diff options
Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r-- | arch/x86/kernel/process_64.c | 56 |
1 files changed, 0 insertions, 56 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index f1fd0889e8af..b35921a670b2 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -499,62 +499,6 @@ void set_personality_ia32(bool x32) } EXPORT_SYMBOL_GPL(set_personality_ia32); -/* - * Called from fs/proc with a reference on @p to find the function - * which called into schedule(). This needs to be done carefully - * because the task might wake up and we might look at a stack - * changing under us. - */ -unsigned long get_wchan(struct task_struct *p) -{ - unsigned long start, bottom, top, sp, fp, ip; - int count = 0; - - if (!p || p == current || p->state == TASK_RUNNING) - return 0; - - start = (unsigned long)task_stack_page(p); - if (!start) - return 0; - - /* - * Layout of the stack page: - * - * ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long) - * PADDING - * ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING - * stack - * ----------- bottom = start + sizeof(thread_info) - * thread_info - * ----------- start - * - * The tasks stack pointer points at the location where the - * framepointer is stored. The data on the stack is: - * ... IP FP ... IP FP - * - * We need to read FP and IP, so we need to adjust the upper - * bound by another unsigned long. - */ - top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; - top -= 2 * sizeof(unsigned long); - bottom = start + sizeof(struct thread_info); - - sp = READ_ONCE(p->thread.sp); - if (sp < bottom || sp > top) - return 0; - - fp = READ_ONCE(*(unsigned long *)sp); - do { - if (fp < bottom || fp > top) - return 0; - ip = READ_ONCE(*(unsigned long *)(fp + sizeof(unsigned long))); - if (!in_sched_functions(ip)) - return ip; - fp = READ_ONCE(*(unsigned long *)fp); - } while (count++ < 16 && p->state != TASK_RUNNING); - return 0; -} - long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) { int ret = 0; |