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Implement vfork system call

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It's implemented by making it issue clone system call internally with
the arguments of (SIGCHLD, 0, 0, 0, 0). The feature in which the caller
of vfork blocks until the child issues exit/execve is not implemented.
Refer to #233.
This commit is contained in:
Masamichi Takagi
2014-09-06 21:37:59 +09:00
parent 0de6a30426
commit 19fa391d4f
2 changed files with 33 additions and 17 deletions
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49
kernel/syscall.c
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@@ -1323,26 +1323,29 @@ SYSCALL_DECLARE(execve)
return 0;
}
SYSCALL_DECLARE(clone)
unsigned long do_fork(int clone_flags, unsigned long newsp,
unsigned long parent_tidptr, unsigned long child_tidptr,
unsigned long tlsblock_base, unsigned long curpc,
unsigned long cursp)
{
int cpuid;
int clone_flags = ihk_mc_syscall_arg0(ctx);
struct process *new;
ihk_mc_user_context_t ctx1;
struct syscall_request request1 IHK_DMA_ALIGN;
dkprintf("clone(): stack_pointr passed in: 0x%lX, stack pointer of caller: 0x%lx\n",
(unsigned long)ihk_mc_syscall_arg1(ctx),
(unsigned long)ihk_mc_syscall_sp(ctx));
dkprintf("do_fork,flags=%08x,newsp=%lx,ptidptr=%lx,ctidptr=%lx,tls=%lx,curpc=%lx,cursp=%lx",
clone_flags, newsp, parent_tidptr, child_tidptr, tlsblock_base, curpc, cursp);
dkprintf("do_fork(): stack_pointr passed in: 0x%lX, stack pointer of caller: 0x%lx\n",
newsp, cursp);
cpuid = obtain_clone_cpuid();
if (cpuid == -1) {
return -EAGAIN;
}
new = clone_process(cpu_local_var(current), ihk_mc_syscall_pc(ctx),
ihk_mc_syscall_arg1(ctx) ? ihk_mc_syscall_arg1(ctx) :
ihk_mc_syscall_sp(ctx),
new = clone_process(cpu_local_var(current), curpc,
newsp ? newsp : cursp,
clone_flags);
if (!new) {
@@ -1395,25 +1398,25 @@ SYSCALL_DECLARE(clone)
if (clone_flags & CLONE_PARENT_SETTID) {
dkprintf("clone_flags & CLONE_PARENT_SETTID: 0x%lX\n",
(unsigned long)ihk_mc_syscall_arg2(ctx));
parent_tidptr);
*(int*)ihk_mc_syscall_arg2(ctx) = new->pid;
*(int*)parent_tidptr = new->pid;
}
if (clone_flags & CLONE_CHILD_CLEARTID) {
dkprintf("clone_flags & CLONE_CHILD_CLEARTID: 0x%lX\n",
(unsigned long)ihk_mc_syscall_arg3(ctx));
child_tidptr);
new->thread.clear_child_tid = (int*)ihk_mc_syscall_arg3(ctx);
new->thread.clear_child_tid = (int*)child_tidptr;
}
if (clone_flags & CLONE_CHILD_SETTID) {
unsigned long phys;
dkprintf("clone_flags & CLONE_CHILD_SETTID: 0x%lX\n",
(unsigned long)ihk_mc_syscall_arg3(ctx));
child_tiptr);
if (ihk_mc_pt_virt_to_phys(new->vm->page_table,
(void *)ihk_mc_syscall_arg3(ctx), &phys)) {
(void *)child_tidptr, &phys)) {
kprintf("ERROR: looking up physical addr for child process\n");
return -EFAULT;
}
@@ -1423,10 +1426,9 @@ SYSCALL_DECLARE(clone)
if (clone_flags & CLONE_SETTLS) {
dkprintf("clone_flags & CLONE_SETTLS: 0x%lX\n",
(unsigned long)ihk_mc_syscall_arg4(ctx));
tlsblock_base);
new->thread.tlsblock_base =
(unsigned long)ihk_mc_syscall_arg4(ctx);
new->thread.tlsblock_base = tlsblock_base;
}
else {
new->thread.tlsblock_base =
@@ -1441,6 +1443,19 @@ SYSCALL_DECLARE(clone)
return new->tid;
}
SYSCALL_DECLARE(vfork)
{
return do_fork(SIGCHLD, 0, 0, 0, 0, ihk_mc_syscall_pc(ctx), ihk_mc_syscall_sp(ctx));
}
SYSCALL_DECLARE(clone)
{
return do_fork((int)ihk_mc_syscall_arg0(ctx), ihk_mc_syscall_arg1(ctx),
ihk_mc_syscall_arg2(ctx), ihk_mc_syscall_arg3(ctx),
ihk_mc_syscall_arg4(ctx), ihk_mc_syscall_pc(ctx),
ihk_mc_syscall_sp(ctx));
}
SYSCALL_DECLARE(set_tid_address)
{
cpu_local_var(current)->thread.clear_child_tid =