Removed the broken arch_thread::current_iframe field and switched to the

same mechanism as NewOS, ie. using the iframe "stack" pointer (using the
new i386_get_current_iframe() function).
Implemented fork() support functions arch_{store|restore}_fork_frame().


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@9292 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Axel Dörfler 2004-10-12 03:52:53 +00:00
parent 21942ca92a
commit adf29fcdda

View File

@ -1,6 +1,6 @@
/*
** Copyright 2002-2004, The OpenBeOS Team. All rights reserved.
** Distributed under the terms of the OpenBeOS License.
** Copyright 2002-2004, The Haiku Team. All rights reserved.
** Distributed under the terms of the Haiku License.
**
** Copyright 2001, Travis Geiselbrecht. All rights reserved.
** Distributed under the terms of the NewOS License.
@ -25,6 +25,7 @@
// from arch_interrupts.S
extern void i386_stack_init(struct farcall *interrupt_stack_offset);
extern void i386_restore_frame_from_syscall(struct iframe frame);
void
@ -43,6 +44,32 @@ i386_pop_iframe(struct thread *thread)
}
/** Returns the current iframe structure of the running thread.
* This function must only be called in a context where it's actually
* sure that such iframe exists; ie. from syscalls, but usually not
* from standard kernel threads.
*/
static struct iframe *
i386_get_current_iframe(void)
{
struct thread *thread = thread_get_current_thread();
ASSERT(thread->arch_info.iframe_ptr >= 0);
return thread->arch_info.iframes[thread->arch_info.iframe_ptr - 1];
}
static inline uint32
get_fs_register(void)
{
uint32 fs;
asm("movl %%fs,%0" : "=r" (fs));
return fs;
}
static inline void
set_fs_register(uint32 segment)
{
@ -85,9 +112,9 @@ arch_thread_init_thread_struct(struct thread *t)
int
arch_thread_init_kthread_stack(struct thread *t, int (*start_func)(void), void (*entry_func)(void), void (*exit_func)(void))
{
unsigned int *kstack = (unsigned int *)t->kernel_stack_base;
unsigned int kstack_size = KSTACK_SIZE;
unsigned int *kstack_top = kstack + kstack_size / sizeof(unsigned int);
addr_t *kstack = (addr_t *)t->kernel_stack_base;
addr_t kstack_size = KSTACK_SIZE;
addr_t *kstack_top = kstack + kstack_size / sizeof(addr_t);
int i;
TRACE(("arch_thread_initialize_kthread_stack: kstack 0x%p, start_func 0x%p, entry_func 0x%p\n",
@ -120,7 +147,7 @@ arch_thread_init_kthread_stack(struct thread *t, int (*start_func)(void), void (
// save the stack position
t->arch_info.current_stack.esp = kstack_top;
t->arch_info.current_stack.ss = (int *)KERNEL_DATA_SEG;
t->arch_info.current_stack.ss = (addr_t *)KERNEL_DATA_SEG;
return 0;
}
@ -249,7 +276,7 @@ arch_thread_enter_uspace(struct thread *t, addr_t entry, void *args1, void *args
status_t
arch_setup_signal_frame(struct thread *t, struct sigaction *sa, int sig, int sig_mask)
{
struct iframe *frame = t->arch_info.current_iframe;
struct iframe *frame = i386_get_current_iframe();
uint32 *stack_ptr = (uint32 *)frame->user_esp;
uint32 *code_ptr;
uint32 *regs_ptr;
@ -264,6 +291,7 @@ arch_setup_signal_frame(struct thread *t, struct sigaction *sa, int sig, int sig
frame->eax = frame->orig_eax;
frame->edx = frame->orig_edx;
frame->eip -= 2;
// undos the "int $99" syscall interrupt (so that it'll be called again)
}
}
@ -323,14 +351,12 @@ int64
arch_restore_signal_frame(void)
{
struct thread *t = thread_get_current_thread();
struct iframe *frame;
struct iframe *frame = i386_get_current_iframe();
uint32 *stack;
struct vregs *regs;
TRACE(("### arch_restore_signal_frame: entry\n"));
frame = t->arch_info.current_iframe;
stack = (uint32 *)frame->user_esp;
t->sig_block_mask = stack[0];
regs = (struct vregs *)stack[1];
@ -359,7 +385,7 @@ arch_restore_signal_frame(void)
void
arch_check_syscall_restart(struct thread *t)
{
struct iframe *frame = t->arch_info.current_iframe;
struct iframe *frame = i386_get_current_iframe();
if ((status_t)frame->orig_eax >= 0 && (status_t)frame->eax == EINTR) {
frame->eax = frame->orig_eax;
@ -368,3 +394,45 @@ arch_check_syscall_restart(struct thread *t)
}
}
/** Saves everything needed to restore the frame in the child fork in the
* arch_fork_arg structure to be passed to arch_restore_fork_frame().
* Also makes sure to return the right value.
*/
void
arch_store_fork_frame(struct arch_fork_arg *arg)
{
struct iframe *frame = i386_get_current_iframe();
// we need to copy the threads current iframe
arg->iframe = *frame;
// we also want fork() to return 0 for the child
arg->iframe.eax = 0;
}
/** Restores the frame from a forked team as specified by the provided
* arch_fork_arg structure.
* Needs to be called from within the child team, ie. instead of
* arch_thread_enter_uspace() as thread "starter".
* This function does not return to the caller, but will enter userland
* in the child team at the same position where the parent team left of.
*/
void
arch_restore_fork_frame(struct arch_fork_arg *arg)
{
struct thread *thread = thread_get_current_thread();
i386_set_tss_and_kstack(thread->kernel_stack_base + KSTACK_SIZE);
// set the CPU dependent GDT entry for TLS (set the current %fs register)
set_tls_context(thread);
// patch up %fs register of the frame
arg->iframe.fs = get_fs_register();
i386_restore_frame_from_syscall(arg->iframe);
}