diff options
| -rw-r--r-- | arch/x86/include/asm/stacktrace.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/switch_to.h | 10 |
2 files changed, 10 insertions, 5 deletions
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index 20ce3db20f24..2e41c50ddf47 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -52,16 +52,13 @@ static inline bool on_stack(struct stack_info *info, void *addr, size_t len) static inline unsigned long * get_frame_pointer(struct task_struct *task, struct pt_regs *regs) { - struct inactive_task_frame *frame; - if (regs) return (unsigned long *)regs->bp; if (task == current) return __builtin_frame_address(0); - frame = (struct inactive_task_frame *)task->thread.sp; - return (unsigned long *)READ_ONCE_NOCHECK(frame->bp); + return &((struct inactive_task_frame *)task->thread.sp)->bp; } #else static inline unsigned long * diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index 5cb436acd463..fcc5cd387fd1 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -36,7 +36,10 @@ static inline void prepare_switch_to(struct task_struct *prev, asmlinkage void ret_from_fork(void); -/* data that is pointed to by thread.sp */ +/* + * This is the structure pointed to by thread.sp for an inactive task. The + * order of the fields must match the code in __switch_to_asm(). + */ struct inactive_task_frame { #ifdef CONFIG_X86_64 unsigned long r15; @@ -48,6 +51,11 @@ struct inactive_task_frame { unsigned long di; #endif unsigned long bx; + + /* + * These two fields must be together. They form a stack frame header, + * needed by get_frame_pointer(). + */ unsigned long bp; unsigned long ret_addr; }; |