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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17BF3C0018C for ; Thu, 9 Nov 2023 00:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229565AbjKIAnn (ORCPT ); Wed, 8 Nov 2023 19:43:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231661AbjKIAnm (ORCPT ); Wed, 8 Nov 2023 19:43:42 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BC70C6; Wed, 8 Nov 2023 16:43:40 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BA41C433CB; Thu, 9 Nov 2023 00:43:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699490619; bh=74tVzDmLPcHwbDDKMqbOB8N7t7wMHGUYDY+FMXFJ2KU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LekKBPpDKpVAqs69PeoufY+Ll7vEGOQ6UMGe4vq8n0G3YeziGosRPHLqvIhKOkqWl TQY08u1shmOVtc/K7G7Z/r42NF4+v2bTZAQ43U+HKUwyn5gzBouHHETsTeek06+uYq uU3+H17p9lWYMJ3yPFg8fMeS3H6fAwDf+KTJ0dC3n1kXpJ9xSpNjSbVTPZecZp6z5C o2ZoXy72Syup4MIeKwbKil72fV0InZAtQe56am3XRQNFnS8QGNAs3qsPoum2VliQlv 0FfkR5NSeCbYdoyPOUcHXluW8GjM6kIANxbWYP2If5yDBfMW8P9EtQRl7YYxmUDvFB VaEa8QpvEqm8w== From: Josh Poimboeuf To: Peter Zijlstra , Steven Rostedt , Ingo Molnar , Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Indu Bhagat , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org Subject: [PATCH RFC 02/10] perf: Remove get_perf_callchain() 'crosstask' argument Date: Wed, 8 Nov 2023 16:41:07 -0800 Message-ID: X-Mailer: git-send-email 2.41.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-toolchains@vger.kernel.org get_perf_callchain() doesn't support cross-task unwinding, so it doesn't make much sense to have 'crosstask' as an argument. Instead, have perf_callchain() adjust 'user' accordingly. Signed-off-by: Josh Poimboeuf --- include/linux/perf_event.h | 2 +- kernel/bpf/stackmap.c | 5 ++--- kernel/events/callchain.c | 6 +----- kernel/events/core.c | 8 ++++---- 4 files changed, 8 insertions(+), 13 deletions(-) diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index f4b05954076c..2d8fa253b9df 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1534,7 +1534,7 @@ extern void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct p extern void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs); extern struct perf_callchain_entry * get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, - u32 max_stack, bool crosstask, bool add_mark); + u32 max_stack, bool add_mark); extern int get_callchain_buffers(int max_stack); extern void put_callchain_buffers(void); extern struct perf_callchain_entry *get_callchain_entry(int *rctx); diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index b0b0fbff7c18..e4827ca5378d 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -294,8 +294,7 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, if (max_depth > sysctl_perf_event_max_stack) max_depth = sysctl_perf_event_max_stack; - trace = get_perf_callchain(regs, kernel, user, max_depth, - false, false); + trace = get_perf_callchain(regs, kernel, user, max_depth, false); if (unlikely(!trace)) /* couldn't fetch the stack trace */ @@ -421,7 +420,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, trace = get_callchain_entry_for_task(task, max_depth); else trace = get_perf_callchain(regs, kernel, user, max_depth, - false, false); + false); if (unlikely(!trace)) goto err_fault; diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index 1e135195250c..aa5f9d11c28d 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -178,7 +178,7 @@ put_callchain_entry(int rctx) struct perf_callchain_entry * get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, - u32 max_stack, bool crosstask, bool add_mark) + u32 max_stack, bool add_mark) { struct perf_callchain_entry *entry; struct perf_callchain_entry_ctx ctx; @@ -209,9 +209,6 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, } if (regs) { - if (crosstask) - goto exit_put; - if (add_mark) perf_callchain_store_context(&ctx, PERF_CONTEXT_USER); @@ -219,7 +216,6 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, } } -exit_put: put_callchain_entry(rctx); return entry; diff --git a/kernel/events/core.c b/kernel/events/core.c index b0d62df7df4e..5e41a3b70bcd 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7592,16 +7592,16 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs) { bool kernel = !event->attr.exclude_callchain_kernel; bool user = !event->attr.exclude_callchain_user; - /* Disallow cross-task user callchains. */ - bool crosstask = event->ctx->task && event->ctx->task != current; const u32 max_stack = event->attr.sample_max_stack; struct perf_callchain_entry *callchain; + /* Disallow cross-task user callchains. */ + user &= !event->ctx->task || event->ctx->task == current; + if (!kernel && !user) return &__empty_callchain; - callchain = get_perf_callchain(regs, kernel, user, - max_stack, crosstask, true); + callchain = get_perf_callchain(regs, kernel, user, max_stack, true); return callchain ?: &__empty_callchain; } -- 2.41.0