From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261728AbVCGJvl (ORCPT ); Mon, 7 Mar 2005 04:51:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261730AbVCGJvl (ORCPT ); Mon, 7 Mar 2005 04:51:41 -0500 Received: from ozlabs.org ([203.10.76.45]:32402 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S261728AbVCGJvi (ORCPT ); Mon, 7 Mar 2005 04:51:38 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16940.9284.79566.526069@cargo.ozlabs.ibm.com> Date: Mon, 7 Mar 2005 20:52:04 +1100 From: Paul Mackerras To: akpm@osdl.org, torvalds@osdl.org Cc: anton@samba.org, linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli Subject: [PATCH] ppc64: kprobes: handle trap variants while processing probes X-Mailer: VM 7.19 under Emacs 21.3.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This patch is from Ananth N Mavinakayanahalli . While processing a kprobe, we were currently not handling all available trap variants available on PowerPC. This lead to the breakage of BUG() handling in ppc64. Signed-off-by: Paul Mackerras diff -Naurp temp/linux-2.6.11-rc3/arch/ppc64/kernel/kprobes.c linux-2.6.11-rc3/arch/ppc64/kernel/kprobes.c --- temp/linux-2.6.11-rc3/arch/ppc64/kernel/kprobes.c 2005-02-03 07:26:53.000000000 +0530 +++ linux-2.6.11-rc3/arch/ppc64/kernel/kprobes.c 2005-02-10 18:08:25.000000000 +0530 @@ -105,8 +105,16 @@ static inline int kprobe_handler(struct p = get_kprobe(addr); if (!p) { unlock_kprobes(); -#if 0 if (*addr != BREAKPOINT_INSTRUCTION) { + /* + * PowerPC has multiple variants of the "trap" + * instruction. If the current instruction is a + * trap variant, it could belong to someone else + */ + kprobe_opcode_t cur_insn = *addr; + if (IS_TW(cur_insn) || IS_TD(cur_insn) || + IS_TWI(cur_insn) || IS_TDI(cur_insn)) + goto no_kprobe; /* * The breakpoint instruction was removed right * after we hit it. Another cpu has removed @@ -116,7 +124,6 @@ static inline int kprobe_handler(struct */ ret = 1; } -#endif /* Not one of ours: let kernel handle it */ goto no_kprobe; } diff -Naurp temp/linux-2.6.11-rc3/include/asm-ppc64/kprobes.h linux-2.6.11-rc3/include/asm-ppc64/kprobes.h --- temp/linux-2.6.11-rc3/include/asm-ppc64/kprobes.h 2005-02-03 07:25:50.000000000 +0530 +++ linux-2.6.11-rc3/include/asm-ppc64/kprobes.h 2005-02-10 18:08:58.000000000 +0530 @@ -35,6 +35,11 @@ typedef unsigned int kprobe_opcode_t; #define BREAKPOINT_INSTRUCTION 0x7fe00008 /* trap */ #define MAX_INSN_SIZE 1 +#define IS_TW(instr) (((instr) & 0xfc0007fe) == 0x7c000008) +#define IS_TD(instr) (((instr) & 0xfc0007fe) == 0x7c000088) +#define IS_TDI(instr) (((instr) & 0xfc000000) == 0x08000000) +#define IS_TWI(instr) (((instr) & 0xfc000000) == 0x0c000000) + #define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)((func_descr_t *)pentry) /* Architecture specific copy of original instruction */