From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicholas Piggin Date: Mon, 18 Oct 2021 06:29:57 +0000 Subject: Re: [PATCH v3 07/12] asm-generic: Define 'func_desc_t' to commonly describe function descriptors Message-Id: <1634538449.eah9b31bbz.astroid@bobo.none> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton , Arnd Bergmann , Benjamin Herrenschmidt , Christophe Leroy , Helge Deller , Greg Kroah-Hartman , "James E.J. Bottomley" , Kees Cook , Michael Ellerman , Paul Mackerras Cc: linux-arch@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Excerpts from Christophe Leroy's message of October 17, 2021 10:38 pm: > We have three architectures using function descriptors, each with its > own type and name. > > Add a common typedef that can be used in generic code. > > Also add a stub typedef for architecture without function descriptors, > to avoid a forest of #ifdefs. > > It replaces the similar 'func_desc_t' previously defined in > arch/powerpc/kernel/module_64.c > > Reviewed-by: Kees Cook > Acked-by: Arnd Bergmann > Signed-off-by: Christophe Leroy > --- [...] > diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h > index a918388d9bf6..33b51efe3a24 100644 > --- a/include/asm-generic/sections.h > +++ b/include/asm-generic/sections.h > @@ -63,6 +63,9 @@ extern __visible const void __nosave_begin, __nosave_end; > #else > #define dereference_function_descriptor(p) ((void *)(p)) > #define dereference_kernel_function_descriptor(p) ((void *)(p)) > +typedef struct { > + unsigned long addr; > +} func_desc_t; > #endif > I think that deserves a comment. If it's just to allow ifdef to be avoided, I guess that's okay with a comment. Would be nice if you could cause it to generate a link time error if it was ever used like undefined functions, but I guess you can't. It's not a necessity though. Thanks, Nick