From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) (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 060CD30E853; Fri, 9 Jan 2026 16:17:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767975465; cv=none; b=DrAHcHtIZ/le9/oPs/cCw0XluPovwe6jPl4QRMiD7lUCSOzWqOpI7X8rEsUFtquzJczhjhNybQt0tUyZMRt+wK+U2yQg+un79rHFkKzlqVQUrmdPWGjSkxEhBjZ5NiPrKz3k0mj26eOh/6ZUwkgbTqboNkOFWI8V/IUiR0q5fnY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767975465; c=relaxed/simple; bh=u4xJagi6nb7Yc6X9FQFypEMGidVDdmf5kxoL21Ph7G4=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=L7oky1HgbYFr5tfoz2Y1yCcCB/tYOiUww+RqAr9PMiAIvFbosM1COx8OIUF6vjkH/vr7R+Fkv8IduOG+s5j/FELpFHQE/NBgfH1mfAu7KXurHnte3xnf1+yMflIaqeWOO4E38sL6U5S7LFIrlIoVIBnk0bK+9gavhyMfyN3rmaA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 40B7F160333; Fri, 9 Jan 2026 16:17:36 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf07.hostedemail.com (Postfix) with ESMTPA id 7C3552002C; Fri, 9 Jan 2026 16:17:33 +0000 (UTC) Date: Fri, 9 Jan 2026 11:18:04 -0500 From: Steven Rostedt To: Jiri Olsa Cc: Masami Hiramatsu , Will Deacon , Mahe Tardy , Peter Zijlstra , bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, Yonghong Song , Song Liu , Andrii Nakryiko , Mark Rutland Subject: Re: [PATCHv2 bpf-next 1/2] arm64/ftrace,bpf: Fix partial regs after bpf_prog_run Message-ID: <20260109111804.481a6f20@gandalf.local.home> In-Reply-To: <20260109093454.389295-1-jolsa@kernel.org> References: <20260109093454.389295-1-jolsa@kernel.org> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspamout06 X-Rspamd-Queue-Id: 7C3552002C X-Stat-Signature: f8aus8gwt9gwwghji8dnqrqaet4ioy6e X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1+dsryzGlYq/IBaVcXmTxW02qO+AtSzCCE= X-HE-Tag: 1767975453-939575 X-HE-Meta: U2FsdGVkX195HTS3PXdoSrXMaKW9jSAqMC2F/Zr2Crpg0MiCloYO/UukNadfj8DBKa27oZ27laPKm/4He9R+NuUHpk6ZGtccKIKcGfY1T9mIju3yta15pVGhCsAjwPOP6oPCBuH/XmjyjXw8274URJ7oA7jwvw5b9EtIk662f2w5s+yFnw8OyJioll9LUPMhshmXpiMGzRVnTS+iMFJgImpS30y4O+Wj1gMyXdQMGCq5Fx+WF0QEa+qLcbzoI456A5q7Jgyv5eEIOt5SDZHm9yUWIjNt/aDsZdfMPQ5ZpY90q7BzwAsiwGprE//EDWLHCDd3z+Ajbnnh14kJleRYrTL+ooQCFoK6kixAZ3n8EeCIvhGQdH0Z/SLDZxU8yTijGfgy/xE9hzqWJAJEcCDEySYDlazdn704J1SZt0Bu7jc= On Fri, 9 Jan 2026 10:34:53 +0100 Jiri Olsa wrote: > Mahe reported issue with bpf_override_return helper not working when > executed from kprobe.multi bpf program on arm. > > The problem is that on arm we use alternate storage for pt_regs object > that is passed to bpf_prog_run and if any register is changed (which > is the case of bpf_override_return) it's not propagated back to actual > pt_regs object. > > Fixing this by introducing and calling ftrace_partial_regs_update function > to propagate the values of changed registers (ip and stack). > > Reported-by: Mahe Tardy > Signed-off-by: Jiri Olsa > --- Reviewed-by: Steven Rostedt (Google) -- Steve