From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH] treewide: remove current_text_addr Date: Sat, 25 Aug 2018 21:56:11 -0700 Message-ID: <7f49eeab-a5cc-867f-58fb-abd266f9c2c9@zytor.com> References: <20180821202900.208417-1-ndesaulniers@google.com> <207784db-4fcc-85e7-a0b2-fec26b7dab81@gmx.de> <81141365-8168-799b-f34f-da5f92efaaf9@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <81141365-8168-799b-f34f-da5f92efaaf9@zytor.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+gla-linux-snps-arc=m.gmane.org@lists.infradead.org To: Helge Deller , Nick Desaulniers , torvalds@linux-foundation.org, akpm@linux-foundation.org Cc: Nicolas Pitre , linux-mips@linux-mips.org, linux-sh@vger.kernel.org, Benjamin Herrenschmidt , Will Deacon , Paul Mackerras , Michael Ellerman , "James E.J. Bottomley" , Geert Uytterhoeven , Catalin Marinas , Vasily Gorbik , Matt Turner , uclinux-h8-devel@lists.sourceforge.jp, Marc Zyngier , Ram Pai , linux-um@lists.infradead.org, Nicholas Piggin , Andy Lutomirski , Shannon Nelson , tglx@linutronix.de, =?UTF-8?Q?Alex_Benn=c3=a9e?= , Richard Henderson , Jiri Kosina , linux-kernel@vger.kerne List-Id: linux-m68k@vger.kernel.org On 08/25/18 20:16, H. Peter Anvin wrote: > On 08/25/18 19:38, H. Peter Anvin wrote: >> >> If it was worthwhile it would make more sense to at least force this >> into the rodata section with the string, something like the attached >> file for an example; however, I have a hunch it doesn't matter. >> > > An even nuttier version which avoids the extra pointer indirection. > Read it and fear. > > -hpa > OK, so one more thing, I guess: it is necessary to suppress the tailcall optimization for _RET_IP_ to make any sense, but that should be pretty simple: static inline void notailcall(void) { asm volatile(""); } -hpa