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From:   Andreas Schwab <schwab@suse.de>
To:     Alistair Francis <alistair23@gmail.com>
Cc:     Alistair Francis <alistair.francis@wdc.com>,
        linux-riscv@lists.infradead.org, Arnd Bergmann <arnd@arndb.de>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH RESEND 0/2] RISC-V: Handle the siginfo_t offset problem
References: <20190703005202.7578-1-alistair.francis@wdc.com>
        <mvmk1czh9y6.fsf@suse.de>
        <CAKmqyKPn9GBg=n1j-ZpEdCN4Qfi5qfNtEVgpgF8rYRpof4eNDA@mail.gmail.com>
Date:   Thu, 04 Jul 2019 09:20:26 +0200
In-Reply-To: <CAKmqyKPn9GBg=n1j-ZpEdCN4Qfi5qfNtEVgpgF8rYRpof4eNDA@mail.gmail.com>
        (Alistair Francis's message of "Wed, 3 Jul 2019 11:40:39 -0700")
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On Jul 03 2019, Alistair Francis <alistair23@gmail.com> wrote:

> On Wed, Jul 3, 2019 at 12:08 AM Andreas Schwab <schwab@suse.de> wrote:
>>
>> On Jul 02 2019, Alistair Francis <alistair.francis@wdc.com> wrote:
>>
>> > In the RISC-V 32-bit glibc port [1] the siginfo_t struct in the kernel
>> > doesn't line up with the struct in glibc. In glibc world the _sifields
>> > union is 8 byte alligned (although I can't figure out why)
>>
>> Try ptype/o in gdb.
>
> That's a useful tip, I'll be sure to use that next time.

It was a serious note.  If the structs don't line up then there is a
mismatch in types that cannot be solved by adding spurious padding.  You
need to fix the types instead.

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."