From nobody Wed Oct 8 18:25:46 2025 Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) (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 9B9F126E6EB; Wed, 25 Jun 2025 23:16:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.14 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750893365; cv=none; b=SCcNNpkGM3SnSuZT83555V0wq3yZhqAl1Ll58ef/ZpxwvHabOjR7cgdp+IaIxrACjTGR0vTHHjyaXikt3vq/lJnXbZI1IhsfLx+gIEPIbn3E0RjBHSBIyDJDQcWnmza+M2QIiubKa1UadgiGFVhfvAYtcETlt6IJzdkBv+xmbYc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750893365; c=relaxed/simple; bh=INPL5mykLyHh9BAddpKD33kEw5Zh1QT3Mw8WI6pEDxg=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=qjAfdRImFNaDTAE6vn4oufQ/KcdNkE2nBuSEhc65zjgTRwsFGdjHo0H0A3uOMftp63SQrbrrTzm4Q3WBNR8Dj8bM3LBNPhni8M6TEqPd63I8jsSjr8mZ4VlQQRuH/HB8SYtmlJsmrPuxNxk/FPnj11vDPrxSDG7GKTw/HgvE6ys= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 358E91A07B5; Wed, 25 Jun 2025 23:16:00 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: nevets@goodmis.org) by omf10.hostedemail.com (Postfix) with ESMTPA id EF9402F; Wed, 25 Jun 2025 23:15:56 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98.2) (envelope-from ) id 1uUZLq-000000044gG-0dBi; Wed, 25 Jun 2025 19:16:22 -0400 Message-ID: <20250625231622.002316317@goodmis.org> User-Agent: quilt/0.68 Date: Wed, 25 Jun 2025 19:15:43 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org, x86@kernel.org Cc: Masami Hiramatsu , Mathieu Desnoyers , Josh Poimboeuf , Peter Zijlstra , Ingo Molnar , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Andrii Nakryiko , Indu Bhagat , "Jose E. Marchesi" , Beau Belgrave , Jens Remus , Linus Torvalds , Andrew Morton , Jens Axboe Subject: [PATCH v11 02/11] perf: Have get_perf_callchain() return NULL if crosstask and user are set References: <20250625231541.584226205@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Stat-Signature: 1p8if5js4t5yq9bh6ff4fygzi1d9fce6 X-Rspamd-Server: rspamout05 X-Rspamd-Queue-Id: EF9402F X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX188kjvS+mWB42wzpmtmJv3x7MsKmJWWSlM= X-HE-Tag: 1750893356-313938 X-HE-Meta: U2FsdGVkX1+XcjmPd0s26qAQpGmBVhaaTwi1VuxJiZDIA/sL7vqGO4HeuRzWIYiwKxChyEHXEtJb0RBXsL+aRbsqQmVOVfxEW55N+tyftmGu/yLgmET1TOiW6ggwQGrp2q1IrGUDKvmqAtlyHeqwskqedyo8bsk7opy/ncgWsfcqd6d1br3HPCJyhyF598UkTvZVVZMMRJIDOXDfcJkcwowBf8ggx9IToDBZYmAmzVBmYhcSkS6WlODjBiDHfrUaSvfqQVBEboP/uHN0OtjC4w5ELrqJGIP7w4iIck6S2JO6oerqFatL/fIMqy2mT+WkwIALsU20vZ6vKA1PZddDaIDZPyNen3aJkcj4K1B60knb+PXGyYTPXmwPH/CkeAZfypEwP3zDKpMOXOv2aUZuMxWXGO+jfWRPgZp8av7TlEU= Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Josh Poimboeuf get_perf_callchain() doesn't support cross-task unwinding for user space stacks, have it return NULL if both the crosstask and user arguments are set. Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) --- kernel/events/callchain.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index b0f5bd228cd8..cd0e3fc7ed05 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -224,6 +224,10 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, = bool user, struct perf_callchain_entry_ctx ctx; int rctx, start_entry_idx; =20 + /* crosstask is not supported for user stacks */ + if (crosstask && user && !kernel) + return NULL; + entry =3D get_callchain_entry(&rctx); if (!entry) return NULL; @@ -240,7 +244,7 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, b= ool user, perf_callchain_kernel(&ctx, regs); } =20 - if (user) { + if (user && !crosstask) { if (!user_mode(regs)) { if (current->mm) regs =3D task_pt_regs(current); @@ -249,9 +253,6 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, b= ool user, } =20 if (regs) { - if (crosstask) - goto exit_put; - if (add_mark) perf_callchain_store_context(&ctx, PERF_CONTEXT_USER); =20 @@ -261,7 +262,6 @@ get_perf_callchain(struct pt_regs *regs, bool kernel, b= ool user, } } =20 -exit_put: put_callchain_entry(rctx); =20 return entry; --=20 2.47.2