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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS 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 328A8C17445 for ; Mon, 11 Nov 2019 14:48:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 006D1214E0 for ; Mon, 11 Nov 2019 14:48:06 +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="KhK41udG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727513AbfKKOsF (ORCPT ); Mon, 11 Nov 2019 09:48:05 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:48642 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727291AbfKKOrQ (ORCPT ); Mon, 11 Nov 2019 09:47:16 -0500 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=AaATmhSi7E/xpNheLLhgNiTpYtvpLuJ1d3ohRJveXHc=; b=KhK41udGKsxqWmmPYZkkJs2Oe3 dQOHZMU+06RtF9c6JumlMRQl4wSqLC4AgNJxu+FEpABQi3m+7xx3rfP7YFsqL1lANwERmt4MxbTCw 092drgIzqgGLIA5l0S7ZrWEXQvOL8ZFjZK53aLEUWdZA2PiMJX6IilXzVlpiTMCZr07INBOWHA5nO sF2sSrffnjYZ1JZWNpnVQXTBa1rXwmruIJZvruzc19uosjh0GLlycovI/ozJTQrc0FVRWKb8iYuur jXRWEIF/z+vRycKte24AiSE56nKBxT+pdFCLk9E+uGrP0vI4J7wnsENQsLlNgcVv3iGw3V4j2C99Y gxnGv8+g==; 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 1iUAyB-0006a6-KE; Mon, 11 Nov 2019 14:47:07 +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 CFCBD306E42; Mon, 11 Nov 2019 15:45:57 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 8B98629A37A80; Mon, 11 Nov 2019 15:47:03 +0100 (CET) Message-Id: <20191111132457.932808000@infradead.org> User-Agent: quilt/0.65 Date: Mon, 11 Nov 2019 14:13:00 +0100 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, alexei.starovoitov@gmail.com Subject: [PATCH -v5 08/17] x86/ftrace: Use text_gen_insn() References: <20191111131252.921588318@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 Replace the ftrace_code_union with the generic text_gen_insn() helper, which does exactly this. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/text-patching.h | 25 ++++++++++++++++++++++++- arch/x86/kernel/alternative.c | 26 -------------------------- arch/x86/kernel/ftrace.c | 32 +++++++------------------------- 3 files changed, 31 insertions(+), 52 deletions(-) --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -80,7 +80,30 @@ static inline int text_opcode_size(u8 op return size; } -extern void *text_gen_insn(u8 opcode, const void *addr, const void *dest); +union text_poke_insn { + u8 text[POKE_MAX_OPCODE_SIZE]; + struct { + u8 opcode; + s32 disp; + } __attribute__((packed)); +}; + +static __always_inline +void *text_gen_insn(u8 opcode, const void *addr, const void *dest) +{ + static union text_poke_insn insn; /* per instance */ + int size = text_opcode_size(opcode); + + insn.opcode = opcode; + + if (size > 1) { + insn.disp = (long)dest - (long)(addr + size); + if (size == 2) + BUG_ON((insn.disp >> 31) != (insn.disp >> 7)); + } + + return &insn.text; +} extern int after_bootmem; extern __ro_after_init struct mm_struct *poking_mm; --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1247,29 +1247,3 @@ void __ref text_poke_bp(void *addr, cons text_poke_loc_init(&tp, addr, opcode, len, emulate); text_poke_bp_batch(&tp, 1); } - -union text_poke_insn { - u8 text[POKE_MAX_OPCODE_SIZE]; - struct { - u8 opcode; - s32 disp; - } __attribute__((packed)); -}; - -void *text_gen_insn(u8 opcode, const void *addr, const void *dest) -{ - static union text_poke_insn insn; /* text_mutex */ - int size = text_opcode_size(opcode); - - lockdep_assert_held(&text_mutex); - - insn.opcode = opcode; - - if (size > 1) { - insn.disp = (long)dest - (long)(addr + size); - if (size == 2) - BUG_ON((insn.disp >> 31) != (insn.disp >> 7)); - } - - return &insn.text; -} --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -58,24 +58,6 @@ int ftrace_arch_code_modify_post_process return 0; } -union ftrace_code_union { - char code[MCOUNT_INSN_SIZE]; - struct { - char op; - int offset; - } __attribute__((packed)); -}; - -static const char *ftrace_text_replace(char op, unsigned long ip, unsigned long addr) -{ - static union ftrace_code_union calc; - - calc.op = op; - calc.offset = (int)(addr - (ip + MCOUNT_INSN_SIZE)); - - return calc.code; -} - static const char *ftrace_nop_replace(void) { return ideal_nops[NOP_ATOMIC5]; @@ -83,7 +65,7 @@ static const char *ftrace_nop_replace(vo static const char *ftrace_call_replace(unsigned long ip, unsigned long addr) { - return ftrace_text_replace(CALL_INSN_OPCODE, ip, addr); + return text_gen_insn(CALL_INSN_OPCODE, (void *)ip, (void *)addr); } static int ftrace_verify_code(unsigned long ip, const char *old_code) @@ -475,20 +457,20 @@ void arch_ftrace_update_trampoline(struc /* Return the address of the function the trampoline calls */ static void *addr_from_call(void *ptr) { - union ftrace_code_union calc; + union text_poke_insn call; int ret; - ret = probe_kernel_read(&calc, ptr, MCOUNT_INSN_SIZE); + ret = probe_kernel_read(&call, ptr, CALL_INSN_SIZE); if (WARN_ON_ONCE(ret < 0)) return NULL; /* Make sure this is a call */ - if (WARN_ON_ONCE(calc.op != 0xe8)) { - pr_warn("Expected e8, got %x\n", calc.op); + if (WARN_ON_ONCE(call.opcode != CALL_INSN_OPCODE)) { + pr_warn("Expected E8, got %x\n", call.opcode); return NULL; } - return ptr + MCOUNT_INSN_SIZE + calc.offset; + return ptr + CALL_INSN_SIZE + call.disp; } void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, @@ -557,7 +539,7 @@ extern void ftrace_graph_call(void); static const char *ftrace_jmp_replace(unsigned long ip, unsigned long addr) { - return ftrace_text_replace(JMP32_INSN_OPCODE, ip, addr); + return text_gen_insn(JMP32_INSN_OPCODE, (void *)ip, (void *)addr); } static int ftrace_mod_jmp(unsigned long ip, void *func)