sh: Fix kernel thread stack corruption with preempt.

When I run a preemptive kernel-2.6.20 for SH7780, a created kthread(pdflush) can not exit by do_exit() in kernel_thread_helper. I think that the created kthread should have a room for 'struct pt_regs' space on the stack top, because __switch_to() will refer to the space as follows using 'regs = task_pt_regs(prev)' and next condition may be true. Signed-off-by: Hideo Saito <[email protected]> Signed-off-by: Paul Mundt <[email protected]>
niw · Mar 5, 2007 · e6bcf56 · e6bcf56
1 parent e523d93
commit e6bcf56
Showing 1 changed file with 2 additions and 3 deletions.
diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c
@@ -250,12 +250,11 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 		childregs->regs[15] = usp;
 		ti->addr_limit = USER_DS;
 	} else {
-		childregs->regs[15] = (unsigned long)task_stack_page(p) +
-							THREAD_SIZE;
+		childregs->regs[15] = (unsigned long)childregs;
 		ti->addr_limit = KERNEL_DS;
 	}
 
-        if (clone_flags & CLONE_SETTLS)
+	if (clone_flags & CLONE_SETTLS)
 		childregs->gbr = childregs->regs[0];
 
 	childregs->regs[0] = 0; /* Set return value for child */