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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 EA1BCC282C0 for ; Wed, 23 Jan 2019 10:04:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD89A20870 for ; Wed, 23 Jan 2019 10:04:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="qmBawP+o" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727420AbfAWKEU (ORCPT ); Wed, 23 Jan 2019 05:04:20 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:11745 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727148AbfAWKET (ORCPT ); Wed, 23 Jan 2019 05:04:19 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 43l18w0wjCz9tyZS; Wed, 23 Jan 2019 11:04:16 +0100 (CET) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=qmBawP+o; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id LecDX33IwxtM; Wed, 23 Jan 2019 11:04:16 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 43l18v6n8vz9tyZK; Wed, 23 Jan 2019 11:04:15 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1548237855; bh=rJWkQ5tIW9mztCMgFG4VMzlkgZQIKaxpeoWBGsdOweI=; h=Subject:From:To:Cc:References:Date:In-Reply-To:From; b=qmBawP+oggKmr9sQrekG/NNTblT0YDrVDWgXj7SmPmDAV7o8e+rBJZNx+bpYK1bWl GXRAgYgrCFtOwha0nXrD2jPcf/s7wlqDFErPqZ6lN6qZv4ReOcriGK5ommxMy/Qho+ 0RpCFMsG0OaFUEa6AeFCMvq1kaCJ3ZncHOV5AMkg= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 131F48B7FF; Wed, 23 Jan 2019 11:04:17 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id 7x2fvWQ_dIfk; Wed, 23 Jan 2019 11:04:16 +0100 (CET) Received: from PO15451 (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 664638B801; Wed, 23 Jan 2019 11:04:16 +0100 (CET) Subject: Re: [PATCH v13 00/10] powerpc: Switch to CONFIG_THREAD_INFO_IN_TASK From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Nicholas Piggin Cc: Mike Rapoport , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: Message-ID: <2e700e1c-5bd9-652e-b535-68a89dd703a1@c-s.fr> Date: Wed, 23 Jan 2019 11:04:16 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 12/01/2019 à 10:55, Christophe Leroy a écrit : > The purpose of this serie is to activate CONFIG_THREAD_INFO_IN_TASK which > moves the thread_info into task_struct. > > Moving thread_info into task_struct has the following advantages: > - It protects thread_info from corruption in the case of stack > overflows. > - Its address is harder to determine if stack addresses are > leaked, making a number of attacks more difficult. I ran null_syscall and context_switch benchmark selftests and the result is surprising. There is slight degradation in context_switch and a significant one on null_syscall: Without the serie: ~# chrt -f 98 ./context_switch --no-altivec --no-vector --no-fp 55542 55562 55564 55562 55568 ... ~# ./null_syscall 2546.71 ns 336.17 cycles With the serie: ~# chrt -f 98 ./context_switch --no-altivec --no-vector --no-fp 55138 55142 55152 55144 55142 ~# ./null_syscall 3479.54 ns 459.30 cycles So 0,8% less context switches per second and 37% more time for one syscall ? Any idea ? Christophe > > Changes since v12: > - Patch 1: Taken comment from Mike (re-introduced the 'panic' in case memblock allocation fails in setup_64.c > - Patch 1: Added alloc_stack() function in setup_32.c to also panic in case of allocation failure. > > Changes since v11: > - Rebased on 81775f5563fa ("Automatic merge of branches 'master', 'next' and 'fixes' into merge") > - Added a first patch to change memblock allocs to functions returning virtual addrs. This removes > the memset() which were the only remaining stuff in irq_ctx_init() and exc_lvl_ctx_init() at the end. > - dropping irq_ctx_init() and exc_lvl_ctx_init() in patch 5 (powerpc: Activate CONFIG_THREAD_INFO_IN_TASK) > - A few cosmetic changes in commit log and code. > > Changes since v10: > - Rebased on 21622a0d2023 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge") > ==> Fixed conflict in setup_32.S > > Changes since v9: > - Rebased on 183cbf93be88 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge") > ==> Fixed conflict on xmon > > Changes since v8: > - Rebased on e589b79e40d9 ("Automatic merge of branches 'master', 'next' and 'fixes' into merge") > ==> Main impact was conflicts due to commit 9a8dd708d547 ("memblock: rename memblock_alloc{_nid,_try_nid} to memblock_phys_alloc*") > > Changes since v7: > - Rebased on fb6c6ce7907d ("Automatic merge of branches 'master', 'next' and 'fixes' into merge") > > Changes since v6: > - Fixed validate_sp() to