From nobody Tue Feb 10 19:16:42 2026 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 34DD222B584 for ; Wed, 5 Feb 2025 10:25:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738751138; cv=none; b=bzkfe9E6b1CBPhIoBx41gs9rdrndsKI4p5Qn1HN57zrXvkF00beNDWhFHf2EUPqLRUp8UWGatmrGAewJ84qoYljbwShC5laYiw8R26AFrolwYdKvVgFgnDyBhNOa3+gRP2YHd9BCWehxlung2RAKmXfcpiMJAdQ5wUB3CSwG6d4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738751138; c=relaxed/simple; bh=Uo3iRwMo30qUuwd+fK7rUxoC49gNZhQz6oTLxcvKrjw=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=e2IubtZardAlouXBmbahD1X4Go1F6hgBLMfIqxtxMNoQZVAUMR5mQurfWqiI2lLhju5W2offX/4s/Zwo35X6j6SkioM4Lcg6RdxKjuF420p3pfKgjYyKooUJ2WigjKkt5Hbmn1yqUE69m2n1mIMTOxhhCtAUzFi3LpUcohKnlPw= 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=egFaWgvu; arc=none smtp.client-ip=90.155.92.199 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="egFaWgvu" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=0c5KDEJ1EMCTvwH6BbR0x0uKuseQOdbaYO4MmFZng44=; b=egFaWgvumZPBW/cOOY2E4oXebI zc10uTwSyWLGuRUeNBdleXsnVcwgO72cTxGNbANZ2hlMUxBS7yFqYnorXnUOMUhNraNUH3ixcCPS3 c+1VKb7w69g3nt1EvpBTMClR4NyHSvwPRNN0vrPTmNsbbI4N6UKnCnqIvmkR+vwhS8o8ndsVLTtXy sKscBHGLRDVrakmbtWlyjsQZB9A7Q/9z1u/QZX/l4X1LaoRUyJVpxoD7laHfqp6vdfqSr1vwa79om 989I3TahhyrbhWiYJtMeIo5hm7RpWuMh9LvgJN1mVMTiidHVvMCqsQ9t6JegDU8zcaECYIgRGdr2u i4M4aPsQ==; Received: from 77-249-17-89.cable.dynamic.v4.ziggo.nl ([77.249.17.89] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tfcb3-0000000GbmC-23Lr; Wed, 05 Feb 2025 10:25:29 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id D34A23061EE; Wed, 5 Feb 2025 11:25:27 +0100 (CET) Message-ID: <20250205102449.342213679@infradead.org> User-Agent: quilt/0.66 Date: Wed, 05 Feb 2025 11:21:30 +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 10/24] perf: Simplify perf_pmu_register() error path 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" The error path of perf_pmu_register() is of course very similar to a subset of perf_pmu_unregister(). Extract this common part in perf_pmu_free() and simplify things. Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 67 ++++++++++++++++++++++------------------------= ----- 1 file changed, 30 insertions(+), 37 deletions(-) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11605,11 +11605,6 @@ static int perf_event_idx_default(struct return 0; } =20 -static void free_pmu_context(struct pmu *pmu) -{ - free_percpu(pmu->cpu_pmu_context); -} - /* * Let userspace know that this PMU supports address range filtering: */ @@ -11815,6 +11810,7 @@ static int pmu_dev_alloc(struct pmu *pmu =20 free_dev: put_device(pmu->dev); + pmu->dev =3D NULL; goto out; } =20 @@ -11836,25 +11832,38 @@ static bool idr_cmpxchg(struct idr *idr, return true; } =20 +static void perf_pmu_free(struct pmu *pmu) +{ + free_percpu(pmu->pmu_disable_count); + if (pmu_bus_running && pmu->dev && pmu->dev !=3D PMU_NULL_DEV) { + if (pmu->nr_addr_filters) + device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); + device_del(pmu->dev); + put_device(pmu->dev); + } + free_percpu(pmu->cpu_pmu_context); +} + int perf_pmu_register(struct pmu *pmu, const char *name, int type) { int cpu, ret, max =3D PERF_TYPE_MAX; =20 + pmu->type =3D -1; + mutex_lock(&pmus_lock); ret =3D -ENOMEM; pmu->pmu_disable_count =3D alloc_percpu(int); if (!pmu->pmu_disable_count) goto unlock; =20 - pmu->type =3D -1; if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) { ret =3D -EINVAL; - goto free_pdc; + goto free; } =20 if (WARN_ONCE(pmu->scope >=3D PERF_PMU_MAX_SCOPE, "Can not register a pmu= with an invalid scope.\n")) { ret =3D -EINVAL; - goto free_pdc; + goto free; } =20 pmu->name =3D name; @@ -11864,24 +11873,23 @@ int perf_pmu_register(struct pmu *pmu, c =20 ret =3D idr_alloc(&pmu_idr, NULL, max, 0, GFP_KERNEL); if (ret < 0) - goto free_pdc; + goto free; =20 WARN_ON(type >=3D 0 && ret !=3D type); =20 - type =3D ret; - pmu->type =3D type; + pmu->type =3D ret; atomic_set(&pmu->exclusive_cnt, 0); =20 if (pmu_bus_running && !pmu->dev) { ret =3D pmu_dev_alloc(pmu); if (ret) - goto free_idr; + goto free; } =20 ret =3D -ENOMEM; pmu->cpu_pmu_context =3D alloc_percpu(struct perf_cpu_pmu_context); if (!pmu->cpu_pmu_context) - goto free_dev; + goto free; =20 for_each_possible_cpu(cpu) { struct perf_cpu_pmu_context *cpc; @@ -11922,8 +11930,10 @@ int perf_pmu_register(struct pmu *pmu, c /* * Now that the PMU is complete, make it visible to perf_try_init_event(). */ - if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu)) - goto free_context; + if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu)) { + ret =3D -EINVAL; + goto free; + } list_add_rcu(&pmu->entry, &pmus); =20 ret =3D 0; @@ -11932,20 +11942,10 @@ int perf_pmu_register(struct pmu *pmu, c =20 return ret; =20 -free_context: - free_percpu(pmu->cpu_pmu_context); - -free_dev: - if (pmu->dev && pmu->dev !=3D PMU_NULL_DEV) { - device_del(pmu->dev); - put_device(pmu->dev); - } - -free_idr: - idr_remove(&pmu_idr, pmu->type); - -free_pdc: - free_percpu(pmu->pmu_disable_count); +free: + if (pmu->type >=3D 0) + idr_remove(&pmu_idr, pmu->type); + perf_pmu_free(pmu); goto unlock; } EXPORT_SYMBOL_GPL(perf_pmu_register); @@ -11964,14 +11964,7 @@ void perf_pmu_unregister(struct pmu *pmu synchronize_srcu(&pmus_srcu); synchronize_rcu(); =20 - free_percpu(pmu->pmu_disable_count); - if (pmu_bus_running && pmu->dev && pmu->dev !=3D PMU_NULL_DEV) { - if (pmu->nr_addr_filters) - device_remove_file(pmu->dev, &dev_attr_nr_addr_filters); - device_del(pmu->dev); - put_device(pmu->dev); - } - free_pmu_context(pmu); + perf_pmu_free(pmu); } EXPORT_SYMBOL_GPL(perf_pmu_unregister);