From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B860C433B4 for ; Fri, 16 Apr 2021 15:02:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E23B361184 for ; Fri, 16 Apr 2021 15:02:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245568AbhDPPCm (ORCPT ); Fri, 16 Apr 2021 11:02:42 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:57832 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245208AbhDPPCQ (ORCPT ); Fri, 16 Apr 2021 11:02:16 -0400 Date: Fri, 16 Apr 2021 15:01:50 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1618585311; 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=q5p/HiBBoL8SnE05EfvmU4VLP0k7Rt1yt5rj7nPNHJ0=; b=lZbYnesmlPzZHGVFWB27TSsHK35UW4wVOYPj/6Pbx8kFykpfQIavFO4sNXyPqO65msPWTH ERgEiXP2agDURt7nUcKRAsly+zc8vPWHlopAkX0qanbF9LXKSfJ/KfyX1atwK8MqFVOW7C YvpvPB55m0hktWRnoBE5jEEjKNniijE8zuAvHllEiPx8iHXUQeycwBh+QmeYAGL9FA7fdY E4KaHTzAio/iIfZ99HqSJ05ePkhzJDiDG79SIktydqYvGiJjcOC+FRtgLlX7M0RjJ/p5qF 7MAJ3bAlZHZ8NrHZXL+b/+lcWiIlQsdUGVInhIbBbP5IUCiIavJqD009kkSFkQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1618585311; 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=q5p/HiBBoL8SnE05EfvmU4VLP0k7Rt1yt5rj7nPNHJ0=; b=ImkdTYUbx6bFMfKN1MRHIXi6MF3BJVrQ2CZyTLEN6ztvC3GwLKq52DZ+tA1ZlSjHw589h0 HOQVTU8+iGXePPCw== From: "tip-bot2 for Marco Elver" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf: Add support for event removal on exec Cc: Peter Zijlstra , Marco Elver , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20210408103605.1676875-5-elver@google.com> References: <20210408103605.1676875-5-elver@google.com> MIME-Version: 1.0 Message-ID: <161858531071.29796.4506820814392849055.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the perf/core branch of tip: Commit-ID: 2e498d0a74e5b88a6689ae1b811f247f91ff188e Gitweb: https://git.kernel.org/tip/2e498d0a74e5b88a6689ae1b811f247f91ff188e Author: Marco Elver AuthorDate: Thu, 08 Apr 2021 12:35:59 +02:00 Committer: Peter Zijlstra CommitterDate: Fri, 16 Apr 2021 16:32:41 +02:00 perf: Add support for event removal on exec Adds bit perf_event_attr::remove_on_exec, to support removing an event from a task on exec. This option supports the case where an event is supposed to be process-wide only, and should not propagate beyond exec, to limit monitoring to the original process image only. Suggested-by: Peter Zijlstra Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210408103605.1676875-5-elver@google.com --- include/uapi/linux/perf_event.h | 3 +- kernel/events/core.c | 70 ++++++++++++++++++++++++++++---- 2 files changed, 64 insertions(+), 9 deletions(-) diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 813efb6..8c5b9f5 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -390,7 +390,8 @@ struct perf_event_attr { text_poke : 1, /* include text poke events */ build_id : 1, /* use build id in mmap2 events */ inherit_thread : 1, /* children only inherit if cloned with CLONE_THREAD */ - __reserved_1 : 28; + remove_on_exec : 1, /* event is removed from task on exec */ + __reserved_1 : 27; union { __u32 wakeup_events; /* wakeup every n events */ diff --git a/kernel/events/core.c b/kernel/events/core.c index 3e3c00f..e4a584b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4248,6 +4248,57 @@ out: put_ctx(clone_ctx); } +static void perf_remove_from_owner(struct perf_event *event); +static void perf_event_exit_event(struct perf_event *event, + struct perf_event_context *ctx); + +/* + * Removes all events from the current task that have been marked + * remove-on-exec, and feeds their values back to parent events. + */ +static void perf_event_remove_on_exec(int ctxn) +{ + struct perf_event_context *ctx, *clone_ctx = NULL; + struct perf_event *event, *next; + LIST_HEAD(free_list); + unsigned long flags; + bool modified = false; + + ctx = perf_pin_task_context(current, ctxn); + if (!ctx) + return; + + mutex_lock(&ctx->mutex); + + if (WARN_ON_ONCE(ctx->task != current)) + goto unlock; + + list_for_each_entry_safe(event, next, &ctx->event_list, event_entry) { + if (!event->attr.remove_on_exec) + continue; + + if (!is_kernel_event(event)) + perf_remove_from_owner(event); + + modified = true; + + perf_event_exit_event(event, ctx); + } + + raw_spin_lock_irqsave(&ctx->lock, flags); + if (modified) + clone_ctx = unclone_ctx(ctx); + --ctx->pin_count; + raw_spin_unlock_irqrestore(&ctx->lock, flags); + +unlock: + mutex_unlock(&ctx->mutex); + + put_ctx(ctx); + if (clone_ctx) + put_ctx(clone_ctx); +} + struct perf_read_data { struct perf_event *event; bool group; @@ -7560,18 +7611,18 @@ void perf_event_exec(void) struct perf_event_context *ctx; int ctxn; - rcu_read_lock(); for_each_task_context_nr(ctxn) { - ctx = current->perf_event_ctxp[ctxn]; - if (!ctx) - continue; - perf_event_enable_on_exec(ctxn); + perf_event_remove_on_exec(ctxn); - perf_iterate_ctx(ctx, perf_event_addr_filters_exec, NULL, - true); + rcu_read_lock(); + ctx = rcu_dereference(current->perf_event_ctxp[ctxn]); + if (ctx) { + perf_iterate_ctx(ctx, perf_event_addr_filters_exec, + NULL, true); + } + rcu_read_unlock(); } - rcu_read_unlock(); } struct remote_output { @@ -11656,6 +11707,9 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, if (!attr->inherit && attr->inherit_thread) return -EINVAL; + if (attr->remove_on_exec && attr->enable_on_exec) + return -EINVAL; + out: return ret;