From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755257AbYKWR26 (ORCPT ); Sun, 23 Nov 2008 12:28:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751049AbYKWR2u (ORCPT ); Sun, 23 Nov 2008 12:28:50 -0500 Received: from qb-out-0506.google.com ([72.14.204.236]:15864 "EHLO qb-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750885AbYKWR2u (ORCPT ); Sun, 23 Nov 2008 12:28:50 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=resent-from:resent-date:resent-message-id:resent-to:date:from:to:cc :subject:message-id:mime-version:content-type:content-disposition :user-agent; b=cJJtROHc43CfQWLwsWRbVe34g0hKXIJLEXNCUOJhBrvKfpE5aYQXPTScUm4pUT1bT2 fyt7zvy4YMamFvM2FNd+JHhpxaP302j2/bCvqV69aSpSVv3OaDN63+IXQdkPIAUWD2b9 kd5/WXWYQYLNFVwnsiZEk6tzkhxoZ5+ilBu44= Date: Sun, 23 Nov 2008 20:21:39 +0300 From: Cyrill Gorcunov To: Ingo Molnar Cc: Alexander van Heukelum , "H. Peter Anvin" , Thomas Gleixner Subject: [RFC -tip] x86: introduce ENTRY(KPROBE_ENTRY)_X86 assembly helpers to catch unbalanced declaration v3 Message-ID: <20081123172139.GC12710@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Impact: improvements It's usefull to catch unbalanced or messed or mixed declarations of ENTRY and KPROBES. These macros would help a bit. For example the following code would compile without problems ENTRY_X86(mcount) retq END_X86(mcount) But if you forget and mess the following form ENTRY_X86(mcount) retq END(mcount) ENTRY_X86(ftrace_caller) The assembler will issue the following message: Error: ENTRY_X86/KPROBE_X86 unbalanced,missed,mixed Actually the checking is performed at every _X86 macro so maybe it's good idea to put ENTRY_KPROBE_FINAL_X86 at the end of .S file to be sure you didn't miss anything. Signed-off-by: Cyrill Gorcunov --- arch/x86/include/asm/linkage.h | 60 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) Index: linux-2.6.git/arch/x86/include/asm/linkage.h =================================================================== --- linux-2.6.git.orig/arch/x86/include/asm/linkage.h +++ linux-2.6.git/arch/x86/include/asm/linkage.h @@ -57,5 +57,65 @@ #define __ALIGN_STR ".align 16,0x90" #endif +/* + * to check ENTRY_X86/END_X86 and + * KPROBE_ENTRY_X86/KPROBE_END_X86 + * unbalanced-missed-mixed appearance + */ +#define __set_entry_x86 .set ENTRY_X86_IN, 0 +#define __unset_entry_x86 .set ENTRY_X86_IN, 1 +#define __set_kprobe_x86 .set KPROBE_X86_IN, 0 +#define __unset_kprobe_x86 .set KPROBE_X86_IN, 1 + +#define __macro_err_x86 .error "ENTRY_X86/KPROBE_X86 unbalanced,missed,mixed" + +#define __check_entry_x86 \ + .ifdef ENTRY_X86_IN; \ + .ifeq ENTRY_X86_IN; \ + __macro_err_x86; \ + .abort; \ + .endif; \ + .endif + +#define __check_kprobe_x86 \ + .ifdef KPROBE_X86_IN; \ + .ifeq KPROBE_X86_IN; \ + __macro_err_x86; \ + .abort; \ + .endif; \ + .endif + +#define __check_entry_kprobe_x86 \ + __check_entry_x86; \ + __check_kprobe_x86 + +#define ENTRY_KPROBE_FINAL_X86 __check_entry_kprobe_x86 + +#define ENTRY_X86(name) \ + __check_entry_kprobe_x86; \ + __set_entry_x86; \ + .globl name; \ + __ALIGN; \ + name: + +#define END_X86(name) \ + __unset_entry_x86; \ + __check_entry_kprobe_x86; \ + .size name, .-name + +#define KPROBE_ENTRY_X86(name) \ + __check_entry_kprobe_x86; \ + __set_kprobe_x86; \ + .pushsection .kprobes.text, "ax"; \ + .globl name; \ + __ALIGN; \ + name: + +#define KPROBE_END_X86(name) \ + __unset_kprobe_x86; \ + __check_entry_kprobe_x86; \ + .size name, .-name; \ + .popsection + #endif /* _ASM_X86_LINKAGE_H */