__,  f->vnum);
+	return -EINVAL;
+
+copyenv:
 	if (f_off_pfn != 0) {
 		printf("%s: Environments currently have a single page.\n");
 		return -EINVAL;
 	}
 
 	memset(dest_page, 0, PAGE_SIZE);
-	memcpy(dest_page, t->env_data, t->env_size);
+	BUG_ON(env->env_size > PAGE_SIZE);
+	memcpy(dest_page, env->env_data, env->env_size);
 
 	return 0;
 }
@@ -53,13 +66,14 @@ struct vm_pager task_env_pager = {
 	},
 };
 
-
 /*
  * For a task that is about to execute, this dynamically
- * generates its environment file.
+ * generates its environment file, and environment data.
  */
-int task_prepare_env_file(struct tcb *t)
+int task_prepare_environment(struct tcb *t)
 {
+	struct envdata *env;
+
 	/* Allocate a new vmfile for this task's environment */
 	if (IS_ERR(t->env_file = vmfile_alloc_init()))
 		return (int)t->env_file;
@@ -75,6 +89,14 @@ int task_prepare_env_file(struct tcb *t)
 	t->env_file->pager = &task_env_pager;
 	list_add(&t->env_file->list, &vm_file_list);
 
+	/* Allocate, initialise and add per-task env data */
+	BUG_ON(!(env = kzalloc(sizeof(struct envdata))));
+	INIT_LIST_HEAD(&env->list);
+	env->env_data = &t->utcb_address;
+	env->env_size = sizeof(t->utcb_address);
+	env->id = t->tid;
+	list_add(&env->list, &env_list);
+
 	return 0;
 }
 

tasks/mm0/src/fault.c

@@ -1,7 +1,7 @@
 /*
  * Page fault handling.
  *
- * Copyright (C) 2007 Bahadir Balban
+ * Copyright (C) 2007, 2008 Bahadir Balban
  */
 #include <vm_area.h>
 #include <task.h>

tasks/mm0/src/init.c

@@ -34,7 +34,7 @@ void init_utcb(void)
 	utcb_page = alloc_page(1);
 	l4_map(utcb_page, utcb_virt, 1, MAP_USR_RW_FLAGS, self_tid());
 
-	/* Also initialise the utcb reference that is used in l4lib. */
+	/* Also initialise the utcb reference that is inside l4lib. */
 	utcb = utcb_virt;
 }
 

tasks/mm0/src/stack.c

@@ -1,4 +1,9 @@
-
+/*
+ * TODO: This is to be used when moving mm0's temporary
+ * stack to a proper place. It's unused for now.
+ *
+ * Copyright (C) 2007, 2008 Bahadir Balban
+ */
 #include <l4/config.h>
 #include <l4/macros.h>
 #include <l4/types.h>

tasks/mm0/src/task.c

@@ -107,14 +107,24 @@ int start_boot_tasks(struct initdata *initdata, struct tcb_head *tcbs)
 			ids.spid = -1;
 		}
 
-		/* Create vm file and tcb */
-		file = vmfile_alloc_init();
+		printf("Creating new thread.\n");
+		/* Create the thread structures and address space */
+		if ((err = l4_thread_control(THREAD_CREATE, &ids)) < 0) {
+			printf("l4_thread_control failed with %d.\n", err);
+			goto error;
+		}
+
+		/* Create a task and use returned space and thread ids. */
+		printf("New task with id: %d, space id: %d\n", ids.tid, ids.spid);
 		task = create_init_tcb(tcbs);
+		task->tid = ids.tid;
+		task->spid = ids.spid;
 
 		/*
 		 * For boot files, we use the physical address of the memory
 		 * file as its mock-up inode.
 		 */
+		file = vmfile_alloc_init();
 		file->vnum = img->phys_start;
 		file->length = img->phys_end - img->phys_start;
 		file->pager = &boot_file_pager;
@@ -132,12 +142,10 @@ int start_boot_tasks(struct initdata *initdata, struct tcb_head *tcbs)
 		 * when faulted, simply copies the task env data to the
 		 * allocated page.
 		 */
-		if (task_prepare_env_file(task) < 0) {
+		if (task_prepare_environment(task) < 0) {
 			printf("Could not create environment file.\n");
 			goto error;
 		}
-		task->env_data = &task->utcb_address;
-		task->env_size = sizeof(task->utcb_address);
 
 		/*
 		 * Task stack starts right after the environment,
@@ -187,18 +195,6 @@ int start_boot_tasks(struct initdata *initdata, struct tcb_head *tcbs)
 			goto error;
 		}
 
-		printf("Creating new thread.\n");
-		/* Create the thread structures and address space */
-		if ((err = l4_thread_control(THREAD_CREATE, &ids)) < 0) {
-			printf("l4_thread_control failed with %d.\n", err);
-			goto error;
-		}
-
-		/* Use returned space and thread ids. */
-		printf("New task with id: %d, space id: %d\n", ids.tid, ids.spid);
-		task->tid = ids.tid;
-		task->spid = ids.spid;
-
 		/* Set up the task's thread details, (pc, sp, pager etc.) */
 		if ((err = l4_exchange_registers(pc, sp, self_tid(), task->tid) < 0)) {
 			printf("l4_exchange_registers failed with %d.\n", err);