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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 256FEC433EF for ; Sat, 16 Jul 2022 23:18:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232125AbiGPXSe (ORCPT ); Sat, 16 Jul 2022 19:18:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232810AbiGPXSA (ORCPT ); Sat, 16 Jul 2022 19:18:00 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A191222BD3 for ; Sat, 16 Jul 2022 16:17:44 -0700 (PDT) Message-ID: <20220716230953.858048083@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1658013462; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=Jzk1Ro7moQj4/ZNdqGDe6vOHP2eSGjateMVY4xuPVLw=; b=ABOqAJ8ZC4ybwE0awspMk33HahjgcjGnviUBghK+dC9qnrV8SnCm6lTrZMxLuZYupBjdo5 Hzl79sPZcu8H5By4Ta/YWxKPOR98XlsQNkXAwNbu6+nGGB3HtP4RbT6urZBuBh+Q/byCMC c8e1nlgTJBOIxuehEm3qtVTaUogEwUOBFtXCJQp8iwlrQi14uhorOuxqPX/fRn0B+XcsCb zeYe6VWHF8ime4A3WbJQv1cnXneJM6BJWPSPA+KtZ5Tv0dLRsd+aBRz9xd3zBOn58vs+up cwfBwHa5E1lyiYppeElTRdCes0zp6ZlspRAuR6u9CfJkCNaZVui9SP5l3fOhkQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1658013462; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=Jzk1Ro7moQj4/ZNdqGDe6vOHP2eSGjateMVY4xuPVLw=; b=5EUd6EGPJWOJ58Rki0DfMwZwyqF9oxESgWMLkJkvEILhwWyMNNcx9fj+0aX+ajxMHp4A2v EBtK/o0Q4h6wJHAg== From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Linus Torvalds , Tim Chen , Josh Poimboeuf , Andrew Cooper , Pawan Gupta , Johannes Wikner , Alyssa Milburn , Jann Horn , "H.J. Lu" , Joao Moreira , Joseph Nuzman , Steven Rostedt Subject: [patch 20/38] x86/alternatives: Provide text_poke_[copy|set]_locked() References: <20220716230344.239749011@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Sun, 17 Jul 2022 01:17:42 +0200 (CEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The upcoming call thunk patching must hold text_mutex and needs access to text_poke_copy() and text_poke_set(), which take text_mutex. Provide _locked postfixed variants to expose the inner workings. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/text-patching.h | 2 + arch/x86/kernel/alternative.c | 48 +++++++++++++++++++++-------------- 2 files changed, 32 insertions(+), 18 deletions(-) --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -45,6 +45,8 @@ extern void *text_poke(void *addr, const extern void text_poke_sync(void); extern void *text_poke_kgdb(void *addr, const void *opcode, size_t len); extern void *text_poke_copy(void *addr, const void *opcode, size_t len); +extern void *text_poke_copy_locked(void *addr, const void *opcode, size_t len); +extern void *text_poke_set_locked(void *addr, int c, size_t len); extern void *text_poke_set(void *addr, int c, size_t len); extern int poke_int3_handler(struct pt_regs *regs); extern void text_poke_bp(void *addr, const void *opcode, size_t len, const void *emulate); --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1225,6 +1225,26 @@ void *text_poke_kgdb(void *addr, const v return __text_poke(text_poke_memcpy, addr, opcode, len); } +void *text_poke_copy_locked(void *addr, const void *opcode, size_t len) +{ + unsigned long start = (unsigned long)addr; + size_t patched = 0; + + if (WARN_ON_ONCE(core_kernel_text(start))) + return NULL; + + while (patched < len) { + unsigned long ptr = start + patched; + size_t s; + + s = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(ptr), len - patched); + + __text_poke(text_poke_memcpy, (void *)ptr, opcode + patched, s); + patched += s; + } + return addr; +} + /** * text_poke_copy - Copy instructions into (an unused part of) RX memory * @addr: address to modify @@ -1239,23 +1259,29 @@ void *text_poke_kgdb(void *addr, const v */ void *text_poke_copy(void *addr, const void *opcode, size_t len) { + mutex_lock(&text_mutex); + addr = text_poke_copy_locked(addr, opcode, len); + mutex_unlock(&text_mutex); + return addr; +} + +void *text_poke_set_locked(void *addr, int c, size_t len) +{ unsigned long start = (unsigned long)addr; size_t patched = 0; if (WARN_ON_ONCE(core_kernel_text(start))) return NULL; - mutex_lock(&text_mutex); while (patched < len) { unsigned long ptr = start + patched; size_t s; s = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(ptr), len - patched); - __text_poke(text_poke_memcpy, (void *)ptr, opcode + patched, s); + __text_poke(text_poke_memset, (void *)ptr, (void *)&c, s); patched += s; } - mutex_unlock(&text_mutex); return addr; } @@ -1270,22 +1296,8 @@ void *text_poke_copy(void *addr, const v */ void *text_poke_set(void *addr, int c, size_t len) { - unsigned long start = (unsigned long)addr; - size_t patched = 0; - - if (WARN_ON_ONCE(core_kernel_text(start))) - return NULL; - mutex_lock(&text_mutex); - while (patched < len) { - unsigned long ptr = start + patched; - size_t s; - - s = min_t(size_t, PAGE_SIZE * 2 - offset_in_page(ptr), len - patched); - - __text_poke(text_poke_memset, (void *)ptr, (void *)&c, s); - patched += s; - } + addr = text_poke_set_locked(addr, c, len); mutex_unlock(&text_mutex); return addr; }