Removed allocation of utcb shared pages by mm0 completely.

- Now libl4 has no references to utcb page or shmat etc.
- Pager does not deal with special case utcb page allocation.
  It instead allocates a shared page from shm memory pool.
- All tasks working to original standard.

Next:
- Add per-thread utcb allocation from the kernel
- Add larger register file for standard ipc
- Add long ipc (up to 1Kb)

libs/c/crt/sys-userspace/arch-arm/crt0.S

@@ -88,7 +88,7 @@ _start:
 	ldr	sp, =__stack
 	bl	platform_init
 	bl	__l4_init
-	bl	main
+	bl	__container_init
 1:
 	b	1b
 

tasks/fs0/include/task.h

@@ -33,7 +33,7 @@ struct task_fs_data {
 struct tcb {
 	l4id_t tid;
 	struct list_head list;
-	unsigned long utcb_address;
+	unsigned long shpage_address;
 	struct task_fd_head *files;
 	struct task_fs_data *fs_data;
 };
@@ -41,7 +41,7 @@ struct tcb {
 /* Structures used when receiving new task info from pager */
 struct task_data {
 	unsigned long tid;
-	unsigned long utcb_address;
+	unsigned long shpage_address;
 };
 
 struct task_data_head {

tasks/fs0/src/syscalls.c

@@ -486,8 +486,8 @@ int sys_readdir(struct tcb *t, int fd, void *buf, int count)
 	// printf("%s/%s\n", __TASKNAME__, __FUNCTION__);
 
 	/* Check address is in task's utcb */
-	if ((unsigned long)buf < t->utcb_address ||
-	    (unsigned long)buf > t->utcb_address + PAGE_SIZE)
+	if ((unsigned long)buf < t->shpage_address ||
+	    (unsigned long)buf > t->shpage_address + PAGE_SIZE)
 		return -EINVAL;
 
 	if (fd < 0 || fd > TASK_FILES_MAX || t->files->fd[fd] == NILFD)

tasks/fs0/src/task.c

@@ -20,6 +20,8 @@
 #include <syscalls.h>
 #include <globals.h>
 
+extern void *shared_page;
+
 struct global_list global_tasks = {
 	.list = { &global_tasks.list, &global_tasks.list },
 	.total = 0,
@@ -118,7 +120,7 @@ void copy_tcb(struct tcb *to, struct tcb *from, unsigned int share_flags)
 }
 
 /* Allocate a task struct and initialise it */
-struct tcb *tcb_create(struct tcb *orig, l4id_t tid, unsigned long utcb,
+struct tcb *tcb_create(struct tcb *orig, l4id_t tid, unsigned long shpage,
 		       unsigned int share_flags)
 {
 	struct tcb *task;
@@ -131,7 +133,7 @@ struct tcb *tcb_create(struct tcb *orig, l4id_t tid, unsigned long utcb,
 		return task;
 
 	task->tid = tid;
-	task->utcb_address = utcb;
+	task->shpage_address = shpage;
 
 	/*
 	 * If there's an original task that means this will be a full
@@ -177,18 +179,18 @@ int task_utcb_attach(struct tcb *t)
 	void *shmaddr;
 
 	/* Use it as a key to create a shared memory region */
-	if ((shmid = shmget((key_t)t->utcb_address, PAGE_SIZE, 0)) == -1)
+	if ((shmid = shmget((key_t)t->shpage_address, PAGE_SIZE, 0)) == -1)
 		goto out_err;
 
 	/* Attach to the region */
-	if ((int)(shmaddr = shmat(shmid, (void *)t->utcb_address, 0)) == -1)
+	if ((int)(shmaddr = shmat(shmid, (void *)t->shpage_address, 0)) == -1)
 		goto out_err;
 
 	/* Ensure address is right */
-	if ((unsigned long)shmaddr != t->utcb_address)
+	if ((unsigned long)shmaddr != t->shpage_address)
 		return -EINVAL;
 
