From: Arnd Bergmann <arnd@arndb.de>
To: Andreas Schwab <schwab@suse.de>
Cc: Yury Norov <ynorov@caviumnetworks.com>,
        linux-arm-kernel@lists.infradead.org, pinskia@gmail.com,
        Prasun.Kapoor@caviumnetworks.com, catalin.marinas@arm.com,
        Nathan_Lynch@mentor.com, linux-kernel@vger.kernel.org, agraf@suse.de,
        klimov.linux@gmail.com, broonie@kernel.org, jan.dakinevich@gmail.com,
        joseph@codesourcery.com, ddaney.cavm@gmail.com,
        bamvor.zhangjian@huawei.com, philipp.tomsich@theobroma-systems.com,
        andrey.konovalov@linaro.org, christoph.muellner@theobroma-systems.com
Subject: Re: [PATCH v6 14/19] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it
Date: Tue, 01 Dec 2015 12:30:56 +0100
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On Tuesday 01 December 2015 12:01:12 Andreas Schwab wrote:
> Arnd Bergmann <arnd@arndb.de> writes:
> 
> > On Tuesday 01 December 2015 10:20:59 Andreas Schwab wrote:
> >> Yury Norov <ynorov@caviumnetworks.com> writes:
> >> 
> >> > There's a tricky bug with signal stack, that Andreas also discovered.
> >> 
> >> That was only a confusion about the compat state of sys_rt_sigaction.
> >> It just requires making sure glibc uses the correct (64bit layout)
> >> struct kernel_sigaction.
> >
> > I don't think we need to use the 64-bit version of sigaction, both
> > kernel and libc are simpler if we use the normal 32-bit version.
> 
> Since glibc has to do the conversion anyway (due to sigset_t), using the
> 64bit layout avoids a second conversion in the kernel.

I don't get the part about sigset_t. Why would glibc want to use the
64-bit layout? This one looks like one of the cases where we absolutely
want to use the 32-bit layout or otherwise get into big trouble if
we ever want to support native ILP32 kernels.

	Arnd
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