exclude NULL sp in 'regain entire stack space' patch (early crash with CONFIG_KMEMLEAK) > > Changes since v5: > - Fixed livepatch_sp setup by using end_of_stack() instead of hardcoding > - Fixed PPC_BPF_LOAD_CPU() macro > > Changes since v4: > - Fixed a build failure on 32bits SMP when include/generated/asm-offsets.h is not > already existing, was due to spaces instead of a tab in the Makefile > > Changes since RFC v3: (based on Nick's review) > - Renamed task_size.h to task_size_user64.h to better relate to what it contains. > - Handling of the isolation of thread_info cpu field inside CONFIG_SMP #ifdefs moved to a separate patch. > - Removed CURRENT_THREAD_INFO macro completely. > - Added a guard in asm/smp.h to avoid build failure before _TASK_CPU is defined. > - Added a patch at the end to rename 'tp' pointers to 'sp' pointers > - Renamed 'tp' into 'sp' pointers in preparation patch when relevant > - Fixed a few commit logs > - Fixed checkpatch report. > > Changes since RFC v2: > - Removed the modification of names in asm-offsets > - Created a rule in arch/powerpc/Makefile to append the offset of current->cpu in CFLAGS > - Modified asm/smp.h to use the offset set in CFLAGS > - Squashed the renaming of THREAD_INFO to TASK_STACK in the preparation patch > - Moved the modification of current_pt_regs in the patch activating CONFIG_THREAD_INFO_IN_TASK > > Changes since RFC v1: > - Removed the first patch which was modifying header inclusion order in timer > - Modified some names in asm-offsets to avoid conflicts when including asm-offsets in C files > - Modified asm/smp.h to avoid having to include linux/sched.h (using asm-offsets instead) > - Moved some changes from the activation patch to the preparation patch. > > Christophe Leroy (10): > powerpc/irq: use memblock functions returning virtual address > book3s/64: avoid circular header inclusion in mmu-hash.h > powerpc: Only use task_struct 'cpu' field on SMP > powerpc: Prepare for moving thread_info into task_struct > powerpc: Activate CONFIG_THREAD_INFO_IN_TASK > powerpc: regain entire stack space > powerpc: 'current_set' is now a table of task_struct pointers > powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU > powerpc/64: Remove CURRENT_THREAD_INFO > powerpc: clean stack pointers naming > > arch/powerpc/Kconfig | 1 + > arch/powerpc/Makefile | 7 ++ > arch/powerpc/include/asm/asm-prototypes.h | 4 +- > arch/powerpc/include/asm/book3s/64/mmu-hash.h | 2 +- > arch/powerpc/include/asm/exception-64s.h | 4 +- > arch/powerpc/include/asm/irq.h | 18 ++-- > arch/powerpc/include/asm/livepatch.h | 6 +- > arch/powerpc/include/asm/processor.h | 39 +-------- > arch/powerpc/include/asm/ptrace.h | 2 +- > arch/powerpc/include/asm/reg.h | 2 +- > arch/powerpc/include/asm/smp.h | 17 +++- > arch/powerpc/include/asm/task_size_user64.h | 42 +++++++++ > arch/powerpc/include/asm/thread_info.h | 19 ----- > arch/powerpc/kernel/asm-offsets.c | 10 ++- > arch/powerpc/kernel/entry_32.S | 66 +++++--------- > arch/powerpc/kernel/entry_64.S | 12 +-- > arch/powerpc/kernel/epapr_hcalls.S | 5 +- > arch/powerpc/kernel/exceptions-64e.S | 13 +-- > arch/powerpc/kernel/exceptions-64s.S | 2 +- > arch/powerpc/kernel/head_32.S | 14 +-- > arch/powerpc/kernel/head_40x.S | 4 +- > arch/powerpc/kernel/head_44x.S | 8 +- > arch/powerpc/kernel/head_64.S | 1 + > arch/powerpc/kernel/head_8xx.S | 2 +- > arch/powerpc/kernel/head_booke.h | 12 +-- > arch/powerpc/kernel/head_fsl_booke.S | 16 ++-- > arch/powerpc/kernel/idle_6xx.S | 8 +- > arch/powerpc/kernel/idle_book3e.S | 2 +- > arch/powerpc/kernel/idle_e500.S | 8 +- > arch/powerpc/kernel/idle_power4.S | 2 +- > arch/powerpc/kernel/irq.c | 114 +++---------------------- > arch/powerpc/kernel/kgdb.c | 28 ------ > arch/powerpc/kernel/machine_kexec_64.c | 6 +- > arch/powerpc/kernel/misc_32.S | 17 ++-- > arch/powerpc/kernel/process.c | 40 ++++----- > arch/powerpc/kernel/setup-common.c | 2 +- > arch/powerpc/kernel/setup_32.c | 25 +++--- > arch/powerpc/kernel/setup_64.c | 51 +++-------- > arch/powerpc/kernel/smp.c | 16 ++-- > arch/powerpc/kernel/trace/ftrace_64_mprofile.S | 6 +- > arch/powerpc/kvm/book3s_hv_hmi.c | 1 + > arch/powerpc/mm/hash_low_32.S | 14 ++- > arch/powerpc/net/bpf_jit32.h | 5 +- > arch/powerpc/sysdev/6xx-suspend.S | 5 +- > arch/powerpc/xmon/xmon.c | 2 +- > 45 files changed, 249 insertions(+), 431 deletions(-) > create mode 100644 arch/powerpc/include/asm/task_size_user64.h >