tile: sanitize copy_thread()

Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-10-23 23:32:21 -04:00
parent 6b14e4198c
commit 008f179487

View file

@ -158,7 +158,7 @@ static void save_arch_state(struct thread_struct *t);
int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
struct task_struct *p, struct pt_regs *unused)
{
struct pt_regs *childregs = task_pt_regs(p);
unsigned long ksp;
@ -184,7 +184,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
/* Record the pid of the task that created this one. */
p->thread.creator_pid = current->pid;
if (unlikely(!regs)) {
if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(childregs, 0, sizeof(struct pt_regs));
memset(&callee_regs[2], 0,
@ -208,25 +208,26 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
*/
task_thread_info(p)->step_state = NULL;
/* Save user stack top pointer so we can ID the stack vm area later. */
p->thread.usp0 = sp;
/*
* Copy the registers onto the kernel stack so the
* return-from-interrupt code will reload it into registers.
*/
*childregs = *regs;
*childregs = *current_pt_regs();
childregs->regs[0] = 0; /* return value is zero */
childregs->sp = sp; /* override with new user stack pointer */
memcpy(callee_regs, &regs->regs[CALLEE_SAVED_FIRST_REG],
if (sp)
childregs->sp = sp; /* override with new user stack pointer */
memcpy(callee_regs, &childregs->regs[CALLEE_SAVED_FIRST_REG],
CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long));
/* Save user stack top pointer so we can ID the stack vm area later. */
p->thread.usp0 = childregs->sp;
/*
* If CLONE_SETTLS is set, set "tp" in the new task to "r4",
* which is passed in as arg #5 to sys_clone().
*/
if (clone_flags & CLONE_SETTLS)
childregs->tp = regs->regs[4];
childregs->tp = childregs->regs[4];
#if CHIP_HAS_TILE_DMA()
@ -587,10 +588,7 @@ int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
SYSCALL_DEFINE4(clone, unsigned long, clone_flags, unsigned long, newsp,
void __user *, parent_tidptr, void __user *, child_tidptr)
{
struct pt_regs *regs = current_pt_regs();
if (!newsp)
newsp = regs->sp;
return do_fork(clone_flags, newsp, regs, 0,
return do_fork(clone_flags, newsp, current_pt_regs(), 0,
parent_tidptr, child_tidptr);
}