Received: by 2002:a25:31c3:0:0:0:0:0 with SMTP id x186csp4103815ybx; Mon, 4 Nov 2019 07:55:34 -0800 (PST) X-Google-Smtp-Source: APXvYqxUT2q6R6A7dCEvriRap44wpueBwkbmIqsk/bviciBWPyhnYWBChOViZoofgMt2Pa6pi6WH X-Received: by 2002:a17:906:d781:: with SMTP id pj1mr24250720ejb.98.1572882934140; Mon, 04 Nov 2019 07:55:34 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1572882934; cv=none; d=google.com; s=arc-20160816; b=YnTPNhgB52ayiKxOZPxLYo0EwjNPKVw9FG6TlwTbx/odteTutTCOEj+Gc7nup1nzk1 dFzPlZfJ2mRZmLjIOb4+r/7JwPDbz6urJECnMVK38eKW+FQmGSrXiQdyM53yuYwJCoi/ I/EV14P6nd/fhW0FRhWL3uwif4Dfk0ZQFsnu+7rri5FA0GGPwZ/Aowwh2pWTWyFy7bcu GeVDmt+t8H51EKHVBFVgSdfC8iRAXWj5iO/i4lOLlTvP8lE3ufJlRnDvXR1BrZJlfCHp 21/xwCH7xBKGKCMO/fXGlQSq8ic1mYDGa3nEu3ysMH53aRMbn+qVr+CjuIg2o55awF5e avrw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=cC0+TBZegfxI9BJ2TOgIhR7ECahtkgeHG/v5YNmjCNE=; b=OEUwjIOCwIFlZlqVEm43yYUkcUzzWqq4v+arRKOx4ndoAUgdW70wfozZckFNFlcBXv MucOMYZqi2jBrqQLGXSVRtc1Ufj0riHC90DM8KhEru9jjuL+55vnTMpNRFAfVoH9fPjO js8qHBebcgI9xgU3TGErn97Pxh6pM0sf/CDzBBaAarUJXV7EUDLQUSID1WbTht/sL1im iy33T5s8VoOczhQfMS/wyOAlo0z+neLrDqn5DEy7Fm/CejqBzCecFWdOnn+3tueMvNcp Fl6pzByO9i12Rgn47LeY7IKGhMGbNoekooMVz6rjj1Zml7nuUl6lpxl3ynsFLWYxusdI Ai4g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f5si7652794edf.232.2019.11.04.07.55.09; Mon, 04 Nov 2019 07:55:34 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729433AbfKDPvl (ORCPT + 99 others); Mon, 4 Nov 2019 10:51:41 -0500 Received: from foss.arm.com ([217.140.110.172]:45972 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727998AbfKDPvl (ORCPT ); Mon, 4 Nov 2019 10:51:41 -0500 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 15BE41FB; Mon, 4 Nov 2019 07:51:40 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CA20A3F71A; Mon, 4 Nov 2019 07:51:37 -0800 (PST) Date: Mon, 4 Nov 2019 15:51:33 +0000 From: Mark Rutland To: linux-arm-kernel@lists.infradead.org, Jessica Yu , Helge Deller , "James E.J. Bottomley" Cc: linux-kernel@vger.kernel.org, amit.kachhap@arm.com, catalin.marinas@arm.com, duwe@suse.de, james.morse@arm.com, 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 Subject: Re: [PATCHv2 2/8] module/ftrace: handle patchable-function-entry Message-ID: <20191104155132.GA1643@lakrids.cambridge.arm.com> References: <20191029165832.33606-1-mark.rutland@arm.com> <20191029165832.33606-3-mark.rutland@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191029165832.33606-3-mark.rutland@arm.com> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jessica, Helge, Are you ok with the module and parisc changes, repectively? The kbuild test robot is happy building this for multiple architectures, Sven has tested that this works correctly on parisc, and others have tested other architectures. I'd like to queue this in the arm64 tree soon if possible. Thanks, Mark. On Tue, Oct 29, 2019 at 04:58:26PM +0000, Mark Rutland wrote: > When using patchable-function-entry, the compiler will record the > callsites into a section named "__patchable_function_entries" rather > than "__mcount_loc". Let's abstract this difference behind a new > FTRACE_CALLSITE_SECTION, so that architectures don't have to handle this > explicitly (e.g. with custom module linker scripts). > > As parisc currently handles this explicitly, it is fixed up accordingly, > with its custom linker script removed. Since FTRACE_CALLSITE_SECTION is > only defined when DYNAMIC_FTRACE is selected, the parisc module loading > code is updated to only use the definition in that case. When > DYNAMIC_FTRACE is not selected, modules shouldn't have this section, so > this removes some redundant work in that case. > > I built parisc generic-{32,64}bit_defconfig with DYNAMIC_FTRACE enabled, > and verified that the