-	// printf("%s: Mapped utcb of task %d @ 0x%x\n",
+	// printf("%s: Mapped shared page of task %d @ 0x%x\n",
 	//       __TASKNAME__, t->tid, shmaddr);
 
 	return 0;
@@ -204,7 +206,7 @@ out_err:
  * the information on the resulting child task.
  */
 int pager_notify_fork(struct tcb *sender, l4id_t parentid,
-		      l4id_t childid, unsigned long utcb_address,
+		      l4id_t childid, unsigned long shpage_address,
 		      unsigned int flags)
 {
 	struct tcb *child, *parent;
@@ -213,7 +215,7 @@ int pager_notify_fork(struct tcb *sender, l4id_t parentid,
 	BUG_ON(!(parent = find_task(parentid)));
 
 	/* Create a child vfs tcb using given parent and copy flags */
-	if (IS_ERR(child = tcb_create(parent, childid, utcb_address, flags)))
+	if (IS_ERR(child = tcb_create(parent, childid, shpage_address, flags)))
 		return (int)child;
 
 	global_add_task(child);
@@ -261,9 +263,9 @@ struct task_data_head *receive_pager_taskdata(void)
 
 	/* Data is expected in the utcb page */
 	// printf("%s: %d Total tasks.\n", __FUNCTION__,
-	//      ((struct task_data_head *)utcb_page)->total);
+	//      ((struct task_data_head *)shared_page)->total);
 
-	return (struct task_data_head *)utcb_page;
+	return (struct task_data_head *)shared_page;
 }
 
 
@@ -274,7 +276,7 @@ int init_task_structs(struct task_data_head *tdata_head)
 	for (int i = 0; i < tdata_head->total; i++) {
 		/* New tcb with fields sent by pager */
 		if (IS_ERR(t = tcb_create(0, tdata_head->tdata[i].tid,
-					  tdata_head->tdata[i].utcb_address,
+					  tdata_head->tdata[i].shpage_address,
 					  0)))
 			return (int)t;
 

tasks/libl4/include/l4lib/arch-arm/utcb.h

@@ -30,7 +30,6 @@ struct utcb {
 } __attribute__((__packed__));
 
 extern struct utcb utcb;
-extern void *utcb_page;
 
 static inline struct utcb *l4_get_utcb()
 {
@@ -48,30 +47,6 @@ static inline void write_mr(unsigned int offset, unsigned int val)
 	l4_get_utcb()->mr[offset] = val;
 }
 
-/*
- * Arguments that are too large to fit in message registers are
- * copied onto another area that is still on the utcb, and the servers
- * map-in the task utcb and read those arguments from there.
- */
-
-static inline int copy_to_utcb(void *arg, int offset, int size)
-{
-	if (offset + size > PAGE_SIZE)
-		return -1;
-
-	memcpy(utcb_page + offset, arg, size);
-	return 0;
-}
-
-static inline int copy_from_utcb(void *buf, int offset, int size)
-{
-	if (offset + size > PAGE_SIZE)
-		return -1;
-
-	memcpy(buf, utcb_page + offset, size);
-	return 0;
-}
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* __ARM_UTCB_H__ */

tasks/libl4/src/init.c

@@ -10,8 +10,6 @@
 #include <l4/macros.h>
 #include INC_GLUE(memlayout.h)
 #include <stdio.h>
-#include <sys/types.h>
-#include <sys/shm.h>
 
 __l4_ipc_t __l4_ipc = 0;
 __l4_map_t __l4_map = 0;

tasks/libposix/chdir.c

@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2008 Bahadir Balban
  */
+#include <shpage.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdarg.h>
@@ -21,8 +22,8 @@ static inline int l4_chdir(const char *pathname)
 	int fd;
 
 	// write_mr(L4SYS_ARG0, (unsigned long)pathname);
-	copy_to_utcb((void *)pathname, 0, strlen(pathname) + 1);
-	write_mr(L4SYS_ARG0, (unsigned long)utcb_page);
+	copy_to_shpage((void *)pathname, 0, strlen(pathname) + 1);
+	write_mr(L4SYS_ARG0, (unsigned long)shared_page);
 
 	/* Call pager with shmget() request. Check ipc error. */
 	if ((fd = l4_sendrecv(VFS_TID, VFS_TID, L4_IPC_TAG_CHDIR)) < 0) {

tasks/libposix/fork.c

@@ -12,6 +12,7 @@
 #include <l4lib/utcb.h>
 #include <l4/macros.h>
 #include INC_GLUE(memory.h)
+#include <posix_init.h>
 
 static inline int l4_fork(void)
 {
@@ -40,9 +41,12 @@ int fork(void)
 		return -1;
 	}
 
