From nobody Mon Feb 9 05:52:18 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 BF1C422C35E 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=Zdkjsqu7pyMaRodbsbZ2tTV62BpLIyyINZV+OOi8QYhBFql0sQ4gAJS/EXKraQWV/Bdg1W5HE2lPzN2jFNjIROFxAYV3zcq9bGTskuXQYJT4YUm0pRAXKoEFQ35vp4fEkBlO1AgWKhXxhODSeTjei0o3W/OdPrG5a5708ZOt3vo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738751140; c=relaxed/simple; bh=VyZRdBAMs530KrDX/IvA+7ZtQx5J6svRBc1QlxxrPn4=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=uIk5KgtJ8JgN4E9X4Kl+FBcYMRP9eWu8iaCM+rTEBf2n/Ue93I8Q2RMS/pszlsUCGPcKveEH+zy0D81VgQJ3NFowBuEWyrP//BnC3LDpdLyU9k+xqENBw6jZs8AoaxOAkFIDQW0utg2L6TmRO+aqEvjQgGmMMjRK2qhoGjpfppI= 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=UlswYVN8; 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="UlswYVN8" 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=eu5ZvhRBqGbSk6AaLgfzXy2QPVH2kRteBU9D7EL3a1k=; b=UlswYVN8AYGp3Qft4WUC8TZ31z Q92UHUTApwYK7JqqUtGo265pLOuA5CYDJWcEKFH85ENAHSetAQUujLokh77gWL9ymz6wkacL4CvFG SvKTPHx1Axfbg17rfKfeiAwUyfWgA6ghdtnogGhM8tRP5V8+Wqd7XCkvPdq5NhFvb6u+9kpSooWSw 5BZYHN58RNuNFMUcuH4Vt/t5hi29bCA0txiA9fHrxx21YBp2TwXWd9G4GWEgj/3UGcs66Wm2vnD3m P+fn3oSNjLUhP8/9y/0TLKeMBPX+ptPLFRnHYoivcBcRlmlqjmjWl09C3OWQAQ2mJUuhBYBl5aK4+ wOvxis/g==; 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 1tfcb3-00000004GPe-2FDa; Wed, 05 Feb 2025 10:25:30 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id DEA513078A4; Wed, 5 Feb 2025 11:25:27 +0100 (CET) Message-ID: <20250205102449.682083733@infradead.org> User-Agent: quilt/0.66 Date: Wed, 05 Feb 2025 11:21:33 +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 13/24] perf: Simplify perf_event_alloc() 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" Using the previous simplifications, transition perf_event_alloc() to the cleanup way of things -- reducing error path magic. Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 60 +++++++++++++++++++---------------------------= ----- 1 file changed, 23 insertions(+), 37 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5360,6 +5361,8 @@ static void __free_event(struct perf_eve call_rcu(&event->rcu_head, free_event_rcu); } =20 +DEFINE_FREE(__free_event, struct perf_event *, if (_T) __free_event(_T)) + /* vs perf_event_alloc() success */ static void _free_event(struct perf_event *event) { @@ -12238,7 +12241,6 @@ perf_event_alloc(struct perf_event_attr void *context, int cgroup_fd) { struct pmu *pmu; - struct perf_event *event; struct hw_perf_event *hwc; long err =3D -EINVAL; int node; @@ -12253,8 +12255,8 @@ perf_event_alloc(struct perf_event_attr } =20 node =3D (cpu >=3D 0) ? cpu_to_node(cpu) : -1; - event =3D kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO, - node); + struct perf_event *event __free(__free_event) =3D + kmem_cache_alloc_node(perf_event_cache, GFP_KERNEL | __GFP_ZERO, node); if (!event) return ERR_PTR(-ENOMEM); =20 @@ -12361,65 +12363,53 @@ perf_event_alloc(struct perf_event_attr * See perf_output_read(). */ if (has_inherit_and_sample_read(attr) && !(attr->sample_type & PERF_SAMPL= E_TID)) - goto err; + return ERR_PTR(-EINVAL); =20 if (!has_branch_stack(event)) event->attr.branch_sample_type =3D 0; =20 pmu =3D perf_init_event(event); - if (IS_ERR(pmu)) { - err =3D PTR_ERR(pmu); - goto err; - } + if (IS_ERR(pmu)) + return (void*)pmu; =20 /* * Disallow uncore-task events. Similarly, disallow uncore-cgroup * events (they don't make sense as the cgroup will be different * on other CPUs in the uncore mask). */ - if (pmu->task_ctx_nr =3D=3D perf_invalid_context && (task || cgroup_fd != =3D -1)) { - err =3D -EINVAL; - goto err; - } + if (pmu->task_ctx_nr =3D=3D perf_invalid_context && (task || cgroup_fd != =3D -1)) + return ERR_PTR(-EINVAL); =20 if (event->attr.aux_output && (!(pmu->capabilities & PERF_PMU_CAP_AUX_OUTPUT) || - event->attr.aux_pause || event->attr.aux_resume)) { - err =3D -EOPNOTSUPP; - goto err; - } + event->attr.aux_pause || event->attr.aux_resume)) + return ERR_PTR(-EOPNOTSUPP); =20 - if (event->attr.aux_pause && event->attr.aux_resume) { - err =3D -EINVAL; - goto err; - } + if (event->attr.aux_pause && event->attr.aux_resume) + return ERR_PTR(-EINVAL); =20 if (event->attr.aux_start_paused) { - if (!(pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE)) { - err =3D -EOPNOTSUPP; - goto err; - } + if (!(pmu->capabilities & PERF_PMU_CAP_AUX_PAUSE)) + return ERR_PTR(-EOPNOTSUPP); event->hw.aux_paused =3D 1; } =20 if (cgroup_fd !=3D -1) { err =3D perf_cgroup_connect(cgroup_fd, event, attr, group_leader); if (err) - goto err; + return ERR_PTR(err); } =20 err =3D exclusive_event_init(event); if (err) - goto err; + return ERR_PTR(err); =20 if (has_addr_filter(event)) { event->addr_filter_ranges =3D kcalloc(pmu->nr_addr_filters, sizeof(struct perf_addr_filter_range), GFP_KERNEL); - if (!event->addr_filter_ranges) { - err =3D -ENOMEM; - goto err; - } + if (!event->addr_filter_ranges) + return ERR_PTR(-ENOMEM); =20 /* * Clone the parent's vma offsets: they are valid until exec() @@ -12443,23 +12433,19 @@ perf_event_alloc(struct perf_event_attr if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) { err =3D get_callchain_buffers(attr->sample_max_stack); if (err) - goto err; + return ERR_PTR(err); event->attach_state |=3D PERF_ATTACH_CALLCHAIN; } } =20 err =3D security_perf_event_alloc(event); if (err) - goto err; + return ERR_PTR(err); =20 /* symmetric to unaccount_event() in _free_event() */ account_event(event); =20 - return event; - -err: - __free_event(event); - return ERR_PTR(err); + return_ptr(event); } =20 static int perf_copy_attr(struct perf_event_attr __user *uattr,