section made it into the .ko files for modules. > > Signed-off-by: Mark Rutland > Reviewed-by: Ard Biesheuvel > Cc: Helge Deller > Cc: Ingo Molnar > Cc: James E.J. Bottomley > Cc: Jessica Yu > Cc: Steven Rostedt > Cc: Sven Schnelle > Cc: linux-parisc@vger.kernel.org > --- > arch/parisc/Makefile | 1 - > arch/parisc/kernel/module.c | 10 +++++++--- > arch/parisc/kernel/module.lds | 7 ------- > include/linux/ftrace.h | 5 +++++ > kernel/module.c | 2 +- > 5 files changed, 13 insertions(+), 12 deletions(-) > delete mode 100644 arch/parisc/kernel/module.lds > > diff --git a/arch/parisc/Makefile b/arch/parisc/Makefile > index 36b834f1c933..dca8f2de8cf5 100644 > --- a/arch/parisc/Makefile > +++ b/arch/parisc/Makefile > @@ -60,7 +60,6 @@ KBUILD_CFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY=1 \ > -DFTRACE_PATCHABLE_FUNCTION_SIZE=$(NOP_COUNT) > > CC_FLAGS_FTRACE := -fpatchable-function-entry=$(NOP_COUNT),$(shell echo $$(($(NOP_COUNT)-1))) > -KBUILD_LDS_MODULE += $(srctree)/arch/parisc/kernel/module.lds > endif > > OBJCOPY_FLAGS =-O binary -R .note -R .comment -S > diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c > index ac5f34993b53..1c50093e2ebe 100644 > --- a/arch/parisc/kernel/module.c > +++ b/arch/parisc/kernel/module.c > @@ -43,6 +43,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -862,7 +863,7 @@ int module_finalize(const Elf_Ehdr *hdr, > const char *strtab = NULL; > const Elf_Shdr *s; > char *secstrings; > - int err, symindex = -1; > + int symindex = -1; > Elf_Sym *newptr, *oldptr; > Elf_Shdr *symhdr = NULL; > #ifdef DEBUG > @@ -946,11 +947,13 @@ int module_finalize(const Elf_Ehdr *hdr, > /* patch .altinstructions */ > apply_alternatives(aseg, aseg + s->sh_size, me->name); > > +#ifdef CONFIG_DYNAMIC_FTRACE > /* For 32 bit kernels we're compiling modules with > * -ffunction-sections so we must relocate the addresses in the > - *__mcount_loc section. > + * ftrace callsite section. > */ > - if (symindex != -1 && !strcmp(secname, "__mcount_loc")) { > + if (symindex != -1 && !strcmp(secname, FTRACE_CALLSITE_SECTION)) { > + int err; > if (s->sh_type == SHT_REL) > err = apply_relocate((Elf_Shdr *)sechdrs, > strtab, symindex, > @@ -962,6 +965,7 @@ int module_finalize(const Elf_Ehdr *hdr, > if (err) > return err; > } > +#endif > } > return 0; > } > diff --git a/arch/parisc/kernel/module.lds b/arch/parisc/kernel/module.lds > deleted file mode 100644 > index 1a9a92aca5c8..000000000000 > --- a/arch/parisc/kernel/module.lds > +++ /dev/null > @@ -1,7 +0,0 @@ > -/* SPDX-License-Identifier: GPL-2.0 */ > - > -SECTIONS { > - __mcount_loc : { > - *(__patchable_function_entries) > - } > -} > diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h > index 9867d90d635e..9141f2263286 100644 > --- a/include/linux/ftrace.h > +++ b/include/linux/ftrace.h > @@ -738,6 +738,11 @@ static inline unsigned long get_lock_parent_ip(void) > > #ifdef CONFIG_FTRACE_MCOUNT_RECORD > extern void ftrace_init(void); > +#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY > +#define FTRACE_CALLSITE_SECTION "__patchable_function_entries" > +#else > +#define FTRACE_CALLSITE_SECTION "__mcount_loc" > +#endif > #else > static inline void ftrace_init(void) { } > #endif > diff --git a/kernel/module.c b/kernel/module.c > index ff2d7359a418..acf7962936c4 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -3222,7 +3222,7 @@ static int find_module_sections(struct module *mod, struct load_info *info) > #endif > #ifdef CONFIG_FTRACE_MCOUNT_RECORD > /* sechdrs[0].sh_size is always zero */ > - mod->ftrace_callsites = section_objs(info, "__mcount_loc", > + mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION, > sizeof(*mod->ftrace_callsites), > &mod->num_ftrace_callsites); > #endif > -- > 2.11.0 >