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Date:   Thu, 06 Apr 2023 15:21:26 +0200
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     "Petr Vorel" <pvorel@suse.cz>
Cc:     "Naresh Kamboju" <naresh.kamboju@linaro.org>,
        "open list" <linux-kernel@vger.kernel.org>,
        "LTP List" <ltp@lists.linux.it>, llvm@lists.linux.dev,
        chrubis <chrubis@suse.cz>,
        "Nathan Chancellor" <nathan@kernel.org>,
        "Anders Roxell" <anders.roxell@linaro.org>,
        =?UTF-8?Q?Daniel_D=C3=ADaz?= <daniel.diaz@linaro.org>,
        "Benjamin Copeland" <ben.copeland@linaro.org>,
        "Tudor Cretu" <tudor.cretu@arm.com>
Subject: Re: LTP: list of failures on 32bit and compat mode
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On Thu, Apr 6, 2023, at 15:17, Petr Vorel wrote:
>> On Thu, Apr 6, 2023, at 14:48, Petr Vorel wrote:
>> >> On Thu, Apr 6, 2023, at 12:56, Petr Vorel wrote:

> Thanks! I've just searched in musl as well, because it didn't make sense to me
> it'd be a code for LTP.
>
> "to catch the fault on ltp" I wonder if it's not actually musl bug.

No, musl is fine here. The problem is that ltp passes an invalid pointer,
expecting to get -EFAULT from the kernel when that faults in
copy_to_user().

There is nothing wrong with musl sanitizing the data behind that
pointer, but then you get a signal instead of the EFAULT error.

     Arnd