From: William Lee Irwin III The stack is now shared with struct thread_info on most arches, not task_t. This mostly affects get_wchan() and stack usage debug. --- 25-akpm/arch/ppc/kernel/process.c | 2 +- 1 files changed, 1 insertion(+), 1 deletion(-) diff -puN arch/ppc/kernel/process.c~ppc32-stack-bounds-checking arch/ppc/kernel/process.c --- 25/arch/ppc/kernel/process.c~ppc32-stack-bounds-checking 2004-04-17 01:11:53.667968144 -0700 +++ 25-akpm/arch/ppc/kernel/process.c 2004-04-17 01:11:53.670967688 -0700 @@ -83,7 +83,7 @@ kernel_stack_top(struct task_struct *tsk unsigned long task_top(struct task_struct *tsk) { - return ((unsigned long)tsk) + sizeof(struct task_struct); + return ((unsigned long)tsk) + sizeof(struct thread_info); } /* check to make sure the kernel stack is healthy */ _