From nobody Wed Apr 8 10:16:02 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 A4EBDC38A2D for ; Mon, 24 Oct 2022 23:47:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230213AbiJXXrw (ORCPT ); Mon, 24 Oct 2022 19:47:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229866AbiJXXrX (ORCPT ); Mon, 24 Oct 2022 19:47:23 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 57106333A9E for ; Mon, 24 Oct 2022 15:05:44 -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 3F74D13D5; Mon, 24 Oct 2022 07:09:06 -0700 (PDT) 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 ESMTPA id DE9793F792; Mon, 24 Oct 2022 07:08:58 -0700 (PDT) From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com, mhiramat@kernel.org, revest@chromium.org, rostedt@goodmis.org, will@kernel.org Subject: [PATCH 3/4] ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses Date: Mon, 24 Oct 2022 15:08:45 +0100 Message-Id: <20221024140846.3555435-4-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221024140846.3555435-1-mark.rutland@arm.com> References: <20221024140846.3555435-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In subsequent patches we'll arrange for architectures to have an ftrace_regs which is entirely distinct from pt_regs. In preparation for this, we need to minimize the use of pt_regs to where strictly necessary in the core ftrace code. This patch adds new ftrace_regs_{get,set}_*() helpers which can be used to manipulate ftrace_regs. When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=3Dy, these can always be used on any ftrace_regs, and when CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=3Dn these can be used when regs are available. A new ftrace_regs_has_args(fregs) helper is added which code can use to check when these are usable. Co-developed-by: Florent Revest Signed-off-by: Florent Revest Signed-off-by: Mark Rutland Cc: Masami Hiramatsu Cc: Steven Rostedt --- arch/powerpc/include/asm/ftrace.h | 17 +++++++++++++++++ arch/s390/include/asm/ftrace.h | 17 +++++++++++++++++ arch/x86/include/asm/ftrace.h | 14 ++++++++++++++ include/linux/ftrace.h | 27 +++++++++++++++++++++++++++ kernel/trace/Kconfig | 6 +++--- 5 files changed, 78 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/f= trace.h index c3eb48f67566..faecb20d78bf 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -44,6 +44,23 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs *= fregs, regs_set_return_ip(&fregs->regs, ip); } =20 +static __always_inline unsigned long +ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs) +{ + return instruction_pointer(&fregs->regs) +} + +#define ftrace_regs_get_argument(fregs, n) \ + regs_get_kernel_argument(&(fregs)->regs, n) +#define ftrace_regs_get_stack_pointer(fregs) \ + kernel_stack_pointer(&(fregs)->regs) +#define ftrace_regs_return_value(fregs) \ + regs_return_value(&(fregs)->regs) +#define ftrace_regs_set_return_value(fregs, ret) \ + regs_set_return_value(&(fregs)->regs, ret) +#define ftrace_override_function_with_return(fregs) \ + override_function_with_return(&(fregs)->regs) + struct ftrace_ops; =20 #define ftrace_graph_func ftrace_graph_func diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h index b8957882404f..5fdc806458aa 100644 --- a/arch/s390/include/asm/ftrace.h +++ b/arch/s390/include/asm/ftrace.h @@ -54,6 +54,12 @@ static __always_inline struct pt_regs *arch_ftrace_get_r= egs(struct ftrace_regs * return NULL; } =20 +static __always_inline unsigned long +ftrace_regs_get_instruction_pointer(const struct ftrace_regs *fregs) +{ + return fregs->regs.psw.addr; +} + static __always_inline void ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, unsigned long ip) @@ -61,6 +67,17 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs *= fregs, fregs->regs.psw.addr =3D ip; } =20 +#define ftrace_regs_get_argument(fregs, n) \ + regs_get_kernel_argument(&(fregs)->regs, n) +#define ftrace_regs_get_stack_pointer(fregs) \ + kernel_stack_pointer(&(fregs)->regs) +#define ftrace_regs_return_value(fregs) \ + regs_return_value(&(fregs)->regs) +#define ftrace_regs_set_return_value(fregs, ret) \ + regs_set_return_value(&(fregs)->regs, ret) +#define ftrace_override_function_with_return(fregs) \ + override_function_with_return(&(fregs)->regs) + /* * When an ftrace registered caller is tracing a function that is * also set by a register_ftrace_direct() call, it needs to be diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h index b73e858bd96f..b3737b42e8a1 100644 --- a/arch/x86/include/asm/ftrace.h +++ b/arch/x86/include/asm/ftrace.h @@ -51,6 +51,20 @@ arch_ftrace_get_regs(struct ftrace_regs *fregs) #define ftrace_regs_set_instruction_pointer(fregs, _ip) \ do { (fregs)->regs.ip =3D (_ip); } while (0) =20 +#define ftrace_regs_get_instruction_pointer(fregs) \ + ((fregs)->regs.ip) + +#define ftrace_regs_get_argument(fregs, n) \ + regs_get_kernel_argument(&(fregs)->regs, n) +#define ftrace_regs_get_stack_pointer(fregs) \ + kernel_stack_pointer(&(fregs)->regs) +#define ftrace_regs_return_value(fregs) \ + regs_return_value(&(fregs)->regs) +#define ftrace_regs_set_return_value(fregs, ret) \ + regs_set_return_value(&(fregs)->regs, ret) +#define ftrace_override_function_with_return(fregs) \ + override_function_with_return(&(fregs)->regs) + struct ftrace_ops; #define ftrace_graph_func ftrace_graph_func void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index e9905f741916..3b13e3c21438 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -125,6 +125,33 @@ static __always_inline struct pt_regs *ftrace_get_regs= (struct ftrace_regs *fregs return arch_ftrace_get_regs(fregs); } =20 +/* + * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs. + * Note: this can be true even when ftrace_get_regs() cannot provide a pt_= regs. + */ +static __always_inline bool ftrace_regs_has_args(struct ftrace_regs *fregs) +{ + if (IS_ENABLED(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)) + return true; + + return ftrace_get_regs(fregs) !=3D NULL; +} + +#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS +#define ftrace_regs_get_instruction_pointer(fregs) \ + instruction_pointer(ftrace_get_regs(fregs)) +#define ftrace_regs_get_argument(fregs, n) \ + regs_get_kernel_argument(ftrace_get_regs(fregs), n) +#define ftrace_regs_get_stack_pointer(fregs) \ + kernel_stack_pointer(ftrace_get_regs(fregs)) +#define ftrace_regs_return_value(fregs) \ + regs_return_value(ftrace_get_regs(fregs)) +#define ftrace_regs_set_return_value(fregs, ret) \ + regs_set_return_value(ftrace_get_regs(fregs), ret) +#define ftrace_override_function_with_return(fregs) \ + override_function_with_return(ftrace_get_regs(fregs)) +#endif + typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); =20 diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index e9e95c790b8e..2c6611c13f99 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -46,10 +46,10 @@ config HAVE_DYNAMIC_FTRACE_WITH_ARGS bool help If this is set, then arguments and stack can be found from - the pt_regs passed into the function callback regs parameter + the ftrace_regs passed into the function callback regs parameter by default, even without setting the REGS flag in the ftrace_ops. - This allows for use of regs_get_kernel_argument() and - kernel_stack_pointer(). + This allows for use of ftrace_regs_get_argument() and + ftrace_regs_get_stack_pointer(). =20 config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE bool --=20 2.30.2