[FS#814] When LEDE is compiled with GCC 7 on at least ar71xx and brcm47xx, Dropbear won't accept connections

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Michael Marley (mamarley) 

Attached to Project - LEDE Project
Summary - When LEDE is compiled with GCC 7 on at least ar71xx and brcm47xx, Dropbear won't accept connections
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - When using the GCC 7.x compiler, I have found that Dropbear in LEDE images for ar71xx (Ubiquiti Unifi) and brcm47xx (generic) (built with the default configuration, other than changing the compiler to GCC 7.x) won't accept incoming SSH connections.  Instead, as soon as a connection is received, it spins the CPU indefinitely and the connecting SSH client hangs.  Nothing relevant is printed in the logs.  This behavior does not occur on x86_64; there Dropbear works fine.

I realize I haven't provided much information here, but I don't really know how to collect anything else on embedded platforms like this.  One of the devices on which I have reproduced this does have a serial adapter though, so I can use that to get any additional information that might be helpful.

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=814