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From:   Dan Williams <dan.j.williams@intel.com>
Date:   Wed, 9 Jun 2021 17:13:25 -0700
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Subject: Re: arch/x86/lib/copy_mc.c:30:1: warning: no previous prototype for 'copy_mc_fragile_handle_tail'
To:     "Luck, Tony" <tony.luck@intel.com>
Cc:     lkp <lkp@intel.com>,
        "kbuild-all@lists.01.org" <kbuild-all@lists.01.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Borislav Petkov <bp@suse.de>
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On Wed, Jun 9, 2021 at 4:55 PM Luck, Tony <tony.luck@intel.com> wrote:
>
> > This routine is only ever called from ASM code, so the fact that there
> > is no C declaration is expected.
>
> Does the asm code really need to call back into C?
>
> Could you just have the asm code do "jmp .L_read_trailing_bytes" (might need to only do that if %ecx is non-zero)?

I could... it turns out when Peter did this:

3693ca81151e x86/uaccess: Move copy_user_handle_tail() into asm

...he did not also go fixup my cargo culting. I'll take a look...