diff options
Diffstat (limited to 'arch/arc/kernel/stacktrace.c')
| -rw-r--r-- | arch/arc/kernel/stacktrace.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c index 11b50959f20e..054511f571df 100644 --- a/arch/arc/kernel/stacktrace.c +++ b/arch/arc/kernel/stacktrace.c @@ -39,15 +39,15 @@ #ifdef CONFIG_ARC_DW2_UNWIND -static void seed_unwind_frame_info(struct task_struct *tsk, - struct pt_regs *regs, - struct unwind_frame_info *frame_info) +static int +seed_unwind_frame_info(struct task_struct *tsk, struct pt_regs *regs, + struct unwind_frame_info *frame_info) { /* * synchronous unwinding (e.g. dump_stack) * - uses current values of SP and friends */ - if (tsk == NULL && regs == NULL) { + if (regs == NULL && (tsk == NULL || tsk == current)) { unsigned long fp, sp, blink, ret; frame_info->task = current; @@ -66,11 +66,15 @@ static void seed_unwind_frame_info(struct task_struct *tsk, frame_info->call_frame = 0; } else if (regs == NULL) { /* - * Asynchronous unwinding of sleeping task - * - Gets SP etc from task's pt_regs (saved bottom of kernel - * mode stack of task) + * Asynchronous unwinding of a likely sleeping task + * - first ensure it is actually sleeping + * - if so, it will be in __switch_to, kernel mode SP of task + * is safe-kept and BLINK at a well known location in there */ + if (tsk->state == TASK_RUNNING) + return -1; + frame_info->task = tsk; frame_info->regs.r27 = TSK_K_FP(tsk); @@ -104,6 +108,8 @@ static void seed_unwind_frame_info(struct task_struct *tsk, frame_info->regs.r63 = regs->ret; frame_info->call_frame = 0; } + + return 0; } #endif @@ -113,11 +119,12 @@ arc_unwind_core(struct task_struct *tsk, struct pt_regs *regs, int (*consumer_fn) (unsigned int, void *), void *arg) { #ifdef CONFIG_ARC_DW2_UNWIND - int ret = 0; + int ret = 0, cnt = 0; unsigned int address; struct unwind_frame_info frame_info; - seed_unwind_frame_info(tsk, regs, &frame_info); + if (seed_unwind_frame_info(tsk, regs, &frame_info)) + return 0; while (1) { address = UNW_PC(&frame_info); @@ -133,6 +140,11 @@ arc_unwind_core(struct task_struct *tsk, struct pt_regs *regs, break; frame_info.regs.r63 = frame_info.regs.r31; + + if (cnt++ > 128) { + printk("unwinder looping too long, aborting !\n"); + return 0; + } } return address; /* return the last address it saw */ |