From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 266B8CA9EA0 for ; Fri, 18 Oct 2019 07:53:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1BDC222C6 for ; Fri, 18 Oct 2019 07:53:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="FTfMehUS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2504724AbfJRHv2 (ORCPT ); Fri, 18 Oct 2019 03:51:28 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:42880 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391192AbfJRHv2 (ORCPT ); Fri, 18 Oct 2019 03:51:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=4svTgr24B3DFbicDirGPWmJ5CQkIQvaSubBKnXTLtnY=; b=FTfMehUSzUJ0WYGWokzcPFTils j7xgBU3sjOT8s3IpsAeuzdN3eOGPbvrovYJut0cHKWH9uw00J9rRFBEfBKr3O8ZQL+F/AN3AbMsav 7vUpbO2igZzn3qzuCKLaf4KgWK3Bj+62B1L+1rLmiuZzmInpmv5fqCY4Pc6WQBQIE+c+zHDf5cP4l OJ4GZWnzi6QQmvZnxVdr0ux3NyL4EJ2vD41ssJ28hLGNfZWUmcjJ4N6SR7geCPBCqfqXCZyUd5uoK WsiPxaY4xX8aPdOFlsSlKgbMDod8iDKvzFnBjHR0N4EcGvYuULDE+B/j7rBHZhYlJpCF18v2ZDBoC qFMZWjEQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iLN2c-0001NN-5J; Fri, 18 Oct 2019 07:51:18 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 131D8306BB9; Fri, 18 Oct 2019 09:50:20 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 53FC92B178115; Fri, 18 Oct 2019 09:51:15 +0200 (CEST) Message-Id: <20191018074634.514629541@infradead.org> User-Agent: quilt/0.65 Date: Fri, 18 Oct 2019 09:35:35 +0200 From: Peter Zijlstra To: x86@kernel.org Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com, torvalds@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org, namit@vmware.com, hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org, jpoimboe@redhat.com, jeyu@kernel.org Subject: [PATCH v4 10/16] x86/alternative: Shrink text_poke_loc References: <20191018073525.768931536@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Employ the fact that all text must be within a s32 displacement of one another to shrink the text_poke_loc::addr field. Make it relative to _stext. This then shrinks struct text_poke_loc to 16 bytes, and consequently increases TP_VEC_MAX from 170 to 256. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/kernel/alternative.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -937,7 +937,7 @@ static void do_sync_core(void *info) } struct text_poke_loc { - void *addr; + s32 rel_addr; /* addr := _stext + rel_addr */ s32 rel32; u8 opcode; const u8 text[POKE_MAX_OPCODE_SIZE]; @@ -948,13 +948,18 @@ static struct bp_patching_desc { int nr_entries; } bp_patching; +static inline void *text_poke_addr(struct text_poke_loc *tp) +{ + return _stext + tp->rel_addr; +} + static int notrace patch_cmp(const void *key, const void *elt) { struct text_poke_loc *tp = (struct text_poke_loc *) elt; - if (key < tp->addr) + if (key < text_poke_addr(tp)) return -1; - if (key > tp->addr) + if (key > text_poke_addr(tp)) return 1; return 0; } @@ -1000,7 +1005,7 @@ int notrace poke_int3_handler(struct pt_ return 0; } else { tp = bp_patching.vec; - if (tp->addr != ip) + if (text_poke_addr(tp) != ip) return 0; } @@ -1078,7 +1083,7 @@ static void text_poke_bp_batch(struct te * First step: add a int3 trap to the address that will be patched. */ for (i = 0; i < nr_entries; i++) - text_poke(tp[i].addr, &int3, sizeof(int3)); + text_poke(text_poke_addr(&tp[i]), &int3, sizeof(int3)); on_each_cpu(do_sync_core, NULL, 1); @@ -1089,7 +1094,7 @@ static void text_poke_bp_batch(struct te int len = text_opcode_size(tp[i].opcode); if (len - sizeof(int3) > 0) { - text_poke((char *)tp[i].addr + sizeof(int3), + text_poke(text_poke_addr(&tp[i]) + sizeof(int3), (const char *)tp[i].text + sizeof(int3), len - sizeof(int3)); do_sync++; @@ -1113,7 +1118,7 @@ static void text_poke_bp_batch(struct te if (tp[i].text[0] == INT3_INSN_OPCODE) continue; - text_poke(tp[i].addr, tp[i].text, sizeof(int3)); + text_poke(text_poke_addr(&tp[i]), tp[i].text, sizeof(int3)); do_sync++; } @@ -1143,7 +1148,7 @@ void text_poke_loc_init(struct text_poke BUG_ON(!insn_complete(&insn)); BUG_ON(len != insn.length); - tp->addr = addr; + tp->rel_addr = addr - (void *)_stext; tp->opcode = insn.opcode.bytes[0]; switch (tp->opcode) { @@ -1192,7 +1197,7 @@ static bool tp_order_fail(void *addr) return true; tp = &tp_vec[tp_vec_nr - 1]; - if ((unsigned long)tp->addr > (unsigned long)addr) + if ((unsigned long)text_poke_addr(tp) > (unsigned long)addr) return true; return false;