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fixed sys_fork and sys_execve for new paging code

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This commit is contained in:
Steffen Vogel 2014-02-18 13:12:19 +01:00
parent 314fa85389
commit 273137f2e7
3 changed files with 72 additions and 23 deletions
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7
arch/x86/kernel/entry64.asm
View file

@ -407,13 +407,6 @@ gdt_flush:
lgdt [gp]
ret
; determines the current instruction pointer (after the jmp)
global read_eip
read_eip:
pop rax ; Get the return address
jmp rax ; Return. Can't use RET because return
; address popped off the stack.
; In just a few pages in this tutorial, we will add our Interrupt
; Service Routines (ISRs) right here!
global isr0

49
arch/x86/kernel/gdt.c
View file

@ -59,7 +59,7 @@ int arch_fork(task_t* task)
{
struct state* state;
task_t* curr_task = per_core(current_task);
size_t esp, state_size;
size_t state_size;
if (BUILTIN_EXPECT(!task, 0))
return -EINVAL;
@ -78,6 +78,7 @@ int arch_fork(task_t* task)
memcpy(task->stack, curr_task->stack, KERNEL_STACK_SIZE);
#ifdef CONFIG_X86_32
size_t esp;
asm volatile ("mov %%esp, %0" : "=m"(esp));
esp -= (size_t) curr_task->stack;
esp += (size_t) task->stack;
@ -107,8 +108,48 @@ int arch_fork(task_t* task)
// This will be the entry point for the new task. read_ip cleanups the stack
asm volatile ("push %0; call read_ip" :: "r"(&state->eip) : "%eax");
#else
#warning Currently, not supported!
return -1;
size_t rsp;
asm volatile ("mov %%rsp, %0" : "=m"(rsp));
rsp -= (size_t) curr_task->stack;
rsp += (size_t) task->stack;
state = (struct state*) (rsp - state_size);
//memset(state, 0x00, state_size);
asm volatile ("push %rax");
asm volatile ("push %rcx");
asm volatile ("push %rdx");
asm volatile ("push %rbx");
asm volatile ("push %rbp");
asm volatile ("push %rsi");
asm volatile ("push %rdi");
asm volatile ("push %r8");
asm volatile ("push %r9");
asm volatile ("push %r10");
asm volatile ("push %r11");
asm volatile ("pop %0" : "=m"(state->r11));
asm volatile ("pop %0" : "=m"(state->r10));
asm volatile ("pop %0" : "=m"(state->r9));
asm volatile ("pop %0" : "=m"(state->r8));
asm volatile ("pop %0" : "=m"(state->rdi));
asm volatile ("pop %0" : "=m"(state->rsi));
asm volatile ("pop %0" : "=m"(state->rbp));
asm volatile ("pop %0" : "=m"(state->rbx));
asm volatile ("pop %0" : "=m"(state->rdx));
asm volatile ("pop %0" : "=m"(state->rcx));
asm volatile ("pop %0" : "=m"(state->rax));
state->rsp = rsp;
task->last_stack_pointer = (size_t*) state;
state->int_no = 0xB16B00B5;
state->error = 0xC03DB4B3;
state->cs = 0x08;
state->ss = 0x10;
asm volatile ("pushf; pop %0" : "=m"(state->rflags)); // store the current RFLAGS
asm volatile ("leaq (%%rip), %0;": "=r"(state->rip)); // store current instruction pointer
state->rflags |= (1 << 9); // enable interrupts
#endif
return 0;
@ -266,7 +307,7 @@ void gdt_install(void)
gdt_set_gate(2, 0, limit,
GDT_FLAG_RING0 | GDT_FLAG_SEGMENT | GDT_FLAG_DATASEG | GDT_FLAG_PRESENT,
GDT_FLAG_4K_GRAN | mode);
/*
* Create code segement for userspace applications (ring 3)
*/

39
kernel/tasks.c
View file

@ -258,13 +258,6 @@ static void NORETURN do_exit(int arg) {
flags = irq_nested_disable();
drop_vma_list();
/*
* This marks all userpages as free. Nevertheless they are still existing
* and used by the MMU until the task finishes. Therefore we need to disable
* context switching by disabling interrupts (see above)! We may also make use
* of the TLB and global kernel pages.
*/
drop_page_map();
#if 1
@ -368,13 +361,17 @@ static int create_task(tid_t* id, entry_point_t ep, void* arg, uint8_t prio, uin
new_task->id = i;
new_task->status = TASK_READY;
new_task->last_stack_pointer = NULL;
new_task->stack = create_stack();
new_task->flags = TASK_DEFAULT_FLAGS;
new_task->prio = prio;
new_task->last_core = 0;
spinlock_init(&new_task->vma_lock);
new_task->vma_list = NULL;
new_task->fildes_table = NULL;
new_task->stack = create_stack();
if (BUILTIN_EXPECT(!new_task->stack, 0)) {
ret = -ENOMEM;
goto out;
}
mailbox_wait_msg_init(&new_task->inbox);
memset(new_task->outbox, 0x00, sizeof(mailbox_wait_msg_t*)*MAX_TASKS);
@ -435,16 +432,18 @@ int sys_fork(void)
goto out;
}
kprintf("sys_fork: parent id = %u, child id = %u\n", parent_task->id , child_task->id); // TODO: remove
atomic_int32_set(&child_task->user_usage, 0);
ret = copy_page_map(child_task, 1);
if (ret < 0) {
if (BUILTIN_EXPECT(ret < 0, 0)) {
ret = -ENOMEM;
goto out;
}
ret = copy_vma_list(child_task);
if (BUILTIN_EXPECT(!ret, 0)) {
if (BUILTIN_EXPECT(ret < 0, 0)) {
ret = -ENOMEM;
goto out;
}
@ -452,6 +451,10 @@ int sys_fork(void)
child_task->id = i;
child_task->last_stack_pointer = NULL;
child_task->stack = create_stack();
if (BUILTIN_EXPECT(!child_task->stack, 0)) {
ret = -ENOMEM;
goto out;
}
// init fildes_table
child_task->fildes_table = kmalloc(sizeof(filp_t)*NR_OPEN);
@ -712,7 +715,7 @@ static int load_task(load_args_t* largs)
memset((void*) stack, 0x00, npages*PAGE_SIZE);
// create vma regions for the user-level stack
flags = VMA_CACHEABLE;
flags = VMA_CACHEABLE | VMA_USER;
if (prog_header.flags & PF_R)
flags |= VMA_READ;
if (prog_header.flags & PF_W)
@ -899,6 +902,9 @@ int sys_execve(const char* fname, char** argv, char** env)
char *dest, *src;
int ret, argc = 0;
int envc = 0;
task_t* curr_task = per_core(current_task);
kprintf("sys_execve: fname = %s, argv = %p, env = %p\n", fname, argv, env); // TODO: remove
node = findnode_fs((char*) fname);
if (!node || !(node->type == FS_FILE))
@ -941,8 +947,17 @@ int sys_execve(const char* fname, char** argv, char** env)
while ((*dest++ = *src++) != 0);
}
spinlock_lock(&curr_task->vma_lock);
// remove old program
drop_vma_list();
vma_t *vma;
for (vma=curr_task->vma_list; vma; vma = vma->next)
pfree((void*) vma->start, vma->end - vma->start);
// TODO: Heap?
spinlock_unlock(&curr_task->vma_lock);
/*
* we use a trap gate to enter the kernel