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Date: Fri, 05 Jan 2024 15:38:05 +0100
From: "Arnd Bergmann" <arnd@arndb.de>
To: "Mark Rutland" <mark.rutland@arm.com>,
 "Leonardo Bras" <leobras@redhat.com>
Cc: "Oleg Nesterov" <oleg@redhat.com>,
 "Catalin Marinas" <catalin.marinas@arm.com>, "Will Deacon" <will@kernel.org>,
 "Mark Brown" <broonie@kernel.org>, "Steven Rostedt" <rostedt@goodmis.org>,
 "Guo Hui" <guohui@uniontech.com>, linux-arm-kernel@lists.infradead.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH v1 1/1] arm64: remove unnecessary ifdefs around is_compat_task()
Content-Type: text/plain

On Fri, Jan 5, 2024, at 14:14, Mark Rutland wrote:
> On Fri, Jan 05, 2024 at 01:15:00AM -0300, Leonardo Bras wrote:
> arch/arm64/kernel/ptrace.c:2121:25: note: each undeclared identifier is 
> reported only once for each function it appears in
> arch/arm64/kernel/ptrace.c:2123:25: error: 'user_aarch32_ptrace_view' 
> undeclared (first use in this function)
>  2123 |                 return &user_aarch32_ptrace_view;
>       |                         ^~~~~~~~~~~~~~~~~~~~~~~~
> make[4]: *** [scripts/Makefile.build:243: arch/arm64/kernel/ptrace.o] 
> Error 1
> make[3]: *** [scripts/Makefile.build:480: arch/arm64/kernel] Error 2
> make[2]: *** [scripts/Makefile.build:480: arch/arm64] Error 2
> make[1]: *** [/home/mark/src/linux/Makefile:1911: .] Error 2
> make: *** [Makefile:234: __sub-make] Error 2
>
> ... and looking at the code, user_aarch32_view and user_aarch32_ptrace_view are
> both defined under ifdeffery for CONFIG_COMPAT, so that's obviously not going
> to work...

I suspect it's enough to remove all of the other
"#ifdef CONFIG_COMPAT" checks in this file and rely on
dead code elimination to remove the rest, but there might
be additional problems if some extern declarations are
hidden in an #ifdef as well.

    Arnd