diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c old mode 100644 new mode 100755 index 1de41328b277fbf4bb70b6a46905218a36a25aa7..96330dd927109882283d1d57c55af861cf69c0cc --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -39,6 +39,7 @@ #include <asm/desc.h> #include <asm/prctl.h> #include <asm/spec-ctrl.h> +#include <asm/unwind.h> #include "process.h" @@ -787,58 +788,23 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) */ unsigned long get_wchan(struct task_struct *p) { - unsigned long start, bottom, top, sp, fp, ip, ret = 0; - int count = 0; + struct unwind_state state; + unsigned long addr = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; - if (!try_get_task_stack(p)) - return 0; - - start = (unsigned long)task_stack_page(p); - if (!start) - goto out; - - /* - * Layout of the stack page: - * - * ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long) - * PADDING - * ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING - * stack - * ----------- bottom = 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; - - sp = READ_ONCE(p->thread.sp); - if (sp < bottom || sp > top) - goto out; - - fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp); - do { - if (fp < bottom || fp > top) - goto out; - ip = READ_ONCE_NOCHECK(*(unsigned long *)(fp + sizeof(unsigned long))); - if (!in_sched_functions(ip)) { - ret = ip; - goto out; - } - fp = READ_ONCE_NOCHECK(*(unsigned long *)fp); - } while (count++ < 16 && p->state != TASK_RUNNING); + for (unwind_start(&state, p, NULL, NULL); !unwind_done(&state); + unwind_next_frame(&state)) { + addr = unwind_get_return_address(&state); + if (!addr) + break; + if (in_sched_functions(addr)) + continue; + break; + } -out: - put_task_stack(p); - return ret; + return addr; } long do_arch_prctl_common(struct task_struct *task, int option,