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Date: Thu, 28 Dec 2023 00:26:14 +0000
From: Al Viro <viro@zeniv.linux.org.uk>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Tanzir Hasan <tanzirh@google.com>, Andy Lutomirski <luto@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
	linux-kernel@vger.kernel.org, Nick Desaulniers <nnn@google.com>
Subject: Re: [PATCH] x86/syscalls: shrink entry/syscall_32.i via IWYU
Message-ID: <20231228002614.GI1674809@ZenIV>
References: <20231227-syscall32-v1-1-9621140d33bd@google.com>
 <20231227233444.GH1674809@ZenIV>
 <8B198413-0C9B-40A2-8478-F22206AAE6FA@zytor.com>
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Sender: Al Viro <viro@ftp.linux.org.uk>

On Wed, Dec 27, 2023 at 03:50:33PM -0800, H. Peter Anvin wrote:
> > /*
> >  * Only the low 32 bits of orig_ax are meaningful, so we return int.
> >  * This importantly ignores the high bits on 64-bit, so comparisons
> 
> __visible is for LTO, no?

If we need it in cases when array defined in entry/syscall_32.c and
used in entry/common.c, I would respectfully suggest that whatever
we need it for is misguided garbage.  I don't think that LTO does
need it, though.  How is arch/x86/entry/{syscall_32,common}.c
different from e.g. fs/{namespace,d_path}.c, where we have
fs/namespace.c:100:__cacheline_aligned_in_smp DEFINE_SEQLOCK(mount_lock);
and
fs/d_path.c:166:        read_seqbegin_or_lock(&mount_lock, &m_seq);
respectively?