From nobody Fri Feb 13 05:44:04 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 6C93B53E25; Fri, 12 Apr 2024 10:03:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712916215; cv=none; b=RrW9+xSLkt+rTM6EhjP0RLPP4jgfCpZu+RhYkBuhf2Bc49MJIhW9T0ckwnK+Xqyhh6YwCKkDps8gYaQpxJvwAtuQLyPGch5/Aqg317SreNcdccDaKCzo/B+u1uLFce4p7CwUCCHiPUw1xutp5T1EvUG15yznYsmBDM7xqZDf+68= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712916215; c=relaxed/simple; bh=Gkf3TjsXOGNG8muDa/jBNo/J4kUcsE62c5t2fcMoIEU=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=Qgee+UBfNnibIbJ5wONYf+kq7vHqbR2NXMRwyLuQaOyvFhU3Zz6yZGUw4YcvA88y3icov1Og5Bl/ZRMFJIAufcaADb4qcy9seOjCPCnxaugGCsuF3IVhLgd3oa+hVPcfTldKS10sAu7TXZNVRNnjxvPTa9seYtEEPztxvUcm87o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=kIBQ+yUr; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=F7DBX9x6; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="kIBQ+yUr"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="F7DBX9x6" Date: Fri, 12 Apr 2024 10:03:27 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1712916208; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SqysCUtdDGvYpQRl+A32nYoQQOTsg6cOew7ligvXDWk=; b=kIBQ+yUraiyGLphQyY/SKklrTNXOrxW28IR80ICE+HozPqpBfk9wpcor6qPG13kMAgOAcF X+9oHHexjB3xjs8eiPoVHpBcgS93LJdvB8B/QXMizFLUIZBV1ZBz5kwq0lVKuEW37eqFtI spz6sW35ueKGBusnVOExvSj6qVaul5rP+ZuFswcJjnXPZ6K1TzvwbuIzYNnQvyjAV9Pqzv 1nnveTlZ4JJfip8e7VT2YVEsUpEEUZK+V4PlGj+IdN81xekmtTCB3cb+XYfJ0vFQm/2D2k WMbxNuueQog6GzUaPHSrx0QzjbomKkk7Kh5by71DyTB6V3jdtgoDwYh7Itwssg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1712916208; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SqysCUtdDGvYpQRl+A32nYoQQOTsg6cOew7ligvXDWk=; b=F7DBX9x69hud3Y7E5JJg5FXkgdQvfLpmy+hhj2yfSrs9kaN4QoyOwQyTI9xpMpjlSbJ5IW LAURAJrh5m79TEDA== From: "tip-bot2 for Kyle Huey" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf/bpf: Reorder bpf_overflow_handler() ahead of __perf_event_overflow() Cc: Kyle Huey , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240412015019.7060-2-khuey@kylehuey.com> References: <20240412015019.7060-2-khuey@kylehuey.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <171291620724.10875.15819552793312286948.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the perf/core branch of tip: Commit-ID: 4c03fe11b96bda60610aca77002e83f37b4a2242 Gitweb: https://git.kernel.org/tip/4c03fe11b96bda60610aca77002e83f37= b4a2242 Author: Kyle Huey AuthorDate: Thu, 11 Apr 2024 18:50:13 -07:00 Committer: Ingo Molnar CommitterDate: Fri, 12 Apr 2024 11:49:48 +02:00 perf/bpf: Reorder bpf_overflow_handler() ahead of __perf_event_overflow() This will allow __perf_event_overflow() to call bpf_overflow_handler(). Signed-off-by: Kyle Huey Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20240412015019.7060-2-khuey@kylehuey.com --- kernel/events/core.c | 183 +++++++++++++++++++++--------------------- 1 file changed, 92 insertions(+), 91 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index fd94e45..ca0a906 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9563,6 +9563,98 @@ static inline bool sample_is_allowed(struct perf_eve= nt *event, struct pt_regs *r return true; } =20 +#ifdef CONFIG_BPF_SYSCALL +static void bpf_overflow_handler(struct perf_event *event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct bpf_perf_event_data_kern ctx =3D { + .data =3D data, + .event =3D event, + }; + struct bpf_prog *prog; + int ret =3D 0; + + ctx.regs =3D perf_arch_bpf_user_pt_regs(regs); + if (unlikely(__this_cpu_inc_return(bpf_prog_active) !=3D 1)) + goto out; + rcu_read_lock(); + prog =3D READ_ONCE(event->prog); + if (prog) { + perf_prepare_sample(data, event, regs); + ret =3D bpf_prog_run(prog, &ctx); + } + rcu_read_unlock(); +out: + __this_cpu_dec(bpf_prog_active); + if (!ret) + return; + + event->orig_overflow_handler(event, data, regs); +} + +static int perf_event_set_bpf_handler(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) +{ + if (event->overflow_handler_context) + /* hw breakpoint or kernel counter */ + return -EINVAL; + + if (event->prog) + return -EEXIST; + + if (prog->type !