From nobody Mon Feb 9 13:01:40 2026 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83F0722C32D for ; Wed, 5 Feb 2025 10:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738751140; cv=none; b=dE5hr5goKRV7pZ7zxy570QiqkbRdW4WBVVdbq0BrG2dU7jIR+Z/XTh2vZIU0ETGFmye7ZLDvKfIKvvsIX+dSDDZjxrSDqQnix4OCXsuzHxQusw1uMX/b8cjyFVHPhoIgAPzszZrsNNO+z1OlnPUrh749D8pE7B9HKtwGPpe/c2M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738751140; c=relaxed/simple; bh=ejCK5vxQbMv7jatQ4Hem5aLISpgvatcVYDYPSTmRmrA=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=IjoHcy9UEe0H9vz43UYQpKvMTr7SWAovEVdeMVSQcY3/eIybKeBA/N6X2cNM2Uj4cWzbELdDAN68axIUhVuzQxbVdQl4WZg0Ah5e/gSY3B6uIru2St2Fch6YAmem59c+GwqYOQHSIV02TQT+mtNDIWWgnxK9Lq6KSzKgBH0az9w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=HL+TPPiP; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="HL+TPPiP" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=tN2WqQdsW+7vvSTtR2P1++oVZtUzPhTpdLXdVmnWZ8A=; b=HL+TPPiP0w1pEuRLpID87rC5gr sO/toELS3ke0IW2IsXEmrw1Bp8MjIeDxUjcyjwnsqR0EuxImPER+Fkt2vCaOUJ7+eLTjP31uzzwon ACetxHE9QMf1uk/XkVu7mGiOq9VAnaKnvxYyIzqhKMChPF8LFCTNiEdfkfbshkEDYw8VTMAnsHpuy n7edfUceu1nwpjpRWEhgYb1I+F9E99ubFojr7SVOIo4IUb4hEJogabcB9dEgd7Bv96pS2cg0ICLh5 7t0BtfGA0OQN4t4FK/c3RjYXetxZ/oQsh6teN6Mj3I1w8xD8eOzAt9CP52BSFYJ7VM+9Wm5fSFm8q 7v4cKF8g==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tfcb2-00000004GPS-2hZU; Wed, 05 Feb 2025 10:25:28 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id B55D530050D; Wed, 5 Feb 2025 11:25:27 +0100 (CET) Message-ID: <20250205102448.458857702@infradead.org> User-Agent: quilt/0.66 Date: Wed, 05 Feb 2025 11:21:22 +0100 From: Peter Zijlstra To: mingo@kernel.org, ravi.bangoria@amd.com, lucas.demarchi@intel.com Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, willy@infradead.org, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com Subject: [PATCH v2 02/24] perf: Ensure bpf_perf_link path is properly serialized References: <20250205102120.531585416@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Ravi reported that the bpf_perf_link_attach() usage of perf_event_set_bpf_prog() is not serialized by ctx->mutex, unlike the PERF_EVENT_IOC_SET_BPF case. Reported-by: Ravi Bangoria Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6001,6 +6001,9 @@ static int perf_event_set_output(struct static int perf_event_set_filter(struct perf_event *event, void __user *ar= g); static int perf_copy_attr(struct perf_event_attr __user *uattr, struct perf_event_attr *attr); +static int __perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie); =20 static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsign= ed long arg) { @@ -6063,7 +6066,7 @@ static long _perf_ioctl(struct perf_even if (IS_ERR(prog)) return PTR_ERR(prog); =20 - err =3D perf_event_set_bpf_prog(event, prog, 0); + err =3D __perf_event_set_bpf_prog(event, prog, 0); if (err) { bpf_prog_put(prog); return err; @@ -10790,8 +10793,9 @@ static inline bool perf_event_is_tracing return false; } =20 -int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *pro= g, - u64 bpf_cookie) +static int __perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) { bool is_kprobe, is_uprobe, is_tracepoint, is_syscall_tp; =20 @@ -10829,6 +10833,20 @@ int perf_event_set_bpf_prog(struct perf_ return perf_event_attach_bpf_prog(event, prog, bpf_cookie); } =20 +int perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) +{ + struct perf_event_context *ctx; + int ret; + + ctx =3D perf_event_ctx_lock(event); + ret =3D __perf_event_set_bpf_prog(event, prog, bpf_cookie); + perf_event_ctx_unlock(event, ctx); + + return ret; +} + void perf_event_free_bpf_prog(struct perf_event *event) { if (!perf_event_is_tracing(event)) { @@ -10848,7 +10866,15 @@ static void perf_event_free_filter(struc { } =20 -int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *pro= g, +static int __perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) +{ + return -ENOENT; +} + +int perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, u64 bpf_cookie) { return -ENOENT;