From patchwork Fri Nov 20 20:24:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Edgecombe, Rick P" X-Patchwork-Id: 11922287 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C7D5DC6379F for ; Fri, 20 Nov 2020 20:31:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92CEE22464 for ; Fri, 20 Nov 2020 20:31:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731082AbgKTUaO (ORCPT ); Fri, 20 Nov 2020 15:30:14 -0500 Received: from mga07.intel.com ([134.134.136.100]:10342 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731023AbgKTUaF (ORCPT ); Fri, 20 Nov 2020 15:30:05 -0500 IronPort-SDR: K2d95Nu4mp/a4670UE8IY5Wnz0GTiZGFqnjXwYRXAq4ZHQKzykQnpYSSNXJsTTAR2rc3xH0g/1 OzZRtPm8nknQ== X-IronPort-AV: E=McAfee;i="6000,8403,9811"; a="235683303" X-IronPort-AV: E=Sophos;i="5.78,357,1599548400"; d="scan'208";a="235683303" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Nov 2020 12:30:03 -0800 IronPort-SDR: E3Uc8tOndvBdwSPq0RRlnOjyyziKbRbBuO7nCsOiNMuCDPsSgn1Bym+Sc3Bcy/sFyeXqTRpAyd 3bo/AIxGPz6A== X-IronPort-AV: E=Sophos;i="5.78,357,1599548400"; d="scan'208";a="342163305" Received: from rpedgeco-mobl.amr.corp.intel.com (HELO localhost.intel.com) ([10.209.105.214]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Nov 2020 12:30:03 -0800 From: Rick Edgecombe To: akpm@linux-foundation.org, jeyu@kernel.org, bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, luto@kernel.org, dave.hansen@linux.intel.com, peterz@infradead.org, x86@kernel.org, rppt@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, dan.j.williams@intel.com Cc: elena.reshetova@intel.com, ira.weiny@intel.com, Rick Edgecombe Subject: [PATCH RFC 06/10] x86/alternatives: Handle perm_allocs for modules Date: Fri, 20 Nov 2020 12:24:22 -0800 Message-Id: <20201120202426.18009-7-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201120202426.18009-1-rick.p.edgecombe@intel.com> References: <20201120202426.18009-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-State: RFC Modules being loaded using perm_allocs may have a separate writable address. Handle this case in alternatives for operations called during module loading. Signed-off-by: Rick Edgecombe --- arch/x86/kernel/alternative.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 2400ad62f330..e6d8a696540b 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -373,7 +373,7 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, struct alt_instr *end) { struct alt_instr *a; - u8 *instr, *replacement; + u8 *instr, *writ_instr, *replacement, *writ_replacement; u8 insn_buff[MAX_PATCH_LEN]; DPRINTK("alt table %px, -> %px", start, end); @@ -391,11 +391,13 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, instr = (u8 *)&a->instr_offset + a->instr_offset; replacement = (u8 *)&a->repl_offset + a->repl_offset; + writ_instr = (u8 *)module_adjust_writable_addr(instr); + writ_replacement = (u8 *)module_adjust_writable_addr(replacement); BUG_ON(a->instrlen > sizeof(insn_buff)); BUG_ON(a->cpuid >= (NCAPINTS + NBUGINTS) * 32); if (!boot_cpu_has(a->cpuid)) { if (a->padlen > 1) - optimize_nops(a, instr); + optimize_nops(a, writ_instr); continue; } @@ -403,13 +405,13 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, DPRINTK("feat: %d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d), pad: %d", a->cpuid >> 5, a->cpuid & 0x1f, - instr, instr, a->instrlen, + writ_instr, instr, a->instrlen, replacement, a->replacementlen, a->padlen); DUMP_BYTES(instr, a->instrlen, "%px: old_insn: ", instr); DUMP_BYTES(replacement, a->replacementlen, "%px: rpl_insn: ", replacement); - memcpy(insn_buff, replacement, a->replacementlen); + memcpy(insn_buff, writ_replacement, a->replacementlen); insn_buff_sz = a->replacementlen; /* @@ -435,7 +437,7 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start, } DUMP_BYTES(insn_buff, insn_buff_sz, "%px: final_insn: ", instr); - text_poke_early(instr, insn_buff, insn_buff_sz); + text_poke_early(writ_instr, insn_buff, insn_buff_sz); } } @@ -496,6 +498,10 @@ void __init_or_module alternatives_smp_module_add(struct module *mod, void *text, void *text_end) { struct smp_alt_module *smp; + void *w_locks = module_adjust_writable_addr(locks); + void *w_locks_end = module_adjust_writable_addr(locks_end); + void *w_text = module_adjust_writable_addr(text); + void *w_text_end = module_adjust_writable_addr(text_end); mutex_lock(&text_mutex); if (!uniproc_patched) @@ -522,7 +528,7 @@ void __init_or_module alternatives_smp_module_add(struct module *mod, list_add_tail(&smp->next, &smp_alt_modules); smp_unlock: - alternatives_smp_unlock(locks, locks_end, text, text_end); + alternatives_smp_unlock(w_locks, w_locks_end, w_text, w_text_end); unlock: mutex_unlock(&text_mutex); } @@ -601,17 +607,18 @@ void __init_or_module apply_paravirt(struct paravirt_patch_site *start, for (p = start; p < end; p++) { unsigned int used; + void *writable = module_adjust_writable_addr(p->instr); BUG_ON(p->len > MAX_PATCH_LEN); /* prep the buffer with the original instructions */ - memcpy(insn_buff, p->instr, p->len); - used = pv_ops.init.patch(p->type, insn_buff, (unsigned long)p->instr, p->len); + memcpy(insn_buff, writable, p->len); + used = pv_ops.init.patch(p->type, insn_buff, (unsigned long)writable, p->len); BUG_ON(used > p->len); /* Pad the rest with nops */ add_nops(insn_buff + used, p->len - used); - text_poke_early(p->instr, insn_buff, p->len); + text_poke_early(writable, insn_buff, p->len); } } extern struct paravirt_patch_site __start_parainstructions[],