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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7ECE2C7EE23 for ; Fri, 9 Jun 2023 03:36:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238122AbjFIDga (ORCPT ); Thu, 8 Jun 2023 23:36:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229615AbjFIDg0 (ORCPT ); Thu, 8 Jun 2023 23:36:26 -0400 X-Greylist: delayed 792 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 08 Jun 2023 20:36:24 PDT Received: from mail-m11877.qiye.163.com (mail-m11877.qiye.163.com [115.236.118.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4222B30F0; Thu, 8 Jun 2023 20:36:23 -0700 (PDT) Received: from [172.23.197.13] (unknown [121.32.254.149]) by mail-m11877.qiye.163.com (Hmail) with ESMTPA id CD1954001E6; Fri, 9 Jun 2023 11:22:51 +0800 (CST) Message-ID: <64f5298c-6712-de7e-7f90-5aeb0d0d770c@sangfor.com.cn> Date: Fri, 9 Jun 2023 11:22:51 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v11 3/8] ARM: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL To: linux@armlinux.org.uk Cc: mhiramat@kernel.org, Steven Rostedt , mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com, rmk+kernel@armlinux.org.uk, palmer@dabbelt.com, paul.walmsley@sifive.com, aou@eecs.berkeley.edu, tglx@linutronix.de, dave.hansen@linux.intel.com, x86@kernel.org, bp@alien8.de, hpa@zytor.com, chenhuacai@kernel.org, zhangqing@loongson.cn, kernel@xen0n.name, mingo@redhat.com, peterz@infradead.org, xiehuan09@gmail.com, dinghui@sangfor.com.cn, huangcun@sangfor.com.cn, dolinux.peng@gmail.com, linux-trace-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20230608215719.7537ce38@gandalf.local.home> Content-Language: en-US From: Donglin Peng In-Reply-To: <20230608215719.7537ce38@gandalf.local.home> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWS1ZQUlXWQ8JGhUIEh9ZQVkZTUxMVhhIH0pMHhlKH0kfGVUTARMWGhIXJBQOD1 lXWRgSC1lBWUpJSlVISVVJTk9VSk9CWVdZFhoPEhUdFFlBWU9LSFVKTkxJSklVSktLVUpCWQY+ X-HM-Tid: 0a889e2daa942eb3kusncd1954001e6 X-HM-MType: 1 X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6OFE6Tzo4LD1IMi0WEhBLOTcf CCEKCzdVSlVKTUNNSUNLQkxIT0lKVTMWGhIXVQseFRwfFBUcFxIVOwgaFRwdFAlVGBQWVRgVRVlX WRILWUFZSklKVUhJVUlOT1VKT0JZV1kIAVlBTE9CTTcG Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/6/9 9:57, Steven Rostedt wrote: > On Sat, 8 Apr 2023 05:42:17 -0700 > Donglin Peng wrote: > >> The previous patch ("function_graph: Support recording and printing >> the return value of function") has laid the groundwork for the for >> the funcgraph-retval, and this modification makes it available on >> the ARM platform. >> >> We introduce a new structure called fgraph_ret_regs for the ARM platform >> to hold return registers and the frame pointer. We then fill its content >> in the return_to_handler and pass its address to the function >> ftrace_return_to_handler to record the return value. >> >> Signed-off-by: Donglin Peng > > I really don't want to add this without an ack from an arm maintainer. > > I have the patches queued (for testing), but I may remove the ones that do > not have the appropriate acks. > > -- Steve > Hi Russell, can I get a ack for arm? > >> --- >> v10: >> - Use CONFIG_FUNCTION_GRAPH_TRACER to control fgraph_ret_regs definition >> >> v9: >> - Fix stack pointer align issues >> - Update the commit message >> >> v8: >> - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL >> --- >> arch/arm/Kconfig | 1 + >> arch/arm/include/asm/ftrace.h | 22 ++++++++++++++++++++++ >> arch/arm/kernel/asm-offsets.c | 8 +++++++- >> arch/arm/kernel/entry-ftrace.S | 10 ++++++---- >> 4 files changed, 36 insertions(+), 5 deletions(-) >> >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig >> index e24a9820e12f..73061379855a 100644 >> --- a/arch/arm/Kconfig >> +++ b/arch/arm/Kconfig >> @@ -98,6 +98,7 @@ config ARM >> select HAVE_FAST_GUP if ARM_LPAE >> select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL >> select HAVE_FUNCTION_ERROR_INJECTION >> + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER >> select HAVE_FUNCTION_GRAPH_TRACER >> select HAVE_FUNCTION_TRACER if !XIP_KERNEL >> select HAVE_GCC_PLUGINS >> diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h >> index 7e9251ca29fe..3c457902b355 100644 >> --- a/arch/arm/include/asm/ftrace.h >> +++ b/arch/arm/include/asm/ftrace.h >> @@ -77,4 +77,26 @@ static inline bool arch_syscall_match_sym_name(const char *sym, >> >> #endif /* ifndef __ASSEMBLY__ */ >> >> +#ifndef __ASSEMBLY__ >> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER >> +struct fgraph_ret_regs { >> + /* r0 - r3 */ >> + unsigned long regs[4]; >> + >> + unsigned long fp; >> + unsigned long __unused; >> +}; >> + >> +static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs) >> +{ >> + return ret_regs->regs[0]; >> +} >> + >> +static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs) >> +{ >> + return ret_regs->fp; >> +} >> +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */ >> +#endif >> + >> #endif /* _ASM_ARM_FTRACE */ >> diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c >> index 38121c59cbc2..18bb85115b21 100644 >> --- a/arch/arm/kernel/asm-offsets.c >> +++ b/arch/arm/kernel/asm-offsets.c >> @@ -23,6 +23,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include "signal.h" >> @@ -170,5 +171,10 @@ int main(void) >> DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page)); >> DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type)); >> DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2)); >> - return 0; >> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER >> + BLANK(); >> + DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs)); >> + BLANK(); >> +#endif >> + return 0; >> } >> diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S >> index 3e7bcaca5e07..d41a1676608c 100644 >> --- a/arch/arm/kernel/entry-ftrace.S >> +++ b/arch/arm/kernel/entry-ftrace.S >> @@ -257,11 +257,13 @@ ENDPROC(ftrace_graph_regs_caller) >> >> #ifdef CONFIG_FUNCTION_GRAPH_TRACER >> ENTRY(return_to_handler) >> - stmdb sp!, {r0-r3} >> - add r0, sp, #16 @ sp at exit of instrumented routine >> + mov ip, sp @ sp at exit of instrumented routine >> + stmdb sp!, {r0-r3, ip, lr} @ fill fgraph_ret_regs >> + mov r0, sp >> bl ftrace_return_to_handler >> - mov lr, r0 @ r0 has real ret addr >> - ldmia sp!, {r0-r3} >> + mov lr, r0 @ r0 has real ret addr >> + ldmia sp, {r0-r3} >> + add sp, sp, #FGRET_REGS_SIZE @ restore stack pointer >> ret lr >> ENDPROC(return_to_handler) >> #endif >