From nobody Mon Feb 9 14:15:20 2026 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 85479C6FD20 for ; Fri, 24 Mar 2023 12:38:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231857AbjCXMiI (ORCPT ); Fri, 24 Mar 2023 08:38:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231289AbjCXMiA (ORCPT ); Fri, 24 Mar 2023 08:38:00 -0400 Received: from mail-m118111.qiye.163.com (mail-m118111.qiye.163.com [115.236.118.111]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 60BC9421E; Fri, 24 Mar 2023 05:37:58 -0700 (PDT) Received: from ubuntu.localdomain (unknown [117.133.56.22]) by mail-m118111.qiye.163.com (Hmail) with ESMTPA id 56892580A58; Fri, 24 Mar 2023 20:37:40 +0800 (CST) From: Donglin Peng To: mhiramat@kernel.org, rostedt@goodmis.org, linux@armlinux.org.uk, mark.rutland@arm.com, will@kernel.org, catalin.marinas@arm.com, palmer@dabbelt.com, paul.walmsley@sifive.com, tglx@linutronix.de, dave.hansen@linux.intel.com, x86@kernel.org, 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 Cc: 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, Donglin Peng Subject: [PATCH v7 3/8] ARM: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL Date: Fri, 24 Mar 2023 05:37:26 -0700 Message-Id: <20230324123731.3801920-4-pengdonglin@sangfor.com.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230324123731.3801920-1-pengdonglin@sangfor.com.cn> References: <20230324123731.3801920-1-pengdonglin@sangfor.com.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWS1ZQUlXWQ8JGhUIEh9ZQVkaTUJDVk4ZTU8fTBgYGR8YGVUTARMWGhIXJBQOD1 lXWRgSC1lBWUpKTFVKSEhVTk1VSUlZV1kWGg8SFR0UWUFZT0tIVUpKS09ISFVKS0tVS1kG X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6Oj46DAw5Sj0IMQ88CkgtEQ8U DD8KCxhVSlVKTUxCTU1KT01KQ09JVTMWGhIXVQseFRwfFBUcFxIVOwgaFRwdFAlVGBQWVRgVRVlX WRILWUFZSkpMVUpISFVOTVVJSVlXWQgBWUFPQ05LNwY+ X-HM-Tid: 0a87139fefa02eb7kusn56892580a58 X-HM-MType: 1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The commit d4815c5d1bbd ("function_graph: Support recording and printing the return value of function") 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 --- arch/arm/Kconfig | 1 + arch/arm/include/asm/ftrace.h | 22 ++++++++++++++++++++++ arch/arm/kernel/entry-ftrace.S | 6 +++++- 3 files changed, 28 insertions(+), 1 deletion(-) 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..e3bed4949558 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 cha= r *sym, =20 #endif /* ifndef __ASSEMBLY__ */ =20 + +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_HAVE_FUNCTION_GRAPH_RETVAL +struct fgraph_ret_regs { + unsigned long regs[4]; + unsigned long fp; +}; + +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_re= t_regs *ret_regs) +{ + return ret_regs->fp; +} +#endif + +#endif + #endif /* _ASM_ARM_FTRACE */ diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S index 3e7bcaca5e07..5f1e74555b25 100644 --- a/arch/arm/kernel/entry-ftrace.S +++ b/arch/arm/kernel/entry-ftrace.S @@ -257,11 +257,15 @@ ENDPROC(ftrace_graph_regs_caller) =20 #ifdef CONFIG_FUNCTION_GRAPH_TRACER ENTRY(return_to_handler) + sub sp, sp, #4 stmdb sp!, {r0-r3} - add r0, sp, #16 @ sp at exit of instrumented routine + add r0, sp, #20 @ sp at exit of instrumented routine + str r0, [sp, #16] + mov r0, sp bl ftrace_return_to_handler mov lr, r0 @ r0 has real ret addr ldmia sp!, {r0-r3} + add sp, sp, #4 @ skip fp ret lr ENDPROC(return_to_handler) #endif --=20 2.25.1