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 5B23DC761A6 for ; Mon, 3 Apr 2023 08:13:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231843AbjDCINj (ORCPT ); Mon, 3 Apr 2023 04:13:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231555AbjDCINi (ORCPT ); Mon, 3 Apr 2023 04:13:38 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 23BA549F3; Mon, 3 Apr 2023 01:13:37 -0700 (PDT) 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 43786FEC; Mon, 3 Apr 2023 01:14:21 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.57.89]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 44A603F6C4; Mon, 3 Apr 2023 01:13:26 -0700 (PDT) Date: Mon, 3 Apr 2023 09:13:20 +0100 From: Mark Rutland To: Donglin Peng Cc: mhiramat@kernel.org, rostedt@goodmis.org, linux@armlinux.org.uk, 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 Subject: Re: [PATCH v10 4/8] arm64: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL Message-ID: References: <8f75bbf69eb49afb8e14b10dad6e091c43cff4e2.1680265828.git.pengdonglin@sangfor.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8f75bbf69eb49afb8e14b10dad6e091c43cff4e2.1680265828.git.pengdonglin@sangfor.com.cn> Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Fri, Mar 31, 2023 at 05:47:40AM -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 ARM64 platform. > > We introduce a new structure called fgraph_ret_regs for the ARM64 > 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 Thanks for working through all the feedback! The structual changes all look good to me, and I've given this a spin to check that it doesn't break graph tracing, so: Reviewed-by: Mark Rutland Tested-by: Mark Rutland Mark. > --- > v10: > - Use CONFIG_FUNCTION_GRAPH_TRACER to control fgraph_ret_regs definition > > v9: > - Update the commit message > > v8: > - Fix issues in ARM64 asm code > - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/ftrace.h | 22 ++++++++++++++++++++++ > arch/arm64/kernel/asm-offsets.c | 13 +++++++++++++ > arch/arm64/kernel/entry-ftrace.S | 27 ++++++++++++++------------- > 4 files changed, 50 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 1023e896d46b..48856d230800 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -195,6 +195,7 @@ config ARM64 > select HAVE_FTRACE_MCOUNT_RECORD > select HAVE_FUNCTION_TRACER > select HAVE_FUNCTION_ERROR_INJECTION > + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER > select HAVE_FUNCTION_GRAPH_TRACER > select HAVE_GCC_PLUGINS > select HAVE_HW_BREAKPOINT if PERF_EVENTS > diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h > index 1c2672bbbf37..657adcbd80a4 100644 > --- a/arch/arm64/include/asm/ftrace.h > +++ b/arch/arm64/include/asm/ftrace.h > @@ -170,4 +170,26 @@ 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 { > + /* x0 - x7 */ > + unsigned long regs[8]; > + > + 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_FTRACE_H */ > diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c > index ae345b06e9f7..75082e0409bf 100644 > --- a/arch/arm64/kernel/asm-offsets.c > +++ b/arch/arm64/kernel/asm-offsets.c > @@ -197,6 +197,19 @@ int main(void) > #endif > #ifdef CONFIG_FUNCTION_TRACER > DEFINE(FTRACE_OPS_FUNC, offsetof(struct ftrace_ops, func)); > +#endif > + BLANK(); > +#ifdef CONFIG_FUNCTION_GRAPH_TRACER > + DEFINE(FGRET_REGS_X0, offsetof(struct fgraph_ret_regs, regs[0])); > + DEFINE(FGRET_REGS_X1, offsetof(struct fgraph_ret_regs, regs[1])); > + DEFINE(FGRET_REGS_X2, offsetof(struct fgraph_ret_regs, regs[2])); > + DEFINE(FGRET_REGS_X3, offsetof(struct fgraph_ret_regs, regs[3])); > + DEFINE(FGRET_REGS_X4, offsetof(struct fgraph_ret_regs, regs[4])); > + DEFINE(FGRET_REGS_X5, offsetof(struct fgraph_ret_regs, regs[5])); > + DEFINE(FGRET_REGS_X6, offsetof(struct fgraph_ret_regs, regs[6])); > + DEFINE(FGRET_REGS_X7, offsetof(struct fgraph_ret_regs, regs[7])); > + DEFINE(FGRET_REGS_FP, offsetof(struct fgraph_ret_regs, fp)); > + DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs)); > #endif > return 0; > } > diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S > index 350ed81324ac..da1443bcf776 100644 > --- a/arch/arm64/kernel/entry-ftrace.S > +++ b/arch/arm64/kernel/entry-ftrace.S > @@ -270,22 +270,23 @@ SYM_FUNC_END(ftrace_stub_graph) > */ > SYM_CODE_START(return_to_handler) > /* save return value regs */ > - sub sp, sp, #64 > - stp x0, x1, [sp] > - stp x2, x3, [sp, #16] > - stp x4, x5, [sp, #32] > - stp x6, x7, [sp, #48] > + sub sp, sp, #FGRET_REGS_SIZE > + stp x0, x1, [sp, #FGRET_REGS_X0] > + stp x2, x3, [sp, #FGRET_REGS_X2] > + stp x4, x5, [sp, #FGRET_REGS_X4] > + stp x6, x7, [sp, #FGRET_REGS_X6] > + str x29, [sp, #FGRET_REGS_FP] // parent's fp > > - mov x0, x29 // parent's fp > - bl ftrace_return_to_handler// addr = ftrace_return_to_hander(fp); > - mov x30, x0 // restore the original return address > + mov x0, sp > + bl ftrace_return_to_handler // addr = ftrace_return_to_hander(regs); > + mov x30, x0 // restore the original return address > > /* restore return value regs */ > - ldp x0, x1, [sp] > - ldp x2, x3, [sp, #16] > - ldp x4, x5, [sp, #32] > - ldp x6, x7, [sp, #48] > - add sp, sp, #64 > + ldp x0, x1, [sp, #FGRET_REGS_X0] > + ldp x2, x3, [sp, #FGRET_REGS_X2] > + ldp x4, x5, [sp, #FGRET_REGS_X4] > + ldp x6, x7, [sp, #FGRET_REGS_X6] > + add sp, sp, #FGRET_REGS_SIZE > > ret > SYM_CODE_END(return_to_handler) > -- > 2.25.1 >