Re: [PATCH v6 14/19] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it

From: Andreas Schwab
Date: Tue Dec 01 2015 - 06:01:53 EST


Arnd Bergmann <arnd@xxxxxxxx> writes:

> On Tuesday 01 December 2015 10:20:59 Andreas Schwab wrote:
>> Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> 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.

> We should always default to using the generic 32-bit structures
> unless there is a strong reason not to.

The goal should be to avoid conversion layers where it makes sense.

Andreas.

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