From patchwork Mon Nov 28 10:12:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guo Ren X-Patchwork-Id: 13057230 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D8745C433FE for ; Mon, 28 Nov 2022 10:12:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EPVU2TtXRvN12h3S4O06KMkq0Xam5ARSp3u6PtQ4Avo=; b=Zryz1hcxkXj6j5 gWd+V8slwRclHUCeUBmGYaF7a3zVsicuDPtm2hd3rbsJsA4u02411DMWiuuXq1S+bQbfumhHrigcZ eFESD/Vp+bapw9BF1iW3uDWihmTq+w1XYLuLJKI+UOzaKIevRlbydYHFcr/mEvevblVpgzWidLLMF mOwK8A92MqRGoYcJsUAG9k8TlP7SAwltQiPb9s4Bi3sQSJDgbqOgRXMktIPX5zva9NSfglmpDc0kR 9EU5F3Qf1q0JdO3IEnmdwS63FsxPHsMa6oYWFccSnr2RJqS/12rmdixuHd0kmRi8I19uZMNHU45mB g+RepDmo8gjQ7BjNfcXQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ozb7j-000wl3-R5; Mon, 28 Nov 2022 10:12:27 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ozb7g-000wje-DV for linux-riscv@lists.infradead.org; Mon, 28 Nov 2022 10:12:26 +0000 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 ams.source.kernel.org (Postfix) with ESMTPS id 1194DB80C90; Mon, 28 Nov 2022 10:12:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60462C433D7; Mon, 28 Nov 2022 10:12:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669630341; bh=OR1E22SfIW28jaKNXJ/IaUulMe996ymxezMSEdVKYYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=svOz3bsmumYNfOUkFxQf/UNebxKeByl7zQCW8z+bWGmjHi7pbAKwaQmz83I9oTz5w dFzgZfkrSfRYRGOiOWMfH4/rwcHKVgt0WYWszRbYzbEmCxjewVYj10mF86mGvAkVrt ik4WNd1kLRvqQAIvg3AuuMBEMHGdr43GyrPc/gUUhtmq1LXgn5VH6FuzpL1XRngr+6 4o29xwf3MpRIrHqDfsaoxpiuqr+xz3OuQj6aIxnAnWxR2SJW2iPQXYb5Mm6MUH7Nz+ hdMB9ms26bTzJVZyixg9NYLLOQ07WNWZYl8Mi0y43dmr8n/JRgGNsSNCsHGxQT/kGi GyhzJhTtpmLjw== From: guoren@kernel.org To: suagrfillet@gmail.com, guoren@kernel.org Cc: aou@eecs.berkeley.edu, bp@suse.de, jolsa@redhat.com, jpoimboe@kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, mark.rutland@arm.com, mhiramat@kernel.org, palmer@dabbelt.com, paul.walmsley@sifive.com, peterz@infradead.org, rostedt@goodmis.org Subject: [PATCH 1/2] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support Date: Mon, 28 Nov 2022 05:12:00 -0500 Message-Id: <20221128101201.4144527-1-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221128_021224_787157_A9FD9C38 X-CRM114-Status: GOOD ( 13.61 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 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 Co-developed-by: Guo Ren Signed-off-by: Guo Ren --- Remove modification of mcount-dyn.S. (Guo Ren) --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/ftrace.h | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 1d0e5838b11b..2828537abfcd 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -278,6 +278,7 @@ config ARCH_RV64I select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && $(cc-option,-fpatchable-function-entry=8) select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE + select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index 84f856a3286e..d2c159cdfa5c 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -114,6 +114,32 @@ 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, unsigned long addr) +{ + /* + * Backup origin detour target (t0) in t1, and set t0 with addr. + * + * Here is the sample code for riscv direct_caller: + * + * addi sp,sp,-16 + * move t0,t1 + * ^^^^^^^^^^ + * sd t0,0(sp) + * sd ra,8(sp) + * call my_direct_func1 + * ld t0,0(sp) + * ld ra,8(sp) + * addi sp,sp,16 + * jr t0 + * + * (Set t0 with t1 for continuous detour, because t1 contains origin detour + * target) + */ + regs->t1 = regs->t0; + regs->t0 = addr; +} + #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */ #endif /* __ASSEMBLY__ */