Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753767AbaDYRsB (ORCPT ); Fri, 25 Apr 2014 13:48:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2459 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753092AbaDYRry (ORCPT ); Fri, 25 Apr 2014 13:47:54 -0400 Date: Fri, 25 Apr 2014 19:47:31 +0200 From: Oleg Nesterov To: Ingo Molnar Cc: Ananth N Mavinakayanahalli , Anton Arapov , David Long , Denys Vlasenko , "Frank Ch. Eigler" , Jim Keniston , Jonathan Lebon , Masami Hiramatsu , Srikar Dronamraju , linux-kernel@vger.kernel.org Subject: [PATCH 4/4] uprobes/x86: Cleanup the usage of UPROBE_FIX_IP/UPROBE_FIX_CALL Message-ID: <20140425174731.GA7979@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140425174704.GA7898@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that UPROBE_FIX_IP/UPROBE_FIX_CALL are mutually exclusive we can use a single "fix_ip_or_call" enum instead of 2 fix_* booleans. This way the logic looks more understandable and clean to me. While at it, join "case 0xea" with other "ip is correct" ret/lret cases. Also change default_post_xol_op() to use "else if" for the same reason. Signed-off-by: Oleg Nesterov --- arch/x86/kernel/uprobes.c | 27 +++++++++++---------------- 1 files changed, 11 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 4c60b7a..4ae2406 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -424,10 +424,9 @@ static int default_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs long correction = (long)(utask->vaddr - utask->xol_vaddr); handle_riprel_post_xol(auprobe, regs, &correction); - if (auprobe->def.fixups & UPROBE_FIX_IP) + if (auprobe->def.fixups & UPROBE_FIX_IP) { regs->ip += correction; - - if (auprobe->def.fixups & UPROBE_FIX_CALL) { + } else if (auprobe->def.fixups & UPROBE_FIX_CALL) { regs->sp += sizeof_long(); if (push_ret_address(regs, utask->vaddr + auprobe->def.ilen)) return -ERESTART; @@ -612,7 +611,7 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn) int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long addr) { struct insn insn; - bool fix_ip = true, fix_call = false; + u8 fix_ip_or_call = UPROBE_FIX_IP; int ret; ret = uprobe_init_insn(auprobe, &insn, is_64bit_mm(mm)); @@ -636,21 +635,20 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, case 0xcb: case 0xc2: case 0xca: - fix_ip = false; + case 0xea: /* jmp absolute -- ip is correct */ + fix_ip_or_call = 0; break; case 0x9a: /* call absolute - Fix return addr, not ip */ - fix_call = true; - fix_ip = false; - break; - case 0xea: /* jmp absolute -- ip is correct */ - fix_ip = false; + fix_ip_or_call = UPROBE_FIX_CALL; break; case 0xff: switch (MODRM_REG(&insn)) { case 2: case 3: /* call or lcall, indirect */ - fix_call = true; + fix_ip_or_call = UPROBE_FIX_CALL; + break; case 4: case 5: /* jmp or ljmp, indirect */ - fix_ip = false; + fix_ip_or_call = 0; + break; } /* fall through */ default: @@ -658,10 +656,7 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, } auprobe->def.ilen = insn.length; - if (fix_ip) - auprobe->def.fixups |= UPROBE_FIX_IP; - if (fix_call) - auprobe->def.fixups |= UPROBE_FIX_CALL; + auprobe->def.fixups |= fix_ip_or_call; auprobe->ops = &default_xol_ops; return 0; -- 1.5.5.1 -- 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/