Date:   Fri, 10 Mar 2023 10:29:31 -0800
From:   Luis Chamberlain <mcgrof@kernel.org>
To:     Arnd Bergmann <arnd@kernel.org>
Cc:     Vincenzo Palazzo <vincenzopalazzodev@gmail.com>,
        Jason Baron <jbaron@akamai.com>, Arnd Bergmann <arnd@arndb.de>,
        Russell King <linux@armlinux.org.uk>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ARM: dyndbg: allow including dyndbg.h in decompressor
Message-ID: <ZAt3CxXavMl4vECg@bombadil.infradead.org>
References: <20230310140133.291594-1-arnd@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230310140133.291594-1-arnd@kernel.org>
Sender: Luis Chamberlain <mcgrof@infradead.org>
Precedence: bulk

On Fri, Mar 10, 2023 at 03:01:26PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> After a change to linux/module.h, dyndbg.h is now included
> indirectly from the decompressor for lz4 support, which in turn
> causes a build failure on 32-bit Arm:
> 
> In file included from include/linux/module.h:30,
>                  from arch/arm/boot/compressed/../../../../lib/lz4/lz4_decompress.c:39,
>                  from arch/arm/boot/compressed/../../../../lib/decompress_unlz4.c:10,
>                  from arch/arm/boot/compressed/decompress.c:59:
> include/linux/dynamic_debug.h: In function 'ddebug_dyndbg_module_param_cb':
> include/linux/dynamic_debug.h:307:14: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
>   307 |         if (!strcmp(param, "dyndbg")) {
>       |              ^~~~~~
> include/linux/dynamic_debug.h:1:1: note: 'strcmp' is defined in header '<string.h>'; did you forget to '#include <string.h>'?
>   +++ |+#include <string.h>
> 
> The decompressor has its own replacement for the linux/string.h contents,
> so the normal declaration is not visible here. Since the function is
> not actually called, it is sufficient to add a declaration, and this
> is in fact the correct one as it matches the definition in
> arch/arm/boot/compressed/string.c.
> 
> Fixes: 7deabd674988 ("dyndbg: use the module notifier callbacks")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> The patch that caused the problem is in linux-next, maybe fold
> the fix into that patch if possible
> ---

Thanks for figuring this out, Arnd! Pushed to modules-next!

  Luis