-	/* If we're a child, we need to initialise the utcb page */
+	/*
+	 * If we're a child, we need to initialise the default
+	 * shared page via posix_init()
+	 */
 	if (ret == 0)
-		utcb_init();
+		posix_init();
 
 	return ret;
 }

tasks/libposix/include/posix/posix_init.h

@@ -0,0 +1,6 @@
+#ifndef __POSIX_INIT_H__
+#define __POSIX_INIT_H__
+
+void posix_init(void);
+
+#endif /* __POSIX_INIT_H__ */

tasks/libposix/include/posix/shpage.h

@@ -0,0 +1,45 @@
+/*
+ * A default shared page is used by every thread
+ * to pass large data for system calls.
+ *
+ * This file contains relevant shpage definitions.
+ */
+#ifndef __LIBPOSIX_SHPAGE_H__
+#define __LIBPOSIX_SHPAGE_H__
+
+#include <l4/macros.h>
+#include <l4lib/arch/syscalls.h>
+#include <l4lib/arch/syslib.h>
+#include <l4lib/ipcdefs.h>
+#include <l4lib/utcb.h>
+#include INC_GLUE(memory.h)
+
+extern void *shared_page;
+
+int shared_page_init(void);
+
+/*
+ * Arguments that are too large to fit in message registers are
+ * copied onto another area that is still on the utcb, and the servers
+ * map-in the task utcb and read those arguments from there.
+ */
+
+static inline int copy_to_shpage(void *arg, int offset, int size)
+{
+	if (offset + size > PAGE_SIZE)
+		return -1;
+
+	memcpy(shared_page + offset, arg, size);
+	return 0;
+}
+
+static inline int copy_from_shpage(void *buf, int offset, int size)
+{
+	if (offset + size > PAGE_SIZE)
+		return -1;
+
+	memcpy(buf, shared_page + offset, size);
+	return 0;
+}
+
+#endif /* __LIBPOSIX_SHPAGE_H__ */

tasks/libposix/init.c

@@ -1,79 +1,30 @@
 /*
- * Shared page initialisation of posix-like tasks.
+ * Main entry point for posix services and applications.
  *
- * POSIX tasks currently use a default shared page for communciation.
- * This could have been also done by long ipc calls.
+ * Copyright (C) 2007-2009 Bahadir Balban
  */
 
-/*
- * Shared page for this task. Used for passing data among ipc
- * parties when message registers are not big enough. Every thread
- * has right to own one, and it has an address unique to every
- * thread. It must be explicitly mapped by both parties of the ipc
- * in order to be useful.
- */
-void *shared_page;
+#include <shpage.h>
+#include <posix_init.h>
 
-/*
- * Obtains a unique address for the task's shared page. Note this
- * just returns the address. This address is used as an shm key
- * to map it via shmget()/shmat() later on.
- */
-static void *shared_page_address(void)
+void posix_init(void)
 {
-	void *addr;
-	int err;
-
-	/* We're asking it for ourself. */
-	write_mr(L4SYS_ARG0, self_tid());
-
-	/* Call pager with utcb address request. Check ipc error. */
-	if ((err = l4_sendrecv(PAGER_TID, PAGER_TID,
-			       L4_IPC_TAG_DEFAULT_SHPAGE)) < 0) {
-		printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);
-		return PTR_ERR(err);
-	}
-
-	/* Check if syscall itself was successful */
-	if (IS_ERR(addr = (void *)l4_get_retval())) {
-		printf("%s: Request UTCB Address Error: %d.\n",
-		       __FUNCTION__, (int)addr);
-		return addr;
-	}
-
-	return addr;
+	/* Non-pager tasks initialise their shared communication page */
+	if (self_tid() != PAGER_TID)
+		shared_page_init();
 }
 
