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=-10.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 39CAECA9EC7 for ; Sat, 2 Nov 2019 12:12:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1BD9020679 for ; Sat, 2 Nov 2019 12:12:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726462AbfKBMMe (ORCPT ); Sat, 2 Nov 2019 08:12:34 -0400 Received: from foss.arm.com ([217.140.110.172]:46692 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726163AbfKBMMd (ORCPT ); Sat, 2 Nov 2019 08:12:33 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 820ED31F; Sat, 2 Nov 2019 05:12:32 -0700 (PDT) Received: from [10.162.0.144] (a075553-lin.blr.arm.com [10.162.0.144]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D83913F718; Sat, 2 Nov 2019 05:12:27 -0700 (PDT) Subject: Re: [PATCHv2 0/8] arm64: ftrace cleanup + FTRACE_WITH_REGS To: Mark Rutland , linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, deller@gmx.de, duwe@suse.de, James.Bottomley@HansenPartnership.com, james.morse@arm.com, jeyu@kernel.org, jpoimboe@redhat.com, jthierry@redhat.com, linux-parisc@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org, svens@stackframe.org, takahiro.akashi@linaro.org, will@kernel.org References: <20191029165832.33606-1-mark.rutland@arm.com> From: Amit Daniel Kachhap Message-ID: <42c113ee-e7fc-3e94-cca0-f05f1c89fdb8@arm.com> Date: Sat, 2 Nov 2019 17:42:25 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20191029165832.33606-1-mark.rutland@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mark, On 10/29/19 10:28 PM, Mark Rutland wrote: > Hi, > > This series is a reworked version of Torsten's FTRACE_WITH_REGS series > [1]. I've tried to rework the existing code in preparatory patches so > that the patchable-function-entry bits slot in with fewer surprises. > This version is based on v5.4-rc3, and can be found in my > arm64/ftrace-with-regs branch [2]. > > Patch 1 adds an (optional) ftrace_init_nop(), which the core code uses > to initialize callsites. This allows us to avoid a synthetic MCOUNT_ADDR > symbol, and more cleanly separates the one-time initialization of the > callsite from dynamic NOP<->CALL modification. Architectures which don't > implement this get the existing ftrace_make_nop() with MCOUNT_ADDR. > > Recently parisc gained ftrace support using patchable-function-entry. > Patch 2 makes the handling of module callsite locations common in > kernel/module.c with a new FTRACE_CALLSITE_SECTION definition, and > removed the newly redundant bits from arch/parisc. > > Patches 3 and 4 move the module PLT initialization to module load time, > which simplifies runtime callsite modification. This also means that we > don't transitently mark the module text RW, and will allow for the > removal of module_disable_ro(). > > Patches 5 and 6 add some trivial infrastructure, with patch 7 finally > adding FTRACE_WITH_REGS support. Additional work will be required for > livepatching (e.g. implementing reliable stack trace), which is > commented as part of patch 7. > > Patch 8 is a trivial cleanup atop of the rest of the series, making the > code easier to read and less susceptible to config-specific breakage. I tested the whole series with my latest in-kernel ptrauth patches [1] and graph_tracer/function_graph_tracer works fine, So for the whole series, Tested-by: Amit Daniel Kachhap Also I gave few minor comments in the individual patches. With those comments, Signed-off-by: Amit Daniel Kachhap Thanks, Amit Daniel [1]: https://patchwork.kernel.org/cover/11195085/ > > Since v1 [3]: > * Add a couple of people to Cc > * Fold in Ard's Reviewed-by tag > * Rename ftrace_code_init_disabled() to ftrace_nop_initialize() > * Move ftrace_init_nop() to , with kerneldoc > * Update kerneldoc for rec parameters > > Thanks, > Mark. > > [1] https://lore.kernel.org/r/20190208150826.44EBC68DD2@newverein.lst.de > [2] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git arm64/ftrace-with-regs > [3] https://lore.kernel.org/r/20191021163426.9408-1-mark.rutland@arm.com > > Mark Rutland (7): > ftrace: add ftrace_init_nop() > module/ftrace: handle patchable-function-entry > arm64: module: rework special section handling > arm64: module/ftrace: intialize PLT at load time > arm64: insn: add encoder for MOV (register) > arm64: asm-offsets: add S_FP > arm64: ftrace: minimize ifdeffery > > Torsten Duwe (1): > arm64: implement ftrace with regs > > arch/arm64/Kconfig | 2 + > arch/arm64/Makefile | 5 ++ > arch/arm64/include/asm/ftrace.h | 23 +++++++ > arch/arm64/include/asm/insn.h | 3 + > arch/arm64/include/asm/module.h | 2 +- > arch/arm64/kernel/asm-offsets.c | 1 + > arch/arm64/kernel/entry-ftrace.S | 140 +++++++++++++++++++++++++++++++++++++-- > arch/arm64/kernel/ftrace.c | 123 ++++++++++++++++++++-------------- > arch/arm64/kernel/insn.c | 13 ++++ > arch/arm64/kernel/module-plts.c | 3 +- > arch/arm64/kernel/module.c | 57 +++++++++++++--- > arch/parisc/Makefile | 1 - > arch/parisc/kernel/module.c | 10 ++- > arch/parisc/kernel/module.lds | 7 -- > include/linux/ftrace.h | 40 ++++++++++- > kernel/module.c | 2 +- > kernel/trace/ftrace.c | 6 +- > 17 files changed, 355 insertions(+), 83 deletions(-) > delete mode 100644 arch/parisc/kernel/module.lds >