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Message-ID: <f5c221f5749e5768c9f0d909175a14910d349456.camel@suse.de>
Subject: Re: [PATCH] compiler: enable CONFIG_OPTIMIZE_INLINING forcibly
From:   Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To:     Masahiro Yamada <yamada.masahiro@socionext.com>,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        linux-arch <linux-arch@vger.kernel.org>,
        linux-kernel@vger.kernel.org,
        Catalin Marinas <catalin.marinas@arm.com>,
        rmk+kernel@arm.linux.org.uk, Will Deacon <will@kernel.org>,
        Stefan Wahren <wahrenst@gmx.net>
Date:   Fri, 27 Sep 2019 12:43:33 +0200
In-Reply-To: <20190830034304.24259-1-yamada.masahiro@socionext.com>
References: <20190830034304.24259-1-yamada.masahiro@socionext.com>
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On Fri, 2019-08-30 at 12:43 +0900, Masahiro Yamada wrote:
> Commit 9012d011660e ("compiler: allow all arches to enable
> CONFIG_OPTIMIZE_INLINING") allowed all architectures to enable
> this option. A couple of build errors were reported by randconfig,
> but all of them have been ironed out.
>=20
> Towards the goal of removing CONFIG_OPTIMIZE_INLINING entirely
> (and it will simplify the 'inline' macro in compiler_types.h),
> this commit changes it to always-on option. Going forward, the
> compiler will always be allowed to not inline functions marked
> 'inline'.
>=20
> This is not a problem for x86 since it has been long used by
> arch/x86/configs/{x86_64,i386}_defconfig.
>=20
> I am keeping the config option just in case any problem crops up for
> other architectures.
>=20
> The code clean-up will be done after confirming this is solid.
>=20
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

[ Adding some ARM people as they might be able to help ]

This was found to cause a regression on a Raspberry Pi 2 B built with
bcm2835_defconfig which among other things has no SMP support.

The relevant logs (edited to remove the noise) are:

[    5.827333] Run /init as init process
Loading, please wait...
Failed to set SO_PASSCRED: Bad address
Failed to bind netlink socket: Bad address
Failed to create manager: Bad address
Failed to set SO_PASSCRED: Bad address
[    9.021623] systemd[1]: SO_PASSCRED failed: Bad address
[!!!!!!] Failed to start up manager.
[    9.079148] systemd[1]: Freezing execution.

I looked into it, it turns out that the call to get_user() in sock_setsocko=
pt()
is returning -EFAULT. Down the assembly rabbit hole that get_user() is I
found-out that it's the macro 'check_uaccess' who's triggering the error.

I'm clueless at this point, so I hope you can give me some hints on what's
going bad here.

Regards,
Nicolas


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