+int main(void);
+
 /*
- * Initialises a non-pager task's default shared memory page
- * using posix semantics. Used during task initialisation
- * and by child tasks after a fork.
+ * Entry point for posix services container.
+ *
+ * This is executed by all posix system services and tasks
+ * that run in this container.
  */
-int shared_page_init(void)
+void __container_init(void)
 {
-	int shmid;
-	void *shmaddr;
-
-	/*
-	 * Initialise shared page only if we're not the pager.
-	 * The pager does it differently for itself.
-	 */
-	BUG_ON(self_tid() == PAGER_TID);
-
-	/* Obtain our utcb page address */
-	utcb_page = l4_utcb_page();
-	//printf("%s: UTCB Read from mm0 as: 0x%x\n", __FUNCTION__,
-	//       (unsigned long)utcb_page);
-
-	/* Use it as a key to create a shared memory region */
-	BUG_ON((shmid = shmget((key_t)utcb_page,
-			       PAGE_SIZE, IPC_CREAT)) < 0);
-
-	/* Attach to the region */
-	BUG_ON((shmaddr = shmat(shmid, utcb_page, 0)) < 0);
-	BUG_ON(shmaddr != utcb_page);
-
-	return 0;
+	posix_init();
+	main();
 }
 
-

tasks/libposix/mkdir.c

@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2008 Bahadir Balban
  */
+#include <shpage.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdarg.h>
@@ -23,8 +24,8 @@ static inline int l4_mkdir(const char *pathname, mode_t mode)
 	int fd;
 
 	// write_mr(L4SYS_ARG0, (unsigned long)pathname);
-	copy_to_utcb((void *)pathname, 0, strlen(pathname) + 1);
-	write_mr(L4SYS_ARG0, (unsigned long)utcb_page);
+	copy_to_shpage((void *)pathname, 0, strlen(pathname) + 1);
+	write_mr(L4SYS_ARG0, (unsigned long)shared_page);
 	write_mr(L4SYS_ARG1, (u32)mode);
 
 	/* Call pager with shmget() request. Check ipc error. */

tasks/libposix/open.c

@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2007 Bahadir Balban
  */
+
 #include <errno.h>
 #include <stdio.h>
 #include <stdarg.h>
@@ -17,13 +18,14 @@
 #include <fcntl.h>
 #include <l4/macros.h>
 #include INC_GLUE(memory.h)
+#include <shpage.h>
 
 static inline int l4_open(const char *pathname, int flags, mode_t mode)
 {
 	int fd;
 
-	copy_to_utcb((void *)pathname, 0, strlen(pathname) + 1);
-	write_mr(L4SYS_ARG0, (unsigned long)utcb_page);
+	copy_to_shpage((void *)pathname, 0, strlen(pathname) + 1);
+	write_mr(L4SYS_ARG0, (unsigned long)shared_page);
 	write_mr(L4SYS_ARG1, flags);
 	write_mr(L4SYS_ARG2, (u32)mode);
 

tasks/libposix/read.c

@@ -3,6 +3,7 @@
  *
  * Copyright (C) 2007 Bahadir Balban
  */
+
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
@@ -14,14 +15,14 @@
 #include <l4lib/os/posix/readdir.h>
 #include <l4/macros.h>
 #include INC_GLUE(memory.h)
-
+#include <shpage.h>
 
 static inline int l4_readdir(int fd, void *buf, size_t count)
 {
 	int cnt;
 
 	write_mr(L4SYS_ARG0, fd);
-	write_mr(L4SYS_ARG1, (unsigned long)utcb_page);
+	write_mr(L4SYS_ARG1, (unsigned long)shared_page);
 	write_mr(L4SYS_ARG2, count);
 
 	/* Call pager with readdir() request. Check ipc error. */
@@ -36,7 +37,7 @@ static inline int l4_readdir(int fd, void *buf, size_t count)
 