=3D BPF_PROG_TYPE_PERF_EVENT) + return -EINVAL; + + if (event->attr.precise_ip && + prog->call_get_stack && + (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) || + event->attr.exclude_callchain_kernel || + event->attr.exclude_callchain_user)) { + /* + * On perf_event with precise_ip, calling bpf_get_stack() + * may trigger unwinder warnings and occasional crashes. + * bpf_get_[stack|stackid] works around this issue by using + * callchain attached to perf_sample_data. If the + * perf_event does not full (kernel and user) callchain + * attached to perf_sample_data, do not allow attaching BPF + * program that calls bpf_get_[stack|stackid]. + */ + return -EPROTO; + } + + event->prog =3D prog; + event->bpf_cookie =3D bpf_cookie; + event->orig_overflow_handler =3D READ_ONCE(event->overflow_handler); + WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); + return 0; +} + +static void perf_event_free_bpf_handler(struct perf_event *event) +{ + struct bpf_prog *prog =3D event->prog; + + if (!prog) + return; + + WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler); + event->prog =3D NULL; + bpf_prog_put(prog); +} +#else +static int perf_event_set_bpf_handler(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) +{ + return -EOPNOTSUPP; +} + +static void perf_event_free_bpf_handler(struct perf_event *event) +{ +} +#endif + /* * Generic event overflow handling, sampling. */ @@ -10441,97 +10533,6 @@ static void perf_event_free_filter(struct perf_eve= nt *event) ftrace_profile_free_filter(event); } =20 -#ifdef CONFIG_BPF_SYSCALL -static void bpf_overflow_handler(struct perf_event *event, - struct perf_sample_data *data, - struct pt_regs *regs) -{ - struct bpf_perf_event_data_kern ctx =3D { - .data =3D data, - .event =3D event, - }; - struct bpf_prog *prog; - int ret =3D 0; - - ctx.regs =3D perf_arch_bpf_user_pt_regs(regs); - if (unlikely(__this_cpu_inc_return(bpf_prog_active) !=3D 1)) - goto out; - rcu_read_lock(); - prog =3D READ_ONCE(event->prog); - if (prog) { - perf_prepare_sample(data, event, regs); - ret =3D bpf_prog_run(prog, &ctx); - } - rcu_read_unlock(); -out: - __this_cpu_dec(bpf_prog_active); - if (!ret) - return; - - event->orig_overflow_handler(event, data, regs); -} - -static int perf_event_set_bpf_handler(struct perf_event *event, - struct bpf_prog *prog, - u64 bpf_cookie) -{ - if (event->overflow_handler_context) - /* hw breakpoint or kernel counter */ - return -EINVAL; - - if (event->prog) - return -EEXIST; - - if (prog->type !=3D BPF_PROG_TYPE_PERF_EVENT) - return -EINVAL; - - if (event->attr.precise_ip && - prog->call_get_stack && - (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) || - event->attr.exclude_callchain_kernel || - event->attr.exclude_callchain_user)) { - /* - * On perf_event with precise_ip, calling bpf_get_stack() - * may trigger unwinder warnings and occasional crashes. - * bpf_get_[stack|stackid] works around this issue by using - * callchain attached to perf_sample_data. If the - * perf_event does not full (kernel and user) callchain - * attached to perf_sample_data, do not allow attaching BPF - * program that calls bpf_get_[stack|stackid]. - */ - return -EPROTO; - } - - event->prog =3D prog; - event->bpf_cookie =3D bpf_cookie; - event->orig_overflow_handler =3D READ_ONCE(event->overflow_handler); - WRITE_ONCE(event->overflow_handler, bpf_overflow_handler); - return 0; -} - -static void perf_event_free_bpf_handler(struct perf_event *event) -{ - struct bpf_prog *prog =3D event->prog; - - if (!prog) - return; - - WRITE_ONCE(event->overflow_handler, event->orig_overflow_handler); - event->prog =3D NULL; - bpf_prog_put(prog); -} -#else -static int perf_event_set_bpf_handler(struct perf_event *event, - struct bpf_prog *prog, - u64 bpf_cookie) -{ - return -EOPNOTSUPP; -} -static void perf_event_free_bpf_handler(struct perf_event *event) -{ -} -#endif - /* * returns true if the event is a tracepoint, or a kprobe/upprobe created * with perf_event_open()