Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030617AbWHIJpY (ORCPT ); Wed, 9 Aug 2006 05:45:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030616AbWHIJpY (ORCPT ); Wed, 9 Aug 2006 05:45:24 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:38025 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1030613AbWHIJpX (ORCPT ); Wed, 9 Aug 2006 05:45:23 -0400 Date: Wed, 9 Aug 2006 10:45:16 +0100 From: Christoph Hellwig To: Ananth N Mavinakayanahalli Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, Prasanna S Panchamukhi , Anil S Keshavamurthy , Jim Keniston , linux-arch@vger.kernel.org Subject: Re: [PATCH 2/3] Kprobes: Define retval helper Message-ID: <20060809094516.GA17993@infradead.org> Mail-Followup-To: Christoph Hellwig , Ananth N Mavinakayanahalli , linux-kernel@vger.kernel.org, Prasanna S Panchamukhi , Anil S Keshavamurthy , Jim Keniston , linux-arch@vger.kernel.org References: <20060807115537.GA15253@in.ibm.com> <20060807120024.GD15253@in.ibm.com> <20060808162559.GB28647@infradead.org> <20060809094311.GA20050@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060809094311.GA20050@in.ibm.com> User-Agent: Mutt/1.4.2.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3795 Lines: 91 On Wed, Aug 09, 2006 at 03:13:11PM +0530, Ananth N Mavinakayanahalli wrote: > > Good idea. You should add parentheses around regs, otherwise the C > > preprocessor might bite users. Also the shouting name is quite ugly. > > In fact it should probably go to asm/system.h or similar and not have > > a kprobes name - it just extracts the return value from a struct pt_regs > > after all. > > Done! How does this look? I added it to asm/ptrace.h so it lives along > with the instruction_pointer() definition. Looks good, but it would be much better if we had it for every single architecture. I've cc'ed linux-arch so the arch maintainers can comments. Even if we don't manage to get every architecture maintainer to help out you should at least add sparc and s390 to have full coverage of architectures with kprobes support > Add the "get_retval" macro that just extracts the return value given the > pt_regs. Useful in situations such as while using function-return > probes. > > Signed-off-by: Ananth N Mavinakayanahalli > > --- > include/asm-i386/ptrace.h | 3 +++ > include/asm-ia64/ptrace.h | 3 +++ > include/asm-powerpc/ptrace.h | 2 ++ > include/asm-x86_64/ptrace.h | 2 ++ > 4 files changed, 10 insertions(+) > > Index: linux-2.6.18-rc3/include/asm-i386/ptrace.h > =================================================================== > --- linux-2.6.18-rc3.orig/include/asm-i386/ptrace.h > +++ linux-2.6.18-rc3/include/asm-i386/ptrace.h > @@ -79,7 +79,10 @@ static inline int user_mode_vm(struct pt > { > return ((regs->xcs & 3) | (regs->eflags & VM_MASK)) != 0; > } > + > #define instruction_pointer(regs) ((regs)->eip) > +#define get_retval(regs) ((regs)->eax) > + > #if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER) > extern unsigned long profile_pc(struct pt_regs *regs); > #else > Index: linux-2.6.18-rc3/include/asm-ia64/ptrace.h > =================================================================== > --- linux-2.6.18-rc3.orig/include/asm-ia64/ptrace.h > +++ linux-2.6.18-rc3/include/asm-ia64/ptrace.h > @@ -237,6 +237,9 @@ struct switch_stack { > * the canonical representation by adding to instruction pointer. > */ > # define instruction_pointer(regs) ((regs)->cr_iip + ia64_psr(regs)->ri) > + > +#define get_retval(regs) ((regs)->r8) > + > /* Conserve space in histogram by encoding slot bits in address > * bits 2 and 3 rather than bits 0 and 1. > */ > Index: linux-2.6.18-rc3/include/asm-powerpc/ptrace.h > =================================================================== > --- linux-2.6.18-rc3.orig/include/asm-powerpc/ptrace.h > +++ linux-2.6.18-rc3/include/asm-powerpc/ptrace.h > @@ -73,6 +73,8 @@ struct pt_regs { > #ifndef __ASSEMBLY__ > > #define instruction_pointer(regs) ((regs)->nip) > +#define get_retval(regs) ((regs)->gpr[3]) > + > #ifdef CONFIG_SMP > extern unsigned long profile_pc(struct pt_regs *regs); > #else > Index: linux-2.6.18-rc3/include/asm-x86_64/ptrace.h > =================================================================== > --- linux-2.6.18-rc3.orig/include/asm-x86_64/ptrace.h > +++ linux-2.6.18-rc3/include/asm-x86_64/ptrace.h > @@ -84,6 +84,8 @@ struct pt_regs { > #define user_mode(regs) (!!((regs)->cs & 3)) > #define user_mode_vm(regs) user_mode(regs) > #define instruction_pointer(regs) ((regs)->rip) > +#define get_retval(regs) ((regs)->rax) > + > extern unsigned long profile_pc(struct pt_regs *regs); > void signal_fault(struct pt_regs *regs, void __user *frame, char *where); > ---end quoted text--- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/