From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-235.mta0.migadu.com [91.218.175.235]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BEE9937E2E1 for ; Fri, 16 Oct 2026 14:20:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.235 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792160456; cv=none; b=fFnYpLuRt77IVhOANpoxHvFeNk4M8lCp14xnMX23ba5+MkznUGOCgs4OZsHXHhCyIsMpVq6bKFw5j66Bz4eP62tAIYq4vE3AI2hN6RcQrDX9blqqMA0KHBKAtPf/Bld6Q5zaVla5WnURcqPAm8kSot7lduVjBt6sJBNQfxofdDY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792160456; c=relaxed/simple; bh=UnkKdmlxZrAfNilILa/BseSLcG/fV1+Rqm2JjBeoV1A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rGdA3G6Tg97M4XRFH3zhmk7wY51V+8inE5DYutn1si2BYV0m68AtgsOL51y2JDJev1IzHN6AOTcnTACYkixUt9vv2Rj/pxnPLoEfAHRioEfJ5lyrE19WMSmo23s6g6HSTDO2bKn3cwM7L6XKv/ydYeoHFlEiAEjJJT2PJTKAHn4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=XxTrDQuP; arc=none smtp.client-ip=91.218.175.235 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="XxTrDQuP" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=UnkKdmlxZrAfNilILa/BseSLcG/fV1+Rqm2JjBeoV1A=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792160451; v=1; x=1792765251; b=XxTrDQuPmQ8p8k+5T8lgK7jo6Tp6IZMhkff8h3aGwmbfhdwuEz6iyKwk8eMTr0RCLGQzCytV iTMqzo1Sv3Lw5oCSQqCxJsEaFFOavt9wRgyFGyQc8xDILAWjsrRNQ69EKG10ng7jDcEbxEl0OrX HU2+DxcMuATmM2llxFQj3Gvg= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id ce7dafab37ac9838; Fri, 16 Oct 2026 14:20:51 +0000 X-Mizu-Trace-ID: ce7dafab37ac9838 X-Migadu-Flow: FLOW_OUT From: Leon Hwang To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , linux-kernel@vger.kernel.org, Leon Hwang Subject: [PATCH bpf-next 1/2] bpf: Initialize ftrace_managed in bpf_trampoline_get() Date: Fri, 16 Oct 2026 22:20:13 +0800 Message-ID: <20261016142014.12420-2-leon.hwang@linux.dev> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261016142014.12420-1-leon.hwang@linux.dev> References: <20261016142014.12420-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit A trampoline managed by ftrace is determined by its target, that said ftrace_managed is already known when the trampoline is initialized. so, set 'ftrace_managed = tr->ip != 0' in bpf_trampoline_get() instead of relying on the first regular or tracing_multi attachment to set it. This makes the backend selection independent of attachment order and keeps the registration callbacks focused on installing the trampoline. No functional change intended. Acked-by: Jiri Olsa Signed-off-by: Leon Hwang --- kernel/bpf/trampoline.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 24edb59238f3..17f2a8133f61 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -475,18 +475,11 @@ static int register_fentry(struct bpf_trampoline *tr, struct bpf_tramp_image *im void *data __maybe_unused) { void *new_addr = im->image; - void *ip = tr->func.addr; - unsigned long faddr; int ret; - faddr = ftrace_location((unsigned long)ip); - if (faddr) { + if (tr->func.ftrace_managed) { if (!tr->fops) return -ENOTSUPP; - tr->func.ftrace_managed = true; - } - - if (tr->func.ftrace_managed) { ret = direct_ops_add(tr, new_addr); } else { ret = bpf_trampoline_update_fentry(tr, 0, NULL, new_addr); @@ -1286,6 +1279,7 @@ struct bpf_trampoline *bpf_trampoline_get(u64 key, memcpy(&tr->func.model, &tgt_info->fmodel, sizeof(tgt_info->fmodel)); tr->func.addr = (void *)tgt_info->tgt_addr; + tr->func.ftrace_managed = tr->ip != 0; out: trampoline_unlock(tr); return tr; @@ -1649,7 +1643,6 @@ static int register_fentry_multi(struct bpf_trampoline *tr, struct bpf_tramp_ima if (bpf_trampoline_use_jmp(tr->flags)) addr = ftrace_jmp_set(addr); - tr->func.ftrace_managed = true; ftrace_hash_add(data->reg, data->entry, ip, addr); tr->cur_image = im; return 0; -- 2.55.0