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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 37EEFC4321D for ; Sat, 18 Aug 2018 12:00:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6C05218A8 for ; Sat, 18 Aug 2018 12:00:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C6C05218A8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726560AbeHRPHp (ORCPT ); Sat, 18 Aug 2018 11:07:45 -0400 Received: from terminus.zytor.com ([198.137.202.136]:41573 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726272AbeHRPHp (ORCPT ); Sat, 18 Aug 2018 11:07:45 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w7IBxqKx1291812 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 18 Aug 2018 04:59:52 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w7IBxqkC1291809; Sat, 18 Aug 2018 04:59:52 -0700 Date: Sat, 18 Aug 2018 04:59:52 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Alexander Shishkin Message-ID: Cc: dave.hansen@linux.intel.com, peterz@infradead.org, acme@redhat.com, mingo@kernel.org, luto@kernel.org, linux-kernel@vger.kernel.org, alexander.shishkin@linux.intel.com, joro@8bytes.org, ak@linux.intel.com, hpa@zytor.com, jolsa@redhat.com, tglx@linutronix.de Reply-To: tglx@linutronix.de, jolsa@redhat.com, hpa@zytor.com, joro@8bytes.org, ak@linux.intel.com, alexander.shishkin@linux.intel.com, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@kernel.org, peterz@infradead.org, acme@redhat.com, dave.hansen@linux.intel.com In-Reply-To: <1528289651-4113-3-git-send-email-adrian.hunter@intel.com> References: <1528289651-4113-3-git-send-email-adrian.hunter@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] kallsyms, x86: Export addresses of PTI entry trampolines Git-Commit-ID: d83212d5dd6761625fe87cc23016bbaa47303271 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: d83212d5dd6761625fe87cc23016bbaa47303271 Gitweb: https://git.kernel.org/tip/d83212d5dd6761625fe87cc23016bbaa47303271 Author: Alexander Shishkin AuthorDate: Wed, 6 Jun 2018 15:54:10 +0300 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 14 Aug 2018 19:12:29 -0300 kallsyms, x86: Export addresses of PTI entry trampolines Currently, the addresses of PTI entry trampolines are not exported to user space. Kernel profiling tools need these addresses to identify the kernel code, so add a symbol and address for each CPU's PTI entry trampoline. Signed-off-by: Alexander Shishkin Acked-by: Andi Kleen Acked-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Joerg Roedel Cc: Thomas Gleixner Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1528289651-4113-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- arch/x86/mm/cpu_entry_area.c | 23 +++++++++++++++++++++++ kernel/kallsyms.c | 28 +++++++++++++++++++++++++++- 2 files changed, 50 insertions(+), 1 deletion(-) diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c index b45f5aaefd74..fab49fd5190f 100644 --- a/arch/x86/mm/cpu_entry_area.c +++ b/arch/x86/mm/cpu_entry_area.c @@ -2,6 +2,7 @@ #include #include +#include #include #include @@ -150,6 +151,28 @@ static void __init setup_cpu_entry_area(int cpu) percpu_setup_debug_store(cpu); } +#ifdef CONFIG_X86_64 +int arch_get_kallsym(unsigned int symnum, unsigned long *value, char *type, + char *name) +{ + unsigned int cpu, ncpu = 0; + + if (symnum >= num_possible_cpus()) + return -EINVAL; + + for_each_possible_cpu(cpu) { + if (ncpu++ >= symnum) + break; + } + + *value = (unsigned long)&get_cpu_entry_area(cpu)->entry_trampoline; + *type = 't'; + strlcpy(name, "__entry_SYSCALL_64_trampoline", KSYM_NAME_LEN); + + return 0; +} +#endif + static __init void setup_cpu_entry_area_ptes(void) { #ifdef CONFIG_X86_32 diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index aa31aa07f2ef..02a0b01380d8 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -432,6 +432,7 @@ int sprint_backtrace(char *buffer, unsigned long address) /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ struct kallsym_iter { loff_t pos; + loff_t pos_arch_end; loff_t pos_mod_end; loff_t pos_ftrace_mod_end; unsigned long value; @@ -443,9 +444,29 @@ struct kallsym_iter { int show_value; }; +int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value, + char *type, char *name) +{ + return -EINVAL; +} + +static int get_ksymbol_arch(struct kallsym_iter *iter) +{ + int ret = arch_get_kallsym(iter->pos - kallsyms_num_syms, + &iter->value, &iter->type, + iter->name); + + if (ret < 0) { + iter->pos_arch_end = iter->pos; + return 0; + } + + return 1; +} + static int get_ksymbol_mod(struct kallsym_iter *iter) { - int ret = module_get_kallsym(iter->pos - kallsyms_num_syms, + int ret = module_get_kallsym(iter->pos - iter->pos_arch_end, &iter->value, &iter->type, iter->name, iter->module_name, &iter->exported); @@ -501,6 +522,7 @@ static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) iter->nameoff = get_symbol_offset(new_pos); iter->pos = new_pos; if (new_pos == 0) { + iter->pos_arch_end = 0; iter->pos_mod_end = 0; iter->pos_ftrace_mod_end = 0; } @@ -515,6 +537,10 @@ static int update_iter_mod(struct kallsym_iter *iter, loff_t pos) { iter->pos = pos; + if ((!iter->pos_arch_end || iter->pos_arch_end > pos) && + get_ksymbol_arch(iter)) + return 1; + if ((!iter->pos_mod_end || iter->pos_mod_end > pos) && get_ksymbol_mod(iter)) return 1;