g********0
发帖数: 6201 | 1 【 以下文字转载自 Military 讨论区 】
发信人: gc01 (gc01), 信区: Military
标 题: 王五波音喜讯：三哥写的787 code potentially catastrophic failure
发信站: BBS 未名空间站 (Fri Apr 3 13:14:48 2020, 美东)
Boeing 787s must be turned off and on every 51 days to prevent 'misleading
data' being shown to pilots
US air safety bods call it 'potentially catastrophic' if reboot directive
not implemented
By Gareth Corfield 2 Apr 2020 at 14:45
http://www.theregister.co.uk/2020/04/02/boeing_787_power_cycle_51_days_stale_data/
The US Federal Aviation Administration has ordered Boeing 787 operators to
switch their aircraft off and on every 51 days to prevent what it called "
several potentially catastrophic failure scenarios" – including the
crashing of onboard network switches.
The airworthiness directive, due to be enforced from later this month,
orders airlines to power-cycle their B787s before the aircraft reaches the
specified days of continuous power-on operation. | d*******p
发帖数: 2525 | 2 why 51 days specific? is a cache used somewhere that will overflow after
exact 51 days? | C*******d
发帖数: 1553 | 3 没准哪里有个hard coded的51天为限的timer | a**********t
发帖数: 631 | 4 整数溢出是49天，51天应该是buffer overflow or memory leak，worst case
scenario.
onboard network switch挂掉还真不见的能怪得到三哥。Marvell/Broadcom maybe. | i******0
发帖数: 609 | 5 算了一下，51天大概有2^32毫秒。感觉是个整数越界的bug。
：why 51 days specific? is a cache used somewhere that will overflow after
：exact 51 days? | d*******p
发帖数: 2525 | 6 no, not 2^32, tha'ts 4294967296, 51 days has 4406400000 ms, so recommending
recycle at 51 days will not work if that's the case, must be memory leak
then
to think about it though, memory leak doesn't make sense to recommend 51
days specifically, that's too precise, memory leak will not be that precise
every time
something else ? |
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