From nobody Thu Sep 18 09:55:42 2025 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 AAFE1C3A5A7 for ; Thu, 8 Dec 2022 09:15:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230330AbiLHJPb (ORCPT ); Thu, 8 Dec 2022 04:15:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230391AbiLHJOl (ORCPT ); Thu, 8 Dec 2022 04:14:41 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A5B84A5AE for ; Thu, 8 Dec 2022 01:13:31 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 59FC4CE233B for ; Thu, 8 Dec 2022 09:13:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABC4BC433D7; Thu, 8 Dec 2022 09:13:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670490808; bh=Hoa73aObPSEr61V8BwDonlIEMV1d/+kTPm058MPAXik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EtVDJ6CaX6ctRP741+6lxXmpiYZzF+TjRp/KjIR/NTIPSan1748KoJvVQCmiWMXY0 e010ogz2UcFmMfCXiTglHK7NPH58QN18V7FIQvURFhrXEZb8NKK41DkZUDQhOtSflp 8Saqrk47n0qh4NhjfE+QF46g4zz5vimKvRjxGgPP4oC8TpVZ6qjvqhbWPdlZD0q2Km /tadawL9XzCt4/7U6gp+2FUufjsq4cr+Y72wTPSJLIaQkWV43tSTucyqP2gUOAv7Yg /Z7EydYfjCyccTqzYtrgCAlq28yeeMlHzzD9im2BJONHI47nmB2DLlf8Gnn4blQfNU dtVECA5OaLihw== From: guoren@kernel.org To: anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de, rostedt@goodmis.org, mhiramat@kernel.org, jolsa@redhat.com, bp@suse.de, jpoimboe@kernel.org, suagrfillet@gmail.com, andy.chiu@sifive.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Guo Ren Subject: [PATCH -next V5 6/7] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support Date: Thu, 8 Dec 2022 04:12:43 -0500 Message-Id: <20221208091244.203407-7-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221208091244.203407-1-guoren@kernel.org> References: <20221208091244.203407-1-guoren@kernel.org> 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" From: Song Shuai This patch adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V. select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide the register_ftrace_direct[_multi] interfaces allowing users to register the customed trampoline (direct_caller) as the mcount for one or more target functions. And modify_ftrace_direct[_multi] are also provided for modifying direct_caller. To make the direct_caller and the other ftrace hooks (eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary register is nominated to store the address of direct_caller in ftrace_regs_caller. After the setting of the address direct_caller by direct_ops->func and the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to by the `jr` inst. Signed-off-by: Song Shuai Tested-by: Guo Ren Signed-off-by: Guo Ren --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/ftrace.h | 6 ++++++ arch/riscv/kernel/mcount-dyn.S | 4 ++++ 3 files changed, 11 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index da59182cb5f1..27c2bc613ecd 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -133,6 +133,7 @@ config RISCV select UACCESS_MEMCPY if !MMU select ZONE_DMA32 if 64BIT select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchab= le-function-entry=3D8) + select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrac= e.h index 84f856a3286e..4539f10fea56 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -114,6 +114,12 @@ struct ftrace_regs; void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); #define ftrace_graph_func ftrace_graph_func + +static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs, uns= igned long addr) +{ + regs->t1 =3D addr; +} + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ =20 #endif /* __ASSEMBLY__ */ diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index 466c6ef217b1..fef7c460f991 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -232,6 +232,7 @@ ENDPROC(ftrace_caller) =20 #else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ ENTRY(ftrace_regs_caller) + move t1, zero SAVE_ABI_REGS 1 PREPARE_ARGS =20 @@ -241,7 +242,10 @@ ftrace_regs_call: =20 =20 RESTORE_ABI_REGS 1 + bnez t1,.Ldirect jr t0 +.Ldirect: + jr t1 ENDPROC(ftrace_regs_caller) =20 ENTRY(ftrace_caller) --=20 2.36.1