From 2d9ba6ae709d8f807acae9d9a06e9f9407e0c415 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <lankes@lfbs.rwth-aachen.de>
Date: Tue, 8 Mar 2011 23:12:38 +0100
Subject: [PATCH] forwarding arguments to the new tasks

---
 include/metalsvm/tasks.h              |   4 +-
 kernel/tasks.c                        | 119 ++++++++++++++++++++++++--
 kernel/tests.c                        |   6 +-
 newlib/examples/hello.c               |   4 +
 newlib/examples/tests.c               |   7 +-
 newlib/src/libgloss/metalsvm/crt0.asm |  16 +---
 6 files changed, 127 insertions(+), 29 deletions(-)

diff --git a/include/metalsvm/tasks.h b/include/metalsvm/tasks.h
index ca1d86a3..c381bb48 100644
--- a/include/metalsvm/tasks.h
+++ b/include/metalsvm/tasks.h
@@ -37,8 +37,8 @@ int multitasking_init(void);
 /* create a kernel task. */
 int create_kernel_task(tid_t*, entry_point_t, void*);
 
-/* create a user level task. if sz is zero, the task with the default stack size will be created */
-int create_user_task(tid_t* id, size_t sz, const char* filename, int argc, char** argv);
+/* create a user level task. */
+int create_user_task(tid_t* id, const char* filename, char** argv);
 
 /* until a child task is terminated, the current task is block */ 
 tid_t wait(int32_t* result);
diff --git a/kernel/tasks.c b/kernel/tasks.c
index 2843daec..9d451bee 100644
--- a/kernel/tasks.c
+++ b/kernel/tasks.c
@@ -241,13 +241,28 @@ int create_kernel_task(tid_t* id, entry_point_t ep, void* arg)
 	return create_task(id, ep, arg);
 }
 
-static int load_task(vfs_node_t* node)
+#define MAX_ARGS	(PAGE_SIZE - 2*sizeof(int) - sizeof(vfs_node_t*))
+
+typedef struct {
+	vfs_node_t* node;
+	int argc;
+	int envc;
+	char buffer[MAX_ARGS];
+} load_args_t;
+
+static int load_task(load_args_t* largs)
 {
-	uint32_t i, addr, npages, flags, stack = 0;
+	uint32_t i, offset, idx;
+	uint32_t addr, npages, flags, stack = 0;
 	elf_header_t header;
 	elf_program_header_t prog_header;
 	//elf_section_header_t sec_header;
+	vfs_node_t* node;
 
+	if (!largs)
+		return -EINVAL;
+
+	node = largs->node;
 	if (!node)
 		return -EINVAL;
 
@@ -361,7 +376,34 @@ static int load_task(vfs_node_t* node)
 		return -ENOMEM;
 	}
 
-	jump_to_user_code(header.entry, stack+DEFAULT_STACK_SIZE-64);
+	// push strings on the stack
+	offset = DEFAULT_STACK_SIZE-MAX_ARGS-8;
+	memcpy((void*) (stack+offset), largs->buffer, MAX_ARGS);
+	idx = offset;
+
+	// push argv on the stack
+	offset -= largs->argc * sizeof(char*);
+	i = 0;
+	while(i<largs->argc) {
+		((char**) (stack+offset))[i] = (char*) (stack+idx);
+		i++;
+		
+		while((i<largs->argc) && ((char*) stack)[idx] != '\0')
+			idx++;
+		idx++;
+	}
+
+	// push pointer to argv
+	offset -= sizeof(char**);
+	*((char***) (stack+offset)) = (char**) (stack + offset + sizeof(char**));
+
+	// push argc on the stack
+	offset -= sizeof(int);
+	*((int*) (stack+offset)) = largs->argc;
+
+	kfree(largs, sizeof(load_args_t));
+
+	jump_to_user_code(header.entry, stack+offset);
 
 	return 0;
 
@@ -373,29 +415,88 @@ invalid:
 
 static int STDCALL user_entry(void* arg)
 {
-	return load_task((vfs_node_t*) arg);
+	return load_task((load_args_t*) arg);
 }
 
-int create_user_task(tid_t* id, size_t sz, const char* fname, int argc, char** argv)
+int create_user_task(tid_t* id, const char* fname, char** argv)
 {
 	vfs_node_t* node;
+	int argc = 0;
+	size_t i, buffer_size = 0;
+	load_args_t* load_args = NULL;
+	char *dest, *src;
 
 	node = findnode_fs((char*) fname);
 	if (!node || !(node->type == FS_FILE))
 		return -EINVAL;
 
-	return create_task(id, user_entry, node);
+	// determine buffer size of argv
+	if (argv) {
+		while (argv[argc]) {
+			buffer_size += (strlen(argv[argc]) + 1);
+			argc++;
+		}
+	}
+
+	if (argc <= 0)
+		return -EINVAL;
+	if (buffer_size >= MAX_ARGS)
+		return -EINVAL;
+
+	load_args = kmalloc(sizeof(load_args_t));
+	if (BUILTIN_EXPECT(!load_args, 0))
+		return -ENOMEM;
+	load_args->node = node;
+	load_args->argc = argc;
+	load_args->envc = 0;
+	dest = load_args->buffer;
+	for (i=0; i<argc; i++) {
+		src = argv[i];
+		while ((*dest++ = *src++) != 0);
+	}
+
+	return create_task(id, user_entry, load_args);
 }
 
 int sys_execve(const char* fname, char** argv, char** env)
 {
 	vfs_node_t* node;
 	vma_t* tmp;
+	size_t i, buffer_size = 0;
+	load_args_t* load_args = NULL;
+	char *dest, *src;
+	int ret, argc = 0;
 
 	node = findnode_fs((char*) fname);
 	if (!node || !(node->type == FS_FILE))
 		return -EINVAL;
 
