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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Mon, 10 Oct 2022 09:42:31 -0700
Message-ID: <CAKwvOdm1yMbUUHGeqnKYBptBEqSO0T4k=sUy5i0Bhy3g41+nDg@mail.gmail.com>
Subject: Re: [PATCH] fs/select: mark do_select noinline_for_stack for 32b
To:     Christoph Hellwig <hch@lst.de>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Nathan Chancellor <nathan@kernel.org>,
        Tom Rix <trix@redhat.com>, Xiaoming Ni <nixiaoming@huawei.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Andi Kleen <ak@linux.intel.com>, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        Eric Dumazet <edumazet@google.com>,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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On Mon, Oct 10, 2022 at 12:44 AM Christoph Hellwig <hch@lst.de> wrote:
>
> On Fri, Oct 07, 2022 at 01:11:40PM -0700, Nick Desaulniers wrote:
> > Effectively a revert of
> > commit ad312f95d41c ("fs/select: avoid clang stack usage warning")
> >
> > Various configs can still push the stack useage of core_sys_select()
> > over the CONFIG_FRAME_WARN threshold (1024B on 32b targets).
> >
> >   fs/select.c:619:5: error: stack frame size of 1048 bytes in function
> >   'core_sys_select' [-Werror,-Wframe-larger-than=]
>
> Btw, I also see a warning here with all my KASAN x86_64 gcc builds.

Thanks for the report.  That might be another interesting data point;
I haven't been able to reproduce that locally though:

$ make -j$(nproc) defconfig
$ ./scripts/config -e KASAN
$ make -j$(nproc) olddefconfig fs/select.o
$ gcc --version | head -n1
gcc (Debian 12.2.0-1) 12.2.0

I also tried enabling CONFIG_KASAN_INLINE=y but couldn't reproduce.
Mind sending me your .config that reproduces this?
-- 
Thanks,
~Nick Desaulniers