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Date:   Sat, 25 Apr 2020 21:47:24 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Jeremy Kerr <jk@ozlabs.org>, Arnd Bergmann <arnd@arndb.de>,
        "Eric W . Biederman" <ebiederm@xmission.com>,
        linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/7] signal: factor copy_siginfo_to_external32 from
 copy_siginfo_to_user32
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        <20200421154204.252921-3-hch@lst.de>
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On Tue, 21 Apr 2020 17:41:59 +0200 Christoph Hellwig <hch@lst.de> wrote:

> To remove the use of set_fs in the coredump code there needs to be a
> way to convert a kernel siginfo to a userspace compat siginfo.
> 
> Call that function copy_siginfo_to_compat and factor it out of
> copy_siginfo_to_user32.
> 
> The existence of x32 complicates this code.  On x32 SIGCHLD uses 64bit
> times for utime and stime.  As only SIGCHLD is affected and SIGCHLD
> never causes a coredump I have avoided handling that case.

x86_64 allmodconfig:

kernel/signal.c: In function 'copy_siginfo_to_external32':
kernel/signal.c:3299:7: error: 'x32_ABI' undeclared (first use in this function); did you mean 'CTL_ABI'?
   if (x32_ABI) {
       ^~~~~~~

I looked at fixing it but surely this sort of thing:


int copy_siginfo_to_user32(struct compat_siginfo __user *to,
			   const struct kernel_siginfo *from)
#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
{
	return __copy_siginfo_to_user32(to, from, in_x32_syscall());
}
int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
			     const struct kernel_siginfo *from, bool x32_ABI)
#endif
{
	...


is too ugly to live?