From nobody Tue Feb 10 19:01:03 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8E49E8F7D; Tue, 2 Apr 2024 02:21:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712024496; cv=none; b=GaXLlehkWXxBzVMpVjlDFysSUCj+xjq5mvLoz2kVwns/D7rh4cuZdVTk0N4kHqMo7yXPLJ5Yxk4L9Jv8HwWp4XzBUmi/CbyTVC67X6eQQ8D+fAAyIAhXFwexG4Vndw972mwrllR2IIK3bL11f3GxNJW3HGjs3B387xtUTu+qKbo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712024496; c=relaxed/simple; bh=CV8kIvJyEvkQbvLwnjBjosZJzgYcjJearDgYKOb9sCA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qTIfZuIrwzhEYDWuedC3F+tSDqSuLtY/LAIezZ3mgyp1TnsNVYHoPQsxw1dbyEZk+LmnE6rfULGtkR/mJ5cgvVfOxoJMQAJzcw8XpeJvRBMPOEz/9l/xjVXzSXViIhCYHgt9SpX3kwEHivOAh1MV3U4Jmc2CkzX8K1zWZMz4BEA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qzBf82vT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qzBf82vT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06870C433F1; Tue, 2 Apr 2024 02:21:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712024496; bh=CV8kIvJyEvkQbvLwnjBjosZJzgYcjJearDgYKOb9sCA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qzBf82vThUOQZ6GfSZxFiPh6FmaD6RWqTT+1BqHXKf+Lk+btUKu4FE0vmh23Yx7t0 cL7lU3BgmdwjOKx97WU3uZDJDyi2UXtMBekXdDox2gj9ZWmwHGtNsiYjc9M7SWmxAC bKNgxqa8C6pf+WgLVbsrfjUsg9f8w//dywF987W/9cUO4fp6oT3N/CWgnNMBQrAvV5 qAtBnRWC8Wx33HZ+QXcD7aY/j3JoS88BqCNvfOB9gbEamYTM2Hc3vcR4hxYfJUDgy3 R1pDhqdHIxU35I1PkEUKYSnsvSiQ0Z0s/0ecDE/RBfe4VC0JTvlYbAHj2yCXBZJJiH 9wP2hyN2HF9vw== From: Andrii Nakryiko To: x86@kernel.org, peterz@infradead.org, mingo@redhat.com, tglx@linutronix.de Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, jolsa@kernel.org, song@kernel.org, kernel-team@meta.com, Andrii Nakryiko , Sandipan Das Subject: [PATCH v5 4/4] perf/x86/amd: don't reject non-sampling events with configured LBR Date: Mon, 1 Apr 2024 19:21:18 -0700 Message-ID: <20240402022118.1046049-5-andrii@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240402022118.1046049-1-andrii@kernel.org> References: <20240402022118.1046049-1-andrii@kernel.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" Now that it's possible to capture LBR on AMD CPU from BPF at arbitrary point, there is no reason to artificially limit this feature to just sampling events. So corresponding check is removed. AFAIU, there is no correctness implications of doing this (and it was possible to bypass this check by just setting perf_event's sample_period to 1 anyways, so it doesn't guard all that much). Reviewed-by: Sandipan Das Signed-off-by: Andrii Nakryiko --- arch/x86/events/amd/lbr.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/x86/events/amd/lbr.c b/arch/x86/events/amd/lbr.c index 33d0a45c0cd3..19c7b76e21bc 100644 --- a/arch/x86/events/amd/lbr.c +++ b/arch/x86/events/amd/lbr.c @@ -310,10 +310,6 @@ int amd_pmu_lbr_hw_config(struct perf_event *event) { int ret =3D 0; =20 - /* LBR is not recommended in counting mode */ - if (!is_sampling_event(event)) - return -EINVAL; - ret =3D amd_pmu_lbr_setup_filter(event); if (!ret) event->attach_state |=3D PERF_ATTACH_SCHED_CB; --=20 2.43.0