ish/kernel/fork.c
2018-01-21 17:40:45 -08:00

135 lines
3.6 KiB
C

#include "debug.h"
#include "kernel/task.h"
#include "fs/fd.h"
#include "kernel/calls.h"
#define CSIGNAL_ 0x000000ff
#define CLONE_VM_ 0x00000100
#define CLONE_FS_ 0x00000200
#define CLONE_FILES_ 0x00000400
#define CLONE_SIGHAND_ 0x00000800
#define CLONE_PTRACE_ 0x00002000
#define CLONE_VFORK_ 0x00004000
#define CLONE_PARENT_ 0x00008000
#define CLONE_THREAD_ 0x00010000
#define CLONE_NEWNS_ 0x00020000
#define CLONE_SYSVSEM_ 0x00040000
#define CLONE_SETTLS_ 0x00080000
#define CLONE_PARENT_SETTID_ 0x00100000
#define CLONE_CHILD_CLEARTID_ 0x00200000
#define CLONE_DETACHED_ 0x00400000
#define CLONE_UNTRACED_ 0x00800000
#define CLONE_CHILD_SETTID_ 0x01000000
#define CLONE_NEWCGROUP_ 0x02000000
#define CLONE_NEWUTS_ 0x04000000
#define CLONE_NEWIPC_ 0x08000000
#define CLONE_NEWUSER_ 0x10000000
#define CLONE_NEWPID_ 0x20000000
#define CLONE_NEWNET_ 0x40000000
#define CLONE_IO_ 0x80000000
#define IMPLEMENTED_FLAGS (CLONE_VM_|CLONE_FILES_|CLONE_FS_|CLONE_VFORK_|CLONE_DETACHED_|CLONE_CHILD_SETTID_)
static int copy_task(struct task *task, dword_t flags, addr_t ctid_addr) {
int err;
struct mem *mem = task->cpu.mem;
if (flags & CLONE_VM_) {
mem_retain(mem);
} else {
task->cpu.mem = mem_new();
pt_copy_on_write(mem, 0, task->cpu.mem, 0, MEM_PAGES);
}
if (flags & CLONE_FILES_) {
task->files->refcount++;
} else {
task->files = fdtable_copy(task->files);
if (IS_ERR(task->files)) {
err = PTR_ERR(task->files);
goto fail_free_mem;
}
}
if (flags & CLONE_FS_) {
task->fs->refcount++;
} else {
task->fs = fs_info_copy(task->fs);
err = _ENOMEM;
if (task->fs == NULL)
goto fail_free_files;
}
err = _EFAULT;
if (flags & CLONE_CHILD_SETTID_)
if (user_put_task(task, ctid_addr, task->pid))
goto fail_free_fs;
// TODO for threads:
// CLONE_SIGHAND
// CLONE_THREAD
// CLONE_SYSVSEM
// CLONE_SETTLS
// CLONE_PARENT_SETTID
// CLONE_CHILD_CLEARTID
return 0;
fail_free_mem:
mem_release(task->cpu.mem);
fail_free_files:
fdtable_release(task->files);
fail_free_fs:
fs_info_release(task->fs);
return err;
}
// eax = syscall number
// ebx = flags
// ecx = stack
// edx, esi, edi = unimplemented garbage
dword_t sys_clone(dword_t flags, addr_t stack, addr_t ptid, addr_t tls, addr_t ctid) {
STRACE("clone(0x%x, 0x%x, 0x%x, 0x%x, 0x%x)", flags, stack, ptid, tls, ctid);
if (flags & ~CSIGNAL_ & ~IMPLEMENTED_FLAGS) {
FIXME("unimplemented clone flags 0x%x", flags & ~CSIGNAL_ & ~IMPLEMENTED_FLAGS);
return _EINVAL;
}
if (ptid != 0 || tls != 0) {
FIXME("clone with ptid or ts not null");
return _EINVAL;
}
if ((flags & CSIGNAL_) != SIGCHLD_) {
FIXME("clone non sigchld");
return _EINVAL;
}
if (stack != 0)
TODO("clone with nonzero stack");
// stack = current->cpu.esp;
struct task *task = task_create(current);
if (task == NULL)
return _ENOMEM;
int err = copy_task(task, flags, ctid);
if (err < 0) {
task_destroy(task);
return err;
}
task->cpu.eax = 0;
task_start(task);
if (flags & CLONE_VFORK_) {
// FIXME this doesn't loop, it must be wrong
lock(&task->exit_lock);
wait_for(&task->vfork_done, &task->exit_lock);
unlock(&task->exit_lock);
}
return task->pid;
}
dword_t sys_fork() {
return sys_clone(SIGCHLD_, 0, 0, 0, 0);
}
dword_t sys_vfork() {
return sys_clone(CLONE_VFORK_ | CLONE_VM_ | SIGCHLD_, 0, 0, 0, 0);
}