Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750796AbWHGLyQ (ORCPT ); Mon, 7 Aug 2006 07:54:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750817AbWHGLyQ (ORCPT ); Mon, 7 Aug 2006 07:54:16 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:31902 "EHLO e3.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1750796AbWHGLyP (ORCPT ); Mon, 7 Aug 2006 07:54:15 -0400 Date: Mon, 7 Aug 2006 17:25:37 +0530 From: Ananth N Mavinakayanahalli To: linux-kernel@vger.kernel.org Subject: [PATCH 1/3] Kprobes: Make kprobe modules more portable Message-ID: <20060807115537.GA15253@in.ibm.com> Reply-To: ananth@in.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3280 Lines: 87 From: Ananth N Mavinakayanahalli This patch introduces KPROBE_ADDR, a macro that abstracts out the architecture-specific artefacts of getting the correct text address given a symbol. While we are at it, also introduce the symbol_name field in struct kprobe to allow for users to just specify the address to be probed in terms of the kernel symbol. In-kernel kprobes infrastructure decodes the actual text address to probe. The symbol resolution happens only if the kprobe.addr isn't explicitly specified. --- Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Prasanna S.P --- include/asm-powerpc/kprobes.h | 2 ++ include/linux/kprobes.h | 8 ++++++++ kernel/kprobes.c | 4 ++++ 3 files changed, 14 insertions(+) Index: linux-2.6.18-rc3/include/asm-powerpc/kprobes.h =================================================================== --- linux-2.6.18-rc3.orig/include/asm-powerpc/kprobes.h +++ linux-2.6.18-rc3/include/asm-powerpc/kprobes.h @@ -44,6 +44,8 @@ typedef unsigned int kprobe_opcode_t; #define IS_TDI(instr) (((instr) & 0xfc000000) == 0x08000000) #define IS_TWI(instr) (((instr) & 0xfc000000) == 0x0c000000) +#define KPROBE_ADDR(name) *((kprobe_opcode_t **)(kallsyms_lookup_name(name))) + #define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)((func_descr_t *)pentry) #define is_trap(instr) (IS_TW(instr) || IS_TD(instr) || \ Index: linux-2.6.18-rc3/include/linux/kprobes.h =================================================================== --- linux-2.6.18-rc3.orig/include/linux/kprobes.h +++ linux-2.6.18-rc3/include/linux/kprobes.h @@ -36,6 +36,7 @@ #include #include #include +#include #ifdef CONFIG_KPROBES #include @@ -49,6 +50,10 @@ /* Attach to insert probes on any functions which should be ignored*/ #define __kprobes __attribute__((__section__(".kprobes.text"))) +#ifndef KPROBE_ADDR /* powerpc has its own definition */ +#define KPROBE_ADDR(name) (kprobe_opcode_t *)(kallsyms_lookup_name(name)) +#endif /* KPROBE_ADDR */ + struct kprobe; struct pt_regs; struct kretprobe; @@ -77,6 +82,9 @@ struct kprobe { /* location of the probe point */ kprobe_opcode_t *addr; + /* Allow user to indicate symbol name of the probe point */ + char *symbol_name; + /* Called before addr is executed. */ kprobe_pre_handler_t pre_handler; Index: linux-2.6.18-rc3/kernel/kprobes.c =================================================================== --- linux-2.6.18-rc3.orig/kernel/kprobes.c +++ linux-2.6.18-rc3/kernel/kprobes.c @@ -446,6 +446,10 @@ static int __kprobes __register_kprobe(s struct kprobe *old_p; struct module *probed_mod; + /* Do the kallsyms lookup only if p->addr == NULL */ + if (!p->addr && (p->symbol_name)) + p->addr = KPROBE_ADDR(p->symbol_name); + if ((!kernel_text_address((unsigned long) p->addr)) || in_kprobes_functions((unsigned long) p->addr)) return -EINVAL; - 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/