Re: xtensa compiler error triggered by 'locking/lockdep: Implement the 'crossrelease' feature'

From: Peter Zijlstra
Date: Sun Sep 10 2017 - 14:40:18 EST

On Sun, Sep 10, 2017 at 11:31:50AM -0700, Guenter Roeck wrote:
> Hi,
> xtensa:allmodconfig fails to build in mainline with compiler errors
> as follows.
> drivers/staging/rtl8723bs/core/rtw_ap.c: In function âexpire_timeout_chkâ:
> drivers/staging/rtl8723bs/core/rtw_ap.c:442:1: internal compiler error:
> in change_address_1, at emit-rtl.c:2126
> drivers/staging/rtl8188eu/core/rtw_ap.c: In function âexpire_timeout_chkâ:
> drivers/staging/rtl8188eu/core/rtw_ap.c:445:1: internal compiler error:
> in change_address_1, at emit-rtl.c:2150
> I tried gcc 6.3, 6.4, and 7.2; they all have the same problem.
> Bisect points to commit b09be676e0f ("locking/lockdep: Implement the
> 'crossrelease' feature").
> The compile error is still seen if I disable CONFIG_LOCKDEP_CROSSRELEASE.
> The image builds fine if I disable both CONFIG_RTL8723BS and CONFIG_R8188EU.

I'm taking it this is specific to the GCC xtensa backend, I've not seen
or heard of any other ICEs wrt this code.

I'd take this up with your compiler team, this is not something we can
do much about.