 	}
 
-	copy_from_utcb(buf, 0, cnt);
+	copy_from_shpage(buf, 0, cnt);
 	return cnt;
 }
 

tasks/libposix/shpage.c

@@ -0,0 +1,96 @@
+/*
+ * Initialise posix-related structures.
+ *
+ * Copyright (C) 2007-2009 Bahadir Balban
+ */
+#include <l4lib/kip.h>
+#include <l4lib/arch/syslib.h>
+#include <l4lib/arch/utcb.h>
+#include <l4lib/ipcdefs.h>
+#include <l4/macros.h>
+#include INC_GLUE(memlayout.h)
+#include <stdio.h>
+#include <shpage.h>
+#include <sys/types.h>
+#include <sys/shm.h>
+#include <shpage.h>
+
+/*
+ * Shared page initialisation of posix-like tasks.
+ *
+ * POSIX tasks currently use a default shared page for communciation.
+ * This could have been also done by long ipc calls.
+ */
+
+/*
+ * Shared page for this task. Used for passing data among ipc
+ * parties when message registers are not big enough. Every thread
+ * has right to own one, and it has an address unique to every
+ * thread. It must be explicitly mapped by both parties of the ipc
+ * in order to be useful.
+ */
+void *shared_page;
+
+/*
+ * Obtains a unique address for the task's shared page. Note this
+ * just returns the address. This address is used as an shm key
+ * to map it via shmget()/shmat() later on.
+ */
+static void *shared_page_address(void)
+{
+	void *addr;
+	int err;
+
+	/* We're asking it for ourself. */
+	write_mr(L4SYS_ARG0, self_tid());
+
+	/* Call pager with utcb address request. Check ipc error. */
+	if ((err = l4_sendrecv(PAGER_TID, PAGER_TID,
+			       L4_IPC_TAG_SHPAGE)) < 0) {
+		printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, err);
+		return PTR_ERR(err);
+	}
+
+	/* Check if syscall itself was successful */
+	if (IS_ERR(addr = (void *)l4_get_retval())) {
+		printf("%s: Request UTCB Address Error: %d.\n",
+		       __FUNCTION__, (int)addr);
+		return addr;
+	}
+
+	return addr;
+}
+
+/*
+ * Initialises a non-pager task's default shared memory page
+ * using posix semantics. Used during task initialisation
+ * and by child tasks after a fork.
+ */
+int shared_page_init(void)
+{
+	int shmid;
+	void *shmaddr;
+
+	/*
+	 * Initialise shared page only if we're not the pager.
+	 * The pager does it differently for itself.
+	 */
+	BUG_ON(self_tid() == PAGER_TID);
+
+	/* Obtain our shared page address */
+	shared_page = shared_page_address();
+
+	//printf("%s: UTCB Read from mm0 as: 0x%x\n", __FUNCTION__,
+	//       (unsigned long)shared_page);
+
+	/* Use it as a key to create a shared memory region */
+	BUG_ON((shmid = shmget((key_t)shared_page,
+			       PAGE_SIZE, IPC_CREAT)) < 0);
+
+	/* Attach to the region */
+	BUG_ON((shmaddr = shmat(shmid, shared_page, 0)) < 0);
+	BUG_ON(shmaddr != shared_page);
+
+	return 0;
+}
+

tasks/libposix/stat.c

@@ -18,6 +18,7 @@
 #include <fcntl.h>
 #include <l4/macros.h>
 #include INC_GLUE(memory.h)
+#include <shpage.h>
 
 static inline int l4_fstat(int fd, void *buffer)
 {
@@ -62,10 +63,10 @@ static inline int l4_stat(const char *pathname, void *buffer)
 	int err;
 	struct kstat ks;
 
-	copy_to_utcb((void *)pathname, 0, strlen(pathname) + 1);
+	copy_to_shpage((void *)pathname, 0, strlen(pathname) + 1);
 
 	/* Pathname address on utcb page */
-	write_mr(L4SYS_ARG0, (unsigned long)utcb_page);
+	write_mr(L4SYS_ARG0, (unsigned long)shared_page);
 
 	/* Pass on buffer that should receive stat */
 	write_mr(L4SYS_ARG1, (unsigned long)&ks);

tasks/mm0/include/boot.h

@@ -7,7 +7,7 @@
 /* Structures to use when sending new task information to vfs */
 struct task_data {
 	unsigned long tid;
-	unsigned long utcb_address;
+	unsigned long shpage_address;
 };
 
 struct task_data_head {

tasks/mm0/src/task.c

@@ -624,7 +624,7 @@ int vfs_send_task_data(struct tcb *vfs)
 	/* Write per-task data for all tasks */
 	list_for_each_entry(t, &global_tasks.list, list) {
 		tdata_head->tdata[li].tid = t->tid;
-		tdata_head->tdata[li].utcb_address = (unsigned long)t->shared_page;
+		tdata_head->tdata[li].shpage_address = (unsigned long)t->shared_page;
 		li++;
 	}