[sheepdog] [PATCH 1/4] trace: fix negative index for ret stack array

[Liu Yuan]

On 09/01/2012 11:26 PM, Liu Yuan wrote:
> In some unusual corner cases, pop_return_trace() will be called first, to
> avoid negative index, we start at the middle of array. On the buffer reader
> side, we can minus TRACE_RET_STACK_LEN / 2 to identify those negative index
> which are actually uselss because we don't store their entry time.

This patch should be held. By static code review, this should not happen, but I did meet
an negative index case, might be caused by other problems. Let's hold it to see
if we can reproduce the problem and fix the root cause.

Thanks,
Yuan