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 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 232AEC531D0 for ; Mon, 27 Jul 2026 14:30:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=TelY/e6rhqBnbaI//+7mxab5yF5lSU4GighDsL8mjtU=; b=SBJ2N0+8y+aUMPgQJE/u0Ie5W0 FpKJ0fNgnbBEn2mdxcdYS1WeeKejOge6fNtHpyxF2Zjh84CISR6QYDZSM6m2i4j5QsuIlpX5opX+6 iyq4WYv4nNCTFnF36btPpkneEY5CuTifQqReo39LTiWQkJgNHabV3oLWbakb5f97tgUJKfwTWL0xL LwEl0tNaJ8XRDtwmrBf1UEY7MPS+cvZMuDovldFrbX1S0yxpaZ/LFBUN3VQVP0ZoivorTYoNNdemv xpfuDl2jK58Y/zI2N0rR2iTcJPS07jHugavDNHVOEsb697Vse2o1yHlEI4gbiCTyWCfyxn+EldCg3 nA9dSE5w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1woML6-00000002zji-2JHg; Mon, 27 Jul 2026 14:29:56 +0000 Received: from out-176.mta1.migadu.com ([95.215.58.176]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1woML1-00000002zho-1xFL for linux-arm-kernel@lists.infradead.org; Mon, 27 Jul 2026 14:29:52 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785162589; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TelY/e6rhqBnbaI//+7mxab5yF5lSU4GighDsL8mjtU=; b=ZyLvmu/MHYpDNbUorLcBJbddnw77+HeD/DLH4+630pkX74zlnxiewseIkfb1Qk4Jrr5wk1 p/eTme8zssK5AaRtUalWpSb6uaj87dcJkyHuzHz+PqgI2S2cA7G0GafjxFncbd3VXndOc0 h047oJQZ2gXZPMmOr+7CsnF2v8yKmCE= From: Leon Hwang To: Catalin Marinas , Will Deacon , Steven Rostedt , Masami Hiramatsu , Mark Rutland , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Shuah Khan , Leon Hwang Cc: bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH 1/2] arm64: ftrace: enable single ftrace_ops for direct calls Date: Mon, 27 Jul 2026 22:28:43 +0800 Message-ID: <20260727142844.21212-2-leon.hwang@linux.dev> In-Reply-To: <20260727142844.21212-1-leon.hwang@linux.dev> References: <20260727142844.21212-1-leon.hwang@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260727_072951_654278_6BEED391 X-CRM114-Status: GOOD ( 11.76 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The BPF tracing multi link updates several direct-call sites through one ftrace_ops. Its implementation is therefore gated by HAVE_SINGLE_FTRACE_DIRECT_OPS in addition to DYNAMIC_FTRACE_WITH_DIRECT_CALLS. Select HAVE_SINGLE_FTRACE_DIRECT_OPS whenever arm64 enables dynamic ftrace direct calls. This enables BPF tracing multi links on arm64. Also generalize the unreachable-trampoline comment because the single-ops path does not use ops->direct_call. Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Leon Hwang --- arch/arm64/Kconfig | 2 ++ arch/arm64/kernel/ftrace.c | 3 +-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 0de419ed780f..c98dca76859b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -188,6 +188,8 @@ config ARM64 CLANG_SUPPORTS_DYNAMIC_FTRACE_WITH_ARGS) select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS \ if DYNAMIC_FTRACE_WITH_ARGS + select HAVE_SINGLE_FTRACE_DIRECT_OPS \ + if DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS \ if (DYNAMIC_FTRACE_WITH_ARGS && !CFI && \ (CC_IS_CLANG || !CC_OPTIMIZE_FOR_SIZE)) diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index e1a3c0b3a051..56ba72a87dfa 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -301,8 +301,7 @@ static bool ftrace_find_callable_addr(struct dyn_ftrace *rec, /* * If a custom trampoline is unreachable, rely on the ftrace_caller - * trampoline which knows how to indirectly reach that trampoline - * through ops->direct_call. + * trampoline which knows how to indirectly reach that trampoline. */ if (*addr != FTRACE_ADDR && !reachable_by_bl(*addr, pc)) *addr = FTRACE_ADDR; -- 2.55.0