+	// determine buffer size of argv
+	if (argv) {
+		while (argv[argc]) {
+			buffer_size += (strlen(argv[argc]) + 1);
+			argc++;
+		}
+	}
+
+	if (argc <= 0)
+		return -EINVAL;
+	if (buffer_size >= MAX_ARGS)
+		return -EINVAL;
+
+	load_args = kmalloc(sizeof(load_args_t));
+	if (BUILTIN_EXPECT(!load_args, 0))
+		return -ENOMEM;
+
+	load_args->node = node;
+	load_args->argc = argc;
+	load_args->envc = 0;
+	dest = load_args->buffer;
+	for (i=0; i<argc; i++) {
+		src = argv[i];
+		while ((*dest++ = *src++) != 0);
+	}
+
 	spinlock_lock(&(per_core(current_task)->vma_lock));
 
 	// remove old program
@@ -414,7 +515,11 @@ int sys_execve(const char* fname, char** argv, char** env)
 	 * => we could directly load the new task
 	 */
 
-	return load_task(node);
+	ret = load_task(load_args);
+
+	kfree(load_args, sizeof(load_args_t));
+
+	return ret;
 }
 
 tid_t wait(int32_t* result) 
diff --git a/kernel/tests.c b/kernel/tests.c
index c62870c2..dec3d299 100644
--- a/kernel/tests.c
+++ b/kernel/tests.c
@@ -102,7 +102,7 @@ static int STDCALL join_test(void* arg)
 
 int test_init(void)
 {
-	char* argv[1] = {"dummy"};
+	char* argv[] = {"/bin/tests", NULL};
 
 	sem_init(&producing, 1);
 	sem_init(&consuming, 0);
@@ -112,8 +112,8 @@ int test_init(void)
 	//create_kernel_task(NULL, join_test, NULL);
 	//create_kernel_task(NULL, producer, NULL);
 	//create_kernel_task(NULL, consumer, NULL);
-	//create_user_task(NULL, 8192, "/bin/hello", 1, argv);
-	create_user_task(NULL, 8192, "/bin/tests", 1, argv);
+	//create_user_task(NULL, "/bin/hello", 1, argv);
+	create_user_task(NULL, "/bin/tests", argv);
 
 	return 0;
 }
diff --git a/newlib/examples/hello.c b/newlib/examples/hello.c
index 9e4fa70d..1c6f1f2f 100644
--- a/newlib/examples/hello.c
+++ b/newlib/examples/hello.c
@@ -27,8 +27,12 @@ extern int errno;
 
 int main(int argc, char** argv)
 {
+	int i;
 	char str[] = "Hello World!!!\n";
 
+	for(i=0; i<argc; i++)
+		printf("argv[%i] = %s\n", i, argv[i]);
+
 	write(1, str, strlen(str));
 
 	printf("Hello from printf!!!\n");
diff --git a/newlib/examples/tests.c b/newlib/examples/tests.c
index 20723195..abe31ea0 100644
--- a/newlib/examples/tests.c
+++ b/newlib/examples/tests.c
@@ -29,14 +29,17 @@ extern int errno;
 
 int main(int argc, char** argv)
 {
-	int status = 0;
+	int i, status = 0;
 	pid_t pid;
 
 	printf("Create child process...\n");
 
+	for(i=0; i<argc; i++)
+		printf("argv[%i] = %s\n", i, argv[i]);
+
 	pid = fork();
 	if (pid == 0) { // child
-		char* args[] = {"/bin/hello", (char*) 0};
+		char* args[] = {"/bin/hello", "one", "two", "three", NULL};
 
 		printf("Hello from child process!\n");
 		execve("/bin/hello", args, environ);
diff --git a/newlib/src/libgloss/metalsvm/crt0.asm b/newlib/src/libgloss/metalsvm/crt0.asm
index 6a42d518..c196a345 100644
--- a/newlib/src/libgloss/metalsvm/crt0.asm
+++ b/newlib/src/libgloss/metalsvm/crt0.asm
@@ -17,10 +17,6 @@
 ; This file is part of MetalSVM.
 
 [BITS 32]
-SECTION .data
-   cmdline DB "cmdline", 0
-   argv DD 0, 0
-
 SECTION .text
 global _start
 extern main
@@ -50,20 +46,10 @@ L2:
    ; call init function
    call __do_global_ctors
 
-   ; build argc/argv pair and then push
-   ; them onto the stack...
-   mov [argv+0], DWORD cmdline
-   mov eax, [esp+4]
-   mov [argv+4], eax
-   push argv
-   push 2
-
+   ; arguments are already on the stack
    ; call the user's function
    call main
 
-   ; remove argc/argv pair
-   add esp, 8
-
    ; call exit from the C library so atexit gets called, and the
    ; C++ destructors get run. This calls our exit routine below    
    ; when it's done.