From patchwork Thu Jan 27 20:38:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12727396 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EA093C433EF for ; Thu, 27 Jan 2022 20:39:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=oqSKJaU43d1mGAB/RJT6Cmj2A1UYbn8I8l4VWv3Wv7A=; b=Mrhwq0/ffncA11 l79K9hR6ksDV94y/sLbpXbzXYSNt1rvaVh0EcVw1xdMv+ZwKD+FZVlZ0jLPBTGr0sTKbVdDmo8F/c eiaTnwYXrplJcb9zYf5wpNgEzdVrMa3+9ZmBBmAr/dZdlsdjsIeAK1rLU5o1dVa8V8yRgm3J6+C3k FW+ilF4Zx56NWkRsCZJVM9IpZD3nF32+oIgvNEOpazUcfJ6RUc03o+0NTaupw+zLI4PPx370ne7Ee 8c51TWgePyoYTzcqkMeXxME0I01FTbY6zifLfnC5lnwjoGA00lBBCZWhH6F7w1+2w8Axz/NVWno0u iXv2nL5xkU7EukpjeI3g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nDBXU-00H76V-6H; Thu, 27 Jan 2022 20:38:40 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nDBXQ-00H76A-Gt for linux-arm-kernel@lists.infradead.org; Thu, 27 Jan 2022 20:38:38 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0DD69618FE; Thu, 27 Jan 2022 20:38:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E89CC340E4; Thu, 27 Jan 2022 20:38:34 +0000 (UTC) Date: Thu, 27 Jan 2022 15:38:32 -0500 From: Steven Rostedt To: LKML Cc: Ingo Molnar , Andrew Morton , Mark Rutland , Yinan Liu , Ard Biesheuvel , Kees Cook , Sachin Sant , linuxppc-dev@lists.ozlabs.org, Russell King , linux-arm-kernel@lists.infradead.org Subject: [PATCH v2] ftrace: Have architectures opt-in for mcount build time sorting Message-ID: <20220127153821.3bc1ac6e@gandalf.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220127_123836_665755_F3DF7514 X-CRM114-Status: GOOD ( 24.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From f7d4ef4e77464e08af38789ea5d3a9cfb80a3d78 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Tue, 25 Jan 2022 09:19:10 -0500 Subject: [PATCH] ftrace: Have architectures opt-in for mcount build time sorting First S390 complained that the sorting of the mcount sections at build time caused the kernel to crash on their architecture. Now PowerPC is complaining about it too. And also ARM64 appears to be having issues. It may be necessary to also update the relocation table for the values in the mcount table. Not only do we have to sort the table, but also update the relocations that may be applied to the items in the table. If the system is not relocatable, then it is fine to sort, but if it is, some architectures may have issues (although x86 does not as it shifts all addresses the same). Add a HAVE_BUILDTIME_MCOUNT_SORT that an architecture can set to say it is safe to do the sorting at build time. Also update the config to compile in build time sorting in the sorttable code in scripts/ to depend on CONFIG_BUILDTIME_MCOUNT_SORT. Link: https://lore.kernel.org/all/944D10DA-8200-4BA9-8D0A-3BED9AA99F82@linux.ibm.com/ Cc: Yinan Liu Cc: Ard Biesheuvel Cc: Kees Cook Reported-by: Sachin Sant Reviewed-by: Mark Rutland Tested-by: Mark Rutland [arm64] Tested-by: Sachin Sant Fixes: 72b3942a173c ("scripts: ftrace - move the sort-processing in ftrace_init") Signed-off-by: Steven Rostedt (Google) --- Changes since v1: https://lore.kernel.org/all/20220127114249.03b1b52b@gandalf.local.home/ - Have CONFIG_BUILDTIME_MCOUNT_SORT depend on DYNAMIC_FTRACE otherwise it fails to build when DYNAMIC_FTRACE is not set because it can not find the mcount section in the sorttable code. arch/arm/Kconfig | 1 + arch/x86/Kconfig | 1 + kernel/trace/Kconfig | 8 +++++++- scripts/Makefile | 2 +- 4 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c2724d986fa0..5256ebe57451 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -82,6 +82,7 @@ config ARM select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32 select HAVE_CONTEXT_TRACKING select HAVE_C_RECORDMCOUNT + select HAVE_BUILDTIME_MCOUNT_SORT select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL select HAVE_DMA_CONTIGUOUS if MMU select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7399327d1eff..46080dea5dba 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -186,6 +186,7 @@ config X86 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING select HAVE_C_RECORDMCOUNT select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION + select HAVE_BUILDTIME_MCOUNT_SORT select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 752ed89a293b..a5eb5e7fd624 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -70,10 +70,16 @@ config HAVE_C_RECORDMCOUNT help C version of recordmcount available? +config HAVE_BUILDTIME_MCOUNT_SORT + bool + help + An architecture selects this if it sorts the mcount_loc section + at build time. + config BUILDTIME_MCOUNT_SORT bool default y - depends on BUILDTIME_TABLE_SORT && !S390 + depends on HAVE_BUILDTIME_MCOUNT_SORT && DYNAMIC_FTRACE help Sort the mcount_loc section at build time. diff --git a/scripts/Makefile b/scripts/Makefile index b082d2f93357..cedc1f0e21d8 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -32,7 +32,7 @@ HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/include HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED endif -ifdef CONFIG_DYNAMIC_FTRACE +ifdef CONFIG_BUILDTIME_MCOUNT_SORT HOSTCFLAGS_sorttable.o += -DMCOUNT_SORT_ENABLED endif