diff options
| -rw-r--r-- | arch/arm/kernel/unwind.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index 1dedc2c7ff4..dd56e11f339 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -212,7 +212,8 @@ static int unwind_exec_insn(struct unwind_ctrl_block *ctrl) ctrl->vrs[14] = *vsp++; ctrl->vrs[SP] = (unsigned long)vsp; } else if (insn == 0xb0) { - ctrl->vrs[PC] = ctrl->vrs[LR]; + if (ctrl->vrs[PC] == 0) + ctrl->vrs[PC] = ctrl->vrs[LR]; /* no further processing */ ctrl->entries = 0; } else if (insn == 0xb1) { @@ -309,18 +310,20 @@ int unwind_frame(struct stackframe *frame) } while (ctrl.entries > 0) { - int urc; - - if (ctrl.vrs[SP] < low || ctrl.vrs[SP] >= high) - return -URC_FAILURE; - urc = unwind_exec_insn(&ctrl); + int urc = unwind_exec_insn(&ctrl); if (urc < 0) return urc; + if (ctrl.vrs[SP] < low || ctrl.vrs[SP] >= high) + return -URC_FAILURE; } if (ctrl.vrs[PC] == 0) ctrl.vrs[PC] = ctrl.vrs[LR]; + /* check for infinite loop */ + if (frame->pc == ctrl.vrs[PC]) + return -URC_FAILURE; + frame->fp = ctrl.vrs[FP]; frame->sp = ctrl.vrs[SP]; frame->lr = ctrl.vrs[LR]; @@ -332,7 +335,6 @@ int unwind_frame(struct stackframe *frame) void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk) { struct stackframe frame; - unsigned long high, low; register unsigned long current_sp asm ("sp"); pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); @@ -362,9 +364,6 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk) frame.pc = thread_saved_pc(tsk); } - low = frame.sp & ~(THREAD_SIZE - 1); - high = low + THREAD_SIZE; - while (1) { int urc; unsigned long where = frame.pc; |